scholarly journals Evidence for Integrated Visual Face and Body Representations in the Anterior Temporal Lobes

2016 ◽  
Vol 28 (8) ◽  
pp. 1178-1193 ◽  
Author(s):  
Bronson B. Harry ◽  
Katja Umla-Runge ◽  
Andrew D. Lawrence ◽  
Kim S. Graham ◽  
Paul E. Downing
Keyword(s):  
Neural Coding ◽  
Temporal Cortex ◽  
Whole Body ◽  
Unexpected Finding ◽  
Body Parts ◽  
Strong Response ◽  
Body Representations ◽  
Temporal Lobes ◽  
Anterior Temporal Lobes ◽  
The Right

Research on visual face perception has revealed a region in the ventral anterior temporal lobes, often referred to as the anterior temporal face patch (ATFP), which responds strongly to images of faces. To date, the selectivity of the ATFP has been examined by contrasting responses to faces against a small selection of categories. Here, we assess the selectivity of the ATFP in humans with a broad range of visual control stimuli to provide a stronger test of face selectivity in this region. In Experiment 1, participants viewed images from 20 stimulus categories in an event-related fMRI design. Faces evoked more activity than all other 19 categories in the left ATFP. In the right ATFP, equally strong responses were observed for both faces and headless bodies. To pursue this unexpected finding, in Experiment 2, we used multivoxel pattern analysis to examine whether the strong response to face and body stimuli reflects a common coding of both classes or instead overlapping but distinct representations. On a voxel-by-voxel basis, face and whole-body responses were significantly positively correlated in the right ATFP, but face and body-part responses were not. This finding suggests that there is shared neural coding of faces and whole bodies in the right ATFP that does not extend to individual body parts. In contrast, the same approach revealed distinct face and body representations in the right fusiform gyrus. These results are indicative of an increasing convergence of distinct sources of person-related perceptual information proceeding from the posterior to the anterior temporal cortex.

An appropriate biomechanical model of seated human subjects exposed to whole-body vibration

2021 ◽  
pp. 146441932110394
Author(s):  
Raj Desai ◽  
Anirban Guha ◽  
Pasumarthy Seshu
Keyword(s):  
Degrees Of Freedom ◽  
Human Subjects ◽  
Computational Cost ◽  
Biomechanical Model ◽  
Whole Body ◽  
Body Parts ◽  
Lumped Parameter ◽  
Long Duration ◽  
The One ◽  
The Right

Long duration automobile-induced vibration is the cause of many ailments to humans. Predicting and mitigating these vibrations through seat requires a good model of seated human body. A good model is the one that strikes the right balance between modelling difficulty and simulation results accuracy. Increasing the number of body parts which have been separately modelled and increasing the number of ways these parts are connected to each other increase the number of degrees of freedom of the entire model. A number of such models have been reported in the literature. These range from simple lumped parameter models with limited accuracy to advanced models with high computational cost. However, a systematic comparison of these models has not been reported till date. This work creates eight such models ranging from 8 to 26 degrees of freedom and tries to identify the model which strikes the right balance between modelling complexity and results accuracy. A comparison of the models’ prediction with experimental data published in the literature allows the identification of a 12 degree of freedom backrest supported model as optimum for modelling complexity and prediction accuracy.

Representation of Action in Occipito-temporal Cortex

2011 ◽  
Vol 23 (7) ◽  
pp. 1765-1780 ◽  
Author(s):  
Alison J. Wiggett ◽  
Paul E. Downing
Keyword(s):  
Cognitive Neuroscience ◽  
Social Cognitive ◽  
Temporal Cortex ◽  
Adaptation Effect ◽  
Whole Body ◽  
Lateral Occipital Complex ◽  
Specific Adaptation ◽  
Face Area ◽  
The Right ◽  
Adaptation Effects

