Partially Distributed Representations of Objects and Faces in Ventral Temporal Cortex

2005 ◽  
Vol 17 (4) ◽  
pp. 580-590 ◽  
Author(s):  
Alice J. O'Toole ◽  
Fang Jiang ◽  
Hervé Abdi ◽  
James V. Haxby
Keyword(s):  
Functional Neuroimaging ◽  
Brain Activity ◽  
Temporal Cortex ◽  
High Spatial Frequency ◽  
Object Classification ◽  
Classification Model ◽  
Neural Structure ◽  
Line Drawings ◽  
Object Categories ◽  
Ventral Temporal Cortex

Object and face representations in ventral temporal (VT) cortex were investigated by combining object confusability data from a computational model of object classification with neural response confusability data from a functional neuroimaging experiment. A pattern-based classification algorithm learned to categorize individual brain maps according to the object category being viewed by the subject. An identical algorithm learned to classify an image-based, view-dependent representation of the stimuli. High correlations were found between the confusability of object categories and the confusability of brain activity maps. This occurred even with the inclusion of multiple views of objects, and when the object classification model was tested with high spatial frequency “line drawings” of the stimuli. Consistent with a distributed representation of objects in VT cortex, the data indicate that object categories with shared image-based attributes have shared neural structure.

scholarly journals Birds of a Feather Flock Together: Experience-Driven Formation of Visual Object Categories in Human Ventral Temporal Cortex

PLoS ONE ◽  
2008 ◽  
Vol 3 (12) ◽  
pp. e3995 ◽  
Author(s):  
Marieke van der Linden ◽  
Jaap M. J. Murre ◽  
Miranda van Turennout
Keyword(s):  
Temporal Cortex ◽  
Visual Object ◽  
Object Categories ◽  
Ventral Temporal Cortex

scholarly journals The Menstrual Cycle Alters Resting-State Cortical Activity: A Magnetoencephalography Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Rika Haraguchi ◽  
Hideyuki Hoshi ◽  
Sayuri Ichikawa ◽  
Mayuko Hanyu ◽  
Kohei Nakamura ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Resting State ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Neural Oscillations ◽  
Median Frequency ◽  
Accurate Interpretation ◽  
High Gamma ◽  
The Right

Resting-state neural oscillations are used as biomarkers for functional diseases such as dementia, epilepsy, and stroke. However, accurate interpretation of clinical outcomes requires the identification and minimisation of potential confounding factors. While several studies have indicated that the menstrual cycle also alters brain activity, most of these studies were based on visual inspection rather than objective quantitative measures. In the present study, we aimed to clarify the effect of the menstrual cycle on spontaneous neural oscillations based on quantitative magnetoencephalography (MEG) parameters. Resting-state MEG activity was recorded from 25 healthy women with normal menstrual cycles. For each woman, resting-state brain activity was acquired twice using MEG: once during their menstrual period (MP) and once outside of this period (OP). Our results indicated that the median frequency and peak alpha frequency of the power spectrum were low, whereas Shannon spectral entropy was high, during the MP. Theta intensity within the right temporal cortex and right limbic system was significantly lower during the MP than during the OP. High gamma intensity in the left parietal cortex was also significantly lower during the MP than during the OP. Similar differences were also observed in the parietal and occipital regions between the proliferative (the late part of the follicular phase) and secretory phases (luteal phase). Our findings suggest that the menstrual cycle should be considered to ensure accurate interpretation of functional neuroimaging in clinical practice.

scholarly journals Multivariate sensitivity to voice during auditory categorization

2015 ◽  
Vol 114 (3) ◽  
pp. 1819-1826 ◽  
Author(s):  
Yune Sang Lee ◽  
Jonathan E. Peelle ◽  
David Kraemer ◽  
Samuel Lloyd ◽  
Richard Granger
Keyword(s):  
Brain Activity ◽  
Temporal Cortex ◽  
Neural Representation ◽  
Current Evidence ◽  
General Role ◽  
Object Categories ◽  
Novel Approach ◽  
Auditory Object ◽  
Mri Study ◽  
Multivariate Pattern

Past neuroimaging studies have documented discrete regions of human temporal cortex that are more strongly activated by conspecific voice sounds than by nonvoice sounds. However, the mechanisms underlying this voice sensitivity remain unclear. In the present functional MRI study, we took a novel approach to examining voice sensitivity, in which we applied a signal detection paradigm to the assessment of multivariate pattern classification among several living and nonliving categories of auditory stimuli. Within this framework, voice sensitivity can be interpreted as a distinct neural representation of brain activity that correctly distinguishes human vocalizations from other auditory object categories. Across a series of auditory categorization tests, we found that bilateral superior and middle temporal cortex consistently exhibited robust sensitivity to human vocal sounds. Although the strongest categorization was in distinguishing human voice from other categories, subsets of these regions were also able to distinguish reliably between nonhuman categories, suggesting a general role in auditory object categorization. Our findings complement the current evidence of cortical sensitivity to human vocal sounds by revealing that the greatest sensitivity during categorization tasks is devoted to distinguishing voice from nonvoice categories within human temporal cortex.

scholarly journals The Representation of Objects in the Human Occipital and Temporal Cortex

2000 ◽  
Vol 12 (supplement 2) ◽  
pp. 35-51 ◽  
Author(s):  
Alumit Ishai ◽  
Leslie G. Ungerleider ◽  
Alex Martin ◽  
James V. Haxby
Keyword(s):  
Temporal Cortex ◽  
Occipital Cortex ◽  
Visual Pathway ◽  
Distributed Representation ◽  
National Academy Of Sciences ◽  
Line Drawings ◽  
Ventral Visual Pathway ◽  
Presentation Formats ◽  
Ventral Temporal Cortex ◽  
Object Form

