Looking back at the stare-in-the-crowd effect: staring eyes do not capture attention in visual search.

The stare-in-the crowd effect refers to the finding that a visual search for a target of staring eyes among averted-eyes distracters is more efficient than the search for an averted-eyes target among staring distracters. This finding could indicate that staring eyes are prioritized in the processing of the search array so that attention is more likely to be directed to their location than to any other. However, visual search is a complex process, which not only depends upon the properties of the target, but also the similarity between the target of the search and the distractor items and between the distractor items themselves. Across five experiments, we show that the search asymmetry diagnostic of the stare-in-the-crowd effect is more likely to be the result of a failure to control for the similarity among distracting items between the two critical search conditions rather than any special attention-grabbing property of staring gazes. Our results suggest that, contrary to results reported in the literature, staring gazes are not prioritized by attention in visual search.

Methodological considerations in cognitive bias research: the next steps.

Field and Christiansen (2012) comment on the importance of establishing and understanding the internal reliability of measures of substance-related cognitive bias, and suggest potential reasons for the poor reliability of some task variants. We agree that the impact of using stimuli personalized to the participant on the reliability of cognitive bias tasks is worthy of systematic investigation. However, some tasks may still be inherently less reliable than others. Ultimately, this debate should be framed within the wider debate on the validity of laboratory models and methods used to assess real-world phenomena.

Internal reliability of measures of substance-related cognitive bias.

AIMS: There is growing interest in cognitive biases related to substance use, but evidence from the anxiety literature suggests that tasks commonly used to assess these may suffer from low internal reliability. We examined the internal reliability of the visual probe and modified Stroop tasks. DESIGN: Secondary analysis of visual probe and modified Stroop task data collected across seven independent studies. SETTING: Human laboratory study. PARTICIPANTS: Healthy volunteers (n=408 across seven independent studies) recruited from the general population on the basis of alcohol or tobacco use. MEASUREMENTS: Visual probe and modified Stroop task measures of substance-related cognitive bias. FINDINGS: Measures of cognitive bias for substance-related cues, as assayed by the visual probe and the modified Stroop tasks, may not be reliable. In particular, the visual probe task showed poor internal reliability, as did unblocked versions of the modified Stroop task. CONCLUSIONS: The modified Stroop task is preferable to the visual probe task as a measure of substance-related cognitive bias, on the basis of its psychometric properties. Studies using cognitive bias tasks should not assume they are reliable, and should routinely report reliability estimates where possible.

Effects of acute alcohol consumption on the perception of eye gaze direction.

Alcohol consumption is associated with increases in aggressive behaviour, but the mechanisms underlying this relationship are poorly understood. One mechanism by which alcohol consumption may influence behaviour is via alterations in the processing of social cues such as gaze. We investigated the effects of acute alcohol consumption on the perception of gaze, using a task in which participants determined whether a stimulus face was looking towards or away from them. Gaze direction varied across trials, allowing calculation of a threshold at which participants considered gaze to switch from direct to averted. Target faces varied in both sex and attractiveness. Thirty social drinkers attended three randomized experimental sessions. At each session, participants consumed 0.0, 0.2 or 0.4 g/kg alcohol, and completed the gaze perception task. A significant three-way interaction involving target sex, participant sex and alcohol dose indicated that alcohol increased the cone of gaze for females viewing male targets (i.e. females were biased towards making a direct gaze judgement), but decreased the cone of gaze for males viewing male targets. Our data indicate that alcohol consumption influences gaze perception, but that these effects vary across sex of both stimulus and rater. These effects may have important implications for alcohol-related violence.

Effects of 7.5% CO(2) inhalation on allocation of spatial attention to facial cues of emotional expression.

Increased vigilance to threat-related stimuli is thought to be a core cognitive feature of anxiety. We sought to investigate the cognitive impact of experimentally induced anxiety, by means of a 7.5% CO(2) challenge, which acts as an unconditioned anxiogenic stimulus, on attentional bias for positive and negative facial cues of emotional expression in the dot-probe task. In two experiments we found robust physiological and subjective effects of the CO(2) inhalation consistent with the claim that the procedure reliably induces anxiety. Data from the dot-probe task demonstrated an attentional bias to emotional facial expressions compared with neutral faces regardless of valence (happy, angry, and fearful). These attentional effects, however, were entirely inconsistent in terms of their relationship with induced anxiety. We conclude that the previously reported poor reliability of this task is the most parsimonious explanation for our conflicting findings and that future research should develop a more reliable paradigm for measuring attentional bias in this field.

The role of trait anxiety in the recognition of emotional facial expressions.

Previous work has suggested that elevated levels of trait anxiety are associated with an increased ability to accurately recognize the facial expression of fear. However, to date, recognition has only been assessed after viewing periods of 10s, despite the fact that the process of emotion recognition from faces typically takes a fraction of this time. The current study required participants with either high or low levels of non-clinical trait anxiety to make speeded emotional classification judgments to a series of facial expressions drawn from seven emotional categories. Following previous work it was predicted that recognition of fearful facial expressions would be more accurate in the high-trait anxious group compared with the low-trait anxious group. However, contrary to this prediction, no anxiety-related differences in emotion perception were observed across all seven emotions. This suggests that anxiety does not influence the perception of fear as has been previously proposed.

Attentional bias to angry faces using the dot-probe task? It depends when you look for it.

A number of studies using the dot-probe task now report the existence of an attentional bias to angry faces in participants who rate highly on scales of anxiety; however, no equivalent bias has been observed in non-anxious populations, despite evidence to the contrary from studies using other tasks. One reason for this discrepancy may be that researchers using the dot-probe task have rarely investigated any effects which might emerge earlier than 500 ms following presentation of the threat-related faces. Accordingly, in the current study we presented pairs of face stimuli with emotional and neutral expressions and probed the allocation of attention to these stimuli for presentation times of 100 and 500 ms. Results showed that at 100 ms there was an attentional bias towards the location of the relatively threatening stimulus (the angry face in angry/neutral pairs and the neutral face in neutral/happy pairs) and this pattern reversed by 500 ms. Comparisons of reaction time (RT) scores with an appropriate baseline suggested that the early bias toward threatening faces may actually arise through inhibition of the relatively least threatening member of a face pair rather than through facilitation of, or vigilance towards, the more threatening stimulus. However the mechanisms governing the observed biases are interpreted, these data provide evidence that probing for the location of spatial attention at 500 ms is not necessarily indicative of the initial allocation of attention between competing emotional facial stimuli.