A fundamental question for social cognitive neuroscience is how and where in the brain the identities and actions of others are represented. Here we present a replication and extension of a study by Kable and Chatterjee [Kable, J. W., & Chatterjee, A. Specificity of action representations in the lateral occipito-temporal cortex. Journal of Cognitive Neuroscience, 18, 1498–1517, 2006] examining the role of occipito-temporal cortex in these processes. We presented full-cue movies of actors performing whole-body actions and used fMRI to test for action- and identity-specific adaptation effects. We examined a series of functionally defined regions, including the extrastriate and fusiform body areas, the fusiform face area, the parahippocampal place area, the lateral occipital complex, the right posterior superior temporal sulcus, and motion-selective area hMT+. These regions were analyzed with both standard univariate measures as well as multivoxel pattern analyses. Additionally, we performed whole-brain tests for significant adaptation effects. We found significant action-specific adaptation in many areas, but no evidence for identity-specific adaptation. We argue that this finding could be explained by differences in the familiarity of the stimuli presented: The actions shown were familiar but the actors performing the actions were unfamiliar. However, in contrast to previous findings, we found that the action adaptation effect could not be conclusively tied to specific functionally defined regions. Instead, our results suggest that the adaptation to previously seen actions across identities is a widespread effect, evident across lateral and ventral occipito-temporal cortex.

scholarly journals A tale of two hemispheres: Contrasting socioemotional dysfunction in right- versus left-lateralised semantic dementia

2013 ◽  
Vol 7 (1) ◽  
pp. 88-95 ◽  
Author(s):  
Muireann Irish ◽  
Fiona Kumfor ◽  
John R. Hodges ◽  
Olivier Piguet
Keyword(s):  
Conceptual Knowledge ◽  
Semantic Processing ◽  
Empathic Concern ◽  
Semantic Dementia ◽  
Facial Emotions ◽  
Temporal Lobes ◽  
Progressive Degeneration ◽  
Left And Right ◽  
Anterior Temporal Lobes ◽  
The Right

ABSTRACT Objective: Semantic dementia, a subtype of frontotemporal lobar degeneration, is characterised by cross-modal loss of conceptual knowledge attributable to progressive degeneration of the left anterior temporal lobe. Much less is known regarding the clinical presentation of SD patients with predominantly right-lateralised atrophy. Recent reports emphasise marked socioemotional and behavioural disturbances in such cases. Given the importance of the right anterior temporal lobes in social cognition, we hypothesised that socioemotional functioning would be disproportionately affected in right versus left-lateralised SD cases. Methods: We assessed well-characterised cases of predominantly right (n=10) and left (n=12) SD and 20 matched healthy controls on tests of emotion processing and interpersonal functioning. Results: Right SD cases showed disproportionate difficulties in the recognition of positive and negative facial emotions, specifically happiness and anger, compared with left SD cases. Deficits in anger recognition persisted in right SD despite covarying for facial and semantic processing. On a contextually rich task of emotion recognition using multimodal videos, no subgroup differences were evident. Finally, empathic concern was rated as significantly lower by caregivers of right versus left SD cases. Overall, the extent of socioemotional disturbance was associated with the degree of behavioural changes in SD. Conclusion: Our results reveal considerable overlap in the extent to which socioemotional processes are disrupted in left and right-lateralised cases of SD. Notably, however, right SD cases show disproportionate deficits for recognition of facial emotions and the capacity for empathic concern, supporting a specialised role for the right anterior temporal lobes in mediating these cognitive functions.

scholarly journals Hemispheric Specialization within the Superior Anterior Temporal Cortex for Social and Nonsocial Concepts

2016 ◽  
Vol 28 (3) ◽  
pp. 351-360 ◽  
Author(s):  
Gorana Pobric ◽  
Matthew A. Lambon Ralph ◽  
Roland Zahn
Keyword(s):  
Social Cognition ◽  
Semantic Representation ◽  
Hemispheric Specialization ◽  
Temporal Cortex ◽  
Hemispheric Differences ◽  
Abstract Concepts ◽  
Temporal Lobes ◽  
Knowledge Domains ◽  
Functional Relevance ◽  
The Right

