Neural strength of visual attention gauged by motion adaptation

Abstract

Single-cell and neuroimaging studies reveal that attention focused on a visual object markedly amplifies neural activity produced by features of the attended object. In a psychophysical study, we found that visual attention could modulate the strength of weak motion signals to the point that the perceived direction of motion, putatively registered early in visual processing, was powerfully altered. This strong influence of attention on early motion processing, beside complementing neurophysiological evidence for attentional modulation early in the visual pathway, can be measured in terms of equivalent motion energy, and thus provides a useful metric for quantifying attention's effects.

Type of Featural Attention Differentially Modulates hMT+ Responses to Illusory Motion Aftereffects

“…The discrepancy between the activation patterns observed with different attention tasks further emphasize the special case of selective attention tasks that focus directly on motion perception and is in agreement with the previous literature (Alais and Blake 1999;Culham et al 2000;Lankheet and Verstraten 1995;Mukai and Watanabe 2001;Shulman 1993;Sohn et al 2001).…”

“…It is worth noting in this context that even weak motion signals can be modulated by selective attention (Alais and Blake 1999;Seidemann and Newsome 1999;Treue and Martinez Trujillo 1999) or contextual influences (Kozak and Castelo-Branco 2009). Huk et al in 2001 observed no net MAE-related increase of hMT ϩ activity in a task directed to near threshold stimulus motion and interpreted this result as an indication that the observed BOLD response characteristics were explained by shifts in attention and/or nonspecific effects of arousal.…”

Attention Alters Feature Space in Motion Processing

“…If this were true, attention would simply increase the contribution of the attended stimulus to the net SMAE (Alais and Blake, 1999) as known from the biased competition framework (Desimone and Duncan, 1995). While this again cannot explain the repulsion effect, it could be a possible explanation for the observed attraction.…”

How Attention Affects Border Ownership in Early Visual Areas

“…Although this link was not made explicit by Fang et al (2009), it has important implications for the complex mechanisms serving attention and adaptation. However, in studies of tilt (Spivey and Spirn, 2000) and motion (Alais and Blake, 1999) aftereffects, attention during adaptation produced stronger aftereffects.…”