scholarly journals Visual information routes in the posterior dorsal and ventral face network studied with intracranial neurophysiology, and white matter tract endpoints

2020 ◽  
Author(s):  
M Babo-Rebelo ◽  
A Puce ◽  
D Bullock ◽  
L Hugueville ◽  
F Pestilli ◽  
...  
Keyword(s):  
White Matter ◽  
Face Processing ◽  
Visual Information ◽  
Temporal Cortex ◽  
Field Potential ◽  
Occipital Cortex ◽  
Inferior Temporal Cortex ◽  
Direct Gaze ◽  
Superior Temporal Cortex ◽  
White Matter Tractography

ABSTRACTOccipito-temporal regions within the face network process perceptual and socio-emotional information, but the dynamics and interactions between different nodes within this network remain unknown. Here, we analyzed intracerebral EEG from 11 epileptic patients viewing a stimulus sequence beginning with a neutral face with direct gaze. The gaze could avert or remain direct, while the emotion changed to fearful or happy. N200 field potential peak latencies indicated that face processing begins in inferior occipital cortex and proceeds anteroventrally to fusiform and inferior temporal cortices, in parallel. The superior temporal sulcus responded preferentially to gaze changes with augmented field potential amplitudes for averted versus direct gaze, and large effect sizes relative to other regions of the network. An overlap analysis of posterior white matter tractography endpoints (from 1066 healthy brains) relative to active intracerebral electrodes from the 11 patients showed likely involvement of both dorsal and ventral posterior white matter pathways. The inferior occipital and temporal sulci likely broadcast their information - the former dorsally to intraparietal sulcus, and the latter between fusiform and superior temporal cortex. Overall, our data call for inclusion of inferior temporal cortex in face processing models, and anchor the superior temporal cortex in dynamic gaze processing.

Modality Dependent Cross-Modal Functional Reorganization Following Congenital Visual Deprivation within Occipital Areas: A Meta-Analysis of Tactile and Auditory Studies

2014 ◽  
Vol 27 (3-4) ◽  
pp. 247-262 ◽  
Author(s):  
Emiliano Ricciardi ◽  
Leonardo Tozzi ◽  
Andrea Leo ◽  
Pietro Pietrini
Keyword(s):  
Visual Information ◽  
Meta Analysis ◽  
Sensory Modality ◽  
Temporal Cortex ◽  
Sensory Information ◽  
Occipital Cortex ◽  
Inferior Temporal Cortex ◽  
Functional Studies ◽  
Superior Parietal Cortex ◽  
Blind Individuals

Cross-modal responses in occipital areas appear to be essential for sensory processing in visually deprived subjects. However, it is yet unclear whether this functional recruitment might be dependent on the sensory channel conveying the information. In order to characterize brain areas showing task-independent, but sensory specific, cross-modal responses in blind individuals, we pooled together distinct brain functional studies in a single based meta-analysis according only to the modality conveying experimental stimuli (auditory or tactile). Our approach revealed a specific functional cortical segregation according to the sensory modality conveying the non-visual information, irrespectively from the cognitive features of the tasks. In particular, dorsal and posterior subregions of occipital and superior parietal cortex showed a higher cross-modal recruitment across tactile tasks in blind as compared to sighted individuals. On the other hand, auditory stimuli activated more medial and ventral clusters within early visual areas, the lingual and inferior temporal cortex. These findings suggest a modality-specific functional modification of cross-modal responses within different portions of the occipital cortex of blind individuals. Cross-modal recruitment can thus be specifically influenced by the intrinsic features of sensory information.

scholarly journals Changes in thalamocortical connectivity as a potential mechanism of cross-modal plasticity in congenitally blind individuals

2018 ◽  
Author(s):  
Theo Marins ◽  
Maite Russo ◽  
Erika Rodrigues ◽  
jorge Moll ◽  
Daniel Felix ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Cortical Thickness ◽  
Visual Information ◽  
Brain Plasticity ◽  
Temporal Cortex ◽  
Occipital Cortex ◽  
Brain Structures ◽  
Congenitally Blind ◽  
Blind Individuals ◽  
Neuroimaging Techniques