Studies of semantic dementia, imaging, and repetitive TMS have suggested that the bilateral anterior temporal lobes (ATLs) underpin a modality-invariant representational hub within the semantic system. Questions remain, however, regarding functional specialization across a variety of knowledge domains within the ATL region. We investigated direct evidence for the functional relevance of the superior ATL in processing social concepts. Using converging evidence from noninvasive brain stimulation and neuropsychology, we demonstrate graded differentiation of right and left superior anterior temporal areas in social cognition. Whereas the left superior ATL is necessary for processing both social and nonsocial abstract concepts, social conceptual processing predominates in the right superior ATL. This graded hemispheric specialization is mirrored in the patient results. Our data shed new light on the classic debate about hemispheric differences in semantic and social cognition. These results are considered in the context of models of semantic representation and the emerging data on connectivity for left and right ATL regions.

scholarly journals Differential Activity for Animals and Manipulable Objects in the Anterior Temporal Lobes

2011 ◽  
Vol 23 (8) ◽  
pp. 2059-2067 ◽  
Author(s):  
Stefano Anzellotti ◽  
Bradford Z. Mahon ◽  
Jens Schwarzbach ◽  
Alfonso Caramazza
Keyword(s):  
Conceptual Knowledge ◽  
Bold Signal ◽  
Object Processing ◽  
Susceptibility Artifacts ◽  
Temporal Lobes ◽  
Semantic Categories ◽  
Temporal Pole ◽  
Anterior Temporal Lobes ◽  
The Right ◽  
Neuropsychological Findings

Neuropsychological evidence has highlighted the role of the anterior temporal lobes in the processing of conceptual knowledge. That putative role is only beginning to be investigated with fMRI as methodological advances are able to compensate for well-known susceptibility artifacts that affect the quality of the BOLD signal. In this article, we described differential BOLD activation for pictures of animals and manipulable objects in the anterior temporal lobes, consistent with previous neuropsychological findings. Furthermore, we found that the pattern of BOLD signal in the anterior temporal lobes is qualitatively different from that in the fusiform gyri. The latter regions are activated to different extents but always above baseline by images of the preferred and of the nonpreferred categories, whereas the anterior temporal lobes tend to be activated by images of the preferred category and deactivated (BOLD below baseline) by images of the nonpreferred category. In our experimental design, we also manipulated the decision that participants made over stimuli from the different semantic categories. We found that in the right temporal pole, the BOLD signal shows some evidence of being modulated by the task that participants were asked to perform, whereas BOLD activity in more posterior regions (e.g., the fusiform gyri) is not modulated by the task. These results reconcile the fMRI literature with the neuropsychological findings of deficits for animals after damage to the right temporal pole and suggest that anterior and posterior regions within the temporal lobes involved in object processing perform qualitatively different computations.

Common Anatomical and External Coding for Hands and Feet in Tactile Attention: Evidence from Event-related Potentials

2010 ◽  
Vol 22 (1) ◽  
pp. 184-202 ◽  
Author(s):  
Tobias Heed ◽  
Brigitte Röder
Keyword(s):  
Event Related Potentials ◽  
Spatial Distance ◽  
Whole Body ◽  
Body Parts ◽  
Visually Guided ◽  
Tactile Attention ◽  
Tactile Stimuli ◽  
Related Potentials ◽  
The Right ◽  
Hands And Feet

Recent studies have suggested that the location of tactile stimuli is automatically recoded from anatomical into external coordinates, independent of the task requirements. However, research has mainly involved the two hands, which may not be representative for the whole body because they are excessively used for the visually guided manipulation of objects and tools. We recorded event-related potentials (ERPs) while participants received tactile stimuli to the hands and feet, but attended only one limb. The hands were placed near the feet either in an uncrossed or a crossed posture, thus varying the spatial distance of each hand from each foot. Centro-parietal ERPs 100–140 msec poststimulus were more positive when stimulating the anatomically same-side hand while attending a foot. They were also more positive when the Euclidean distance between the stimulated hand and the attended foot was small rather than large. When a foot was stimulated and a hand attended, a similar modulation of foot ERPs was observed for the right foot. To assess the spatial distance between two limbs in space, the external location of both must be known. The present ERP results therefore suggest that not only the hands but also other body parts are remapped into external coordinates. The use of both anatomical and external coordinates may facilitate the control of actions toward tactile events and the choice of the most suitable effector.

scholarly journals The contribution of stimulating multiple body parts simultaneously to the illusion of owning an entire artificial body

