| 1. |
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| 2. |
- Aaltonen, Olli, et al.
(författare)
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Brain responses reveal hardwired detection of native-language rule violations
- 2008
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 444:1, s. 56-59
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Tidskriftsartikel (refereegranskat)abstract
- Mismatch negativity (MMN) is a neural correlate of the preattentive detection of any change in the acoustic characteristics of sounds. Here we provide evidence that violations of a purely phonological constraint in a listener's native language can also elicit the brain's automatic change-detection response. The MMN differed between Finnish and Estonian listeners, conditions being equal except for the native language of the listeners. We used two experimental conditions: synthetic vowels in isolation and the same vowels embedded in a pseudo-word context. MMN responses to isolated vowels were similar for Finns and Estonians, while the same vowels in a pseudoword context elicited different MMN patterns depending on the listener's mother tongue.
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| 3. |
- Ahola, Angela S., et al.
(författare)
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Is Justice Really Blind? : Effects of Crime Descriptions, Defendant Gender and Appearance, and Legal Practitioner Gender on Sentences and Defendant Evaluations in a Mock Trial
- 2010
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Ingår i: Psychiatry, Psychology and Law. - : Informa UK Limited. - 1321-8719 .- 1934-1687. ; 17:2, s. 304-324
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Tidskriftsartikel (refereegranskat)abstract
- Two experiments were conducted to investigate how sources of information can bias the judicial process. Experiment 1 investigated the effects of photographs of victims’ injury, and of vivid verbal victim injury description, on the evaluation and sentencing of a defendant in a mock criminal trial. The participants were presented with five different crime accounts: (a) vandalism, (b) arson, (c) child abuse, (d) child molestation, and (e) homicide, all committed by male perpetrators, and were asked to evaluate the trustworthiness, culpability, aggressiveness, guilt, and other crime-relevant personality traits of the defendant, and to set imprisonment sentences. Results of Experiment 1 showed that exposure to photographs of crime victim injuries as well as vivid crime descriptions had only weak and non-significant effects on defendant evaluations, but imprisonment terms tended to be longer in the Photo condition than in the No photo condition. To further investigate the possible effects of photographic information on judicial processes for different crimes (child molestation, child abuse, homicide), Experiment 2 was conducted with legal practitioners (judges, members of Swedish juries, law students, counsels for the defence, prosecutors, police officers) as evaluators. Results showed three tendencies: (a) a ‘‘same-sex penalty effect’’: sentencing evaluators (judges, jurors) evaluated a defendant of the same gender as the evaluator, more harshly than one of the opposite gender, (b) a ‘‘male penalty effect’’: non-sentencing evaluators (police officers, counsels for the defence, prosecutors, and law students) evaluated and judged a male defendant more harshly than a female, and (c) for female non-sentencing evaluators, the male penalty effect was enhanced for the more attractive defendants. Overall, the results suggest that defendant gender, defendant appearance, evaluator gender, and evaluator profession can affect the outcome of a criminal trial.
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| 4. |
- Ahola, Angela S., et al.
(författare)
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Justice Needs a Blindfold : Effects of Gender and Attractiveness on Prison Sentences and Attributions of Personal Characteristics in a Judicial Process
- 2009
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Ingår i: Psychiatry, Psychology and Law. - : Informa UK Limited. - 1321-8719 .- 1934-1687. ; 16:1, s. 90-100
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the effect of gender and facial characteristics of criminal offenders on attributions of crime-relevant traits. The stimulus pictures portrayed women and men of varying attractiveness. Participants were presented with pictures of these female or male faces along with accompanying crime accounts. The crime account described the individual in the picture as a person who had committed one of the following crimes: theft, fraud, drug crime, child molestation, child abuse, or homicide. After reading one case account the participants were asked to evaluate the credibility and other crime-relevant personality traits of the offender. Results showed that female defendants were rated more favourably than were male defendants. Gender worked to the advantage of the female perpetrator. There were also slight tendencies towards more lenient appraisal of the more attractive women.
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| 5. |
- Bertheim, Ulf, et al.
(författare)
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Loss of hyaluronan in the basement membrane zone of the skin correlates to the degree of stiff hands in diabetes patients
- 2002
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Ingår i: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 82:5, s. 329-334
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Tidskriftsartikel (refereegranskat)abstract
- Glycosaminoglycans are important components of all extracellular matrices. One of the glycosaminoglycans is hyaluronan, which is ubiquitously distributed throughout the connective tissue. Hyaluronan is especially abundant in the skin, in which it is of both structural and functional importance. This study describes the localization and distribution of hyaluronan in the skin of healthy individuals and of 23 patients with insulin-dependent diabetes mellitus and various degrees of limited joint mobility. In normal skin, hyaluronan staining was seen in all layers but most prominently in the papillary dermis and the basement membrane zone. In the skin from diabetic patients with normal or only moderately restricted mobility of the hands (limited joint mobility grades 0 and 1), the distribution of hyaluronan was similar to that of normal skin. In the skin of patients with severe restriction in joint mobility (limited joint mobility grade 2) the staining pattern was significantly different with weak hyaluronan staining in the papillary dermis and the basement membrane zone almost devoid of hyaluronan. Moreover, an increased epidermal thickness in the latter patients was evident as well as a pronounced hyaluronan staining compared with normal epidermis.
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| 6. |
- Dentoni Litta, Eugenio, 1986-
(författare)
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Integration of thulium silicate for enhanced scalability of high-k/metal gate CMOS technology
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- High-k/metal gate stacks have been introduced in CMOS technology during the last decade in order to sustain continued device scaling and ever-improving circuit performance. Starting from the 45 nm technology node, the stringent requirements in terms of equivalent oxide thickness and gate current density have rendered the replacement of the conventional SiON/poly-Si stack unavoidable. Although Hf-based technology has become the de facto industry standard for high-k/metal gate MOSFETs, problematic long-term scalability has motivated the research of novel materials and solutions to fulfill the target performances expected of gate stacks in future technology nodes.In this work, integration of a high-k interfacial layer has been identified as the most promising approach to improve gate dielectric scalability, since this technology presents the advantage of potential compatibility with both current Hf-based and plausible future higher-k materials. Thulium silicate has been selected as candidate material for integration as interfacial layer, thanks to its unique properties which enabled the development of a straightforward integration process achieving well-controlled and repeatable growth in the sub-nm thickness regime, a contribution of 0.25+-0.15 nm to the total EOT, and high quality of the interface with Si.Compatibility with industry-standard CMOS integration flows has been kept as a top priority in the development of the new technology. To this aim, a novel ALD process has been developed and characterized, and a manufacturable process flow for integration of thulium silicate in a generic gate stack has been designed. The thulium silicate interfacial layer technology has been verified to be compatible with standard integration flows, and fabrication of high-k/metal gate MOSFETs with excellent electrical characteristics has been demonstrated.The possibility to achieve high performance devices by integration of thulium silicate in current Hf-based technology has been specifically demonstrated, and the TmSiO/HfO2 dielectric stack has been shown to be compatible with the industrial requirements of operation in the sub-nm EOT range (down to 0.6 nm), reliable device operation over a 10 year expected lifetime, and compatibility with common threshold voltage control techniques. The thulium silicate interfacial layer technology has been especially demonstrated to be superior to conventional chemical oxidation in terms of channel mobility at sub-nm EOT, since the TmSiO/HfO2 dielectric stack achieved ~20% higher electron and hole mobility compared to state-of-the-art SiOx/HfO2 devices at the same EOT. Such performance enhancement can provide a strong advantage in the EOT-mobility trade-off which is commonly observed in scaled gate stacks, and has been linked by temperature and stress analyses to the higher physical thickness of the high-k interfacial layer, which results in attenuated remote phonon scattering compared to a SiOx interfacial layer achieving the same EOT.
