scholarly journals Feature Diagnosticity Affects Representations of Novel and Familiar Objects

2014 ◽  
Vol 26 (12) ◽  
pp. 2735-2749 ◽  
Author(s):  
Nina S. Hsu ◽  
Margaret L. Schlichting ◽  
Sharon L. Thompson-Schill
Keyword(s):  
Fruits And Vegetables ◽  
Temporal Cortex ◽  
Familiar Object ◽  
Behavioral Effects ◽  
Diagnostic Features ◽  
Novel Objects ◽  
Human Participants ◽  
Ventral Temporal Cortex ◽  
Concept Representations ◽  
The Impact

Many features can describe a concept, but only some features define a concept in that they enable discrimination of items that are instances of a concept from (similar) items that are not. We refer to this property of some features as feature diagnosticity. Previous work has described the behavioral effects of feature diagnosticity, but there has been little work on explaining why and how these effects arise. In this study, we aimed to understand the impact of feature diagnosticity on concept representations across two complementary experiments. In Experiment 1, we manipulated the diagnosticity of one feature, color, for a set of novel objects that human participants learned over the course of 1 week. We report behavioral and neural evidence that diagnostic features are likely to be automatically recruited during remembering. Specifically, individuals activated color-selective regions of ventral temporal cortex (specifically, left fusiform gyrus and left inferior temporal gyrus) when thinking about the novel objects, although color information was never explicitly probed during the task. Moreover, multiple behavioral and neural measures of the effects of feature diagnosticity were correlated across participants. In Experiment 2, we examined relative color association in familiar object categories, which varied in feature diagnosticity (fruits and vegetables, household items). Taken together, these results offer novel insights into the neural mechanisms underlying concept representations by demonstrating that automatic recruitment of diagnostic information gives rise to behavioral effects of feature diagnosticity.

scholarly journals The nature of the animacy organization in human ventral temporal cortex

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Sushrut Thorat ◽  
Daria Proklova ◽  
Marius V Peelen
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Temporal Cortex ◽  
Behavioral Experiments ◽  
Diagnostic Features ◽  
Social Agents ◽  
Independent Components ◽  
Ventral Temporal Cortex ◽  
Organizing Principles ◽  
The Continuum

The principles underlying the animacy organization of the ventral temporal cortex (VTC) remain hotly debated, with recent evidence pointing to an animacy continuum rather than a dichotomy. What drives this continuum? According to the visual categorization hypothesis, the continuum reflects the degree to which animals contain animal-diagnostic features. By contrast, the agency hypothesis posits that the continuum reflects the degree to which animals are perceived as (social) agents. Here, we tested both hypotheses with a stimulus set in which visual categorizability and agency were dissociated based on representations in convolutional neural networks and behavioral experiments. Using fMRI, we found that visual categorizability and agency explained independent components of the animacy continuum in VTC. Modeled together, they fully explained the animacy continuum. Finally, clusters explained by visual categorizability were localized posterior to clusters explained by agency. These results show that multiple organizing principles, including agency, underlie the animacy continuum in VTC.

scholarly journals Learning Warps Object Representations in the Ventral Temporal Cortex

2016 ◽  
Vol 28 (7) ◽  
pp. 1010-1023 ◽  
Author(s):  
Alex Clarke ◽  
Philip J. Pell ◽  
Charan Ranganath ◽  
Lorraine K. Tyler
Keyword(s):  
Critical Role ◽  
Temporal Cortex ◽  
Real Life ◽  
Visual Object ◽  
Object Representations ◽  
Pattern Similarity ◽  
Contextual Associations ◽  
Ventral Temporal Cortex ◽  
Pattern Information ◽  
The Impact

The human ventral temporal cortex (VTC) plays a critical role in object recognition. Although it is well established that visual experience shapes VTC object representations, the impact of semantic and contextual learning is unclear. In this study, we tracked changes in representations of novel visual objects that emerged after learning meaningful information about each object. Over multiple training sessions, participants learned to associate semantic features (e.g., “made of wood,” “floats”) and spatial contextual associations (e.g., “found in gardens”) with novel objects. fMRI was used to examine VTC activity for objects before and after learning. Multivariate pattern similarity analyses revealed that, after learning, VTC activity patterns carried information about the learned contextual associations of the objects, such that objects with contextual associations exhibited higher pattern similarity after learning. Furthermore, these learning-induced increases in pattern information about contextual associations were correlated with reductions in pattern information about the object's visual features. In a second experiment, we validated that these contextual effects translated to real-life objects. Our findings demonstrate that visual object representations in VTC are shaped by the knowledge we have about objects and show that object representations can flexibly adapt as a consequence of learning with the changes related to the specific kind of newly acquired information.