Recently, we identified, using fMRI, three bilateral regions in the ventral temporal cortex that responded preferentially to faces, houses, and chairs [Ishai, A., Ungerleider, L. G., Martin, A., Schouten, J. L., & Haxby, J. Y. (1999). Distributed representation of objects in the human ventral visual pathway. Proceedings of the National Academy of Sciences, U.S.A., 96, 9379-9384]. Here, we report differential patterns of activation, similar to those seen in the ventral temporal cortex, in bilateral regions of the ventral occipital cortex. We also found category-related responses in the dorsal occipital cortex and in the superior temporal sulcus. Moreover, rather than activating discrete, segregated areas, each category was associated with its own differential pattern of response across a broad expanse of cortex. The distributed patterns of response were similar across tasks (passive viewing, delayed matching) and presentation formats (photographs, line drawings). We propose that the representation of objects in the ventral visual pathway, including both occipital and temporal regions, is not restricted to small, highly selective patches of cortex but, instead, is a distributed representation of information about object form. Within this distributed system, the representation of faces appears to be less extensive as compared to the representations of nonface objects.

scholarly journals Detailed Exploration of Face-related Processing in Congenital Prosopagnosia: 2. Functional Neuroimaging Findings

2005 ◽  
Vol 17 (7) ◽  
pp. 1150-1167 ◽  
Author(s):  
Galia Avidan ◽  
Uri Hasson ◽  
Rafael Malach ◽  
Marlene Behrmann
Keyword(s):  
Face Processing ◽  
Functional Neuroimaging ◽  
Block Design ◽  
Temporal Cortex ◽  
Normal Pattern ◽  
Line Drawings ◽  
Face Representation ◽  
Congenital Prosopagnosia ◽  
Adaptation Experiment ◽  
Cortical Regions

Specific regions of the human occipito-temporal cortex are consistently activated in functional imaging studies of face processing. To understand the contribution of these regions to face processing, we examined the pattern of fMRI activation in four congenital prosopagnosic (CP) individuals who are markedly impaired at face processing despite normal vision and intelligence, and with no evidence of brain damage. These individuals evinced a normal pattern of fMRI activation in the fusiform gyrus (FFA) and in other ventral occipito-temporal areas, in response to faces, buildings, and other objects, shown both as line drawings in detection and discrimination tasks and under more naturalistic testing conditions when no task was required. CP individuals also showed normal adaptation levels in a block-design adaptation experiment and, like control subjects, exhibited evidence of global face representation in the FFA. The absence of a BOLD-behavioral correlation (profound behavioral deficit, normal face-related activation in the ventral occipito-temporal cortex) challenges existing accounts of face representation, and suggests that activation in these cortical regions per se is not sufficient to ensure intact face processing.

scholarly journals Object novelty and value coding segregate across functionally connected brain networks

2019 ◽  
Author(s):  
Ali Ghazizadeh ◽  
MohammadAmin Fakharian ◽  
Arash Amini ◽  
Whitney Griggs ◽  
David A. Leopold ◽  
...  
Keyword(s):  
Brain Activity ◽  
Brain Networks ◽  
Temporal Cortex ◽  
Common Currency ◽  
Activation Dynamics ◽  
Fractal Patterns ◽  
The Common ◽  
Ventral Temporal Cortex ◽  
Value Coding ◽  
The Brain

AbstractNovel and valuable objects are motivationally attractive for animals including primates. However, little is known about how novelty and value processing is organized across the brain. We used fMRI in macaques to map brain activity to fractal patterns varying in either novelty or value dimensions in the context of functionally connected brain networks determined at rest. Results show unique combinations of novelty and value coding across the brain networks. Networks in the ventral temporal cortex and in the parietal cortex showed preferential coding of novelty and value dimensions, respectively, while a wider network composed of temporal and prefrontal areas (TP network), along with functionally connected portions of the striatum, amygdala, and claustrum, responded to both dimensions with similar activation dynamics. Our results support emergence of a common currency signal in the TP network that may underlie the common attitudes toward novel and valuable objects.

Behavior in the Brain

2010 ◽  
Vol 24 (2) ◽  
pp. 76-82 ◽  
Author(s):  
Martin M. Monti ◽  
Adrian M. Owen
Keyword(s):  
Motor Behavior ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Motor Output ◽  
The Unconscious ◽  
Ethical Implications ◽  
Brain Responses ◽  
Minimally Conscious ◽  
Brain Insults ◽  
Brain Behavior

Recent evidence has suggested that functional neuroimaging may play a crucial role in assessing residual cognition and awareness in brain injury survivors. In particular, brain insults that compromise the patient’s ability to produce motor output may render standard clinical testing ineffective. Indeed, if patients were aware but unable to signal so via motor behavior, they would be impossible to distinguish, at the bedside, from vegetative patients. Considering the alarming rate with which minimally conscious patients are misdiagnosed as vegetative, and the severe medical, legal, and ethical implications of such decisions, novel tools are urgently required to complement current clinical-assessment protocols. Functional neuroimaging may be particularly suited to this aim by providing a window on brain function without requiring patients to produce any motor output. Specifically, the possibility of detecting signs of willful behavior by directly observing brain activity (i.e., “brain behavior”), rather than motoric output, allows this approach to reach beyond what is observable at the bedside with standard clinical assessments. In addition, several neuroimaging studies have already highlighted neuroimaging protocols that can distinguish automatic brain responses from willful brain activity, making it possible to employ willful brain activations as an index of awareness. Certainly, neuroimaging in patient populations faces some theoretical and experimental difficulties, but willful, task-dependent, brain activation may be the only way to discriminate the conscious, but immobile, patient from the unconscious one.

Sign in / Sign up

Export Citation Format

Share Document