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| 7. |
- Duan, Rui-Dong, et al.
(författare)
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Human meconium contains significant amounts of alkaline sphingomyelinase, neutral ceramidase, and sphingolipid metabolites.
- 2007
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Ingår i: Pediatric Research. - : Springer Science and Business Media LLC. - 1530-0447 .- 0031-3998. ; 61:1, s. 61-66
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Tidskriftsartikel (refereegranskat)abstract
- Intestinal alkaline sphingomyelinase (Alk-SMase) and neutral ceramidase may catalyze the hydrolysis of endogenous sphin-gomyelin (SM) and milk SM in human-milk fed infants. The enzymes generate sphingolipid metabolites that may influence gut maturation. Alk-SMase also inactivates platelet-activating factor (PAF) that is involved in the pathogenesis of necrotizing enterocolitis (NEC). We examined whether the two enzymes are expressed in both preterm and term infants and analyzed Alk-SMase, neutral ceramidase, SM, and sphingolipid metabolites in meconium. Meconium was collected from 46 preterm (gestational ages 23-36 wk) and 38 term infants (gestational ages 37-42 wk) and analyzed for Alk-SMase using C-14-choline-labeled SM and for neutral ceramidase using C-14-octanoyl-sphingosine as substrates. Molecular species of SM, ceramide, and sphingosine were analyzed by high-performance liquid chromatography mass spectroscopy. Meconium contained significant levels of Alk-SMase and ceramidase at all gestational ages. It also contained 16-24 carbon molecular species of SM, palmitoyl-and stearoyl-sphingosine, and sphingosine. There were positive correlations between levels of SM and ceramide and between ceramide and sphingosine levels. In conclusion, Alk-SMase and ceramidase are expressed in the gut of both preterm and term newborn infants and may generate bioactive sphingolipid messengers.
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| 8. |
- Dåderman, Anna Maria, 1953-, et al.
(författare)
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Interrater Reliability of Psychopathy Checklist-Revised : Results on Multiple Analysis Levels for a Sample of Patients Undergoing Forensic Psychiatric Evaluation
- 2018
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Ingår i: Criminal justice and behavior. - : SAGE Publications. - 0093-8548 .- 1552-3594. ; 45:2, s. 234-263
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Tidskriftsartikel (refereegranskat)abstract
- Scores from the Psychopathy Checklist–Revised (PCL-R) are used to support decisions regarding personal liberty. In our study, performed in an applied forensic psychiatric setting, intraclass correlation coefficients (ICC) for absolute agreement, single rater (ICCA1) were .89 for the total score, .82 for Factor 1, .88 for Factor 2, and .78 to .86 for the four facets. These results stand in contrast to lower reliabilities found in a majority of field studies. Disagreement among raters made a low contribution (0%-5%) to variability of scores on the total score, factor, and facet level. For individual items, ICCA1 varied from .38 to .94, with >.80 for seven of the 20 items. Items 17 (“Many short-term marital relationshipsâ€) and 19 (“Revocation of conditional releaseâ€) showed very low reliabilities (.38 and .43, respectively). The importance of knowledge about factors that can affect scoring of forensic instruments (e.g., education, training, experience, motivation, raters’ personality, and quality of file data) is emphasized.
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| 9. |
- Dåderman, Anna Maria, 1953-, et al.
(författare)
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Leading with a cool head and a warm heart : trait-based leadership resources linked to task performance, perceived stress, and work engagement
- 2023
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Ingår i: Current Psychology. - : Springer Nature. - 1046-1310 .- 1936-4733. ; 42, s. 29559-29580
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Tidskriftsartikel (refereegranskat)abstract
- Leaders of today need to achieve well in terms of task performance, perceiving low stress, and having high levels of work engagement. One may ask whether trait-based leadership resource factors can be identified and how such resource factors might relate to task performance, perceived stress, and work engagement. Our aim was to test the hypothesis, derived from Hobfoll’s motivational Conservation of Resources (COR) theory, that there are trait-based leadership resource factors, which are differentially correlated to the leaders’ task performance, perceived stress, and work engagement. Leaders (N = 344) aged from 23 to 65 years (M = 49, SD = 8.6; 58% women) completed an online questionnaire including measures of task performance, perceived stress, work engagement, personality traits, trait emotional intelligence, empathy, performance-related self-esteem, compassionate and rational leadership competence, and coping resources for stress. Using exploratory factor analysis, we identified four trait-based leadership resource factors. With Bonferroni adjustment, and controlling for sex, age, number of years in the current managerial position, self-deceptive enhancement, and impression management, only Rational Mastery was significantly positively correlated with task performance. Rational Mastery, Efficient Coping, and Modesty were negatively correlated with perceived stress, and all factors except Modesty, but including the fourth (Good-Heartedness) were positively correlated with work engagement. Organizations striving for sustainable work conditions should support trait-based leadership, which depends not only on a task-oriented resource such as rational mastery, but also on human-oriented resources such as efficient coping, modesty, and good-heartedness, all of them being differentially related to task performance, perceived stress, and work engagement.
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| 10. |
- Dåderman, Anna Maria, 1953-, et al.
(författare)
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Psychopathy Assessment with PCL-R has High Interrater Reliability if Conducted Without Bias
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Scores of the Psychopathy Checklist-Revised (PCL-R) are used to support decisions regarding personal liberty. There is increasing concern about its interrater reliability in applied contexts, where low reliabilites have been obtained. We report a study in which 12 forensic psychiatric staff raters assessed 43 male offenders for psychopathy using the PCL-R. These ratings were compared with those obtained at a second occasion from separate interviews utilizing similar file data by an independent researcher, experienced as an expert for the defense. Intraclass correlation coefficients were high; .89 for the PCL-R total scale, .82 for Factor 1, and .38 – .94 for individual items. These results stand in contrast to the considerably lower reliabilities found in recent field studies, mainly conducted within adversary judicial systems. In such contexts, ratings may be biased. Interrater reliability of PCL-R is likely be increased if raters utilize similar data.
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| 11. |
- Dåderman, Anna M., et al.
(författare)
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Using the Karolinska Scales of Personality on male juvenile delinquents: relationships between scales and factor structure.
- 2005
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Ingår i: Nordic Journal of Psychiatry. - : Informa UK Limited. - 0803-9488 .- 1502-4725. ; 59:6, s. 448-456
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to investigate relationships between scales from the Karolinska Scales of Personality (KSP) and the factor structure of the KSP in a sample of male juvenile delinquents. The KSP was administered to a group of male juvenile delinquents (n = 55, mean age 17 years; standard deviation = 1.2) from four Swedish national correctional institutions for serious offenders. As expected, the KSP showed appropriate correlations between the scales. Factor analysis (maximum likelihood) arrived at a four-factor solution in this sample, which is in line with previous research performed in a non-clinical sample of Swedish males. More research is needed in a somewhat larger sample of juvenile delinquents in order to confirm the present results regarding the factor solution.
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| 12. |
- Dåderman, Anna Maria, 1953-, et al.
(författare)
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Using the Karolinska Scales of Personality on male juveniles in correctional institutions : some psychometric issues
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The overriding aim of the present study was to psychometrically evaluate the Karolinska Scales of Personality (KSP) in a delinquent sample. The KSP was administered to a group of male juvenile delinquents (N = 47, mean age 17 years; SD = 1.2) from four representative Swedish national correctional institutions for serious offenders with conduct disorder, and evaluated by means of statistical methods. As expected, reliability in terms of internal consistency, measured by Cronbach's alpha, for some basic scales (Socialization, Muscular Tension, Somatic Anxiety, and Impulsiveness) was high (> .70). However, according to previous research, all aggressiveness and hostility-related scales, with the exception of Verbal aggression scale, showed low reliability. Reliability in terms of homogeneity, measured by mean interitem correlations, was acceptable (> .20) for 6 out of 15 scales. Factor analysis (maximum likelihood) arrived in this sample at a four-factor solution. Issues regardingthe interpretation of reliability, in terms of Cronbach's alpha or scale homogeneity, are highlighted. The concepts of reliability of personality measures in deviant groups are discussed and also possible guidelines for the construction of personality inventories in groups of this kind. The results are briefly discussed from a cultural perspective.
