| 1. |
- Ackerley, Rochelle, 1980, et al.
(author)
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The role of tactile afference in shaping motor behaviour and implications for prosthetic innovation
- 2015
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In: Neuropsychologia. - : Elsevier BV. - 0028-3932. ; 79:B, s. 192-205
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Journal article (peer-reviewed)abstract
- The present review focusses on how tactile somatosensory afference is encoded and processed, and how this information is interpreted and acted upon in terms of motor control. We relate the fundamental workings of the sensorimotor system to the rehabilitation of amputees using modern prosthetic interventions. Our sense of touch is central to our everyday lives, from allowing us to manipulate objects accurately to giving us a sense of self-embodiment. There are a variety of specialised cutaneous mechanoreceptive afferents, which differ in terms of type and density according to the skin site. In humans, there is a dense innervation of our hands, which is reflected in their vast over-representation in somatosensory and motor cortical areas. We review the accumulated evidence from animal and human studies about the precise interplay between the somatosensory and motor systems, which is highly integrated in many brain areas and often not separable. The glabrous hand skin provides exquisite, discriminative detail about touch, which is useful for refining movements. When these signals are disrupted, such as through injury or amputation, the consequences are considerable. The development of sensory feedback in prosthetics offers a promising avenue for the full integration of a missing body part. Real-time touch feedback from motor intentions aids in grip control and the ability to distinguish different surfaces, even introducing the possibility of pleasure in artificial touch. Thus, our knowledge from fundamental research into sensorimotor interactions should be used to develop more realistic and integrative prostheses. (C) 2015 Elsevier Ltd. All rights reserved.
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| 2. |
- Alemán Bañón, José, 1977-, et al.
(author)
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Anticipating information structure : An event-related potentials study of focus assignment via the it-cleft
- 2019
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In: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 134
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Journal article (peer-reviewed)abstract
- The present study uses event-related potentials to investigate the role of prediction in the processing of information structure, a domain of language that belongs to the level of the discourse. Twenty-three native speakers of English read short contexts including three Noun Phrases (NPs) (e.g., Either an adviser or an agent can be helpful to a banker), followed by a wh-question that established the discourse role of each referent (In your opinion, which of the two should a banker hire?). The NP that the question was about (banker) was the Topic, and the two NPs that could fill the slot opened by the wh-question (adviser, agent) were the Focus NPs. The participants’ brain activity was recorded with EEG while they read the responses to the wh-questions, which differed along two dimensions: (1) the availability of the it-cleft construction (In my opinion, [it is] an agent…), a Focus-devoted device that makes Focus assignment predictable in the response; and (2) the discourse role of the target noun (Focus, Topic), which corresponds to the first referent in the response (In my opinion, [it is] an agent/a banker…). Crucially, we manipulated the phonological properties of the Focus and Topic nouns such that, if the Topic noun began with a consonant (e.g., a banker), both nouns that could fill the slot opened by the wh-question began with a vowel (e.g., an agent, an adviser) (counterbalanced in the overall design). This allowed us to measure effects of prediction at the prenominal article, before the integration of semantic and discourse information took place. The analyses on prenominal articles revealed an N400 effect for articles that were unexpected based on the phonological properties of the Focus nouns, but only in the conditions with the it-cleft. This effect emerged between 250 and 400 ms, with a frontal bias. The analyses on the noun revealed that violations of information structure (i.e., cases where the it-cleft was followed by the Topic noun) yielded a broadly distributed P600 effect, relative to appropriately clefted (i.e., focused) nouns. A similar (but numerically less robust) effect emerged for Topic relative to Focus NPs in the conditions without the it-cleft, suggesting that, in the absence of a constraining cue, comprehenders still assigned Focus to the first referent in the response. Overall, these results suggest that, when reading answers to wh-questions, comprehenders use information structure constraints (i.e., prior context + the it-cleft) to anticipate the form that the response should take (i.e., how information should be packaged).
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| 3. |
- Boraxbekk, Carl-Johan, 1980-, et al.
