Neural Correlates of High-Level Adaptation-Related Aftereffects

2010 ◽  
Vol 103 (3) ◽  
pp. 1410-1417 ◽  
Author(s):  
Csaba Cziraki ◽  
Mark W. Greenlee ◽  
Gyula Kovács
Keyword(s):  
Prolonged Exposure ◽  
Activity Patterns ◽  
Body Part ◽  
Neural Correlates ◽  
Relative Activity ◽  
The Body ◽  
Perceptual Bias ◽  
Face Area ◽  
Extrastriate Body Area ◽  
High Level

Prolonged exposure to complex stimuli, such as faces, biases perceptual decisions toward nonadapted, dissimilar stimuli, leading to contrastive aftereffects. Here we tested the neural correlates of this perceptual bias using a functional magnetic resonance imaging adaptation (fMRIa) paradigm. Adaptation to a face or hand stimulus led to aftereffects by biasing the categorization of subsequent ambiguous face/hand composite stimuli away from the adaptor category. The simultaneously observed fMRIa in the face-sensitive fusiform face area (FFA) and in the body-part–sensitive extrastriate body area (EBA) depended on the behavioral response of the subjects: adaptation to the preferred stimulus of the given area led to larger signal reduction during trials when it biased perception than during trials when it was less effective. Activity in two frontal areas correlated positively with the activity patterns in FFA and EBA. Based on our novel adaptation paradigm, the results suggest that the adaptation-induced aftereffects are mediated by the relative activity of category-sensitive areas of the human brain as demonstrated by fMRI.

scholarly journals FFA and OFA encode distinct types of face identity information

2020 ◽  
Author(s):  
Maria Tsantani ◽  
Nikolaus Kriegeskorte ◽  
Katherine Storrs ◽  
Adrian Lloyd Williams ◽  
Carolyn McGettigan ◽  
...  
Keyword(s):  
Brain Activity ◽  
Activity Patterns ◽  
Brain Regions ◽  
Image Encoding ◽  
Low Level ◽  
Social Traits ◽  
Face Area ◽  
Face Similarity ◽  
And Gender ◽  
High Level

AbstractFaces of different people elicit distinct functional MRI (fMRI) patterns in several face-selective brain regions. Here we used representational similarity analysis to investigate what type of identity-distinguishing information is encoded in three face-selective regions: fusiform face area (FFA), occipital face area (OFA), and posterior superior temporal sulcus (pSTS). We used fMRI to measure brain activity patterns elicited by naturalistic videos of famous face identities, and compared their representational distances in each region with models of the differences between identities. Models included low-level to high-level image-computable properties and complex human-rated properties. We found that the FFA representation reflected perceived face similarity, social traits, and gender, and was well accounted for by the OpenFace model (deep neural network, trained to cluster faces by identity). The OFA encoded low-level image-based properties (pixel-wise and Gabor-jet dissimilarities). Our results suggest that, although FFA and OFA can both discriminate between identities, the FFA representation is further removed from the image, encoding higher-level perceptual and social face information.

scholarly journals Shape-independent object category responses revealed by MEG and fMRI decoding

2016 ◽  
Vol 115 (4) ◽  
pp. 2246-2250 ◽  
Author(s):  
Daniel Kaiser ◽  
Damiano C. Azzalini ◽  
Marius V. Peelen
Keyword(s):  
Visual Cortex ◽  
Activity Patterns ◽  
Stimulus Onset ◽  
The Body ◽  
The Other ◽  
Response Patterns ◽  
Body Parts ◽  
Object Category ◽  
High Level ◽  
Large Clusters

Neuroimaging research has identified category-specific neural response patterns to a limited set of object categories. For example, faces, bodies, and scenes evoke activity patterns in visual cortex that are uniquely traceable in space and time. It is currently debated whether these apparently categorical responses truly reflect selectivity for categories or instead reflect selectivity for category-associated shape properties. In the present study, we used a cross-classification approach on functional MRI (fMRI) and magnetoencephalographic (MEG) data to reveal both category-independent shape responses and shape-independent category responses. Participants viewed human body parts (hands and torsos) and pieces of clothing that were closely shape-matched to the body parts (gloves and shirts). Category-independent shape responses were revealed by training multivariate classifiers on discriminating shape within one category (e.g., hands versus torsos) and testing these classifiers on discriminating shape within the other category (e.g., gloves versus shirts). This analysis revealed significant decoding in large clusters in visual cortex (fMRI) starting from 90 ms after stimulus onset (MEG). Shape-independent category responses were revealed by training classifiers on discriminating object category (bodies and clothes) within one shape (e.g., hands versus gloves) and testing these classifiers on discriminating category within the other shape (e.g., torsos versus shirts). This analysis revealed significant decoding in bilateral occipitotemporal cortex (fMRI) and from 130 to 200 ms after stimulus onset (MEG). Together, these findings provide evidence for concurrent shape and category selectivity in high-level visual cortex, including category-level responses that are not fully explicable by two-dimensional shape properties.

