| 1. |
- Basaran, Sumeyye, et al.
(författare)
-
The Swedish version of the Alabama parenting questionnaire : Psychometric evaluation and norm data
- 2024
-
Ingår i: Scandinavian Journal of Psychology. - 0036-5564 .- 1467-9450. ; 65:4, s. 628-638
-
Tidskriftsartikel (refereegranskat)abstract
- The Alabama parenting questionnaire (APQ) is a commonly used instrument for assessing parenting practices and evaluating treatment outcomes of parent-training interventions targeting child conduct problems. In the present study we translated and developed a Swedish version of the APQ parent version and tested it on a community sample of 799 parents of children between 6 and 15 years with diverse socioeconomic backgrounds. Data were collected through an online survey distributed through school newsletters and social media. Exploratory factor analysis (EFA) suggested a five-factor model with 23 items. Four of these factors correspond to the subscales suggested in the original version of the APQ: inconsistent discipline, poor monitoring, involvement, and positive parenting. The fifth subscale from the original APQ, corporal punishment, did not show up as a factor in our data sample. Instead, a new factor, which we refer to as contingency management, was revealed. A confirmatory factor analysis further suggested some misalignment between the original APQ subscale structure and our sample, which we interpret as a signal that the instrument may need refinement to better reflect contemporary parenting methods in diverse cultural contexts. Despite this limitation, and with the exclusion of the corporal punishment subscale, which should be employed judiciously, our results suggest that the Swedish version of the APQ can be a useful instrument in measuring parenting practices in Sweden. We present norm data stratified by child age, which practitioners and researchers can use as a reference for assessment of parenting practices in the Swedish population.
|
|
| 2. |
- Bhardwaj, Manisha, et al.
(författare)
-
Do people take stimulus correlations into account in visual search?
- 2016
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:3
-
Tidskriftsartikel (refereegranskat)abstract
- In laboratory visual search experiments, distractors are often statistically independent of each other. However, stimuli in more naturalistic settings are often correlated and rarely independent. Here, we examine whether human observers take stimulus correlations into account in orientation target detection. We find that they do, although probably not optimally. In particular, it seems that low distractor correlations are overestimated. Our results might contribute to bridging the gap between artificial and natural visual search tasks.
|
|
| 3. |
- Forsgren, Mattias, et al.
(författare)
-
”The report of my death was an exaggeration” – no evidence to rule out associative learning in non-stationary probability learning
- 2023
-
Ingår i: Proceedings of the 18th SweCog Conference, Swedish Cognitive Society, Göteborg 2023, 5-6 October. - : THE UNIVERSITY OF SKÖVDE. - 9789198903805 ; , s. 27-30
-
Konferensbidrag (refereegranskat)abstract
- The debate between empiricists and rationalists on whether human knowledge primarily stems from observations or reason has recently been reinvigorated in the context of learning of non-stationary probabilities. An (implicit) consensus has emerged in it being modelled using some version of the delta-rule – a gradient descent algorithm for associative learning. This has been challenged by recent work claiming that new experiment data is only compatible with a model which tests discrete hypotheses about the underlying probability distribution, why associative models must be rejected. Here, we show that this claim was premature. Using maximum likelihood based fitting and formal, quantitative model comparison, we show that a combination of the delta-rule and sequential evidence accumulation can indeed explain all available data substantially better than the suggested hypothesis testing model. We conclude that there is no evidence to rule out a role for associative learning. However, this does not mean that we should instead rule out models involving hypotheses about the world. Outside the lab, we often have rich cognitive models that we must somehow reconcile with a stream of observations. How that happens should be a principal concern in future work.
|
|
| 4. |
- Hannus, Aave, et al.
(författare)
-
Visual search near threshold : Some features are more equal than others.
