Experimentally-induced dissociation impairs visual memory

Dissociation is a phenomenon common in a number of psychological disorders and has been frequently suggested to impair memory for traumatic events. In this study we explored the effects of dissociation on visual memory. A dissociative state was induced experimentally using a mirror-gazing task and its short-term effects on memory performance were investigated. Sixty healthy individuals took part in the experiment. Induced dissociation impaired visual memory performance relative to a control condition; however, the degree of dissociation was not associated with lower memory scores in the experimental group. The results have theoretical and practical implications for individuals who experience frequent dissociative states such as patients with posttraumatic stress disorder (PTSD).     

Delineating the contributions of sustained attention and working memory to individual differences in mindfulness

Mindfulness can be deconstructed into two constituent components: present-moment awareness and acceptance. Attention and working memory are theorized to contribute to individual differences in trait mindfulness, although the precise relationship among these constructs remains unclear. The purpose of the present study was to evaluate the association of neurocognitive indices of attention and working memory with a bidimensional trait measure of mindfulness. Fifty-five psychiatrically and neurologically healthy adults completed the Conners Continuous Performance Test, Penn Letter N-back Test, and Philadelphia Mindfulness Scale. Results indicated that present-moment awareness was associated with a response speed variability measure of sustained attention, whereas acceptance was more strongly linked to working memory efficiency, even after accounting for general intellectual ability. These findings suggest that sustained attention and working memory capacities may differentially subserve individual differences in present-moment awareness and acceptance, thereby illuminating our understanding of the cognitive mechanisms which may underlie trait mindfulness.     

The indirect effect of attention bias on memory via interpretation bias: Evidence for the combined cognitive bias hypothesis in subclinical depression

Little research has investigated functional relations among attention, interpretation, and memory biases in depressed samples. The present study tested the indirect effect of attention bias on memory through interpretation bias as an intervening variable in a mixed sample of non-depressed and subclinically depressed individuals. Subclinically depressed and non-depressed individuals completed a spatial cueing task (to measure attention bias), followed by a scrambled sentences test (to measure interpretation bias), and an incidental free recall task (to measure memory bias). Bias-corrected bootstrapping yielded evidence for the hypothesised indirect effect model, in that an emotional bias in attention is related to a congruent bias in interpretative choices which are in turn reflected in memory. These findings extend previous research and provide further support for the combined cognitive bias hypothesis in depression. Theoretical and clinical implications of our findings are discussed.     

Attentional interference by threat and post-traumatic stress disorder: The role of thought control strategies

Attentional interference by threat is associated with PTSD, but the mechanisms of this relationship remain unclear. Attentional interference might be related to increased use of maladaptive thought control strategies, such as suppressing unwanted thoughts (thought suppression) or replacing threatening thoughts with everyday concerns (worry), which increase PTSD risk. Conversely, attentional interference might be associated with reduced use of adaptive strategies, such as talking about threatening thoughts (social control), which decrease PTSD risk. This study tested if thought control strategies mediate the relationship between attentional interference and PTSD. Sixty-one male Vietnam-era veterans completed measures of PTSD symptoms and thought control strategies. Participants also completed a Visual Search Task measuring attentional interference, which required participants to identify a target letter string among a group of threat or neutral words. Attentional interference by threat was related to PTSD symptoms, and mediation analyses revealed significant indirect effects of attentional interference through thought suppression and worry. Attentional interference was related to re-experiencing and avoidance, but not hyperarousal, symptom clusters. Thought suppression was a unique mediator for re-experiencing, whereas thought suppression and worry both mediated the relationship with avoidance. These results offer evidence for maladaptive thought control strategies as a mechanism linking attentional biases for threat to PTSD.     

The effect of facial attractiveness on temporal perception

Previous research suggests that feelings of fear, dislike, shame and sadness affect our perception of duration (Droit-Volet et al., 2004; Gil et al., 2009). The current study sought to expand our understanding of the variables which moderate temporal perception by examining whether the attractiveness of a face influenced its perceived duration. Participants completed a verbal estimation task in which they judged the duration of attractive, unattractive and neutral faces. The results showed that participants underestimated the duration of unattractive faces relative to attractive and neutral faces. Estimates of unattractive faces were also less accurate than those of the attractive and neutral faces. The results are consistent with Gil et al.'s (2009) suggestion that the duration of disliked stimuli are underestimated relative to liked and neutral stimuli because they detract attention from temporal perception. Analysis of the slope and intercept of the estimation gradients supports Zakay and Block's (1997) suggestion that reduced attention to time results in a multiplicative underestimation of duration.     