(author)
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Investigating the influence of KIBRA and CLSTN2 genetic polymorphisms on cross-sectional and longitudinal measures of memory performance and hippocampal volume in older individuals
- 2015
-
In: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 78, s. 10-17
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Journal article (peer-reviewed)abstract
- The variability of episodic memory decline and hippocampal atrophy observed with increasing age may partly be explained by genetic factors. KIBRA (kidney and brain expressed protein) and CLSTN2 (calsyntenin 2) are two candidate genes previously linked to episodic memory performance and volume of the hippocampus, a key memory structure. However, whether polymorphisms in these two genes also influence age-related longitudinal memory decline and hippocampal atrophy is still unknown. Using data from two independent cohorts, the Sydney Memory and Ageing Study and the Older Australian Twins Study, we investigated whether the KIBRA and CLSTN2 genetic polymorphisms (rs17070145 and rs6439886) are associated with episodic memory performance and hippocampal volume in older adults (65–90 years at baseline). We were able to examine these polymorphisms in relation to memory and hippocampal volume using cross-sectional data and, more importantly, also using longitudinal data (2 years between testing occasions). Overall we did not find support for an association of KIBRA either alone or in combination with CLSTN2 with memory performance or hippocampal volume, nor did variation in these genes influence longitudinal memory decline or hippocampal atrophy in two cohorts of older adults.
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| 4. |
- Boraxbekk, Carl-Johan, 1980-, et al.
(author)
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Motor and mental training in older people : Transfer, interference, and associated functional neural responses
- 2016
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In: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 89, s. 371-377
-
Journal article (peer-reviewed)abstract
- Learning new motor skills may become more difficult with advanced age. In the present study, we randomized 56 older individuals, including 30 women (mean age 70.6 years), to 6 weeks of motor training, mental (motor imagery) training, or a combination of motor and mental training of a finger tapping sequence. Performance improvements and post-training functional magnetic resonance imaging (fMRI) were used to investigate performance gains and associated underlying neural processes. Motor only training and a combination of motor and mental training improved performance in the trained task more than mental-only training. The fMRI data showed that motor training was associated with a representation in the premotor cortex and mental training with a representation in the secondary visual cortex. Combining motor and mental training resulted in both premotor and visual cortex representations. During fMRI scanning, reduced performance was observed in the combined motor and mental training group, possibly indicating interference between the two training methods. We concluded that motor and motor imagery training in older individuals is associated with different functional brain responses. Furthermore, adding mental training to motor training did not result in additional performance gains compared to motor-only training and combining training methods may result in interference between representations, reducing performance.
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| 5. |
- Bruno, Davide, et al.
(author)
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A study on the specificity of the association between hippocampal volume and delayed primacy performance in cognitively intact elderly individuals.
- 2015
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In: Neuropsychologia. - : Elsevier BV. - 1873-3514 .- 0028-3932. ; 69, s. 1-8
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Journal article (peer-reviewed)abstract
- Delayed recall at the primacy position (first few items on a list) has been shown to predict cognitive decline in cognitively intact elderly participants, with poorer delayed primacy performance associated with more pronounced generalized cognitive decline during follow-up. We have previously suggested that this association is due to delayed primacy performance indexing memory consolidation, which in turn is thought to depend upon hippocampal function. Here, we test the hypothesis that hippocampal size is associated with delayed primacy performance in cognitively intact elderly individuals. Data were analyzed from a group (N=81) of cognitively intact participants, aged 60 or above. Serial position performance was measured with the Buschke selective reminding test (BSRT). Hippocampal size was automatically measured via MRI, and unbiased voxel-based analyses were also conducted to explore further regional specificity of memory performance. We conducted regression analyses of hippocampus volumes on serial position performance; other predictors included age, family history of Alzheimer's disease (AD), APOE ε4 status, education, and total intracranial volume. Our results collectively suggest that there is a preferential association between hippocampal volume and delayed primacy performance. These findings are consistent with the hypothesis that delayed primacy consolidation is associated with hippocampal size, and shed light on the relationship between delayed primacy performance and generalized cognitive decline in cognitively intact individuals, suggesting that delayed primacy consolidation may serve as a sensitive marker of hippocampal health in these individuals.
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| 6. |
- Ferri, Francesca, et al.