- 2006
-
Ingår i: Journal of Vision. - : Association for Research in Vision and Ophthalmology (ARVO). - 1534-7362. ; 6:4
-
Tidskriftsartikel (refereegranskat)abstract
- While searching for objects, we combine information from multiple visual modalities. Classical theories of visual search assume that features are processed independently prior to an integration stage. Based on this, one would predict that features that are equally discriminable in single feature search should remain so in conjunction search. We test this hypothesis by examining whether search accuracy in feature search predicts accuracy in conjunction search. Subjects searched for objects combining color and orientation or size; eye movements were recorded. Prior to the main experiment, we matched feature discriminability, making sure that in feature search, 70% of saccades were likely to go to the correct target stimulus. In contrast to this symmetric single feature discrimination performance, the conjunction search task showed an asymmetry in feature discrimination performance: In conjunction search, a similar percentage of saccades went to the correct color as in feature search but much less often to correct orientation or size. Therefore, accuracy in feature search is a good predictor of accuracy in conjunction search for color but not for size and orientation. We propose two explanations for the presence of such asymmetries in conjunction search: the use of conjunctively tuned channels and differential crowding effects for different features.
|
|
| 5. |
- Keshvari, Shaiyan, et al.
(författare)
-
No evidence for an item limit in change detection
- 2013
-
Ingår i: PloS Computational Biology. - : Public Library of Science (PLoS). - 1553-734X .- 1553-7358. ; 9:2
-
Tidskriftsartikel (refereegranskat)abstract
- Change detection is a classic paradigm that has been used for decades to argue that working memory can hold no more than a fixed number of items (“item-limit models”). Recent findings force us to consider the alternative view that working memory is limited by the precision in stimulus encoding, with mean precision decreasing with increasing set size (“continuous-resource models”). Most previous studies that used the change detection paradigm have ignored effects of limited encoding precision by using highly discriminable stimuli and only large changes. We conducted two change detection experiments (orientation and color) in which change magnitudes were drawn from a wide range, including small changes. In a rigorous comparison of five models, we found no evidence of an item limit. Instead, human change detection performance was best explained by a continuous-resource model in which encoding precision is variable across items and trials even at a given set size. This model accounts for comparison errors in a principled, probabilistic manner. Our findings sharply challenge the theoretical basis for most neural studies of working memory capacity.
|
|
| 6. |
- Keshvari, Shaiyan, et al.
(författare)
-
Probabilistic computation in human perception under variability in encoding precision
- 2012
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:6
-
Tidskriftsartikel (refereegranskat)abstract
- A key function of the brain is to interpret noisy sensory information. To do so optimally, observers must, in many tasks, take into account knowledge of the precision with which stimuli are encoded. In an orientation change detection task, we find that encoding precision does not only depend on an experimentally controlled reliability parameter (shape), but also exhibits additional variability. In spite of variability in precision, human subjects seem to take into account precision near-optimally on a trial-to-trial and item-to-item basis. Our results offer a new conceptualization of the encoding of sensory information and highlight the brain's remarkable ability to incorporate knowledge of uncertainty during complex perceptual decision-making.
|
|
| 7. |
- Ma, Wei Ji, et al.
(författare)
-
Behavior and neural basis of near-optimal visual search.
- 2011
-
Ingår i: Nature Neuroscience. - : Springer Science and Business Media LLC. - 1097-6256 .- 1546-1726. ; 14:6
-
Tidskriftsartikel (refereegranskat)abstract
- The ability to search efficiently for a target in a cluttered environment is one of the most remarkable functions of the nervous system. This task is difficult under natural circumstances, as the reliability of sensory information can vary greatly across space and time and is typically a priori unknown to the observer. In contrast, visual-search experiments commonly use stimuli of equal and known reliability. In a target detection task, we randomly assigned high or low reliability to each item on a trial-by-trial basis. An optimal observer would weight the observations by their trial-to-trial reliability and combine them using a specific nonlinear integration rule. We found that humans were near-optimal, regardless of whether distractors were homogeneous or heterogeneous and whether reliability was manipulated through contrast or shape. We present a neural-network implementation of near-optimal visual search based on probabilistic population coding. The network matched human performance.
|
|
| 8. |
- Mazyar, Helga, et al.