2020 ◽  
Author(s):  
Sophie H. O’Kane ◽  
H. Henrik Ehrsson
Keyword(s):  
Onset Time ◽  
Body Part ◽  
Whole Body ◽  
Multisensory Perception ◽  
Entire Body ◽  
Body Ownership ◽  
Body Parts ◽  
The Right ◽  
Three Body ◽  
Full Body

AbstractThe full-body ownership illusion exploits multisensory perception to induce a feeling of ownership for an entire artificial body. Whilst previous research has shown that the synchronous visuotactile stimulation of a single body part is sufficient for illusory ownership over the whole body, the effect of combining multisensory stimulation across multiple body parts remains unknown. Therefore, 48 healthy adults participated in conditions of a full-body ownership illusion involving synchronous or asynchronous visuotactile stimulation to one, two or three body parts simultaneously (2 x 3 design). We developed a novel questionnaire to isolate the sense of ownership of five specific body parts (left leg, right leg, left arm, right arm, and trunk) from the full-body ownership experience and sought not only to test for greater (part and whole) body ownership in synchronous versus asynchronous stimulation, but also, potentially varying degrees of illusion intensity related to the number of body parts stimulated. As expected, illusory full-body ownership and all five body-part ownership ratings were significantly higher following synchronous stimulation (all p values ≤.01). Since non-stimulated body parts also received significantly higher ownership ratings following synchronous stimulation, the results are consistent with an illusion engaging the entire body. We further noted that ownership ratings for the right body parts (often stimulated) were significantly higher than ownership ratings for the left body parts (never stimulated). Regarding explicit feelings of full-body ownership, subjective ratings were not significantly enhanced by increasing the number of synchronously stimulated body parts (synchronicity x number stimulated interaction; p.099). Instead, median ratings indicated a moderate affirmation (+1) of full-body illusory sensation for all three synchronous conditions; a finding mirrored by full-body illusion onset time. The results support the notion that feelings of full-body ownership are mediated by a generalisation from stimulated part(s)-to-whole, supported by processes related to multisensory body perception.

scholarly journals Semantic Processing in the Anterior Temporal Lobes: A Meta-analysis of the Functional Neuroimaging Literature

2010 ◽  
Vol 22 (6) ◽  
pp. 1083-1094 ◽  
Author(s):  
M. Visser ◽  
E. Jefferies ◽  
M. A. Lambon Ralph
Keyword(s):  
Semantic Processing ◽  
Functional Neuroimaging ◽  
Meta Analysis ◽  
Temporal Cortex ◽  
Specific Pattern ◽  
Temporal Lobes ◽  
Dementia Patients ◽  
Baseline Task ◽  
Picture Stimuli ◽  
Anterior Temporal Lobes

The role of the anterior temporal lobes (ATLs) in semantic cognition is not clear from the current literature. Semantic dementia patients show a progressive and a specific semantic impairment, following bilateral atrophy of the ATLs. Neuroimaging studies of healthy participants, however, do not consistently show ATL activation during semantic tasks. Consequently, several influential theories of semantic memory do not ascribe a central role to the ATLs. We conducted a meta-analysis of 164 functional neuroimaging studies of semantic processing to investigate factors that might contribute to the inconsistency in previous results. Four factors influenced the likelihood of finding ATL activation: (1) the use of PET versus fMRI, reflecting the fact that fMRI but not PET is sensitive to distortion artifacts caused by large variations in magnetic susceptibility in the area of the ATL; (2) a field of view (FOV) of more than 15 cm, thereby ensuring whole-brain coverage; (3) the use of a high baseline task to prevent subtraction of otherwise uncontrolled semantic activation; (4) the inclusion of the ATL as an ROI. The type of stimuli or task did not influence the likelihood of ATL activation, consistent with the view that this region underpins an amodal semantic system. Spoken words, written words, and picture stimuli produced overlapping ATL peaks. On average, these were more inferior for picture-based tasks. We suggest that the specific pattern of ATL activation may be influenced by stimulus type due to variations across this region in the degree of connectivity with modality-specific areas in posterior temporal cortex.

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