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| 13. |
- Eisler, Hannes, et al.
(författare)
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Psychophysical issues in the study of time perception.
- 2008
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Ingår i: Psychology of time. - : Emerald, Bingley, UK. - 9780080469775 ; , s. 75-109
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Bokkapitel (refereegranskat)abstract
- This chapter on psychophysical issues in the study of time perception is organized around two main research topics: one topic is related to questions concerning the comparison of successive time intervals; and the other topic is related to the psychophysical function for duration.
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| 14. |
- Englund, Mats P., et al.
(författare)
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Beware how you compare : comparison direction dictates stimulus-valence-modulated presentation-order effects in preference judgment
- 2013
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Ingår i: Attention, Perception & Psychophysics. - : Springer Science and Business Media LLC. - 1943-3921 .- 1943-393X. ; 75:5, s. 1001-1011
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Tidskriftsartikel (refereegranskat)abstract
- Englund and Hellstrom (Journal of Behavioral Decision Making 25: 82-94, 2012a) found a tendency to prefer the left (first-read) of two attractive alternatives but the right (second-read) of two unattractive alternatives-a valence-dependent word-order effect (WOE). They used stimulus pairs spaced horizontally, and preference was indicated by choosing one of several written statements (e. g., apple I like more than pear). The results were interpreted as being due to stimulus position, with the magnitude of the left stimulus having a greater impact on the comparison outcome than the magnitude of the right. Here we investigated the effects of the positioning of the stimuli versus the semantics of the response alternatives (i.e., comparison direction) on the relative impacts of the stimuli. Participants rated preferences for stimuli spaced horizontally with the response alternatives not dictating a comparison direction (Exp. 1), and stimuli spaced vertically using Englund and Hellstrom's (Journal of Behavioral Decision Making 25: 82-94, 2012a) response alternatives, which dictate a comparison direction semantically (Exp. 2). The results showed that the valence-dependent WOE found by Englund and Hellstrom (Journal of Behavioral Decision Making 25: 82-94, 2012a) was not due to the horizontal stimulus positioning per se, but to the induced comparison direction, with the effect probably being mediated by attention directed at the subject of the comparison. We concluded that a set comparison direction is required for the valence-dependent WOE to appear, and that using Hellstrom's sensation-weighting model to determine stimulus weights is a way to verify the comparison direction.
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| 15. |
- Englund, Mats P., et al.
(författare)
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Goodness-level dependent word-order effect in preference comparison : Semantics is an important factor
- 2009
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Ingår i: Fechner Day 2009. - Galway, Irland : International Society for Psychophysics.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Hellström (2003) and Englund (2008) found a goodness-level dependent word-order effect (WOE) for preference judgment–a tendency to prefer the left (first read) of two good alternatives and the right (second) of two bad ones. Stimuli were spaced horizontally, and participants indicated preference by choosing one of several written statements (e.g., “apple I like more than pear”). The results were described as being due to a higher weight for the left/first stimulus than for the right/second. In the present study, Experiment 1 was similar to the previous studies, except that the stimuli were spaced vertically. In Experiment 2, stimuli were spaced horizontally, but preference was indicated by symbols instead of statements. The results of Experiment 1 essentially replicated the earlier findings, with a higher weight for the upper (first read) stimulus, but those of Experiment 2 did not. These results suggest that the semantic structure of the preference statements is an important factor behind the goodness-level dependent WOE.
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| 16. |
- Englund, Mats P., 1979-, et al.
(författare)
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If you have a choice, you have trouble : Stimulus valence modulates presentation-order effects in preference judgment
- 2012
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Ingår i: Journal of Behavioral Decision Making. - : Wiley. - 0894-3257 .- 1099-0771. ; 25:1, s. 82-94
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that the presentation order of choice options often affects decision outcomes to a significant degree. However, despite the significance and wide occurrence of the effects, they are ignored in most preference models. Furthermore, psychophysical findings of stimulus-magnitude dependent presentation-order effects have not been acknowledged previously in the cognitive literature on preference judgments. Thus, the potential moderating effect of the level of stimulus magnitude (here, valence) on the direction and size of order effects in preference judgment has not been investigated previously. In two experiments, participants (117 and 204, respectively) rated their preference for pairs of everyday-type objects and phenomena (e.g., apple–pear, headache–stomachache). Stimuli were spaced horizontally, and each participant received them in one of two opposite within-pair presentation orders. Participants also rated the stimuli's valence on a scale from very bad to very good. The results showed a positive correlation between the rated valence and the tendency to prefer the first-mentioned (left) stimulus; that is, the effect was greatest, and opposite, for choices between the most attractive and the most unattractive options, respectively. In terms of Hellström's (1979) sensation-weighting model, the positive correlation is caused by a higher weight (i.e., impact on the preference judgment) for the left stimulus than for the right, which is possibly due to the left stimulus being compared to the right. The results suggest that researchers may have failed previously to find important moderators of presentation-order effects in preference judgment due to the failure to use sufficiently attractive or unattractive stimuli.
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| 17. |
- Englund, Mats P., et al.
(författare)
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Presentation-Order Effects for Aesthetic Stimulus Preference
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- For preference comparisons of paired successive musical excerpts, Koh (1967) found time-order effects (TOEs) that correlated negatively with stimulus valence–a tendency to prefer the first of two unpleasant excerpts and vice versa. Here we present three experiments designed to investigate whether valence-level dependent order effects for aesthetic preference (a) can be accounted for using Hellström’s (e.g., 1979) sensation-weighting (SW) model, (b) can be generalized to successive and to simultaneous visual stimuli, and (c) vary, in accordance with the stimulus weighting, with interstimulus interval (ISI; successive stimuli) or stimulus duration (simultaneous stimuli). Participants compared paired successive jingles (Experiment 1), successive color patterns (Experiment 2), and simultaneous color patterns (Experiment 3), selecting the preferred stimulus in each pair. Results were described well with the SW model: In Experiments 1 and 2, there were consistently higher weights for the second stimulus than for the first and negatively valence-level dependent TOEs. In Experiment 3, there was no consistent laterality effect on the stimulus weighting and no valence-level dependent SOE. In terms of the SW model, the valence-level dependent TOEs can be explained as a consequence of the differential stimulus weighting in combination with stimulus valence varying from low to high, and the absence of valence-level dependent SOEs as a consequence of the absence of systematic differential stimulus weighting. For successive stimuli, there were no important effects of ISI on the stimulus weighting and TOEs, and, for simultaneous stimuli, there was only a small effect of duration on the stimulus weighting, possibly reflecting stimulus scanning.
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| 18. |
- Englund, Mats P., 1979-, et al.
