RT Journal Article
SR Electronic
T1 Temporal Expectation Improves the Quality of Sensory Information
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 8424
OP 8428
DO 10.1523/JNEUROSCI.0804-12.2012
VO 32
IS 24
A1 Rohenkohl, Gustavo
A1 Cravo, André M.
A1 Wyart, Valentin
A1 Nobre, Anna C.
YR 2012
UL http://www.jneurosci.org/content/32/24/8424.abstract
AB It is increasingly clear that we extract patterns of temporal regularity between events to optimize information processing. Whereas some of the mechanisms for facilitating action preparation and execution have been well documented, much less is understood about whether and how temporal expectations influence visual perception. We used a psychophysical paradigm and computational modeling to investigate the mechanisms by which temporal expectation can modulate visual perception. Visual targets appeared in a stream of noise-patches separated by a fixed (400 ms regular condition) or jittered (200/300/400/500/600 ms irregular condition) intervals. Targets were visual gratings tilted 45° clockwise or counter-clockwise, presented at one of seven contrast levels. Human observers were required to perform an orientation discrimination (i.e., left or right). Psychometric functions for contrast sensitivity fitted for the regular and irregular conditions indicated that temporal expectation modulates perceptual processing by enhancing the contrast sensitivity of visual targets. This increase in the signal strength was accompanied by a reduction in reaction times. A diffusion model indicated that rhythmic temporal expectation enhanced the signal-to-noise gain of the sensory evidence upon which decisions were made. These effects support the idea that temporal structure of external events can entrain the attentional focus and psychophysical data, optimizing the processing of relevant sensory information.