(author)
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Emotion-inducing approaching sounds shape the boundaries of multisensory peripersonal space
- 2015
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In: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 70, s. 468-475
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Journal article (peer-reviewed)abstract
- In order to survive in a complex environment, inhabited by potentially threatening and noxious objects or living beings, we need to constantly monitor our surrounding space, especially in the vicinity of our body. Such a space has been commonly referred to as ones peripersonal space (PPS). In this study we investigated whether emotion-inducing approaching sound sources impact the boundaries of PPS. Previous studies have indeed showed that the boundaries of PPS are not fixed but modulate according to properties of stimuli in the surrounding environment. In Experiment 1, participants performed a simple tactile detection task of targets presented to their right hand. Concurrently, they were presented with intensity-changing task-irrelevant artificial sound sources perceived as approaching toward their body. The physical properties of the sound elicited emotional responses of either neutral or negative valence. Results showed larger PPS when the approaching stimulus had negative as compared to neutral emotional valence. In Experiment 2, we used ecological sounds which content (i.e., psychological associations to the sound producing source), rather than physical properties, elicited emotional responses of negative, positive or neutral valence. In agreement with results from experiment 1, we found larger PPS when the approaching stimuli had negative emotional valence as compared to both neutral and positive ones. Results are discussed within the theoretical framework that conceives PPS as a safety zone around ones body. (C) 2015 Elsevier Ltd. All rights reserved.
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| 7. |
- Grassini, Simone, et al.
(author)
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Pattern matters : Snakes exhibiting triangular and diamond-shaped skin patterns modulate electrophysiological activity in human visual cortex
- 2019
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In: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 131, s. 62-72
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Journal article (peer-reviewed)abstract
- The neural and perceptual mechanisms that support the efficient visual detection of snakes in humans are still not fully understood. According to the Snake Detection Theory, selection pressures posed by snakes on early primates have shaped the development of the visual system. Previous studies in humans have investigated early visual electrophysiological activity in response to snake images vs. various alternative dangerous or non-dangerous stimuli. These studies have shown that the Early Posterior Negativity (EPN) component is selectively elicited by snake or snake-like images. Recent findings yielded the complementary/alternative hypothesis that early humans (and possibly other primates) evolved an aversion especially for potentially harmful triangular shapes, such as teeth, claws or spikes. In the present study we investigated the effect of triangular and diamond-shaped patterns in snake skins on the ERP correlates of visual processing in humans. In the first experiment, we employed pictures of snakes displaying either triangular/diamond-shaped patterns or no particular pattern on their skins, and pictures of frogs as control. Participants observed a random visual presentation of these pictures. Consistent with previous studies, snakes elicited an enhanced negativity between 225 and 300 ms (EPN) compared to frogs. However, snakes featuring triangular/diamond-shaped patterns on their skin produced an enhanced EPN compared to the snakes that did not display such patterns. In a second experiment we used pictures displaying only skin patterns of snakes and frogs. Results from the second experiment confirmed the results of the first experiment, suggesting that triangular snake-skin patterns modulate the activity in human visual cortex. Taken together, our results constitute an important contribution to the snake detection theory.
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| 8. |
- Halje, Pär, et al.
(author)
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Inferior frontal oscillations reveal visuo-motor matching for actions and speech: evidence from human intracranial recordings.
- 2015
-
In: Neuropsychologia. - : Elsevier BV. - 1873-3514 .- 0028-3932. ; 79:B, s. 206-214
-
Journal article (peer-reviewed)abstract
- The neural correspondence between the systems responsible for the execution and recognition of actions has been suggested both in humans and non-human primates. Apart from being a key region of this visuo-motor observation-execution matching (OEM) system, the human inferior frontal gyrus (IFG) is also important for speech production. The functional overlap of visuo-motor OEM and speech, together with the phylogenetic history of the IFG as a motor area, has led to the idea that speech function has evolved from pre-existing motor systems and to the hypothesis that an OEM system may exist also for speech. However, visuo-motor OEM and speech OEM have never been compared directly. We used electrocorticography to analyze oscillations recorded from intracranial electrodes in human fronto-parieto-temporal cortex during visuo-motor (executing or visually observing an action) and speech OEM tasks (verbally describing an action using the first or third person pronoun). The results show that neural activity related to visuo-motor OEM is widespread in the frontal, parietal, and temporal regions. Speech OEM also elicited widespread responses partly overlapping with visuo-motor OEM sites (bilaterally), including frontal, parietal, and temporal regions. Interestingly a more focal region, the inferior frontal gyrus (bilaterally), showed both visuo-motor OEM and speech OEM properties independent of orolingual speech-unrelated movements. Building on the methodological advantages in human invasive electrocorticography, the present findings provide highly precise spatial and temporal information to support the existence of a modality-independent action representation system in the human brain that is shared between systems for performing, interpreting and describing actions.