(författare)
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Presentation-order effects for aesthetic stimulus preference
- 2012
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Ingår i: Attention, Perception & Psychophysics. - : Springer Science and Business Media LLC. - 1943-3921 .- 1943-393X. ; 74:7, s. 1499-1511
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Tidskriftsartikel (refereegranskat)abstract
- For preference comparisons of paired successive musical excerpts, Koh (American Journal of Psychology, 80, 171-185, 1967) found time-order effects (TOEs) that correlated negatively with stimulus valence-the first (vs. the second) of two unpleasant (vs. two pleasant) excerpts tended to be preferred. We present three experiments designed to investigate whether valence-level-dependent order effects for aesthetic preference (a) can be accounted for using Hellstrom's (e.g., Journal of Experimental Psychology: Human Perception and Performance, 5, 460-477, 1979) sensation-weighting (SW) model, (b) can be generalized to successive and to simultaneous visual stimuli, and (c) vary, in accordance with the stimulus weighting, with interstimulus interval (ISI; for successive stimuli) or stimulus duration (for simultaneous stimuli). Participants compared paired successive jingles (Exp. 1), successive color patterns (Exp. 2), and simultaneous color patterns (Exp. 3), selecting the preferred stimulus. The results were well described by the SW model, which provided a better fit than did two extended versions of the Bradley-Terry-Luce model. Experiments 1 and 2 revealed higher weights for the second stimulus than for the first, and negatively valence-level-dependent TOEs. In Experiment 3, there was no laterality effect on the stimulus weighting and no valence-level-dependent space-order effects (SOEs). In terms of the SW model, the valence-level-dependent TOEs can be explained as a consequence of differential stimulus weighting in combination with stimulus valence varying from low to high, and the absence of valence-level-dependent SOEs as a consequence of the absence of differential weighting. For successive stimuli, there were no important effects of ISI on weightings and TOEs, and, for simultaneous stimuli, duration had only a small effect on the weighting.
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| 19. |
- Englund, Mats P., 1979-
(författare)
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Valence-Level Dependent Presentation-Order Effects in Preference Judgments
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Reversal of the stimulus-presentation order often affects the outcome in paired stimulus comparison. Psychophysicists have found that the size and direction of the order effects depend on the compared stimuli’s magnitudes, but this magnitude dependence does not seem to have been recognized previously in cognitive research on preference judgment. The main objective of the present doctoral thesis was to investigate whether analogous valence-level dependent order effects exist for preference judgments of aesthetic preference of visual and of auditory stimuli (Study I) and of everyday objects and phenomena (e.g., Apple-Pear, Headache-Stomachache) denoted by labels and presented in a simple survey-questionnaire format (Studies II-III). An additional objective was to investigate if potential valence-level dependent order effects in Studies I-III could be accounted for using Hellström’s (1979, 2000) sensation weighting (SW) model. In Study I, there were valence-level dependent order effects favoring the second of two pleasant stimuli but the first of two unpleasant stimuli presented successively, but there were none for stimuli presented simultaneously. In Study II, there were valence-level dependent word-order effects (WOEs) favoring the left and first-read of two attractive stimuli but the right and last-read of two unattractive ones. Results were well accounted for using the SW model with a higher weight (i.e., greater impact on the comparison) for the second and the left stimulus in Studies I and II, respectively, and the valence level varying from low to high. Results of Study III indicate that the valence-level dependent WOEs in Study II were not due to the spatial positioning (left-right) of the stimuli but to the comparison being directed; the first read stimulus was compared to the second read, yielding a higher weight for the first read stimulus. The present results demonstrate robust order effects large enough to be of theoretical as well as practical relevance.
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| 20. |
- Fernaeus, Sven-Erik, et al.
(författare)
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Conceptual elaboration versus direct lexical access in WAIS-similarities : differential effects of white-matter lesions and gray matter volumes
- 2018
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Ingår i: Aging, Neuropsychology and Cognition. - : Informa UK Limited. - 1382-5585 .- 1744-4128. ; 25:6, s. 893-903
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Tidskriftsartikel (refereegranskat)abstract
- Wechsler Adult Intelligence Scale (WAIS) subscale Similarities have been classified as a test of either verbal comprehension or of inductive reasoning. The reason may be that items divide into two categories. We tested the hypothesis of heterogeneity of items in WAIS-Similarities. Consecutive patients at a memory clinic and healthy controls participated in the study. White-matter hyperintensities (WMHs) and normalized temporal lobe volumes were measured based on Magnetic resonance Imaging (MRI), and tests of verbal memory and attention were used in addition to WAIS-Similarities to collect behavioural data. Factor analysis supported the hypothesis that two factors are involved in the performance of WAIS-similarities: (1) semiautomatic lexical access and (2) conceptual elaboration. These factors were highly correlated but provided discriminative diagnostic information: In logistic regression analyses, scores of the lexical access factor and of the conceptual elaboration factor discriminated patients with mild cognitive impairment from Alzheimer’s disease patients and from healthy controls, respectively. High scores of WMH, indicating periventricular white-matter lesions, predicted factor scores of direct lexical access but not those of conceptual elaboration, which were predicted only by medial and lateral temporal lobe volumes.
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| 21. |
- Fernaeus, Sven-Erik, et al.
(författare)
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Cut the coda : early fluency intervals predict diagnoses
- 2008
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Ingår i: Cortex. - : Elsevier BV. - 0010-9452 .- 1973-8102. ; 44:2, s. 161-169
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was threefold: (i) to clarify whether letter and category fluency tap different cognitive abilities; (ii) to make diagnostic comparisons and predictions using temporally resolved fluency data; (iii) to challenge and test the widely made assumption that 1-min sum scores are the fluency test measure of choice in the diagnosis of dementia. Scores from six 10-sec intervals of letter and category fluency tests were obtained from 240 participants including cognitive levels ranging from mild subjective cognitive complaints to Alzheimer's disease. Factor analysis revealed clearly separate factors corresponding to letter and category fluency. Category fluency was markedly impaired in Alzheimer's disease but not in Mild Cognitive Impairment. Only scores from relatively early intervals predicted Alzheimer's disease and Mild Cognitive Impairment. The conclusions are (i) letter and category fluency are different tests, category fluency being the best diagnostic predictor; (ii) it would be possible to administer category fluency tests only for 30 sec, because after this point the necessary differential diagnostic information about the patient's word fluency capacity has already been gathered.
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| 22. |
- Fernaeus, Sven-Erik, et al.
(författare)
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Memory factors in Rey AVLT : implications for early staging of cognitive decline
- 2014
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Ingår i: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564 .- 1467-9450. ; 55:6, s. 546-553
-
Tidskriftsartikel (refereegranskat)abstract
- Supraspan verbal list learning is widely used to assess dementia and related cognitive disorders where declarative memory deficits are a major clinical sign. While the overall learning rate is important for diagnosis, serial position patterns may give insight into more specific memory processes in patients with cognitive impairment. This study explored these patterns in a memory clinic clientele. One hundred eighty three participants took the Rey Auditory-Verbal Learning Test (RAVLT). The major groups were patients with Alzheimer's disease (AD), Vascular Dementia (VD), Mild Cognitive Impairment (MCI), and Subjective Cognitive Impairment (SCI) as well as healthy controls (HC). Raw scores for the five trials and five serial partitions were factor analysed. Three memory factors were found and interpreted as Primacy, Recency, and Resistance to Interference. AD and MCI patients had impaired scores in all factors. SCI patients were significantly impaired in the Resistance to Interference factor, and in the Recency factor at the first trial. The main conclusion is that serial position data from word list testing reflect specific memory capacities which vary with levels of cognitive impairment.
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| 23. |
- Fuchtbauer, Laila, et al.
(författare)
-
Increased Number of Retinal Vessels in Acromegaly.
