Feature-based inhibition underlies the affective consequences of attention

Rapid selection of a target in the presence of similar distractors can cause subsequent affective evaluation of a distractor to be more negative than that for the selected object. This distractor devaluation effect has previously been attributed to an association of attentional inhibition with the distractor's representation. Here, we investigated whether the associated inhibition leading to distractor devaluation is object based or feature based. Using colour-tinted face and building stimuli in a two-item simple visual search, followed by evaluation of face stimuli on a trustworthiness scale, we report that emotional evaluation was modified by prior attention whenever the search stimuli and the to-be-evaluated face shared the distractor feature, regardless of whether face identity seen in the two successive tasks matched or not. These data support the notion that inhibition can be feature-based and show that such inhibition can have emotional consequences

Modelling distractor devaluation (DD) and its neurophysiological correlates

A series of recent studies have shown that selective attention can influence the emotional value of both selected as well as ignored items. Specifically, ignored items (distractors) were consistently rated less positively in emotional evaluations, following attentional selection, relative to (typically) simultaneously presented items (targets). Furthermore, a known electrophysiological index of attentional selectivity (N2pc) was shown to correlate with the magnitude of the observed ‘distractor devaluation’ (DD). A neural model is presented here to account for these findings by means of a plausible mechanism linking attentional processes to emotional evaluations. This mechanism relies on the transformation of attentional inhibition of the distractor into a reduction of the value of that distractor. The model is successful in reproducing the existent behavioural results as well as the observed link between the magnitude of the attentional N2pc and the magnitude of DD. Moreover, the model proposes a series of testable hypotheses as well as specific predictions that call for further experimental investigation

Influence of attentional demands on the processing of emotional facial expressions in the amygdala

Recent studies have cast doubts on the appealing idea that the processing of threat-related stimuli in the amygdala is unconstrained by the availability of attentional resources. However, these studies exclusively used face stimuli presented at fixation and it is unclear whether their conclusion can apply to peripheral face stimuli. Thus, we designed an experiment in which we manipulated the perceptual attentional load of the task used to divert attention from peripheral face stimuli: participants were presented simultaneously with four peripheral pictures (two faces, either both neutral or both fearful, and two houses) that were slightly tilted, and had to match two of these pictures (defined by their position on the screen) either for orientation of the tilt or for identity. The identity task was confirmed to involve greater attentional load than the orientation task by differences in accuracy, reaction times, subsequent face recognition performance, and patterns of activation in several cortical regions. In the orientation task, ignored fearful faces led to stronger activation in the right amygdala than ignored neutral faces. However, this differential response was abolished when participants performed the difficult identity-matching task. Thus, emotional processing of peripheral faces in the amygdala also appears to depend on the available perceptual attentional resources