Exploring the breadth of the top-down representations that control attentional disengagement

Eye-tracking analysis of attentional disengagement in phobic and non-phobic individuals

This study investigated threat-related attention biases using a new visual search paradigm with eye tracking, which allows for measuring attentional disengagement in isolation. This is crucial as previous studies have been unable to distinguish between engagement, disengagement, and behavioral freezing. Thirty-three participants (Mage = 28.75 years, SD = 8.98; 21 women) with self-reported specific phobia (spiders, snakes, and pointed objects) and their matched controls (Mage = 28.38 years, SD = 8.66; 21 women) took part in the experiment. The participants were instructed to initially focus on a picture in the center of the screen, then search for a target picture in an outer circle consisting of six images, and respond via a button press whether the object in the target picture was oriented to the left or right. We found that phobic individuals show delayed disengagement and slower decision times compared with non-phobic individuals, regardless of whether the stimulus was threat-related or neutral. These results indicate that phobic individuals tend to exhibit poorer attentional control mechanisms and problems inhibiting irrelevant information. We also confirmed a threat-unrelated shared feature effect with complex stimuli (delayed disengagement when an attended stimulus and an unattended target share common stimulus features). This process might play a role in various experimental setups investigating attentional disengagement that has not yet been considered. These findings are important, as good attentional control may serve as a protective mechanism against anxiety disorders.

Dissociation of drug and negative emotional cue induced attentional bias in individuals with methamphetamine-use disorder

BACKGROUND AND OBJECTIVES

Although both drugs and negative emotions can trigger drug craving or relapse in individuals with methamphetamine-use disorder (MUD), it remains unclear whether individuals with MUD have attentional biases toward both drug and negative emotional cues and whether this bias involves attention orientation or difficulty in attention disengagement. This study aimed to measure different components of attentional bias toward drug-related and negative emotional cues in individuals with MUD.

METHODS

Two dot-probe tasks were used to investigate attentional bias toward drug (drug task) and negative emotional cues (emotion task) in individuals with MUD. Forty-three males with MUD (average age of 43.44 ± 11.91 years, average drug-use duration of 11.35 ± 8.39 years) participated in the study voluntarily.

RESULTS

There was a significant interaction between the task type and location (p = .01). Specifically, for drug cues, participants showed significant difficulty in attention disengagement toward drug cues (p = .01); however, no attention orientation (p = .46). For negative emotional cues, neither significant attention orientation (p = .07) nor significant difficulty in attention disengagement (p = .50) was found.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Attentional bias in individuals with MUD was highly selective for drug cues; thus, difficulty in attention disengagement from drug cues can be considered a potential mediating mechanism for attentional bias modification interventions for individuals with MUD. This study served to generate hypotheses or suggest future experiments on interventions for individuals with MUD.

Attentional disengagement effect based on relevant features

In visual search tasks, distractors similar to the target can attract our attention and affect the speed of attentional disengagement. The attentional disengagement refers to shifting attention away from stimuli that are not relevant to the task. Previous studies mainly focused on the attentional disengagement of one feature dimension. However, the mechanisms of different feature dimensions on attentional disengagement in single and conjunction visual search remain unclear. In the current study, we adopted the oculomotor disengagement paradigm and used saccade latency as an indicator to explore the effects of different feature dimensions of center stimuli on attentional disengagement. In both single and conjunction feature search tasks, participants began each search by fixating on a center stimulus that appeared simultaneously with search display but would not be the target. Participants were instructed to ensure the first saccade to the target location. In Experiments 1A (single feature search) and 1B (conjunction feature search), we found that the attentional disengagement was significantly delayed or accelerated when center stimuli shared color features with the target or salient distractor, but not in shape feature. Moreover, we found that the difference between the two feature dimensions might be caused by their different search difficulty (Experiment 1C). Therefore, in Experiment 2, we matched the difficulty of searching for color and shape tasks before exploring whether there were differences in the effects of different feature dimensions on attentional disengagement. However, the results in Experiment 2 were similar to those in Experiment 1A, indicating that the different effects of feature dimensions on attentional disengagement were caused by feature asymmetry. Therefore, in Experiment 3, we improved the salient discernibility of shape dimension and matched color search to it. The results showed that although the attentional disengagement was delayed in shape dimension, it was still smaller than that in color dimension. Our results supported that goal-oriented attention sets were the main cause of delayed attentional disengagement. By series of experiments, we found that the utilization of different feature dimensions was associated with task difficulty and the features asymmetry in both single and conjunction visual search.

Delayed disengagement from irrelevant fixation items: Is it generally functional?

In a circular visual search paradigm, the disengagement of attention is automatically delayed when a fixated but irrelevant center item shares features of the target item. Additionally, if mismatching letters are presented on these items, response times (RTs) are slowed further, while matching letters evoke faster responses (Wright, Boot, & Brockmole, 2015a). This is interpreted as a functional reason of the delayed disengagement effect in terms of deeper processing of the fixation item. The purpose of the present study was the generalization of these findings to unfamiliar symbols and to linear instead of circular layouts. Experiments 1 and 2 replicated the functional delayed disengagement effect with letters and symbols. In Experiment 3, the search layout was changed from circular to linear and only saccades from left to right had to be performed. We did not find supportive data for the proposed functional nature of the effect. In Experiments 4 and 5, we tested whether the unidirectional saccade decision, a potential blurring by adjacent items, or a lack of statistical power was the cause of the diminished effects in Experiment 3. With increased sample sizes, the delayed disengagement effect as well as its functional underpinning were now observed consistently. Taken together, our results support prior assumptions that delayed disengagement effects are functionally rooted in a deeper processing of the fixation items. They also generalize to unfamiliar symbols and linear display layouts.

Attention capture, processing speed, and inattentional blindness

Previous theories of inattentional blindness (IB; a phenomenon of observers failing to notice a salient but unexpected event when attention is already occupied) have suggested that an unexpected object reaches conscious awareness when: 1) the location of the unexpected object and attention align, and 2) the unexpected object undergoes sufficient processing. Moreover, it is expected that the same factors that influence the allocation of observers' attention in attention capture studies influence what reaches conscious awareness in IB studies. We explored the degree to which individual differences in susceptibility to attention capture and processing speed are important predictors of IB. One hundred forty-six participants (from Study 1 of Roque, Wright, & Boot, 2016) completed four classic attention (implicit) capture tasks designed to assess stimulus-driven and contingent capture. Following the completion of these capture tasks, participants completed a sustained IB (multiple object tracking) task where an unexpected event appeared during the final critical trial. Indices of stimulus-driven and contingent capture were derived from the capture tasks, and a measure of processing speed was derived from aggregating reaction times from the three speed-based capture tasks. Surprisingly, results of logistic regression analyses revealed no relationship between measures of implicit and explicit capture (noticing the unexpected event). However, consistent with the a priori hypothesis, processing speed did predict IB. Findings suggest that attention capture is unrelated to the noticing of an unexpected stimulus, but efficient encoding and recognition of a stimulus is an important factor.