- 2020
-
Ingår i: European journal of endocrinology. - 1479-683X. ; 182:3, s. 293-302
-
Tidskriftsartikel (refereegranskat)abstract
- Excess of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as in acromegaly, is associated with an increased risk of diabetes, but whether retinal vessels are altered is unknown. The aim of this study was to evaluate retinal vessel morphology in patients with acromegaly at diagnosis and after treatment and to describe the prevalence of diabetic retinopathy in patients with long-standing acromegaly and diabetes.Two independent observational studies, one being prospective and the other retrospective and cross-sectional.Retinal vessel morphology of 26 patients with acromegaly was examined at diagnosis and 1 year after treatment and compared to 13 healthy controls. Cross-sectional evaluation of 39 patients with long-standing acromegaly and diabetes was performed. Fundus photographs were digitally analyzed for vessel morphology.Patients with acromegaly had a median (interquartile range) of 34.3 (30.0-39.0) vessel branching points compared to 27.0 (24.0-29.0) for healthy controls (P < 0.001). Tortuosity of arterioles and venules remained unchanged. Vessel morphology did not change significantly after treatment. Patients with acromegaly and diabetes for a median of 14 years also had a high number of branching points [34.2 (32.5-35.6)], but the prevalence of diabetic retinopathy was not higher than expected in diabetic patients without acromegaly.Patients with acromegaly have an increased number of vascular branching points in the retina without an alteration of macroscopic vessel morphology. This is consistent with an angiogenic effect of GH/IGF-1 in humans. The prevalence of diabetic retinopathy was not increased in patients with acromegaly and diabetes.
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| 24. |
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| 25. |
- Hellström, Göran, et al.
(författare)
-
Seasonal thermal energy storage - the HYDROCK concept
- 2001
-
Ingår i: Bulletine of Engineering Geology and the Environment. ; 60, s. 145-156
-
Tidskriftsartikel (refereegranskat)abstract
- A method for seasonal storage of heat or cold in the bedrock (the HYDROCK concept) is presented and its thermal performance discussed.
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| 26. |
- Hellström, Göran, et al.
(författare)
-
Seasonal thermal energy storage - The HYDROCK concept
- 2001
-
Ingår i: Bulletin of Engineering Geology and the Environment. - : Springer Science and Business Media LLC. - 1435-9529 .- 1435-9537. ; 60:2, s. 145-156
-
Tidskriftsartikel (refereegranskat)abstract
- A method for seasonal storage of heat or cold in the bedrock (the HYDROCK concept) is presented and its thermal performance discussed. It involves the use of a fractured bedrock at shallow depths (ca. 50-250 m), where existing fractures are stimulated or new fractures artificially created and used as flow-paths for a heat/cold carrier (usually water). The fracture surfaces are used as heat exchangers and the bedrock is loaded and unloaded to suit the energy needs. Propants are injected into the fractures to keep them open and reduce the energy needed for pumping water through the system. Field tests confirm that stacked parallel fractures can be produced by hydraulic fracturing. The thermal performance of the store is modelled and compared with a ducted ground heat store. It is shown that the HYDROCK store may yield 10-20% more energy during extraction than a ducted ground heat store for similar amounts of injected energy. This indicates that the HYDROCK concept is competitive as a seasonal energy store and may be of particular importance as an alternative energy source where existing methods cannot be economically justified.
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| 27. |
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| 28. |
- Hellström, Lars, 1974-, et al.
(författare)
-
Branch Thinning and the Large-Scale, Self-Similar Structure of Trees
- 2018
-
Ingår i: American Naturalist. - : UNIV CHICAGO PRESS. - 0003-0147 .- 1537-5323. ; 192:1, s. E37-E47
-
Tidskriftsartikel (refereegranskat)abstract
- Branch formation in trees has an inherent tendency toward exponential growth, but exponential growth in the number of branches cannot continue indefinitely. It has been suggested that trees balance this tendency toward expansion by also losing branches grown in previous growth cycles. Here, we present a model for branch formation and branch loss during ontogeny that builds on the phenomenological assumption of a branch carrying capacity. The model allows us to derive approximate analytical expressions for the number of tips on a branch, the distribution of growth modules within a branch, and the rate and size distribution of tree wood litter produced. Although limited availability of data makes empirical corroboration challenging, we show that our model can fit field observations of red maple (Acer rubrum) and note that the age distribution of discarded branches predicted by our model is qualitatively similar to an empirically observed distribution of dead and abscised branches of balsam poplar (Populus balsamifera). By showing how a simple phenomenological assumptionthat the number of branches a tree can maintain is limitedleads directly to predictions on branching structure and the rate and size distribution of branch loss, these results potentially enable more explicit modeling of woody tissues in ecosystems worldwide, with implications for the buildup of flammable fuel, nutrient cycling, and understanding of plant growth.
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| 29. |
- Hellström, Magnus, et al.
(författare)
-
Fågelräkning och ringmärkning vid Ottenby fågelstation 2015
- 2015
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Vid Ottenby fågelstation sker standardiserad fångst av flyttfåglar. Insamlad data används för att registrera populationstrender, fenologitrender samt för beräkning av årlig häckningsframgång. Under 2015 fångades totalt 19 083 fåglar av 100 arter i den standardiserade fångsten. Summan ligger knappt 5 % över referensvär-det.Våren: Totalt under våren fångades 6 874 fåglar vilket ligger nära 25 % över referensvärdet, främst förklarat av goda summor för rödhake. Våren visade relativt genomsnittliga summor för många arter men svarthätta och göktyta är exempel där fångsten överskred referensvärdet ordentligt. Gräshoppsångare, domherre och ortolansparv fångades inte alls och även rödvingetrast, rosenfink, gulsparv och grönsångare fångades i antal långt under medelvärdet. Blåhaken fortsätter sin oroande sentida kräftgång med endast tre individer fångade under våren (vilket ska jämföras med ett referensvärde på 51 individer).Hösten: Trädgårdsfångsten gav 8 640 fåglar, vilket är knappt 7 % under referensvärdet. Goda fångstsummor erhölls för bland annat gransångare och gärdsmyg men även för mindre flugsnappare och både hus– och ladusvala. Låga summor noterades för t.ex. blåhake, grönfink, rödvingetrast och gulsparv. Inte en enda göktyta, rosenfink eller ortolansparv noterades i fångsten.Vadare: Totalt fångades 3 569 vadare vilket är drygt 5 % över referensvärdet. Summan förklaras i hög grad av en god förekomst av kärrsnäppor. Myrsnäppa fångades i goda antal, långt över medel, medan flera andra arter tvärtom visade svaga fångstsummor. Fångsten fick dessvärre avbrytas tidigt under sommaren (innan årsungarna anlände) på grund av förekomst av mink på udden.Fenologi: Sveriges flyttfåglar anländer allt tidigare om våren, och förändringen framgår tydligt i fångstse-rien. Vintern 2014/2015 var mild och vårsträcket förlöpte enligt det tidiga schema som vi numera vant oss vid. Under vårflyttningen visar 15 arter signifikanta förändringar i sitt fenologiska uppträdande och i samtliga fall handlar det om en tidigareläggning av schemat. I genomsnitt uppvisade de 33 analyserade arterna ett medeldatum som 2015 låg 5,0 dagar tidigare än vid mätningarnas början 1979. Gruppen med kort- och medeldistansflyttare anlände med ett medeldatum 3,7 dagar tidigare än vid standardiseringens början 1979 och för tropikflyttare gällde 6,3 dagar. Tittar man på hela den standardiserade perioden 1979–2015 uppvisar arterna en genomsnittlig förändring av motsvarande storlek: -4,0 dagar. Därmed blev 2015 ett år som förstär-ker mönstret under 2000-talet med tidiga ankomstdatum.Häckningsframgång: Andelen ungfåglar i höstfångsten uppgick under 2015 till 83 %. Detta värde är mycket lågt och utgör det tredje lägsta sedan den standardiserade höstfångsten inleddes 1972. Försommaren 2015 var på många håll i landet kall, blåsig och nederbördsrik och att häckningsutfallet skulle bli dåligt var därför väntat.
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| 30. |
- Hellström, Åke
(författare)
-
Anatomy of stimulus comparison.