Circadian flight activity of Simulium spp. (Diptera: Simuliidae) sampled with a vehicle-mounted net in central Nigeria

1985 ◽  
Vol 75 (1) ◽  
pp. 23-34 ◽  
Author(s):  
D. M. Roberts ◽  
R. J. Irving-Bell
Keyword(s):  
Activity Patterns ◽  
Relative Activity ◽  
Flight Activity ◽  
Main Peak ◽  
Large Numbers ◽  
Level Of Activity ◽  
Males And Females ◽  
Gravid Females ◽  
High Level ◽  
Level 2

AbstractA vehicle-mounted net was used to study the circadian flight activity of several species of Simulium in a northern Guinea savanna area in Nigeria during the dry season. The sampling method yielded large numbers of both sexes of Simulium squamosum (Endertein) of the, S. damnosum Theobald complex, S. hargreavesi Gibbins, S. vorax Pomeroy, S. adersi Pomeroy, S. hirsutum Pomeroy and other species. The main peak of activity of all species recorded occurred just after sunset and there was a smaller peak just before sunrise. Flies continued to be caught at a low level 2·5 h after sunset when sampling ceased. Differences in the activity patterns of S. squamosum males and females and of the other species were analysed. Of the S. squamosum females caught, 12% were blood-fed; these and gravid females were mainly active in the evening, while the blood-thirsty flies had a high level of activity throughout the day. Differences between species in the relative activity of blood-thirsty and gravid flies, and nulliparous and parous flies are noted.

scholarly journals A Hybrid Model for Concurrent Interaction Recognition from Videos

2016 ◽  
Vol 11 (4) ◽  
pp. 553
Author(s):  
M. Sivarathinabala ◽  
S. Abirami
Keyword(s):  
Hybrid Model ◽  
Human Behavior ◽  
Hidden Markov ◽  
Body Part ◽  
The Body ◽  
Temporal Correlations ◽  
Interaction Recognition ◽  
Single Person ◽  
High Level ◽  
Human Behavior Analysis

<p>Human behavior analysis plays an important role in understanding the high-level human activities from surveillance videos. Human behavior has been identified using gestures, postures, actions, interactions and multiple activities of humans. This paper has been analyzed by identifying concurrent interactions, that takes place between multiple peoples. In order to capture the concurrency, a hybrid model has been designed with the combination of Layered Hidden Markov Model (LHMM) and Coupled HMM (CHMM). The model has three layers called as pose layer, action layer and interaction layer, in which pose and action of the single person has been defined in the layered model and the interaction of two persons or multiple persons are defined using CHMM. This hybrid model reduces the training parameters and the temporal correlations over the frames are maintained. The spatial and temporal information are extracted and from the body part attributes, the simple human actions as well as concurrent actions/interactions are predicted. In addition, we further evaluated the results on various datasets also, for analyzing the concurrent interaction between the peoples.</p>

scholarly journals A Thorough Examination of Morning Activity Patterns in Adults with Arthritis and Healthy Controls Using Actigraphy Data

2020 ◽  
Vol 4 (3) ◽  
pp. 78-88
Author(s):  
Alison Keogh ◽  
Niladri Sett ◽  
Seamas Donnelly ◽  
Ronan Mullan ◽  
Diana Gheta ◽  
...  
Keyword(s):  
Digital Health ◽  
Activity Patterns ◽  
Wearable Sensors ◽  
Area Under The Curve ◽  
Relative Activity ◽  
Rate Of Change ◽  
Healthy Controls ◽  
Clinical Biomarkers ◽  
Time Period ◽  
High Level

<b><i>Background:</i></b> Wearable sensors allow researchers to remotely capture digital health data, including physical activity, which may identify digital biomarkers to differentiate healthy and clinical cohorts. To date, research has focused on high-level data (e.g., overall step counts) which may limit our insights to <i>whether</i> people move differently, rather than <i>how</i> they move differently. <b><i>Objective:</i></b> This study therefore aimed to use actigraphy data to thoroughly examine activity patterns during the first hours following waking in arthritis patients (<i>n</i> = 45) and healthy controls (<i>n</i> = 30). <b><i>Methods:</i></b> Participants wore an Actigraph GT9X Link for 28 days. Activity counts were analysed and compared over varying epochs, ranging from 15 min to 4 h, starting with waking in the morning. The sum, and a measure of rate of change of cumulative activity in the period immediately after waking (area under the curve [AUC]) for each time period, was calculated for each participant, each day, and individual and group means were calculated. Two-tailed independent <i>t</i> tests determined differences between the groups. <b><i>Results:</i></b> No differences were seen for summed activity counts across any time period studied. However, differences were noted in the AUC analysis for the discrete measures of relative activity. Specifically, within the first 15, 30, 45, and 60 min following waking, the AUC for activity counts was significantly higher in arthritis patients compared to controls, particularly at the 30 min period (<i>t</i> = –4.24, <i>p</i> = 0.0002). Thus, while both cohorts moved the same amount, the way in which they moved was different. <b><i>Conclusion:</i></b> This study is the first to show that a detailed analysis of actigraphy variables could identify activity pattern changes associated with arthritis, where the high-level daily summaries did not. Results suggest discrete variables derived from raw data may be useful to help identify clinical cohorts and should be explored further to determine if they may be effective clinical biomarkers.