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| 9. |
- Hellerstedt, Robin, et al.
(author)
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Tracking the intrusion of unwanted memories into awareness with event-related potentials
- 2016
-
In: Neuropsychologia. - 0028-3932. ; 89, s. 510-523
-
Journal article (peer-reviewed)abstract
- Involuntary retrieval of unwanted memories is a common symptom in several clinical disorders, including post-traumatic stress disorder. With an aim to track the temporal dynamics of such memory intrusions, we recorded electrophysiological measures of brain activity while participants engaged in a Think/No-Think task. We presented the left hand word (the cue) of previously encoded word pairs in green or red font. We asked participants to think of the associated right hand word (the associate) when the cue appeared in green (Think condition) and to avoid thinking of the associate when the cue appeared in red (No-Think condition). To isolate cases when participants experienced an intrusive memory, at the end of each trial, participants judged whether the response had come to mind; we classified memories that came to mind during No-Think trials, despite efforts to stop retrieval, as intrusions. In an event-related potential (ERP) analysis, we observed a negative going slow wave (NSW) effect that indexed the duration of a trace in mnemonic awareness; whereas voluntary retrieval and maintenance of the associate was related to a sustained NSW that lasted throughout the 3-s recording epoch, memory intrusions generated short-lived NSWs that were rapidly truncated. Based on these findings, we hypothesize that the intrusion-NSW reflects the associate briefly penetrating working memory. More broadly, these findings exploit the high temporal resolution of ERPs to track the online dynamics of memory intrusions.
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| 10. |
- Igelström, Kajsa, 1980-, et al.
(author)
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The inferior parietal lobule and temporoparietal junction : A network perspective
- 2017
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In: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 105, s. 70-83
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Journal article (peer-reviewed)abstract
- Information processing in specialized, spatially distributed brain networks underlies the diversity and complexity of our cognitive and behavioral repertoire. Networks converge at a small number of hubs – highly connected regions that are central for multimodal integration and higher-order cognition. We review one major network hub of the human brain: the inferior parietal lobule and the overlapping temporoparietal junction (IPL/TPJ). The IPL is greatly expanded in humans compared to other primates and matures late in human development, consistent with its importance in higher-order functions. Evidence from neuroimaging studies suggests that the IPL/TPJ participates in a broad range of behaviors and functions, from bottom-up perception to cognitive capacities that are uniquely human. The organization of the IPL/TPJ is challenging to study due to the complex anatomy and high inter-individual variability of this cortical region. In this review we aimed to synthesize findings from anatomical and functional studies of the IPL/TPJ that used neuroimaging at rest and during a wide range of tasks. The first half of the review describes subdivisions of the IPL/TPJ identified using cytoarchitectonics, resting-state functional connectivity analysis and structural connectivity methods. The second half of the article reviews IPL/TPJ activations and network participation in bottom-up attention, lower-order self-perception, undirected thinking, episodic memory and social cognition. The central theme of this review is to discuss how network nodes within the IPL/TPJ are organized and how they participate in human perception and cognition.
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| 11. |
- Koivisto, Mika, et al.
(author)
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TMS-EEG reveals hemispheric asymmetries in top-down influences of posterior intraparietal cortex on behavior and visual event-related potentials
- 2017
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In: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 107, s. 94-101
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Journal article (peer-reviewed)abstract
- Clinical data and behavioral studies using transcranial magnetic stimulation (TMS) suggest right-hemisphere dominance for top-down modulation of visual processing in humans. We used concurrent TMS-EEG to directly test for hemispheric differences in causal influences of the right and left intraparietal cortex on visual event-related potentials (ERPs). We stimulated the left and right posterior part of intraparietal sulcus (IPS1) while the participants were viewing and rating the visibility of bilaterally presented Gabor patches. Subjective visibility ratings showed that TMS of right IPS shifted the visibility toward the right hemifield, while TMS of left IPS did not have any behavioral effect. TMS of right IPS, but not left one, reduced the amplitude of posterior N1 potential, 180–220 ms after stimulus-onset. The attenuation of N1 occurred bilaterally over the posterior areas of both hemispheres. Consistent with previous TMS-fMRI studies, this finding suggests that the right IPS has top-down control on the neural processing in visual cortex. As N1 most probably reflects reactivation of early visual areas, the current findings support the view that the posterior parietal cortex in the right hemisphere amplifies recurrent interactions in ventral visual areas during the time-window that is critical for conscious perception.