- 2005
-
Ingår i: Fechner Day 2005. ; , s. 113-118
-
Bokkapitel (refereegranskat)abstract
- Stimulus comparison by human observers is a more complex process than the subtraction carried out by a simple comparator. This is shown by the patterns of time- and space-order "errors." Specifically, experiments show that the two compared stimuli exert differential influence on the comparative response. This invalidates models based on additive bias or semantic congruity. The sensation-weighting (SW) model can account for many of the results. One important consequence is that the discriminability of two stimuli depends on which of them is varied.
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| 31. |
- Hellström, Åke, et al.
(författare)
-
Assessment and interpretation of bias in 2AFC stimulus comparison through chronometric analysis
- 2011
-
Ingår i: Fechner Day 2011. - Raanana, Israel : International Society for Psychophysics.
-
Konferensbidrag (refereegranskat)abstract
- Random-walk and diffusion models for two-choice comparison of paired successive or simultaneous stimuli focus on response time (RT), modeled as the time needed to reach one or the other barrier, and its relation to the response probabilities. Logit P1 = ln[P1/(1-P1)], where P1 is the probability of responding ”first greater,” can be seen as a measure of subjective stimulus difference, d. Signed response speed (SRS), ±1/RT with the sign of the response, yields another d measure. The two measures are highly correlated and, importantly, the intercept in the regression of logit P1 on mean SRS estimates the asymmetry of the starting point relative to the barriers, that is, the bias. New analyses of data from Patching, Englund, and Hellström (2011) show that this bias helps explain the variability of the time-and space order errors. Possible connections of the bias with the parameters in Hellström’s (2003) sensation-weighting (SW) model are explored.
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| 32. |
- Hellström, Åke, et al.
(författare)
-
Cross-modality in comparisons of successive stimuli
- 2012
-
Ingår i: Fechner Day 2012. - Ottawa, Kanada : The International Society for Psychophysics. ; , s. 168-173
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Two experiments were performed to study effects of modality, temporal position, and their in- teraction on comparisons of successive stimuli. In Experiment 1, intramodal (tone-tone and line-line) and crossmodal (tone-line and line-tone) stimulus pairs, with two interstimulus in- tervals (ISIs), were presented. Participants indicated which stimulus was the “stronger.” Time-order effects (TOEs) were studied using the classic D% measure as well as weighting coefficients from Hellström’s sensation weighting model. TOEs were found in both intramo- dal and crossmodal comparisons. The classic pause-function (more negative TOE with longer ISIs) was found in all pair types except tone-line. In Experiment 2, participants indicated which of two lines was the longer, or which of two tones was the louder. Intramodal anchors, crossmodal anchors, or no anchors were interpolated between the stimuli. Anchoring tended to yield negative TOEs and to diminish the first stimulus’ weight. Intramodal anchoring of tone-tone pairs yielded low stimulus weights, suggesting stimulus interference.
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| 33. |
- Hellström, Åke, et al.
(författare)
-
Effects of sensitivity, bias, and stimulus presentation order in comparative discrimination of interval durations : A univariate and multivariate study
- 2018
-
Ingår i: Fechner Day 2018. - : International Society for Psychophysics. ; , s. 266-271
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- According to the sensation weighting model (SWM), stimulus magnitude level dependent time-order errors (TOEs) in stimulus comparison arise from uneven stimulus weighting, levered by asymmetry of an internal reference level; the weighting also causes discriminability to depend on the presentation order of standard (St) and comparison stimulus (Co) (the Type B effect). Both of these effects, as well as judgment bias, determine the measured difference limen (DL). In two duration discrimination experiments, these contributions to the DL were explored, using an adaptive staircase method. The compared intervals were filled auditory or empty visual. The interstimulus interval was 900 ms and the St duration 100, 215, 464, or 1000 ms in a blocked design. In univariate as well as multivariate analyses, the SWM’s predictions were confirmed on the individual level, and the contributions of sensitivity, bias, and weighting in building the DL were assessed.
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| 34. |
- Hellström, Åke
(författare)
-
Explaining the anomalous results of stimulus comparison : Noisy target correlates help optimize discrimination
- 2022
-
Ingår i: Fechner Day 2022. - Lund : International Society for Psychophysics. ; , s. 37-40
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The basic idea of weighting in stimulus comparison has become widely accepted. However, Hellström's (1979) sensation-weighting model (SWM) for stimulus comparison is still controversial. The full range of results of the experiment that the SWM was originally based on has remained neglected. Some of these results are "anomalous" and must be seen as a serious challenge for modelers who seek to apply currently popular ideas, such as Bayesian optimization, to stimulus comparison. Here, based on the SWM, the weighing-in of reference levels for discrimination optimization is discussed, emphasizing the potential role of noisy target correlates (NTCs).
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| 35. |
- Hellström, Åke
(författare)
-
In memoriam : Hannes Eisler, 1923-2015
- 2015
-
Ingår i: Fechner Day 2015 <em></em>. - Québec, Canada : International Society for Psychophysics. ; , s. xi-xii
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Our very distinguished member, Professor Hannes Eisler, Stockholm University, has left us. He died on May 28, 2015, at the age of 91. He was a member of the ISP from its beginnings. At Fechner Day 2014 in Lund, Sweden, Hannes lectured on "Some research tips from 55 years' psychophysics." Informally, he named this presentation his "swan song."Hannes was born in Vienna, Austria, 1923, and at the age of 15 fled to Sweden to escape the Nazis. Initially Hannes worked as a farm hand but quickly progressed to study at high school and later at Stockholm University, where he became an adept of Gösta Ekman, the Swedish pioneer of quantitative psychology. After spending a year in S. S. Stevens’ lab at Harvard, Hannes was awarded his Ph.D. in Stockholm 1963. In 1994, as the result of a petition from all Swedish psychology professors, the Swedish government awarded Hannes Eisler the rank and honor of Professor – a rare recognition of scientific merit.During his long career, Hannes authored a large number of publications and made many important contributions to our field. His doctoral dissertation was about the relation between magnitude and category scales. Later on, he turned much of his interest toward time perception in people as well as in mice. Perhaps the most impressive of his contributions is the Parallel Clock model for temporal reproduction and comparison1, which arose from Hannes’ arduous and meticulous investigation of long known anomalies in time perception; specifically, breaks in psychophysical functions. Noting the positions of those breaks in reproduction data led him to the counter-intuitive realization that participants use a seemingly odd strategy in immediate reproduction of temporal intervals: subjectively matching the reproduction, not to the standard, but to one-half of the total duration. Using this model it is possible to estimate the psycho-physical function for time from reproduction data, and Hannes published a huge collection of temporal power function exponents2 – much cited but all too often with no understanding of how they were determined.Hannes was intellectually perspicacious and possessed research talent in abundance. Modesty, good nature, along with deep and diverse cultural interests, sense of humor, and appreciation of the good things in life, were some of his other characteristics. Scientific seminars on various topics were enriched by his insightful comments until a heart attack sadly ended his long life.I miss Hannes immensely, as a very good old friend, a respected senior colleague, and a mentor – even the word guru feels very appropriate.
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| 36. |
- Hellström, Åke
(författare)
-
Integration of stimulus dimensions in judgments of area and shape : Modeling guided by level curves
- 2015
-
Ingår i: Fechner Day 2015. - Québec, Canada : International Society for Psychophysics. ; , s. 17-17
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In the horizontal-vertical (H-V) illusion (Künnapas, 1958) the judged V/H ratio is larger than the physical ratio. This tendency is not found in V/H ratio judgments of rectangles (Gärling & Dalkvist, 1977), but these judgments are not based on the simple ratio of V and H: Level-curves (iso-judgment contours) of logarithmized data show that the larger dimension is more important than the smaller. Developmentally, judgments of rectangular area have been described as changing from adding V and H in children to multiplying them in adults (Wilkening, 1979). However, level curves demonstrate deviations from simple models at all ages. Adults’ area judgments show a greater importance of the larger dimension, and also a greater importance of H than of V, but accurate modeling is difficult. Here, level-curve plots (using R’s contour function) prove invaluable for graphic guidance of modeling by displaying systematic judgment tendencies that go unnoticed with conventional factorial plots.
