Visual feature processing in the early visual cortex affects duration perception.

Abstract

Event timing engages a distributed neural network including cortical and subcortical structures. However, it remains unclear whether the early visual cortex contributes to event timing. Here we showed that the processes of nontemporal visual features such as orientation and spatial location, which are coded by the early visual cortex, contribute to the temporal representation of a visual stimulus. Participants were presented with 2 successive Gabor patches (a prime and a target) with different orientations or spatial locations. The subjective duration of the target was significantly reduced when it was preceded by the prime compared with when presented alone. More important, this duration-compression effect varied systematically as a function of orientation similarity or spatial proximity between the prime and the target and was influenced by how the prime and the target were perceptually grouped. Our results suggest that repetition suppression of neural activity in response to orientation may contribute to the observed duration distortion and that neurons in the early visual cortex with small receptive fields and orientation selectivity may be involved in visual temporal perception. Our findings help to understand the functional role of early visual cortex in event timing in humans.

An investigation of the spatial selectivity of the duration after-effect

“…The results reported here are in strong contrast with the result of studies investigating the effect of adaptation to other temporal and non-temporal stimulus features on perceived duration (Johnston et al, 2006;Ortega et al, 2012;Zhou et al, 2014). In general, these studies report strong spatial selectivity indicating an origin in early visual areas (e.g.…”

“…One possible explanation for these results is the adaptation to low-level visual stimulus properties (such as luminance, contrast, or spatial frequency) that occur for the 0°distance presentations. Previous studies have shown that adaptation to lowlevel visual features can cause compression in perceived duration and that these effects are spatially localized to about 2-4 degrees of visual angle (Zhou et al, 2014). As such, adaptation to lowlevel visual features could explain the increase in perceived duration for the stimuli presented at the non-zero distances.…”

“…Therefore, encoding duration information at an early stage of visual processing would potentially allow for more precise encoding of the onset and offset of an event, resulting in more accurate duration encoding. Furthermore, several studies on duration perception have shown that adaptation to both temporal and non-temporal visual features can cause changes in the perceived duration of subsequent events, which are restricted to the location at which adaptation took place (Johnston, Arnold, & Nishida, 2006;Ortega, Guzman-Martinez, Grabowecky & Suzuki, 2012;Zhou, Yang, Mao, & Han, 2014). For example, it has been shown that adapting to the temporal frequency content of a stimulus can cause spatially localized shifts in the perceived duration of subsequent events.…”

Situational context is important: perceptual grouping modulates temporal perception

“…Specifically, a repeated or predictable stimulus appears to last shorter than other unexpected stimuli of equal duration (Matthews 2011;Pariyadath and Eagleman 2007), and the effect seems dependent on the state of perceptual grouping between successive events (Zhou et al 2014b). Oftentimes in previous studies, the preceding context and/or the targets are modified (Matthews 2011;Pariyadath and Eagleman 2007;Zhou et al 2014b); thus, it is not clear whether the observed duration effect is due to the local context before the offset of target or to the holistic organization covering the whole stimulus sequence. For example, in one of our pilot experiments, we employed a three-item visual sequence with the target (the second item) being more similar to either the first (e.g., a sequence of red, red, and green blobs) or the third item (e.g., a sequence of green, red, and red blobs).…”

“…In parallel to the modulation of non-temporal feature representation by perceptual grouping, the apparent duration of an event in the sub-second range is often distorted by its temporal context (Rose and Summers 1995;Thorpe and Trehub 1989;Zhou et al 2014b). Specifically, a repeated or predictable stimulus appears to last shorter than other unexpected stimuli of equal duration (Matthews 2011;Pariyadath and Eagleman 2007), and the effect seems dependent on the state of perceptual grouping between successive events (Zhou et al 2014b).…”