Rebounding V1 activity and a new visual aftereffect

Abstract

A serendipitous observation led to this study of V1 activity rebounds, which occur well after stimulus offset, and their relationship to visual aftereffects. We found that when a stimulus bar and background were simultaneously turned off, there was strong delayed rebounding activity (distinct from any off response). The neural rebound started 350-500 ms after stimulus offset, and its magnitude and duration were correlated with the prior visual response of the cell. In human psychophysical experiments, we found a delayed aftereffect that may be a perceptual correlate of the activity rebound. Both the rebound activity and the perceptual aftereffect disappeared if the stimulus bar and background were not extinguished together. The magnitude of the rebound varied with the spatial scale of the background even though background size had little effect on the visual response. It thus appeared that rebound magnitude was determined by a relatively large integration area. The aftereffect was not seen when the bar and background offsets were presented to different eyes, suggesting an early neural (monocular) basis for the aftereffect. Overall, we find a strong correlation between rebound activity and the perceived aftereffect. In addition to providing a possible explanation and neural correlate of a visual aftereffect, rebounding activity may provide new insight into the dynamics of early visual processing.

Visual exposure enhances stimulus encoding and persistence in primary cortex

“…Previous studies have shown that brief stimulus presentations at high contrast produce strong persistent activity in primary visual cortex (Funayama et al, 2015;Huang et al, 2008). In our data, the flashed visual stimulus evoked a biphasic population response (example in Figure 1A), with an initial transient component which started immediately after stimulus onset and a delayed reverberatory component which started ~200 ms after stimulus offset.…”

“…Moreover, the influence had behavioral consequences: in a psychophysics task in which human subjects were asked to report the direction of motion of a drifting grating, their response latencies were modulated by a preceding matching or non-matching grating flash, presented 0.5 seconds earlier (Funayama et al, 2015). In a separate study, a simultaneous change in both stimulus and background gave rise to delayed activity in macaque V1 (Huang et al, 2008). The magnitude of the delayed response varied with the size of the background and was strongly correlated with the perception of a visual aftereffect (~300 ms post-stimulus) demonstrated through human psychophysics.…”

“…Yet, stimulus-evoked responses in the primary visual cortex propagate through the local circuitry in wave-like patterns (Benucci et al, 2007;Xu et al, 2007, Grinvald Arieli and Janke) and can persist long after the cessation of stimulation (Benucci et al, 2009;Funayama et al, 2015;Huang et al, 2008;Nikolić et al, 2009). These complex and temporally-extended population responses have been implicated in reward timing (Chubykin et al, 2013;Gavornik et al, 2009;Shuler and Bear, 2006), working memory (Harrison and Tong, 2009;Munneke et al, 2010;Supèr et al, 2001) and are known to interact with (Benucci et al, 2009;Funayama et al, 2015;Gavornik and Bear, 2014;Nikolić et al, 2009;Wolff et al, 2017) and modulate the perception of (Brascamp et al, 2007;Fischer and Whitney, 2014;Funayama et al, 2015;Huang et al, 2008;Kahneman et al, 1992) subsequent visual stimulation. These dynamic properties exhibited by early visual neurons together with the exposure-dependent changes of stimulusresponses, suggest a direct involvement of primary visual cortex in the active distributed representation of more complex visual features, thus supporting a more constructive interpretation of primary cortex function (Olshausen and Field, 2005).…”

“…In particular, we examine how brief, repetitive exposure to a large set of abstract visual shapes (letters of the Latin alphabet and Arabic numerals), affects the capacity of a hypothetical downstream decoder to identify the presented stimulus based on population activity. We employ brief stimulus presentations at high contrast, known to induce strong reverberatory population activity (Funayama et al, 2015;Huang et al, 2008;Nikolić et al, 2009) and report exposure-driven changes in single-unit response properties, i.e. stimulus discrimination, firing rate magnitude and variability.…”

Rebound Spiking as a Neural Mechanism for Surface Filling-in

“…In V1, rebound activity is also observed. Here responses leading to rebound activity are feature selective having similar orientation selectivity as the visual response (Huang, Levine, & Paradiso, 2008;). In our model, feed-forward excitation and surround inhibition are also feature specific.…”