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| 12. |
- Linnavalli, Tanja, et al.
(author)
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Phoneme processing skills are reflected in children's MMN responses
- 2017
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In: Neuropsychologia. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0028-3932 .- 1873-3514. ; 101, s. 76-84
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Journal article (peer-reviewed)abstract
- Phonological awareness (PA), the core contributor in phoneme processing abilities, has a link to later reading skills in children. However, the associations between PA and neural auditory discrimination are not clear. We used event-related potential (ERP) methodology and neuropsychological testing to monitor the neurocognitive basis of phonological awareness in typically developing children. We measured 5-6-year-old children's (N = 70) phoneme processing, word completion and perceptual reasoning skills and compared their test results to their brain responses to phonemic changes, separately for each test. We found that children performing better in Phoneme processing test showed larger mismatch negativity (MMN) responses than children scoring lower in the same test. In contrast, no correspondence between test scores and brain responses was found for Auditory closure. Thus, the results suggest that automatic auditory change detection is linked to phoneme awareness in preschool children.
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| 13. |
- Olofsson, Jonas K., et al.
(author)
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Long-term episodic memory decline is associated with olfactory deficits only in carriers of ApoE-є4
- 2016
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In: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 85, s. 1-9
-
Journal article (peer-reviewed)abstract
- The ɛ4 allele of the Apolipoprotein E gene is a genetic risk factor for late-onset dementia of the Alzheimers' type (DAT), which is characterized by loss of both episodic memoryand olfactory functions. Little is known about the possible role of ɛ4 in the association between ongoing episodic memory decline and olfactory deficits in the general population, but such information is relevant in determining the relevance of olfaction as a marker of DAT risk. The present study was based on a large, population-based sample (n=1087, aged 45–90 years, of which 324 were ɛ4-carriers). Episodic memory change rates were established using data collected every 5 years for a 10–20 year interval leading up to an olfactory assessment using the Scandinavian Odor Identification Test at the last wave of data collection. Participants were classified according to whether or not their episodic memory ability declined more rapidly than the age-typical norm (by >1SD). Our main result is that only in ɛ4-carriers was episodic memory decline associated with odor identification impairment. In individuals without ɛ4, odor identification was unrelated to episodic memory decline status. Follow-up analyses indicated that this moderation by ɛ4 was due to the olfactory nature of the identification test, and that the effect was not caused by 63 individuals with dementia. Our results suggest that the ɛ4 determines the functional association between ongoing episodic memory decline and olfaction. These findings are consistent with the notion that ɛ4-carriers with DAT, compared to non-carriers, display a cortical atrophy pattern that is more focused on mediotemporal lobe regions supporting olfactory and episodic memory functions. Olfactory and memory assessments might provide complementary information on mediotemporal atrophy prior to clinical dementia onset, but the ɛ4 should be considered when using olfactory assessment as an early-stage indicator.
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| 14. |
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| 15. |
- Patil, Indrajeet, et al.
(author)
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Neuroanatomical basis of concern-based altruism in virtual environment
- 2018
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In: Neuropsychologia. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0028-3932 .- 1873-3514. ; 116, s. 34-43
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Journal article (peer-reviewed)abstract
- Costly altruism entails helping others at a cost to the self and prior work shows that empathic concern (EC) for the well-being of distressed and vulnerable individuals is one of the primary motivators of such behavior. However, extant work has investigated costly altruism with paradigms that did not feature self-relevant and severe costs for the altruist and have solely focused on neurofunctional, and not neuroanatomical, correlates. In the current study, we used a contextually-rich virtual reality environment to study costly altruism and found that individuals who risked their own lives in the virtual world to try to save someone in danger had enlarged right anterior insula and exhibited greater empathic concern than those who did not. These findings add to the growing literature showing the role of caring motivation in promoting altruism and prosociality and its neural correlates in the right anterior insula.
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| 16. |
- Pfabigan, DM, et al.
