Eye movements are captured by a perceptually simple conditioned stimulus in the absence of explicit contingency knowledge.

Abstract

Past reports suggest that threatening materials can impact the efficiency of goal-directed behavior. However, questions remain about whether a conditional stimulus (CS) can capture attention as previous results may have been influenced by voluntary prioritization of a to-be-ignored CS. In 2 experiments, eye tracking was used to evaluate whether neutral, perceptually simple materials capture attention when they take on aversive properties via probabilistic fear conditioning with strict methods in place to eliminate voluntary CS prioritization. During training, participants attempted to fixate search targets (i.e., horizontally or vertically oriented rectangles) as quickly as possible to avoid shock. In reality, shock administration was related to rectangle orientation so that 1 rectangle (CS+) predicted shock more often than the other (CS-). Subsequently rectangles became distractors and were to be ignored. At this point, participants were instructed to fixate a new target and incidences of CS capture were examined. Results showed that saccades were made more quickly to the CS+ than the CS- as training progressed, and that oculomotor capture by irrelevant rectangles occurred more often for the CS+ than the CS-. An independent physiological index (skin conductance response) confirmed that contingencies had been learned, as SCR magnitude was greater for CS+ than CS- trials early in the test phase. These effects were documented despite the absence of explicit contingency knowledge, assessed using a postexperimental questionnaire. Collectively, these outcomes indicate that a CS can capture attention despite being task-irrelevant, and that these effects do not depend on conscious awareness of learned contingencies. (PsycINFO Database Record

The influence of emotional stimuli on the oculomotor system: A review of the literature

“…In these studies, the threatening distractor captured not only covert attention but also the eyes more often than a nonthreatening distractor (Hopkins et al, 2016;Mulckhuyse & Dalmaijer, 2016). This was demonstrated even when participants were not explicitly aware of the contingency between the distractor and the threat (Hopkins et al, 2016). Other studies corroborate the findings that fear-conditioned distractors increase exogenously driven error saccades.…”

“…1b). With this paradigm, it was found that endogenously driven saccades to the target are slowed more by a threatening distractor than by a nonthreatening distractor (Hopkins, Helmstetter, & Hannula, 2016;Mulckhuyse & Dalmaijer, 2016). These results indicate that the threatening distractor captured covert attention automatically and thereby delayed the programming of a saccade to a different location.…”

“…Most studies that investigated the effect of attentional capture by an emotional stimulus on oculomotor behavior found faster saccades to the emotional stimulus, reflecting enhanced attentional capture (Bannerman, Milders, de Gelder, et al, 2009;, 2010a, 2010bNummenmaa et al, 2009;Schmidt et al 2015Schmidt et al , 2017, slower saccades away from an emotional stimulus, reflecting delayed attentional disengagement (Bannerman et al, 2010a(Bannerman et al, , 2010bBelopolsky et al, 2011;Hopkins et al, 2016;Mulckhuyse & Dalmaijer, 2016;Schmidt et al, 2015Schmidt et al, , 2017, stronger deviations toward an emotional distractor (McSorley & van Reekum, 2013;Mulckhuyse et al, 2013), or away from an emotional distractor (Mulckhuyse et al, 2013;Nummenmaa et al, 2009;Schmidt et al, 2012). However, because of the set-up of most studies, emotional attention is never isolated from endogenous and exogenous attention, but rather most studies show an integration of emotion with endogenous or exogenous attentional processes (see also Brosch, Pourtois, Sander, & Vuilleumier, 2011).…”

“…Exogenous attentional capture, most especially, seems to be enhanced by emotion (Carretié, 2014). For instance, studies that did find an effect of emotion often presented the emotional stimulus as a sudden onset (Bannerman, Milders, de Gelder, et al, 2009;, 2010a, 2010bHopkins et al, 2016;Mulckhuyse & Dalmaijer, 2016;Schmidt et al, 2015Schmidt et al, , 2017, whereas in visual search studies that did not find an effect of emotion, the stimulus display including the target and distractor were presented together and for relatively long durations (DeVue & Grimshaw, 2017;Hunt et al, 2007a). In other words, there was no additional luminance transient present together with the emotional signal.…”

“…In the emotional version of the additional singleton paradigm (Theeuwes et al, 1998), in which an additional sudden onset distractor is presented among distractors and a target in a circular array, the effect of emotion on exogenous saccades was shown. In these studies, the threatening distractor captured not only covert attention but also the eyes more often than a nonthreatening distractor (Hopkins et al, 2016;Mulckhuyse & Dalmaijer, 2016). This was demonstrated even when participants were not explicitly aware of the contingency between the distractor and the threat (Hopkins et al, 2016).…”