Briana L. Kennedy

When Emotion Blinds: A Spatiotemporal Competition Account of Emotion-Induced Blindness

Emotional visual scenes are such powerful attractors of attention that they can disrupt perception of other stimuli that appear soon afterward, an effect known as emotion-induced blindness. What mechanisms underlie this impact of emotion on perception? Evidence suggests that emotion-induced blindness may be distinguishable from closely related phenomena such as the orienting of spatial attention to emotional stimuli or the central resource bottlenecks commonly associated with the attentional blink. Instead, we suggest that emotion-induced blindness reflects relatively early competition between targets and emotional distractors, where spontaneous prioritization of emotional stimuli leads to suppression of competing perceptual representations potentially linked to an overlapping point in time and space.

Emotion-induced blindness reflects competition at early and late processing stages: an ERP study.

Emotion-induced blindness (EIB) refers to impaired awareness of items appearing soon after an irrelevant, emotionally arousing stimulus. Superficially, EIB appears to be similar to the attentional blink (AB), a failure to report a target that closely follows another relevant target. Previous studies of AB using event-related potentials suggest that the AB results from interference with selection (N2 component) and consolidation (P3b component) of the second target into working memory. The present study applied a similar analysis to EIB and, similarly, found that an irrelevant emotional distractor suppressed the N2 and P3b components associated with the following target at short lags. Emotional distractors also elicited a positive deflection that appeared to be similar to the PD component, which has been associated with attempts to suppress salient, irrelevant distractors (Kiss, Grubert, Petersen, & Eimer, 2012; Sawaki, Geng, & Luck, 2012; Sawaki & Luck, 2010). These results suggest that irrelevant emotional pictures gain access to working memory, even when observers are attempting to ignore them and, like the AB, prevent access of a closely following target.

The Rapid Perceptual Impact of Emotional Distractors

The brief presentation of an emotional distractor can temporarily impair perception of a subsequent, rapidly presented target, an effect known as emotion-induced blindness (EIB). How rapidly does this impairment unfold? To probe this question, we examined EIB for targets that immediately succeeded (“lag-1”) emotional distractors in a rapid stream of items relative to EIB for targets at later serial positions. Experiments 1 and 2 suggested that emotional distractors interfere with items presented very soon after them, with impaired target perception emerging as early as lag-1. Experiment 3 included an exploratory examination of individual differences, which suggested that EIB onsets more rapidly among participants scoring high in measures linked to negative affect.

Neural signatures of dynamic emotion constructs in the human brain

How is emotion represented in the brain: is it categorical or along dimensions? In the present study, we applied multivariate pattern analysis (MVPA) to magnetoencephalography (MEG) to study the brains temporally unfolding representations of different emotion constructs. First, participants rated 525 images on the dimensions of valence and arousal and by intensity of discrete emotion categories (happiness, sadness, fear, disgust, and sadness). Thirteen new participants then viewed subsets of these images within an MEG scanner. We used Representational Similarity Analysis (RSA) to compare behavioral ratings to the unfolding neural representation of the stimuli in the brain. Ratings of valence and arousal explained significant proportions of the MEG data, even after corrections for low-level image properties. Additionally, behavioral ratings of the discrete emotions fear, disgust, and happiness significantly predicted early neural representations, whereas rating models of anger and sadness did not. Different emotion constructs also showed unique temporal signatures. Fear and disgust - both highly arousing and negative - were rapidly discriminated by the brain, but disgust was represented for an extended period of time relative to fear. Overall, our findings suggest that 1) dimensions of valence and arousal are quickly represented by the brain, as are some discrete emotions, and 2) different emotion constructs exhibit unique temporal dynamics. We discuss implications of these findings for theoretical understanding of emotion and for the interplay of discrete and dimensional aspects of emotional experience.