(author)
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Event-related potentials in performance monitoring are influenced by the endogenous opioid system.
- 2015
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In: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 77, s. 242-252
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Journal article (peer-reviewed)abstract
- Recent research suggests that not only the dopamine neurotransmitter system but also the endogenous opioid system is involved in performance monitoring and the generation of prediction error signals. Heightened performance monitoring is also associated with psychopathology such as internalizing disorders. Therefore, the current study investigated the potential link between the functional opioid peptide prodynorphin (PDYN) 68 bp VNTR genetic polymorphism and neuronal correlates of performance monitoring. To this end, 47 healthy participants genotyped for this polymorphism, related to high-, intermediate-, and low-expression levels of PDYN, performed a choice-reaction task while their electroencephalogram (EEG) was recorded. On the behavioural level, no differences between the three PDYN groups could be observed. EEG data, however, showed significant differences. High PDYN expression individuals showed heightened neural error processing indicated by higher ERN amplitudes, compared to intermediate and low expression individuals. Later stages of error processing, indexed by late Pe amplitudes, and stimulus-driven conflict processing, indexed by N2 amplitudes, were not affected by PDYN genotype. The current results corroborate the notion of an indirect effect of endogenous opioids on performance monitoring, probably mediated by the mesencephalic dopamine system. Overall, enhanced ERN amplitudes suggest a hyper-active performance monitoring system in high PDYN expression individuals, and this might also be an indicator of a higher risk for internalizing disorders.
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| 17. |
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| 18. |
- Salminen-Vaparanta, Niina, et al.
(author)
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Does TMS on V3 block conscious visual perception?
- 2019
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In: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 128, s. 223-231
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Journal article (peer-reviewed)abstract
- Primary visual cortex (V1) and extrastriate V2 are necessary for the emergence of visual consciousness, but the effects of involvement of extrastriate V3 on visual consciousness is unclear. The objective of this study was to examine the causal role of V3 in visual consciousness in humans. We combined neuronavigated transcranial magnetic stimulation (TMS) with a computational model of the TMS-induced electric field to test whether or not the intact processing of visual input in V3, like in V1 and V2, is necessary for conscious visual perception. We targeted the stimulation both to V2 and to V3. If TMS of V3 blocks conscious visual perception of stimuli, then activation in V3 is a causally necessary prerequisite for conscious perception of stimuli. According to the alternative hypothesis, TMS of V3 will not block the conscious visual perception of stimuli, because the pathways from V1 to the higher cortical areas that go around V3 provide sufficient visual input for the emergence of conscious visual perception. The results showed that TMS interfered with conscious perception of features, detection of stimulus presence and the ability to discriminate the letter stimuli both when TMS was targeted either to V3 or to V2. For the conscious detection of stimulus presence, the effect was significantly stronger when V2 was stimulated than when V3 was stimulated. The results of the present study suggest that in addition to the primary visual cortex and V2, also V3 causally contributes to the generation of the most basic form of visual consciousness. Importantly, the results also indicate that V3 is necessary for visual perception in general, not only for visual consciousness.
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| 19. |
- Sjöberg, Rickard L., et al.
(author)
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The supplementary motor area syndrome and cognitive control
- 2019
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In: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 129, s. 141-145
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Journal article (peer-reviewed)abstract
- The Supplementary Motor Area (SMA)-syndrome is a transient disturbance of the ability to initiate voluntary motor and speech actions that will often occur immediately after neurosurgical resections in the dorsal superior frontal gyrus but will typically have disappeared after 3 months. The purpose of the present study was to investigate the extent to which this syndrome is associated with alterations in cognitive control. Five patients who were to different extents affected by the SMA-syndrome after surgery for WHO grade II gliomas in the left hemisphere, were tested with the color word interference (Stroop) test; the Bergen dichotic listening test and for letter and category verbal fluency before surgery, 1–2 days after surgery and approximately 3 months after surgery. Results suggest that the motor symptoms known as the SMA syndrome co-occur with pronounced deficits in cognitive control.
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| 20. |
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| 21. |
- Ziaei, Maryam, et al.
