Neural Indices of Emotional Distraction

<p>Emotional stimuli capture our attention. The preferential processing of emotional information is an adaptive mechanism that when relevant to our goal highlights potentially important aspects in the environment. However, when emotional information is task-irrelevant, their presence in the environment can trigger involuntary shifts in attention that cause detriments to performance. One challenge to investigating emotional distraction in the lab is how to objectively investigate the allocation of attention between different elements on the same stimulus display (e.g. between the task and the distractors). One neural measure that overcomes this issue is the Steady-State-Visual-Evoked-Potential (SSVEP). An SSVEP is the neural response of the visual cortex to a flickering stimulus and can be used as a measure of attentional resource allocation (Norcia, Appelbaum, Ales, Cottereau, & Rossion, 2015). In the past, emotional distraction has been studied using spatially separated tasks and distractors. The current thesis presents two experiments using SSVEPs to investigate emotional distraction in a superimposed design. Experiment 1 aimed to conceptually replicate Hindi Attar and colleagues (2010) who developed an SSVEP emotional distraction paradigm to examine attentional resource allocation between background task-irrelevant emotional distractors and a foreground dot-motion task. Participants viewed a stimulus display of moving, flickering dots, while positive or neutrally valanced distractors (or unidentifiable scrambles) were presented in the background of the task. SSVEPs were reduced in the presence of positive intact compared to neutral intact distractors suggesting that the presentation of task-irrelevant emotional stimuli in the same spatial location as a foreground task initiates an involuntary shift of attention away from the task. Unexpectedly, in both Experiments 1 and 2 valence differences were found in SSVEPs between positive and neutral scrambled images; this suggests that there are some perceptual differences between the stimulus sets (e.g. colour) contributing to the drop in SSVEP found for positive intact images. Importantly, in the SSVEP analysis significant valence x image type interactions were found, demonstrating that the drop for positive images was stronger for intact than scrambled image conditions, suggesting that a significant amount of the drop in SSVEP was driven by a difference in valence between the intact distractors. Behavioural results also suggest evidence for emotional distraction through reduced hit rate in the presence of positive intact images compared to neutral intact images in Experiment 1, and reduced detection sensitivity and response criterion for positive intact images in Experiment 2. Overall, the current thesis demonstrates support for the hypothesis that emotional information is more distracting than neutral information and provides a valuable starting point for the examination of emotion attention interactions when the task and distractors share the same location. Future studies could use SSVEPs to examine neural processing differences between emotional and neutral scrambled images.</p>

Neural Indices of Emotional Distraction

<p>Emotional stimuli capture our attention. The preferential processing of emotional information is an adaptive mechanism that when relevant to our goal highlights potentially important aspects in the environment. However, when emotional information is task-irrelevant, their presence in the environment can trigger involuntary shifts in attention that cause detriments to performance. One challenge to investigating emotional distraction in the lab is how to objectively investigate the allocation of attention between different elements on the same stimulus display (e.g. between the task and the distractors). One neural measure that overcomes this issue is the Steady-State-Visual-Evoked-Potential (SSVEP). An SSVEP is the neural response of the visual cortex to a flickering stimulus and can be used as a measure of attentional resource allocation (Norcia, Appelbaum, Ales, Cottereau, & Rossion, 2015). In the past, emotional distraction has been studied using spatially separated tasks and distractors. The current thesis presents two experiments using SSVEPs to investigate emotional distraction in a superimposed design. Experiment 1 aimed to conceptually replicate Hindi Attar and colleagues (2010) who developed an SSVEP emotional distraction paradigm to examine attentional resource allocation between background task-irrelevant emotional distractors and a foreground dot-motion task. Participants viewed a stimulus display of moving, flickering dots, while positive or neutrally valanced distractors (or unidentifiable scrambles) were presented in the background of the task. SSVEPs were reduced in the presence of positive intact compared to neutral intact distractors suggesting that the presentation of task-irrelevant emotional stimuli in the same spatial location as a foreground task initiates an involuntary shift of attention away from the task. Unexpectedly, in both Experiments 1 and 2 valence differences were found in SSVEPs between positive and neutral scrambled images; this suggests that there are some perceptual differences between the stimulus sets (e.g. colour) contributing to the drop in SSVEP found for positive intact images. Importantly, in the SSVEP analysis significant valence x image type interactions were found, demonstrating that the drop for positive images was stronger for intact than scrambled image conditions, suggesting that a significant amount of the drop in SSVEP was driven by a difference in valence between the intact distractors. Behavioural results also suggest evidence for emotional distraction through reduced hit rate in the presence of positive intact images compared to neutral intact images in Experiment 1, and reduced detection sensitivity and response criterion for positive intact images in Experiment 2. Overall, the current thesis demonstrates support for the hypothesis that emotional information is more distracting than neutral information and provides a valuable starting point for the examination of emotion attention interactions when the task and distractors share the same location. Future studies could use SSVEPs to examine neural processing differences between emotional and neutral scrambled images.</p>