scholarly journals Division of Labor between Lateral and Ventral Extrastriate Representations of Faces, Bodies, and Objects

2011 ◽  
Vol 23 (12) ◽  
pp. 4122-4137 ◽  
Author(s):  
John C. Taylor ◽  
Paul E. Downing
Keyword(s):  
Temporal Cortex ◽  
Evidence Base ◽  
Body Area ◽  
Face Area ◽  
Extrastriate Body Area ◽  
Occipital Face Area ◽  
High Level ◽  
Future Work ◽  
Human Neuroimaging ◽  
Broad Region

The occipito-temporal cortex is strongly implicated in carrying out the high-level computations associated with vision. In human neuroimaging studies, focal regions are consistently found within this broad region that respond strongly and selectively to faces, bodies, or objects. A notable feature of these selective regions is that they are found in pairs. In the posterior-lateral occipito-temporal cortex, focal selectivity is found for faces (occipital face area), bodies (extrastriate body area), and objects (lateral occipital). These three areas are found bilaterally and at close quarters to each other. Likewise, in the ventro-medial occipito-temporal cortex, three similar category-selective regions are found, also in proximity to each other: for faces (fusiform face area), bodies (fusiform body area), and objects (posterior fusiform). Here we review some of the extensive evidence on the functional properties of these areas with two aims. First, we seek to identify principles that distinguish the posterior-lateral and ventro-medial clusters of selective regions but that apply generally within each cluster across the three stimulus kinds. Our review identifies and elaborates several principles by which these relationships hold. In brief, the posterior-lateral representations are more primitive, local, and stimulus-driven relative to the ventro-medial representations, which in contrast are more invariant to visual features, global, and linked to the subjective percept. Second, because the evidence base of studies that compare both posterior-lateral and ventro-medial representations of faces, bodies, and objects is still relatively small, we seek to provoke more cross-talk among the research strands that are traditionally separate. We identify several promising approaches for such future work.

Nutrients Mediate Bioavailability and Turnover of Proteins in Mammals

2019 ◽  
Vol 20 (7) ◽  
pp. 661-665
Author(s):  
Cunxi Nie ◽  
Fei Xie ◽  
Ning Ma ◽  
Yueyu Bai ◽  
Wenju Zhang ◽  
...  
Keyword(s):  
The Body ◽  
Biologically Active ◽  
Nitrogen Excretion ◽  
Dietary Proteins ◽  
Restricted Diet ◽  
Nutritional Interventions ◽  
Body Tissues ◽  
Utilization Of Protein ◽  
High Level ◽  
Protein Restricted Diet

As a major component of biologically active compounds in the body, proteins contribute to the synthesis of body tissues for the renewal and growth of the body. The high level of dietary protein and the imbalance of amino acid (AA) composition in mammals result in metabolic disorders, inefficient utilization of protein resources and increased nitrogen excretion. Fortunately, nutritional interventions can be an effective way of attenuating the nitrogen excretion and increasing protein utilization, which include, but are not limited to, formulating the AA balance and protein-restricted diet supplementing with essential AAs, and adding probiotics in the diet. This review highlights recent advances in the turnover of dietary proteins and mammal’s metabolism for health, in order to improve protein bioavailability through nutritional approach.

Making Up 3D Bodies

2021 ◽  
Vol 4 (2) ◽  
pp. 1-9
Author(s):  
Kiona Hagen Niehaus ◽  
Rebecca Fiebrink
Keyword(s):  
Software Tool ◽  
The Body ◽  
Design Parameters ◽  
Artistic Practice ◽  
Human Form ◽  
Modeling Systems ◽  
Exploratory Approach ◽  
Disability Status ◽  
High Level ◽  
The Impact

This paper describes the process of developing a software tool for digital artistic exploration of 3D human figures. Previously available software for modeling mesh-based 3D human figures restricts user output based on normative assumptions about the form that a body might take, particularly in terms of gender, race, and disability status, which are reinforced by ubiquitous use of range-limited sliders mapped to singular high-level design parameters. CreatorCustom, the software prototype created during this research, is designed to foreground an exploratory approach to modeling 3D human bodies, treating the digital body as a sculptural landscape rather than a presupposed form for rote technical representation. Building on prior research into serendipity in Human-Computer Interaction and 3D modeling systems for users at various levels of proficiency, among other areas, this research comprises two qualitative studies and investigation of the impact on the first author's artistic practice. Study 1 uses interviews and practice sessions to explore the practices of six queer artists working with the body and the language, materials, and actions they use in their practice; these then informed the design of the software tool. Study 2 investigates the usability, creativity support, and bodily implications of the software when used by thirteen artists in a workshop. These studies reveal the importance of exploration and unexpectedness in artistic practice, and a desire for experimental digital approaches to the human form.

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