scholarly journals Novel objects with causal schemas elicit selective responses in tool- and hand-selective lateral occipito-temporal cortex

2021 ◽  
Author(s):  
Anna Leshinskaya ◽  
Mira Bajaj ◽  
Sharon L. Thompson-Schill
Keyword(s):  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Essential Property ◽  
Neural Responses ◽  
Still Images ◽  
Event Sequences ◽  
Environmental Event ◽  
Parahippocampal Cortex ◽  
Novel Objects ◽  
Human Participants

Tool-selective lateral occipito-temporal cortex (LOTC) responds preferentially to images of tools (hammers, brushes) relative to non-tool objects (clocks, shoes). What drives these responses? Tools have elongated shapes and are more likely to have motor associations, but another essential property is that they exert causal effects on the environment. We tested whether LOTC would respond to novel objects associated with a tool-canonical schema in which their actions cause other events. To do so, we taught male and female human participants about novel objects embedded in animated event sequences, which varied in the temporal order of their events. Causer objects moved prior to the appearance of an environmental event (e.g., stars) while Reactor objects moved after an identical event; objects were matched on shape and motor association. During fMRI, participants viewed still images of these novel objects. We localized tool-selective LOTC and non-tool-selective parahippocampal cortex (PHC) by contrasting neural responses to images of familiar tools and non-tools. We found that LOTC responded more to Causers than Reactors; this effect was absent and weaker in right PHC. We also localized responses to images of hands, which elicit overlapping responses with tools. Across inferior temporal cortex, voxels’ tool and hand selectivity positively predicted a preferential response to Causers, and non-tool selectivity negatively so. We conclude that a causal schema typical of tools is sufficient to drive LOTC, and more generally, that preferential responses to domains across the temporal lobe may reflect the relational event structures typical of those domains.

scholarly journals Faster than thought: Detecting sub-second activation sequences with sequential fMRI pattern analysis

2020 ◽  
Author(s):  
Lennart Wittkuhn ◽  
Nicolas W. Schuck
Keyword(s):  
Human Brain ◽  
Time Scales ◽  
Temporal Cortex ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen Level ◽  
Activation Patterns ◽  
Neural Computations ◽  
Time Courses ◽  
Human Participants ◽  
Ventral Temporal Cortex

AbstractNeural computations are often anatomically localized and executed on sub-second time scales. Understanding the brain therefore requires methods that offer sufficient spatial and temporal resolution. This poses a particular challenge for the study of the human brain because non-invasive methods have either high temporal or spatial resolution, but not both. Here, we introduce a novel multivariate analysis method for conventional blood-oxygen-level dependent functional magnetic resonance imaging (BOLD fMRI) that allows to study sequentially activated neural patterns separated by less than 100 ms with anatomical precision. Human participants underwent fMRI and were presented with sequences of visual stimuli separated by 32 to 2048 ms. Probabilistic pattern classifiers were trained on fMRI data to detect the presence of image-specific activation patterns in early visual and ventral temporal cortex. The classifiers were then applied to data recorded during sequences of the same images presented at increasing speeds. Our results show that probabilistic classifier time courses allowed to detect neural representations and their order, even when images were separated by only 32 ms. Moreover, the frequency spectrum of the statistical sequentiality metric distinguished between sequence speeds on sub-second versus supra-second time scales. These results survived when data with high levels of noise and rare sequence events at unknown times were analyzed. Our method promises to lay the groundwork for novel investigations of fast neural computations in the human brain, such as hippocampal replay.