ABSTRACTEvidence of cross-modal plasticity in blind individuals has been reported over the past decades showing that non-visual information is carried and processed by classical “visual” brain structures. This feature of the blind brain makes it a pivotal model to explore the limits and mechanisms of brain plasticity. However, despite recent efforts, the structural underpinnings that could explain cross-modal plasticity in congenitally blind individuals remain unclear. Using advanced neuroimaging techniques, we mapped the thalamocortical connectivity and assessed cortical thickness and integrity of white matter of congenitally blind individuals and sighted controls to test the hypothesis that aberrant thalamocortical pattern of connectivity can pave the way for cross-modal plasticity. We described a direct occipital takeover by the temporal projections from the thalamus, which would carry non-visual information (e.g. auditory) to the visual cortex in congenitally blinds. In addition, the amount of thalamo-occipital connectivity correlated with the cortical thickness of primary visual cortex (V1), supporting a probably common (or related) reorganization phenomena. Our results suggest that aberrant thalamocortical connectivity as one possible mechanism of cross-modal plasticity in blinds, with potential impact on cortical thickness of V1.SIGNIFICANT STATEMENTCongenitally blind individuals often develop greater abilities on spared sensory modalities, such as increased acuity in auditory discrimination and voice recognition, when compared to sighted controls. These functional gains have been shown to rely on ‘visual’ cortical areas of the blind brain, characterizing the phenomenon of cross-modal plasticity. However, its anatomical underpinnings in humans have been unsuccessfully pursued for decades. Recent advances of non-invasive neuroimaging techniques allowed us to test the hypothesis of abnormal thalamocortical connectivity in congenitally blinds. Our results showed an expansion of the thalamic connections to the temporal cortex over those that project to the occipital cortex, which may explain, the cross-talk between the visual and auditory systems in congenitally blind individuals.

scholarly journals Dynamic Population Coding of Category Information in Inferior Temporal and Prefrontal Cortex

2008 ◽  
Vol 100 (3) ◽  
pp. 1407-1419 ◽  
Author(s):  
Ethan M. Meyers ◽  
David J. Freedman ◽  
Gabriel Kreiman ◽  
Earl K. Miller ◽  
Tomaso Poggio
Keyword(s):  
Prefrontal Cortex ◽  
Visual Information ◽  
Activity Patterns ◽  
Temporal Cortex ◽  
Relevant Information ◽  
Population Coding ◽  
Inferior Temporal Cortex ◽  
Category Information ◽  
Almost All ◽  
Dynamic Population

Most electrophysiology studies analyze the activity of each neuron separately. While such studies have given much insight into properties of the visual system, they have also potentially overlooked important aspects of information coded in changing patterns of activity that are distributed over larger populations of neurons. In this work, we apply a population decoding method to better estimate what information is available in neuronal ensembles and how this information is coded in dynamic patterns of neural activity in data recorded from inferior temporal cortex (ITC) and prefrontal cortex (PFC) as macaque monkeys engaged in a delayed match-to-category task. Analyses of activity patterns in ITC and PFC revealed that both areas contain “abstract” category information (i.e., category information that is not directly correlated with properties of the stimuli); however, in general, PFC has more task-relevant information, and ITC has more detailed visual information. Analyses examining how information coded in these areas show that almost all category information is available in a small fraction of the neurons in the population. Most remarkably, our results also show that category information is coded by a nonstationary pattern of activity that changes over the course of a trial with individual neurons containing information on much shorter time scales than the population as a whole.

scholarly journals Neural Correlates of Letter-String Length and Lexicality during Reading in a Regular Orthography

2003 ◽  
Vol 15 (7) ◽  
pp. 1052-1062 ◽  
Author(s):  
T. N. Wydell ◽  
T. Vuorinen ◽  
P. Helenius ◽  
R. Salmelin
Keyword(s):  
Letter String ◽  
Visual Analysis ◽  
Temporal Cortex ◽  
Occipital Cortex ◽  
String Length ◽  
Cortical Level ◽  
Behavioral Studies ◽  
Superior Temporal Cortex ◽  
Dual Route ◽  
Length Effects

