scholarly journals A TMS-EROS investigation of the role of feedback to early visual cortex in visual awareness.

2019 ◽  
Vol 19 (10) ◽  
pp. 169a
Author(s):  
Ramisha Knight ◽  
Gabriele Gratton ◽  
Monica Fabiani ◽  
Diane M Beck
Keyword(s):  
Visual Cortex ◽  
Visual Awareness ◽  
Early Visual Cortex

scholarly journals Widespread Suppression of High-Order Visual Cortex During Blinks and External Predictable Visual Interruptions

2018 ◽  
Author(s):  
Tal Golan ◽  
Shany Grossman ◽  
Leon Y Deouell ◽  
Rafael Malach
Keyword(s):  
Visual Cortex ◽  
Visual Awareness ◽  
General Purpose ◽  
High Order ◽  
Still Images ◽  
Visual Hierarchy ◽  
Retinal Input ◽  
Early Visual Cortex ◽  
High Level

AbstractSpontaneous eye blinks generate frequent potent interruptions to the retinal input and yet go unnoticed. As such, they provide an attractive approach to the study of the neural correlates of visual awareness. Here, we tested the potential role of predictability in generating blink-related effects using fMRI. While participants attentively watched still images of faces and houses, we monitored naturally occurring spontaneous blinks and introduced three kinds of matched visual interruptions: cued voluntary blinks, self-initiated (and hence, predictable) external darkenings, and physically similar but unpredictable external darkenings. These events’ impact was inspected using fMRI across the visual hierarchy. In early visual cortex, both spontaneous and voluntary blinks, as well as predictable and unpredictable external darkenings, led to largely similar positive responses in peripheral representations. In mid- and high-level visual cortex, all predictable conditions (spontaneous blinks, voluntary blinks, and self-initiated external darkenings) were associated with signal decreases. In contrast, unpredictable darkenings were associated with signal increases. These findings suggest that general-purpose prediction-related mechanisms are involved in producing a small but widespread suppression of mid- and high-order visual regions during blinks. Such suppression may down-regulate responses to predictable transients in the human visual hierarchy.

Determinants of motion response anisotropies in human early visual cortex: The role of configuration and eccentricity

NeuroImage ◽  
2014 ◽  
Vol 100 ◽  
pp. 564-579 ◽  
Author(s):  
Ryan T. Maloney ◽  
Tamara L. Watson ◽  
Colin W.G. Clifford
Keyword(s):  
Visual Cortex ◽  
Motion Response ◽  
Early Visual Cortex

scholarly journals Feedback contribution to surface motion perception in the human early visual cortex

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ingo Marquardt ◽  
Peter De Weerd ◽  
Marian Schneider ◽  
Omer Faruk Gulban ◽  
Dimo Ivanov ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Motion Perception ◽  
Depth Distribution ◽  
Ultra High Field ◽  
Surface Perception ◽  
Surface Motion ◽  
Surface Segmentation ◽  
Early Visual Cortex ◽  
Illusory Perception

Human visual surface perception has neural correlates in early visual cortex, but the role of feedback during surface segmentation in human early visual cortex remains unknown. Feedback projections preferentially enter superficial and deep anatomical layers, which provides a hypothesis for the cortical depth distribution of fMRI activity related to feedback. Using ultra-high field fMRI, we report a depth distribution of activation in line with feedback during the (illusory) perception of surface motion. Our results fit with a signal re-entering in superficial depths of V1, followed by a feedforward sweep of the re-entered information through V2 and V3. The magnitude and sign of the BOLD response strongly depended on the presence of texture in the background, and was additionally modulated by the presence of illusory motion perception compatible with feedback. In summary, the present study demonstrates the potential of depth-resolved fMRI in tackling biomechanical questions on perception.

scholarly journals Visual working memory representations in visual and parietal cortex do not remap after eye movements

2019 ◽  
Author(s):  
Tao He ◽  
Matthias Ekman ◽  
Annelinde R.E. Vandenbroucke ◽  
Floris P. de Lange
Keyword(s):  
Working Memory ◽  
Visual Cortex ◽  
Eye Movements ◽  
Visual Field ◽  
Visual System ◽  
Visual Working Memory ◽  
Parietal Cortex ◽  
List Type ◽  
Early Visual Cortex

ABSTRACTIt has been suggested that our visual system does not only process stimuli that are directly available to our eyes, but also has a role in maintaining information in VWM over a period of seconds. It remains unclear however what happens to VWM representations in the visual system when we make saccades. Here, we tested the hypothesis that VWM representations are remapped within the visual system after making saccades. We directly compared the content of VWM for saccade and no-saccade conditions using MVPA of delay-related activity measured with fMRI. We found that when participants did not make a saccade, VWM representations were robustly present in contralateral early visual cortex. When making a saccade, VWM representations degraded in contralateral V1-V3 after the saccade shifted the location of the remembered grating to the opposite visual field. However, contrary to our hypothesis we found no evidence for the representations of the remembered grating at the saccadic target location in the opposite visual field, suggesting that there is no evidence for remapping of VWM in early visual cortex. Interestingly, IPS showed persistent VWM representations in both the saccade and no-saccade condition. Together, our results indicate that VWM representations in early visual cortex are not remapped across eye movements, potentially limiting the role of early visual cortex in VWM storage.HighlightsVisual working memory (VWM) representations do not remap after making saccadesEye movement degrade VWM representations in early visual cortex, limiting the role of early visual cortex in VWM storageParietal cortex shows persistent VWM representations across saccades

scholarly journals Role of early visual cortex in trans-saccadic memory of object features

2015 ◽  
Vol 15 (11) ◽  
pp. 7 ◽  
Author(s):  
Pankhuri Malik ◽  
Joost C. Dessing ◽  
J. Douglas Crawford
Keyword(s):  
Visual Cortex ◽  
Early Visual Cortex ◽  
In Trans ◽  
Object Features
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