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| 37. |
- Hellström, Åke, et al.
(författare)
-
Intramodal and crossmodal pairing and anchoring in comparisons of successive stimuli
- 2014
-
Ingår i: Attention, Perception & Psychophysics. - : Springer Science and Business Media LLC. - 1943-3921 .- 1943-393X. ; 76:4, s. 1197-1211
-
Tidskriftsartikel (refereegranskat)abstract
- Two experiments were conducted to study effects of modality, temporal position, and their interaction on comparisons of successive stimuli. In Experiment 1, intramodal (tone-tone and line-line) and crossmodal (tone-line and line-tone) stimulus pairs, with two interstimulus intervals (ISIs), 400 and 2,000 ms, were presented. Participants indicated which stimulus was the stronger. Time-order errors (TOEs) were assessed using the D% measure and were found in all types of pairs. Variation in TOEs across conditions was well accounted for by changes in parameters (stimulus weights, reference levels) in an extended version of Hellstrom's sensation weighting (SW) model. With an ISI of 2,000 ms, the first stimulus had a lower weight (less impact on the response) than did the second stimulus. More negative TOEs were found with the longer ISI in all pair types except tone-line. In Experiment 2, participants indicated which of two lines was the longer or which of two tones was the louder. An intra-or crossmodal anchor, or no anchor, was interpolated between the stimuli. Anchoring tended to reduce the weight of the first stimulus, suggesting interference with memory, and to yield negative TOEs. Intramodal anchors yielded reduced weights of both stimuli, most dramatically for tones, suggesting an additional effect of stimulus interference. Response times decreased with crossmodal anchors. For line-line pairs, strong negative TOEs were found. In both experiments, the variation in TOE across conditions was well accounted for by the SW model.
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| 38. |
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| 39. |
|
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| 40. |
- Hellström, Åke, et al.
(författare)
-
Sensation weighting in duration discrimination : A univariate, multivariate, and varied-design study of presentation-order effects
- 2020
-
Ingår i: Attention, Perception & Psychophysics. - : Springer Science and Business Media LLC. - 1943-3921 .- 1943-393X. ; 82, s. 3196-3220
-
Tidskriftsartikel (refereegranskat)abstract
- Stimulus discriminability is often assessed by comparisons of two successive stimuli: a fixed standard (St) and a varied comparison stimulus (Co). Hellstrom's sensation weighting (SW) model describes the subjective difference between St and Co as a difference between two weighted compounds, each comprising a stimulus and its internal reference level (ReL). The presentation order of St and Co has two important effects: Relative overestimation of one stimulus is caused by perceptual time-order errors (TOEs), as well as by judgment biases. Also, sensitivity to changes in Co tends to differ between orders StCo and CoSt: the Type B effect. In three duration discrimination experiments, difference limens (DLs) were estimated by an adaptive staircase method. The SW model was adapted for modeling of DLs generated with this method. In Experiments 1 and 2, St durations were 100, 215, 464, and 1,000 ms in separate blocks. TOEs and Type B effects were assessed with univariate and multivariate analyses, and were well accounted for by the SW model, suggesting that the two effects are closely related, as this model predicts. With short St durations, lower DLs were found with the order CoSt than with StCo, challenging alternative models. In Experiment 3, St durations of 100 and 215 ms, or 464 and 1,000 ms, were intermixed within a block. From the SW model this was predicted to shift the ReL for the first-presented interval, thereby also shifting the TOE. This prediction was confirmed, strengthening the SW model's account of the comparison of stimulus magnitudes.
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| 41. |
- Hellström, Åke
(författare)
-
Temporal asymmetry and “magnet effect” in similarity and discrimination of prototypical and nonprototypical stimuli : Consequences of differential sensation weighting
- 2007
-
Ingår i: Fechner Day 2007. ; , s. 283-288
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The judged similarity between two successive stimuli is higher when the less prototypical stimulus is the first in the pair than when it is the last. Also, the rated similarity between a scalar and a nonscalar melody is greater when the nonscalar melody comes first rather than last in the pair, and a change from a mistuned to a tuned musical interval is harder to detect than when the order is reversed. Such time-order asymmetries can be accounted for by a generalization of Hellström’s sensation-weighting model, with a lower weight for the first stimulus as is usual when two successive stimuli are compared. This would result in assimi-lation of a first-presented nonprototypical stimulus toward the prototype, increasing its similarity to a more prototypical last-presented stimulus. Also, fewer “different” judgments, but not worse discrimination from variants, occur for prototypical than for nonprototypical stimuli; the so-called perceptual magnet effect appears to be a methodology-based artifact.
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| 42. |
- Hellström, Åke
(författare)
-
Time- and space-order effects in stimulus comparison in the light of response-time data
- 2008
-
Ingår i: Fechner Day 2008. ; , s. 139-144
-
Konferensbidrag (refereegranskat)abstract
- As has been found experimentally, magnitude comparison of paired successive or simultaneous stimuli can be described as being based on differential subtractive weighting of the stimulus-induced sensations ψ1 and ψ2, causing time- and space-order effects (TOEs andSOEs). In the simplest case, the comparison equation becomes: d = s1 (ψ1 - ψr) - s2 (ψ2 - ψr), where ψr is the reference level (ReL). New analyses of response-time data from stimulus comparison experiments (Hellström, 2003) show that signed response speed, the inverse of response time with the sign of the subjective difference d, carries similar information on d as measures based on transformed proportions of "1st greater," "equal," and "2nd greater" responses. Sensation weighting is similar for fast and slow responses, which suggests that it arises in a preceding processing stage, and strengthens the notion that the weighting, and thereby TOEs and SOEs, is of perceptual origin.
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| 43. |
- Hellström, Åke
(författare)
-
Time-order effects and generalized subjective magnitude in crossmodal stimulus comparison
- 2014
-
Ingår i: Proceedings of the 30th Annual Meeting of the International Society for Psychophysics. - Lund, Sweden : International Society for Psychophysics. ; , s. 33-33
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Crossmodal comparability for stimulus magnitudes on modalities lacking a common intensity aspect, such as line length and tone loudness, may rest on a more general magnitude concept.In a recent study1, possible time-order error (TOE)-like effects were looked for in crossmodal comparison of successive stimuli. Hellstro ̈m’s2 sensation-weighting (SW) model was adapted for use as a descriptive and analytical tool. According to this model, the real comparison takes place between two weighted subjective compounds, each built up by the sensation magnitudes of a stimulus (weight s1 or s2) and of its reference level (ReL) (weight 1 − s1 or 1 − s2).Intramodally (tone-tone, line-line) and crossmodally (tone-line, line-tone) paired stimuli, with duration 150 ms and ISIs 400 and 2000 ms, were compared for their strength, with the alternatives 1st stronger, 2nd stronger, and equal, yielding scaled subjective difference (D) of +100, 0, and -100. The extended SW model, for a pair with a tone followed by a line, isD=kT[s1(Φ1T −Φ0T)+(1−s1)(Φr1T −Φ0T)]−kL[s2(Φ2L −Φ0L)+(1−s2)(Φr2L −Φ0L)]+b 1a = s1kT (Φ1T −Φr1T )−s2kL(Φ2L −Φr2L)+kT (Φr1T −Φ0T )−kL(Φr2L −Φ0L)+b, 1bwhere Φ is the physical stimulus magnitude on a scale, -4 through +4 for lines as well as tones (90–170 mm, and 74.7–81.1 dB). It was assumed that, within these ranges, Φ = k(Φ − Φ0), where Ψ is the subjective magnitude and Φ0 is the Φ value for Ψ = 0. k is a modality-specific scale factor. Subscripts T and L indicate tone and line; 1 and 2 indicate temporal position. Φr is the physical magnitude of the ReL. b is possible bias. The experimental design, varying both stimulus magnitudes, allowed estimation of the relevant model parameters from the data.Comparing a tone and a line for their “strength” was indeed feasible, yielding weighting effects and TOEs (assessed by mean D) resembling those in intramodal comparison. In terms of the SW model, with ISI = 2000 ms s1 < s2. TOEs were generally more negative with the 2000–ms than with the 200–ms ISI. The results were well accounted for by the SW model.Eq. 1b implies that the effective subjective magnitude of each paired stimulus is its ReL plus its deviation from the ReL multiplied by s. Estimates of kT and kL were similar, indi- cating crossmodally similar ranges of Ψ. Based on this and on findings3, 4 that context effects are much stronger crossmodally than intramodally, it may be hypothesized that in crossmodal comparison the k value for each modality becomes inversely related to the range or spread of the sensation magnitudes in the modality. In the SW model (Eq. 1b) this would mean that the stimulus-dependent parts of the compared magnitudes are standardized quantities, like z values. These would be dimensionless, removing the need for an intermodal “currency exchange” and accounting for comparability of subjective magnitudes in very different modalities.
