Enhanced detection of gaze toward an object: Sociocognitive influences on visual search

Attentional priming in Go No-Go search tasks

Go/No-Go responses in visual search yield different estimates of the operation of visual attention than more standard present versus absent tasks. Such minor methodological tweaks have a surprisingly large effect on measures that have, for the last half-century or so, formed the backbone of prominent theories of visual attention. Secondly, priming effects in visual search have a dominating influence on visual search, accounting for effects that have been attributed to top-down guidance in standard theories. Priming effects in visual search have, however, never been investigated for searches involving Go/No-Go present/absent decisions. Here, Go/No-Go tasks were used to assess visual search for an odd-one-out face, defined either by color or facial expression. The Go/No-Go responses for the color-based task were very fast for both present and absent trials and notably, they resulted in negative slopes of RT and set size. Interestingly "Go" responses were even faster for the target absent case. The "Go" responses were, on the other hand, much slower for expression and became higher with increased set-size, particularly for the target-absent response. Priming effects were considerable for the feature search, but for expression, the target absent priming was strong, but did not occur for target present trials, arguing that repetition priming for this search mainly reflects priming of context rather than target features. Overall, the results reinforce the point that Go/No-Go tasks are highly informative for theoretical accounts of visual attention and are shown here to cast a new light on attentional priming.

Attention neglects a stare-in-the-crowd: Unanticipated consequences of prediction-error coding

Direct gaze - someone looking at you - is an important and subjectively-salient stimulus. Its processing is thought to be enhanced by the brain's internalised predictions - priors - that effectively specify it as the most likely gaze direction. Current consensus holds that, befitting its presumed importance, direct gaze attracts attention more powerfully than other gazes. Conversely, some Predictive Coding (PC) models, in which exogenous attention is drawn to stimuli that violate predictions, may be construed as making the opposite claim - i.e., exogenous attention should be biased away from direct gaze (which conforms to internal predictions), toward averted gaze (which does not). Here, searching displays with salient, 'odd-one-out' gazes, we observed attentional bias (in rapid, initial saccades) toward averted gaze, as would be expected by PC models. However, this pattern obtained only when conditions highlighted gaze-uniqueness. We speculate that, in our experiments, task requirements determined how prediction influenced perception.