scholarly journals Retinotopically occluded subsections of early visual cortex contain contextual information about individual scenes, category and depth.

2015 ◽  
Vol 15 (12) ◽  
pp. 516
Author(s):  
Andrew Morgan ◽  
Lucy Petro ◽  
Luca Vizioli ◽  
Lars Muckli
Keyword(s):  
Visual Cortex ◽  
Contextual Information ◽  
Early Visual Cortex

scholarly journals Predictive coding of auditory and contextual information in early visual cortex – evidence from layer specific fMRI brain reading

2015 ◽  
Vol 15 (12) ◽  
pp. 720 ◽  
Author(s):  
Lars Muckli ◽  
Luca Vizioli ◽  
Lucy Petro ◽  
Federico De Martino ◽  
Petra Vetter
Keyword(s):  
Visual Cortex ◽  
Contextual Information ◽  
Predictive Coding ◽  
Early Visual Cortex

Selection of events in time enhances activity throughout early visual cortex

2012 ◽  
Vol 108 (12) ◽  
pp. 3239-3252 ◽  
Author(s):  
Khena M. Swallow ◽  
Tal Makovski ◽  
Yuhong V. Jiang
Keyword(s):  
Visual Cortex ◽  
Contextual Information ◽  
Brain Regions ◽  
Target Tone ◽  
Other Information ◽  
Early Visual Cortex ◽  
Cortical Regions ◽  
Visual Cortical ◽  
System Selection ◽  
Selection Of

Temporal selection poses unique challenges to the perceptual system. Selection is needed to protect goal-relevant stimuli from interference from new sensory input. In addition, contextual information that occurs at the same time as goal-relevant stimuli may be critical for learning. Using fMRI, we characterized how visual cortical regions respond to the temporal selection of auditory and visual stimuli. Critically, we focused on brain regions that are not involved in processing the target itself. Participants pressed a button when they heard a prespecified target tone and did not respond to other tones. Although more attention was directed to auditory input when the target tone was selected, activity in primary visual cortex increased more after target tones than after distractor tones. In contrast to spatial attention, this effect was larger in V1 than in V2 and V3. It was present in regions not typically involved in representing the target stimulus. Additional experiments demonstrated that these effects were not due to multimodal processing, rare targets, or motor responses to the targets. Thus temporal selection of behaviorally relevant stimuli enhances, rather than reduces, activity in perceptual regions involved in processing other information.

scholarly journals Decoding the future from past experience: learning shapes predictions in early visual cortex

2015 ◽  
Vol 113 (9) ◽  
pp. 3159-3171 ◽  
Author(s):  
Caroline D. B. Luft ◽  
Alan Meeson ◽  
Andrew E. Welchman ◽  
Zoe Kourtzi
Keyword(s):  
Visual Cortex ◽  
Large Scale ◽  
Sequence Structure ◽  
Neural Populations ◽  
Early Visual Cortex ◽  
Temporal Structures ◽  
Future Events ◽  
Sensory Predictions ◽  
Actual Stimulus ◽  
The Brain

Learning the structure of the environment is critical for interpreting the current scene and predicting upcoming events. However, the brain mechanisms that support our ability to translate knowledge about scene statistics to sensory predictions remain largely unknown. Here we provide evidence that learning of temporal regularities shapes representations in early visual cortex that relate to our ability to predict sensory events. We tested the participants' ability to predict the orientation of a test stimulus after exposure to sequences of leftward- or rightward-oriented gratings. Using fMRI decoding, we identified brain patterns related to the observers' visual predictions rather than stimulus-driven activity. Decoding of predicted orientations following structured sequences was enhanced after training, while decoding of cued orientations following exposure to random sequences did not change. These predictive representations appear to be driven by the same large-scale neural populations that encode actual stimulus orientation and to be specific to the learned sequence structure. Thus our findings provide evidence that learning temporal structures supports our ability to predict future events by reactivating selective sensory representations as early as in primary visual cortex.

scholarly journals Reinstatement of Associative Memories in Early Visual Cortex Is Signaled by the Hippocampus

2014 ◽  
Vol 34 (22) ◽  
pp. 7493-7500 ◽  
Author(s):  
S. E. Bosch ◽  
J. F. M. Jehee ◽  
G. Fernandez ◽  
C. F. Doeller
Keyword(s):  
Visual Cortex ◽  
Associative Memories ◽  
Early Visual Cortex

Timing of activity in early visual cortex as revealed by transcranial magnetic stimulation

Neuroreport ◽  
1999 ◽  
Vol 10 (12) ◽  
pp. 2631-2634 ◽  
Author(s):  
Erik Corthout ◽  
Bob Uttl ◽  
Vincent Walsh ◽  
Mark Hallett ◽  
Alan Cowey
Keyword(s):  
Visual Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Early Visual Cortex

scholarly journals Preparatory Activity in Posterior Temporal Cortex Causally Contributes to Object Detection in Scenes

2015 ◽  
Vol 27 (11) ◽  
pp. 2117-2125 ◽  
Author(s):  
Reshanne R. Reeder ◽  
Francesca Perini ◽  
Marius V. Peelen
Keyword(s):  
Visual Cortex ◽  
Object Detection ◽  
Activity Patterns ◽  
Temporal Cortex ◽  
Relevant Information ◽  
Visual Selective Attention ◽  
Object Categories ◽  
Preparatory Attention ◽  
Preparatory Activity ◽  
Early Visual Cortex

Theories of visual selective attention propose that top–down preparatory attention signals mediate the selection of task-relevant information in cluttered scenes. Neuroimaging and electrophysiology studies have provided correlative evidence for this hypothesis, finding increased activity in target-selective neural populations in visual cortex in the period between a search cue and target onset. In this study, we used online TMS to test whether preparatory neural activity in visual cortex is causally involved in naturalistic object detection. In two experiments, participants detected the presence of object categories (cars, people) in a diverse set of photographs of real-world scenes. TMS was applied over a region in posterior temporal cortex identified by fMRI as carrying category-specific preparatory activity patterns. Results showed that TMS applied over posterior temporal cortex before scene onset (−200 and −100 msec) impaired the detection of object categories in subsequently presented scenes, relative to vertex and early visual cortex stimulation. This effect was specific to category level detection and was related to the type of attentional template participants adopted, with the strongest effects observed in participants adopting category level templates. These results provide evidence for a causal role of preparatory attention in mediating the detection of objects in cluttered daily-life environments.

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