The impact of increased consumption of fruits and vegetables on cortisol and cortisone excretion in 24-h urine of children

2015 ◽  
Vol 122 (03) ◽  
Author(s):  
J Esche ◽  
L Shi ◽  
A Sánchez-Guijo ◽  
MF Hartmann ◽  
S Wudy ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
The Impact

scholarly journals The Impact of a Produce Prescription Programme on Healthy Food Purchasing and Diabetes-Related Health Outcomes

2021 ◽  
pp. 1-24
Author(s):  
Julian Xie ◽  
Ashley Price ◽  
Neal Curran ◽  
Truls Østbye
Keyword(s):  
Health Outcomes ◽  
Fruits And Vegetables ◽  
Healthy Food ◽  
Grocery Store ◽  
Diabetes Control ◽  
Food Purchasing ◽  
Significant Relationships ◽  
Expenditure Share ◽  
The Impact

Abstract Objective: To evaluate a Produce Prescription Programme’s utilisation, and its effects on healthy food purchasing and diabetes control among participants with type 2 diabetes. Design: Prospective cohort study using participants’ electronic health records (EHR) and food transaction data. Participants were categorized as “Frequent Spenders” and “Sometimes Spenders” based on utilisation frequency. Multivariate regressions assessed utilisation predictors; and programme effects on fruit/vegetable purchasing (spending, expenditure share, variety) and on diabetes-related outcomes (HbA1c, BMI, blood pressure). Setting: Patients enrolled by clinics in Durham, North Carolina, USA. Participants received $40 monthly for fruits and vegetables at a grocery store chain. Subjects: 699 food-insecure participants (353 with diabetes). Results: Being female and older was associated with higher programme utilisation; hospitalisations were negatively associated with programme utilisation. Frequent Spender status was associated with $8.77 more in fruit/vegetable spending (p < 0.001), 3.3% increase in expenditure share (p = 0.007), and variety increase of 2.52 fruits and vegetables (p < 0.001). For $10 of Produce Prescription Dollars spent, there was an $8.00 increase in fruit/vegetable spending (p < 0.001), 4.1% increase in expenditure share, and variety increase of 2.3 fruits/vegetables (p < 0.001). For the 353 participants with diabetes, there were no statistically significant relationships between programme utilisation and diabetes control. Conclusions: Programme utilisation was associated with healthier food purchasing, but the relatively short study period and modest intervention prevent making conclusions about health outcomes. Produce Prescription Programmes can increase healthy food purchasing among food-insecure people, which may improve chronic disease care.

scholarly journals Going “Green” in the Prevention and Management of Atherothrombotic Diseases: The Role of Dietary Polyphenols

2021 ◽  
Vol 10 (7) ◽  
pp. 1490
Author(s):  
Ana Reis ◽  
Sara Rocha ◽  
Victor de Freitas
Keyword(s):  
Risk Factors ◽  
Fruits And Vegetables ◽  
Current Knowledge ◽  
Cholesterol Biosynthesis ◽  
Dietary Polyphenols ◽  
Nutritional Strategy ◽  
Flavonoid Intake ◽  
Health Promoting ◽  
Socio Economic Impact ◽  
The Impact

During the 20th century processed and ready-to-eat foods became routinely consumed resulting in a sharp rise of fat, salt, and sugar intake in people’s diets. Currently, the global incidence of obesity, raised blood lipids, hypertension, and diabetes in an increasingly aged population contributes to the rise of atherothrombotic events and cardiovascular diseases (CVD) mortality. Drug-based therapies are valuable strategies to tackle and help manage the socio-economic impact of atherothrombotic disorders though not without adverse side effects. The inclusion of fresh fruits and vegetables rich in flavonoids to human diets, as recommended by WHO offers a valuable nutritional strategy, alternative to drug-based therapies, to be explored in the prevention and management of atherothrombotic diseases at early stages. Though polyphenols are mostly associated to color and taste in foods, food flavonoids are emerging as modulators of cholesterol biosynthesis, appetite and food intake, blood pressure, platelet function, clot formation, and anti-inflammatory signaling, supporting the health-promoting effects of polyphenol-rich diets in mitigating the impact of risk factors in atherothrombotic disorders and CVD events. Here we overview the current knowledge on the effect of polyphenols particularly of flavonoid intake on the atherothrombotic risk factors and discuss the caveats and challenges involved with current experimental cell-based designs.

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