RT Journal Article
SR Electronic
T1 Attention to Bright Surfaces Enhances the Pupillary Light Reflex
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 2199
OP 2204
DO 10.1523/JNEUROSCI.3440-12.2013
VO 33
IS 5
A1 Binda, Paola
A1 Pereverzeva, Maria
A1 Murray, Scott O.
YR 2013
UL http://www.jneurosci.org/content/33/5/2199.abstract
AB One longstanding question is how early in the visual system attention exerts its influence. Here we show that an effect of attention can be measured at the earliest possible stage of visual information processing, as a change in the optics of the eye. We tested human subjects and found that covertly attending to bright surfaces results in an enhanced pupillary light reflex (PLR)—the pupillary constriction that occurs in response to light increments. The PLR optimizes the optical quality of the retinal image across illumination conditions, increasing sensitivity by modulating retinal illumination, and improving acuity by reducing spherical aberrations. The attentional modulation of the PLR that we describe constitutes a new mechanism through which vision is affected by attention; we discuss three alternatives for the neural substrates of this effect, including the possibility that attention might act indirectly, via its well established effects in early visual cortex.