Is delayed foveal feedback critical for extra-foveal perception?

Abstract

Recent neuroimaging evidence suggests that visual inputs arising beyond the fovea can be 'fed back' to foveal visual cortex to construct a new retinotopic representation. However, whether these representations are critical for extra-foveal perception remains unclear. Using transcranial magnetic stimulation we found that relatively late (350-400 msec) disruption of foveal retinotopic cortex impaired perceptual discrimination of objects in the periphery. These results are consistent with the hypothesis that feedback to the foveal retinotopic cortex is crucial for extra-foveal perception, and provide additional evidence for 'constructive' feedback in human vision.

Temporally flexible feedback signal to foveal cortex for peripheral object recognition

“…Recent studies have pointed to the possibility that there is a feedback signal from high-level cortex to foveal retinotopic cortex when discriminating objects presented in the periphery (1)(2)(3)(4). Consistent with this hypothesis, we found that foveal noise presented 250 ms after the appearance of peripheral objects selectively disrupted discrimination performance in the periphery.…”

“…Neuroimaging results have shown that object category information from peripherally presented images can be decoded from the foveal retinotopic cortex when subjects perform an object discrimination task (1). Further, subjects' behavioral performance is impaired when transcranial magnetic stimulation (TMS) is applied to the posterior foveal cortex at 350-400 ms after peripheral stimuli onset (2), consistent with the hypothesis of a feedback signal that directly affects behavior. Performance given a peripheral target can also be modulated psychophysically, by presenting information at the fovea (3,4).…”

“…Recent studies have identified a potential feedback signal specific to the foveal cortex (1,2). Neuroimaging results have shown that object category information from peripherally presented images can be decoded from the foveal retinotopic cortex when subjects perform an object discrimination task (1).…”

Effects of Literacy in Early Visual and Occipitotemporal Areas of Chinese and French Readers

“…Alternatively, those activations might not reflect local changes in the functional properties of area V1 but an expertise-dependent amplification related for instance to visual working memory (Harrison & Tong, 2009;Serences, Ester, Vogel, & Awh, 2009) or a process where early visual cortex acts as a "scratchpad" for increasing the precision of perceptual decisions (Chambers, Allen, Maizey, & Williams, 2013;Lee, Mumford, Romero, & Lamme, 1998). Arguably, such a perceptual decision-making process may be more prominent in Latin alphabet reading, where up to nine letters extending beyond the central field of view have to be read than during the perception of Chinese words comprising two to three foveal characters (see discussion of between-script differences below).…”

“…If the role of early and intermediate cortices in reading is one of a "scratchpad" (Chambers et al, 2013;Lee et al, 1998), then the V3v/hV4 "scratchpad" neurons have larger receptive fields (Zeki, 1993) and are capable of representing more complex features than in V1/ V2 (e.g., Carlson, Rasquinha, Zhang, & Connor, 2011). This would make them more suitable for representing more complex Chinese characters and combining them with a more complex phonological feedback (Ziegler & Goswami, 2005).…”