(författare)
-
Does precision decrease with set size?
- 2012
-
Ingår i: Journal of Vision. - : Association for Research in Vision and Ophthalmology (ARVO). - 1534-7362. ; 12:6
-
Tidskriftsartikel (refereegranskat)abstract
- The brain encodes visual information with limited precision. Contradictory evidence exists as to whether the precision with which an item is encoded depends on the number of stimuli in a display (set size). Some studies have found evidence that precision decreases with set size, but others have reported constant precision. These groups of studies differed in two ways. The studies that reported a decrease used displays with heterogeneous stimuli and tasks with a short-term memory component, while the ones that reported constancy used homogeneous stimuli and tasks that did not require short-term memory. To disentangle the effects of heterogeneity and short-memory involvement, we conducted two main experiments. In Experiment 1, stimuli were heterogeneous, and we compared a condition in which target identity was revealed before the stimulus display with one in which it was revealed afterward. In Experiment 2, target identity was fixed, and we compared heterogeneous and homogeneous distractor conditions. In both experiments, we compared an optimal-observer model in which precision is constant with set size with one in which it depends on set size. We found that precision decreases with set size when the distractors are heterogeneous, regardless of whether short-term memory is involved, but not when it is homogeneous. This suggests that heterogeneity, not short-term memory, is the critical factor. In addition, we found that precision exhibits variability across items and trials, which may partly be caused by attentional fluctuations.
|
|
| 9. |
- Mazyar, Helga, et al.
(författare)
-
Independence is elusive : set size effects on encoding precision in visual search
- 2013
-
Ingår i: Journal of Vision. - 1534-7362. ; 13:5
-
Tidskriftsartikel (refereegranskat)abstract
- Looking for a target in a visual scene becomes more difficult as the number of stimuli increases. In a signal detection theory view, this is due to the cumulative effect of noise in the encoding of the distractors, and potentially on top of that, to an increase of the noise (i.e., a decrease of precision) per stimulus with set size, reflecting divided attention. It has long been argued that human visual search behavior can be accounted for by the first factor alone. While such an account seems to be adequate for search tasks in which all distractors have the same, known feature value (i.e., are maximally predictable), we recently found a clear effect of set size on encoding precision when distractors are drawn from a uniform distribution (i.e., when they are maximally unpredictable). Here we interpolate between these two extreme cases to examine which of both conclusions holds more generally as distractor statistics are varied. In one experiment, we vary the level of distractor heterogeneity; in another we dissociate distractor homogeneity from predictability. In all conditions in both experiments, we found a strong decrease of precision with increasing set size, suggesting that precision being independent of set size is the exception rather than the rule.
|
|
| 10. |
- Van den Berg, Ronald, 1979-, et al.
(författare)
-
A crowding model of visual clutter
- 2009
-
Ingår i: Journal of Vision. - : Association for Research in Vision and Ophthalmology (ARVO). - 1534-7362. ; 9:4
-
Tidskriftsartikel (refereegranskat)abstract
- Visual information is difficult to search and interpret when the density of the displayed information is high or the layout is chaotic. Visual information that exhibits such properties is generally referred to as being "cluttered." Clutter should be avoided in information visualizations and interface design in general because it can severely degrade task performance. Although previous studies have identified computable correlates of clutter (such as local feature variance and edge density), understanding of why humans perceive some scenes as being more cluttered than others remains limited. Here, we explore an account of clutter that is inspired by findings from visual perception studies. Specifically, we test the hypothesis that the so-called "crowding" phenomenon is an important constituent of clutter. We constructed an algorithm to predict visual clutter in arbitrary images by estimating the perceptual impairment due to crowding. After verifying that this model can reproduce crowding data we tested whether it can also predict clutter. We found that its predictions correlate well with both subjective clutter assessments and search performance in cluttered scenes. These results suggest that crowding and clutter may indeed be closely related concepts and suggest avenues for further research.
|
|