The deliberate control of emotional experience through control of expressions

Recent research suggests that deliberate manipulation of expressive behaviours might self-regulate emotional experiences. Eighty people were first induced to adopt emotional expressions in a successfully disguised procedure that identified whether their feelings were affected by their expressive behaviour when they were unaware of the nature and purpose of that behaviour. They then deliberately attempted to change emotional feelings by adopting or inhibiting emotional behaviours, or by focusing on or being distracted from situational cues for emotion. Participants more responsive to their own behaviour in the disguised procedure felt more intensely when they adopted emotional behaviours, and less intensely when they inhibited those behaviours. In contrast, people identified as unresponsive to their own emotional behaviour were most affected by deliberate focus on or distraction from emotional thoughts. The effectiveness of techniques for emotional self-regulation depends on a match with characteristics of the person.     

When emotion does and does not impair performance: A Garner theory of the emotional Stroop effect

It takes people longer to name the ink colour of emotion or threat words than that of neutral words, the emotional Stroop effect (ESE). In three experiments with normal and patient populations, we show that the ESE is a special case of a generic attention model and effect entailed in Garner's speeded classification paradigm. Guided by the Garner model we demonstrate that task-irrelevant dimensions that differ in salience can produce the ESE and mimic it with neutral stimuli. When each word appears in a constant colour, as mandated in the correlation condition of the Garner design, the ESE is eliminated. This important result is consistent with the attention account of the ESE. We conclude that when emotion stimuli appear in a random fashion they interfere with task performance. However, when emotion stimuli are correlated with features of the ongoing task they help task performance not least due to their extreme salience.     

Attentional and behavioural responses of spider fearfuls to virtual spiders

This study employed an immersed virtual environment (IVE) in the Nijmegen RIVERlab to study spider fearfuls’ attentional and motor reactions to virtual spiders. The participants were exposed to virtual spiders while completing an unrelated task, walking freely through a virtual museum. Compared to non-fearful controls, spider fearfuls showed an increase in state anxiety, they spent more time looking at spiders, and they exhibited spontaneous behavioural avoidance of spiders and visually similar objects. The results extend, and to some degree contradict, those of earlier studies with static pictures, and they speak to the usefulness of state-of-the-art IVEs in fundamental anxiety research.     

The role of controlled attention on recall in major depression

Information processing biases are hallmark features of major depressive disorder (MDD). Depressed individuals display biased memory and attention for negative material. Given that memory is highly dependent on attention for initial encoding, understanding the interplay of these processes may provide important insight into mechanisms that produce memory biases in depression. In particular, attentional control—the ability to selectively attend to task-relevant information by both inhibiting the processing of irrelevant information and disengaging attention from irrelevant material—may be one area of impairment in MDD. In the current study, clinically depressed (MDD: n = 15) and never depressed (non-MDD: n = 22) participants' line of visual gaze was assessed while participants viewed positive and negative word pairs. For each word pair, participants were instructed to attend to one word (target) and ignore one word (distracter). Free recall of study stimuli was then assessed. Depressed individuals displayed greater recall of negatively valenced target words following the task. Although there were no group differences in attentional control in the context of negative words, attention to negative targets mediated the relationship between depression status and recall of negative words. Results suggest a stronger link between attention and memory for negative material in MDD.     

Attentional bias in high- and low-anxious individuals: Evidence for threat-induced effects on engagement and disengagement

Attentional bias to threatening visual stimuli (words or pictures) is commonly present in anxious individuals, but not in non-anxious people. There is evidence to show that attentional bias to threat can be induced in all individuals when threat is imposed by threat not of symbolic nature, but by cues that predict aversive stimulation (loud noise or electric shock). However, it is not known whether attentional bias in such situations is still influenced by individual differences in anxiety. This question was addressed in two experiments using a spatial cuing task in which visual cues predicted the occurrence of an aversive event consisting of a loud human scream. Speeded attentional engagement to threat cues was positively correlated with trait anxiety in Experiment 1. Experiment 2 showed that speeded attentional engagement was present only in participants selected for high anxiety but not in low-anxious participants. In both experiments, slower disengagement from threat cues was found in all participants, irrespective of their trait anxiety levels.