Behavioral studies have shown that short letter strings are read faster than long letter-strings and words are read faster than nonwords. Here, we describe the dynamics of letter-string length and lexicality effects at the cortical level, using magnetoencephalography, during a reading task in Finnish with long (eight-letter) and short (four-letter) word/nonword stimuli. Length effects were observed in two spatially and temporally distinct cortical activations: (1) in the occipital cortex at about 100 msec by the strength of activation, regardless of the lexical status of the stimuli, and (2) in the left superior temporal cortex between 200 and 600 msec by the duration of activation, with words showing a smaller effect than nonwords. A significant lexicality effect was also evident in this later activation, with stronger activation and longer duration for nonwords than words. There seem to be no distinct cortical areas for reading words and nonwords. The early length effect is likely to be due to the low-level visual analysis common to all stimulus letter-strings. The later lexicality and length effects apparently reflect converging lexico-semantic and phonological influences, and are discussed in terms of dual-route and single-route connectionist models of reading.

Form-From-Motion: MEG Evidence for Time Course and Processing Sequence

2003 ◽  
Vol 15 (2) ◽  
pp. 157-172 ◽  
Author(s):  
M. A. Schoenfeld ◽  
M. Woldorff ◽  
E. Düzel ◽  
H. Scheich ◽  
H.-J. Heinze ◽  
...  
Keyword(s):  
Spatial Attention ◽  
Time Course ◽  
Temporal Cortex ◽  
Occipital Cortex ◽  
Inferior Temporal Cortex ◽  
Cortical Region ◽  
Motion Cues ◽  
Form Analysis ◽  
Msec Delay ◽  
Visual Cortical

The neural mechanisms and role of attention in the processing of visual form defined by luminance or motion cues were studied using magnetoencephalography. Subjects viewed bilateral stimuli composed of moving random dots and were instructed to covertly attend to either left or right hemifield stimuli in order to detect designated target stimuli that required a response. To generate form-from-motion (FFMo) stimuli, a subset of the dots could begin to move coherently to create the appearance of a simple form (e.g., square). In other blocks, to generate form-from-luminance (FFLu) stimuli that served as a control, a gray stimulus was presented superimposed on the randomly moving dots. Neuromagnetic responses were observed to both the FFLu and FFMo stimuli and localized to multiple visual cortical stages of analysis. Early activity in low-level visual cortical areas (striate/early extrastriate) did not differ for FFLu versus FFMo stimuli, nor as a function of spatial attention. Longer latency responses elicited by the FFLu stimuli were localized to the ventral-lateral occipital cortex (LO) and the inferior temporal cortex (IT). The FFMo stimuli also generated activity in the LO and IT, but only after first eliciting activity in the lateral occipital cortical region corresponding to MT/V5, resulting in a 50–60 msec delay in activity. All of these late responses (MT/V5, LO, and IT) were significantly modulated by spatial attention, being greatly attenuated for ignored FFLu and FFMo stimuli. These findings argue that processing of form in IT that is defined by motion requires a serial processing of information, first in the motion analysis pathway from V1 to MT/V5 and thereafter via the form analysis stream in the ventral visual pathway to IT.

scholarly journals Neuroanatomical correlates of impulsive traits in children aged 9 to 10

2020 ◽  
Author(s):  
Max Michael Owens ◽  
Courtland Hyatt ◽  
Joshua Gray ◽  
Josh Miller ◽  
Donald Lynam ◽  
...  
Keyword(s):  
White Matter ◽  
Sensation Seeking ◽  
Adaptive Functioning ◽  
Temporal Cortex ◽  
Negative Urgency ◽  
Mixed Effect ◽  
Mixed Effect Models ◽  
Dorsolateral Prefrontal ◽  
White Matter Tractography ◽  
Critical Regions

