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Efficient processing of the visual environment necessitates the integration of incoming sensory evidence with concurrent contextual inputs and mnemonic content from our past experiences. To examine how this integration takes place in the brain, we isolated different types of feedback signals from the neural patterns of non-stimulated areas of the early visual cortex in humans (i.e., V1 and V2). Using multivariate pattern analysis, we showed that both contextual and time-distant information, coexist in V1 and V2 as feedback signals. In addition, we found that the extent to which mnemonic information is reinstated in V1 and V2 depends on whether the information is retrieved episodically or semantically. Critically, this reinstatement was independent on the retrieval route in the object-selective cortex. These results demonstrate that our early visual processing contains not just direct and indirect information from the visual surrounding, but also memory-based predictions., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interests., (Copyright © 2022. Published by Elsevier Inc.)

Despite mental imagery's ubiquitous role in human perception, cognition and behavior, one standout question remains unanswered: Why does imagery vary so much from one individual to the next? Here, we used a behavioral paradigm that measures the functional impact of a mental image on subsequent conscious perception and related these measures to the anatomy of the early visual cortex estimated by fMRI retinotopic mapping. We observed a negative relationship between primary visual cortex (V1) surface area and sensory imagery strength, but found positive relationships between V1 and imagery precision (spatial location and orientation). Hence, individuals with a smaller V1 tended to have stronger, but less precise imagery. In addition, subjective vividness of imagery was positively related to prefrontal cortex volume, but unrelated to V1 anatomy. Our findings present the first evidence for the importance of the V1 layout in shaping the strength of human imagination., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Recent findings indicate that visual feedback derived from episodic memory can be traced down to the earliest stages of visual processing, whereas feedback stemming from schema-related memories only reach intermediate levels in the visual processing hierarchy. In this opinion piece, we examine these differences in light of the 'what' and 'where' streams of visual perception. We build upon this new framework to propose that the memory deficits observed in aphantasics might be better understood as a difference in high-level feedback processing along the 'what' stream, rather than an episodic memory impairment. [ABSTRACT FROM AUTHOR]

Summary: The right and left visual hemifields are represented in different cerebral hemispheres and are bound together by connections through the corpus callosum. Much has been learned on the functions of these connections from split-brain patients [], but little is known about their contribution to conscious visual perception in healthy humans. We used diffusion tensor imaging and functional magnetic resonance imaging to investigate which callosal connections contribute to the subjective experience of a visual motion stimulus that requires interhemispheric integration. The “motion quartet” is an ambiguous version of apparent motion that leads to perceptions of either horizontal or vertical motion []. Interestingly, observers are more likely to perceive vertical than horizontal motion when the stimulus is presented centrally in the visual field []. This asymmetry has been attributed to the fact that, with central fixation, perception of horizontal motion requires integration across hemispheres whereas perception of vertical motion requires only intrahemispheric processing []. We are able to show that the microstructure of individually tracked callosal segments connecting motion-sensitive areas of the human MT/V5 complex (hMT/V5+; []) can predict the conscious perception of observers. Neither connections between primary visual cortex (V1) nor other surrounding callosal regions exhibit a similar relationship. [ABSTRACT FROM AUTHOR]