Affective stimuli capture attention regardless of categorical distinctiveness: An emotion-induced blindness study

Affective stimuli capture attention, whether their affective value stems from emotional content or a history of reward. The uniqueness of such stimuli within their experimental contexts might imbue them with an enhanced categorical distinctiveness that accounts for their impact on attention. Indeed, in emotion-induced blindness, categorically distinctive neutral pictures disrupt target perception, albeit to a lesser degree than do emotional pictures. Here, we manipulated the categorical distinctiveness of distractors in an emotion-induced blindness task. Participants searched within RSVP streams for a target that followed an emotional or a neutral distractor picture. In a categorically homogenous condition, all non-distractor items were exemplars from a uniform category, thus enhancing the distractors categorical distinctiveness. In a categorically heterogeneous condition, each non-distractor item represented a distinct category. Neutral distractors disrupted target perception only in the homogenous condition, but emotional distractors did so regardless of their categorical distinctiveness.

Spatiotemporal competition and task-relevance shape the spatial distribution of emotional interference during rapid visual processing: Evidence from gaze-contingent eye-tracking

People’s ability to perceive rapidly presented targets can be disrupted both by voluntary encoding of a preceding target and by spontaneous attention to salient distractors. Distinctions between these sources of interference can be found when people search for a target in multiple rapid streams instead of a single stream: voluntary encoding of a preceding target often elicits subsequent perceptual lapses across the visual field, whereas spontaneous attention to emotionally salient distractors appears to elicit a spatially localized lapse, giving rise to a theoretical account suggesting that emotional distractors and subsequent targets compete spatiotemporally during rapid serial visual processing. We used gaze-contingent eye-tracking to probe the roles of spatiotemporal competition and memory encoding on the spatial distribution of interference caused by emotional distractors, while also ruling out the role of eye-gaze in driving differences in spatial distribution. Spontaneous target perception impairments caused by emotional distractors were localized to the distractor location regardless of where participants fixated. But when emotional distractors were task-relevant, perceptual lapses occurred across both streams while remaining strongest at the distractor location. These results suggest that spatiotemporal competition and memory encoding reflect a dual-route impact of emotional stimuli on target perception during rapid visual processing.

Miss it and miss out: Counterproductive nonspatial attentional capture by task-irrelevant, value-related stimuli

Recent studies of visual search suggest that learning about valued outcomes (rewards and punishments) influences the likelihood that distractors will capture spatial attention and slow search for a target, even when those value-related distractors have never themselves been the targets of search. In the present study, we demonstrated a related effect in the context of temporal, rather than spatial, selection. Participants were presented with a temporal stream of pictures in a fixed central location and had to identify the orientation of a rotated target picture. Response accuracy was reduced if the rotated target was preceded by a “valued” distractor picture that signaled that a correct response to the target would be rewarded (and an incorrect response punished), relative to a distractor picture that did not signal reward or punishment. This effect of signal value on response accuracy was short-lived, being most prominent with a short lag between distractor and target. Impairment caused by a valued distractor was observed if participants were explicitly instructed regarding its relation to reward/punishment (Exps. 1, 3, and 4), or if they could learn this relationship only via trial-by-trial experience (Exp. 2). These findings show that the influence of signal value on attentional capture extends to temporal selection, and also demonstrate that value-related distractors can interfere with the conscious perception of subsequent target information.

Proactive Deprioritization of Emotional Distractors Enhances Target Perception.

There are many situations in which it is important to focus on a task in the face of emotional distraction. Yet, emotional distractors can impair our ability to report items that appear soon after them, an effect known as emotion-induced blindness (EIB). To what degree does it help to know about emotional distractors ahead of time? Can we deprioritize emotional distractors when forewarned that they will appear? To address this question, we tested whether participants could overcome EIB when forewarned about the nature of an emotional distractor. On each trial, participants searched for 1 target (a rotated picture) presented within a rapid serial visual stream of upright images. An aversive, erotic, or neutral distractor could precede the target by either 200 or 400 ms. At the start of some trials, participants were informed which kind of distractor would appear on that trial, but in other trials they received no advance information. Results revealed that the provision of distractor information significantly improved target perception as early as 200 ms following both aversive and erotic distractors. These results suggest that people can “brace themselves” in the service of an attentional task by proactively deprioritizing emotional distractors.