Background: Impulsivity refers to a set of traits that are generally negatively related to critical domains of adaptive functioning and are core features of numerous psychiatric disorders. Methods: The current study examined the gray and white matter correlates of five impulsive traits measured using an abbreviated version of the UPPS-P impulsivity scale in children aged 9 to 10 (N = 11,052) from the Adolescent Brain and Cognitive Development (ABCD) study. Linear mixed effect models and elastic net regression were used to examine features of regional gray matter and white matter tractography most associated with each UPPS-P scale; intraclass correlations were computed to examine the similarity of the neuroanatomical correlates among the scales. Results: Positive Urgency showed the most robust association with neuroanatomy, with similar but less robust associations found for Negative Urgency. Perseverance showed little association with neuroanatomy. Premeditation and Sensation Seeking showed intermediate associations with neuroanatomy. Critical regions across measures include the dorsolateral prefrontal cortex, lateral temporal cortex, and orbitofrontal cortex; critical tracts included the superior longitudinal fasciculus and inferior fronto-occipital fasciculus. Negative Urgency and Positive Urgency showed the greatest neuroanatomical similarity. Conclusions: Some UPPS-P traits share neuroanatomical correlates, while others have distinct correlates or essentially no relation to neuroanatomy. UPPS-P traits tended to account for relatively little variance in neuroanatomy (i.e., model R2 < 1%) and effects were spread throughout the brain, highlighting the importance of well powered samples.

Ventral Prefrontal Cortex

2021 ◽  
pp. 236-284
Author(s):  
Richard E. Passingham
Keyword(s):  
Prefrontal Cortex ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Long Term Memory ◽  
Frontal Eye Field ◽  
Visual Inputs ◽  
Superior Temporal Cortex ◽  
Eye Field ◽  
Ventral Prefrontal Cortex

The ventral prefrontal cortex learns to associate objects, faces, and vocalizations, and its connectional fingerprint explains why it alone can do so. It receives visual inputs from the inferior temporal cortex and auditory ones from the superior temporal cortex. It combines these inputs with those from the orbital prefrontal (PF) cortex so as to specify the goal that is currently desirable. This is then transformed into the target of search via connections with the frontal eye field and the target for manual retrieval via connections with the premotor areas. The ventral PF cortex can also learn to form associations between objects, for example by linking them into categories. These can be retrieved from long-term memory via connections with the hippocampus.

scholarly journals Sensitive period for white-matter connectivity of superior temporal cortex in deaf people

2011 ◽  
Vol 33 (2) ◽  
pp. 349-359 ◽  
Author(s):  
Yanyan Li ◽  
Guosheng Ding ◽  
James R. Booth ◽  
Ruiwang Huang ◽  
Yating Lv ◽  
...  
Keyword(s):  
White Matter ◽  
Temporal Cortex ◽  
Sensitive Period ◽  
Deaf People ◽  
Superior Temporal Cortex ◽  
White Matter Connectivity

scholarly journals Musical hallucinations in elderly patients with visuospatial impairment: two case reports

2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Chiara Luppi ◽  
Francesca Santagata ◽  
Margherita Marchetti ◽  
Giuliana Bottignole ◽  
Pasqualina Sapone ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
White Matter ◽  
Case Reports ◽  
Temporal Cortex ◽  
Pharmacological Therapy ◽  
Auditory Hallucinations ◽  
Emission Tomography ◽  
Inferior Temporal Cortex ◽  
Vascular Events ◽  
Positron Emission

Musical hallucinations are an uncommon type of auditory hallucinations, they widely occur in elderly. Our group analyzed medical history, pharmacological therapy, neuropsychological pattern, audiometric testing, electroencephalogram, cerebral magnetic resonance and cerebral fludeoxyglucose-positron emission tomography (FDG-PET) of two patients. FDGPET showed in both patients hypometabolism pronounced in posterior regions. In particular the medial-inferior temporal cortex and the occipital associative areas were affected. Moreover, neuropsychological pattern suggested a visuospatial-executive deficit, conformed to the occipital involvement. Our reported cases might suggest that musical hallucinations have been arisen from a combination of peripheral and central dysfunction. A further explanation might be that musical hallucinations result from multiple white matter lacunar lesions due to small vascular events. A question is whether musical hallucinations might be primarily associated with occipital areas hypometabolism and visuospatial alterations typically associated with Levy body dementia (LBD).

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