(author)
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Age-related alterations in functional connectivity patterns during working memory encoding of emotional items
- 2017
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In: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 94, s. 1-12
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Journal article (peer-reviewed)abstract
- Previous findings indicate age-related differences in frontal-amygdala connectivity during emotional processing. However, direct evidence for age differences in brain functional activation and connectivity during emotional processing and concomitant behavioral implications is lacking. In the present study, we examined the impact of aging on the neural signature of selective attention to emotional information during working memory (WM) encoding. Participants completed an emotional WM task in which they were asked to attend to emotional targets and ignore irrelevant distractors. Despite an overall reduction in accuracy for older relative to younger adults, no behavioral age effect was observed as a function of emotional valence. The functional connectivity patterns of left ventrolateral prefrontal cortex showed that younger adults recruited one network for encoding of both positive and negative emotional targets and this network contributed to higher memory accuracy in this cohort. Older adults, on the other hand, engaged two distinct networks for encoding of positive and negative targets. The functional connectivity analysis using left amygdala further demonstrated that older adults recruited one single network during encoding of positive as well as negative targets whereas younger adults recruited this network only for encoding of negative items. The engagement of amygdala functional network also contributed to higher memory performance and faster response times in older adults. Our findings provide novel insights into the differential roles of functional brain networks connected to the medial PFC and amygdala during encoding of emotionally-valenced items with advancing age.
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| 22. |
- Ziaei, Maryam, et al.
(author)
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Amygdala functional network during recognition of own-age vs. other-age faces in younger and older adults
- 2019
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In: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 129, s. 10-20
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Journal article (peer-reviewed)abstract
- Facial cues, such as a person's age, provide important information for social interactions. Processing such facial cues can be affected by observer bias. However, there is currently no consensus regarding how the brain is processing facial cues related to age, and if facial age processing changes as a function of the age of the observer (i.e., own-age bias). The primary study aim was to investigate functional networks involved in processing own-age vs. other-age faces among younger and older adults and determine how emotional expression of the face modulates own-age vs. other-age face processing. The secondary study aim was to examine the relation between higher social cognitive processes (i.e., empathy) and modulation of brain activity by facial age and emotional expression. During functional magnetic resonance imaging (fMRI) younger and older participants were asked to recognize happy, angry, and neutral expressions in own-age and other-age faces. Functional connectivity analyses with the amygdala as seed showed that for own-age faces both age groups recruited a network of regions including the anterior cingulate and anterior insula that was involved in empathy and detection of salient information. Brain-behavior analyses furthermore showed that empathic responses in younger, but not in older, participants were positively correlated with engagement of the medial prefrontal cortex during processing of angry own-age faces. These findings identify the neurobehavioral correlates of facial age processing, and its modulation by emotion expression, and directly link facial cue processing to higher-order social cognitive functioning.
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| 23. |
- Åhs, Fredrik, et al.
(author)
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Spatial proximity amplifies valence in emotional memory and defensive approach-avoidance
- 2015
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In: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 70, s. 476-85
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Journal article (peer-reviewed)abstract
- In urban areas, people often have to stand or move in close proximity to others. The egocentric distance to stimuli is a powerful determinant of defensive behavior in animals. Yet, little is known about how spatial proximity to others alters defensive responses in humans. We hypothesized that the valence of social cues scales with egocentric distance, such that proximal social stimuli have more positive or negative valence than distal stimuli. This would predict enhanced defensive responses to proximal threat and reduced defensive responses to proximal reward. We tested this hypothesis across four experiments using 3-D virtual reality simulations. Results from Experiment 1 confirmed that proximal social stimuli facilitate defensive responses, as indexed by fear-potentiated startle, relative to distal stimuli. Experiment 2 revealed that interpersonal defensive boundaries flexibly increase with aversive learning. Experiment 3 examined whether spatial proximity enhances memory for aversive experiences. Fear memories for social threats encroaching on the body were more persistent than those acquired at greater interpersonal distances, as indexed by startle. Lastly, Experiment 4 examined how egocentric distance influenced startle responses to social threats during defensive approach and avoidance. Whereas fear-potentiated startle increased with proximity when participants actively avoided receiving shocks, startle decreased with proximity when participants tolerated shocks to receive monetary rewards, implicating opposing gradients of distance on threat versus reward. Thus, proximity in egocentric space amplifies the valence of social stimuli that, in turn, facilitates emotional memory and approach-avoidance responses. These findings have implications for understanding the consequences of increased urbanization on affective interpersonal behavior.
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