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| 44. |
- Hellström, Åke, et al.
(författare)
-
Time-order errors and standard-position effects in duration discrimination : An experimental study and an analysis by the sensation-weighting model
- 2015
-
Ingår i: Attention, Perception & Psychophysics. - : Springer Science and Business Media LLC. - 1943-3921 .- 1943-393X. ; 77:7, s. 2409-2423
-
Tidskriftsartikel (refereegranskat)abstract
- Studies have shown that the discriminability of successive time intervals depends on the presentation order of the standard (St) and the comparison (Co) stimuli. Also, this order affects the point of subjective equality. The first effect is here called the standard-position effect (SPE); the latter is known as the time-order error. In the present study, we investigated how these two effects vary across interval types and standard durations, using Hellstrom's sensation-weighting model to describe the results and relate them to stimulus comparison mechanisms. In Experiment 1, four modes of interval presentation were used, factorially combining interval type (filled, empty) and sensory modality (auditory, visual). For each mode, two presentation orders (St-Co, Co-St) and two standard durations (100 ms, 1,000 ms) were used; half of the participants received correctness feedback, and half of them did not. The interstimulus interval was 900 ms. The SPEs were negative (i.e., a smaller difference limen for St-Co than for Co-St), except for the filled-auditory and empty-visual 100-ms standards, for which a positive effect was obtained. In Experiment 2, duration discrimination was investigated for filled auditory intervals with four standards between 100 and 1,000 ms, an interstimulus interval of 900 ms, and no feedback. Standard duration interacted with presentation order, here yielding SPEs that were negative for standards of 100 and 1,000 ms, but positive for 215 and 464 ms. Our findings indicate that the SPE can be positive as well as negative, depending on the interval type and standard duration, reflecting the relative weighting of the stimulus information, as is described by the sensation-weighting model.
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| 45. |
- Hellström, Åke, et al.
(författare)
-
Weber fractions and time-order errors for long and short durations : implications for modeling
- 2013
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Ingår i: Fechner Day 2013. - Freiburg, Germany : International Society for Psychophysics. ; , s. 28-28
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Using a weighted up-down procedure, in each of eight conditions 28 participants compared durations of auditory (noise bursts) or visual (LED flashes) intervals; filled or unfilled with 3-ms markers; with or without feedback. Standards (Sts) were 100 and 1000 ms, and the ISI 900 ms. Intermixedly, presentation orders were St-Comparison (Co) and Co-St. TOEs were positive for St=100-ms and negative for St=1000 ms. Weber fractions (WFs, JND/St) were lowered by feedback. For visual-filled and visual-empty, WFs were highest for St=100 ms. For auditory-filled and visual-empty, St interacted with Order: lowest WFs occurred for St-Co with St=1000 ms, but for Co-St with St=100 ms. Lowest average WFs occurred with St-Co for visual-filled, but with Co-St for visual-empty. The results refute the generalization of better discrimination with St-Co than with Co-St (”type-B effect”), and support the notion of sensation weighting: flexibly differential impact weights of the compared durations in generating the response.
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| 49. |
- Jangsten, Elisabeth, 1954, et al.
(författare)
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A comparison of active management and expectant management of the third stage of labour: a Swedish randomised controlled trial.
- 2011
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Ingår i: BJOG : an international journal of obstetrics and gynaecology. - : Wiley. - 1471-0528 .- 1470-0328. ; 118:3, s. 362-9
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Tidskriftsartikel (refereegranskat)abstract
- Please cite this paper as: Jangsten E, Mattsson L, Lyckestam I, Hellström A, Berg M. A comparison of active management and expectant management of the third stage of labour: a Swedish randomised controlled trial. BJOG 2011;118:362-369. Objective To compare blood loss in women actively and expectantly managed in the third stage of labour. Design Randomised controlled trial (RCT). Setting Two delivery units at a Swedish university hospital. Population Healthy women with normal pregnancies, at gestational age 34-43weeks, with singleton cephalic presentation and expected vaginal delivery. Methods The women were randomly allocated to either active (n=903) or expectant (n=899) management of the third stage of labour. Main outcome measures The primary outcome was blood loss>1000ml, and secondary outcomes were mean blood loss, duration of third stage, retained placenta, haemoglobin level and blood transfusion. Results Blood loss>1000ml occurred in 10% of the actively managed group and 16.8% of the expectantly managed group (P<0.001). Mean blood loss was 535ml in the actively managed group and 680ml in the expectantly managed group (P<0.001). A prolonged duration of the third stage was associated with increased blood loss. Increased placenta weight was associated with increased blood loss. The haemoglobin level was 118g/dl in actively managed women and 115g/dl in expectantly managed women (P<0.001) the day after childbirth. The occurrence of retained placenta and the number of blood transfusions did not differ between the groups. Conclusions Active management of the third stage of labour was associated with less blood loss compared with expectant management. It is reasonable to advocate this regime, especially in primiparous women.
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| 50. |
- Jangsten, Elisabeth, 1954, et al.
(författare)
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Afterpains : A Comparison Between Active and Expectant Management of the Third Stage of Labor
- 2011
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Ingår i: Birth. - : Wiley-Blackwell. - 0730-7659 .- 1523-536X. ; 38:4, s. 294-301
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Tidskriftsartikel (refereegranskat)abstract
- Background: Management of the third stage of labor, the period following the birth of the infant until delivery of the placenta, is crucial. Active management using synthetic oxytocin has been advocated to decrease blood loss. It has been suggested, but not studied, that oxytocin may increase afterpains. The aim of this study was to compare womens experience of pain intensity when the third stage of labor was managed actively and expectantly and their experience of afterpains. Methods: A single-blind, randomized, controlled trial was performed at two delivery units in Sweden in a population of healthy women with normal, singleton pregnancies, gestational age of 34 to 43 weeks, cephalic presentation, and expected vaginal delivery. Women (n = 1,802) were randomly allocated to either active management or expectant management of the third stage of labor. Afterpains were assessed by Visual Analog Scale (VAS) and the Pain-o-Meter (POM-WDS) 2 hours after delivery of the placenta and the day after childbirth. Results: At 2 hours after childbirth, women in the actively managed group had lower VAS pain scores than expectantly managed women (p = 0.014). Afterpains were scored as more intense the day after, compared with 2 hours after, childbirth in both groups. Multiparas scored more intense afterpains, compared with primiparas, irrespective of management (p < 0.001). Conclusions: Active management of the third stage of labor does not provoke more intense afterpains than expectant management. (BIRTH 38: 4 December 2011)
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