Proactive Control of Emotional Distraction: An ERP Investigation

<p>According to the Dual Mechanisms of Control (DMC) framework (Braver, 2012) distraction can be controlled either proactively (i.e., before the onset of a distractor) or reactively (i.e., after the onset of a distractor). Research clearly indicates that, when distractors are emotionally neutral, proactive mechanisms are more effective at controlling distraction than reactive mechanisms. However, whether proactive control mechanisms can control irrelevant emotional distractions as effectively as neutral distraction is not known. In the current thesis I examined cognitive control over emotional distraction. In Experiment 1, I tested whether proactive mechanisms can control emotional distraction as effectively as neutral distraction. Participants completed a distraction task. On each trial, they determined whether a centrally presented target letter (embedded amongst a circle of ‘o’s) was an ‘X’ or an ‘N’, while ignoring peripheral distractors (negative, neutral, or positive images). Distractors were presented on either a low proportion (25%) or a high proportion (75%) of trials, to evoke reactive and proactive cognitive control strategies, respectively. Emotional images (both positive and negative) produced more distraction than neutral images in the low distractor frequency (i.e., reactive control) condition. Critically, emotional distraction was almost abolished in the high distractor frequency condition; emotional images were only slightly more distracting than neutral images, suggesting that proactive mechanisms can control emotional distraction almost as effectively as neutral distraction. In Experiment 2, I replicated and extended Experiment 1. ERPs were recorded while participants completed the distraction task. An early index (the early posterior negativity; EPN) and a late index (the late positive potential; LPP) of emotional processing were examined to investigate the mechanisms by which proactive control minimises emotional distraction. The behavioural results of Experiment 2 replicated Experiment 1, providing further support for the hypothesis that proactive mechanisms can control emotional distractions as effectively as neutral distractions. While proactive control was found to eliminate early emotional processing of positive distractors, it paradoxically did not attenuate late emotional processing of positive distractors. On the other hand, proactive control eliminated late emotional processing of negative distractors. However, the early index of emotional processing was not a reliable index of negative distractor processing under either reactive or proactive conditions. Taken together, my findings show that proactive mechanisms can effectively control emotional distraction, but do not clearly establish the mechanisms by which this occurs.</p>

EEG evidence for the effective proactive control of emotional distraction

<p>Recent behavioural studies using an emotional flanker task have found that task-irrelevent emotional images are more distracting than neutral images under infrequent, but not frequent, distractor conditions.It has been proposed the effective control of distraction in the high distractor frequency condition may be due to a shift to a proactive control strategy, whereby a potential distraction is anticipated and minimised in advance. However, although it is well established that proactive control is effective at reducingneutral distraction, it is not yet clear whether emotional distraction can be effectively proactively controlled. In this thesis, I used EEG to measure pre-stimulus indices of proactive control in order to determine whether proactive control is responsible for the effective control of emotional and neutral distraction in the high distractor frequency condition, as well asto examine whether proactive control differs according whether a neutral or emotional distraction is anticipated.In addition to replicating the previous behavioural findings, posterior EEG alpha was found to be tonically suppressed in the high compared to low distractor frequency condition, strongly supporting the hypothesis that proactive control was engaged in the high distractor frequency condition. By contrast, there was no difference in phasic alpha suppression (i.e., the drop in alpha in response to fixation onset) between conditions, indicating that the more effective control of distraction in the high frequency distractor conditions was due to a sustained proactive control strategy, rather than greater trial-by-trial preparation to attend to the target. In addition, no alpha lateralisation was found, indicating the mechanisms by which distraction was proactively controlled did not include the preparatory suppression of expected distractor locations. Finally, tonic alpha did not differ according to the expected distractor valence, but phasic alpha suppression was more pronounced when negative, compared to neutral or positive, distractors were expected, independent of distractor frequency condition. This suggests proactive control was also used to some extent in the low distractor frequency condition, but more importantly also provides initial evidence that the proactive control of negative distraction may be unique. Taken together, my findings provide compelling evidence that emotional distraction can be effectively proactively controlled. Future research is needed to determine the mechanisms by which this occurs, and whether the proactive control of emotional distraction is particularly effortful.</p>

EEG evidence for the effective proactive control of emotional distraction

<p>Recent behavioural studies using an emotional flanker task have found that task-irrelevent emotional images are more distracting than neutral images under infrequent, but not frequent, distractor conditions.It has been proposed the effective control of distraction in the high distractor frequency condition may be due to a shift to a proactive control strategy, whereby a potential distraction is anticipated and minimised in advance. However, although it is well established that proactive control is effective at reducingneutral distraction, it is not yet clear whether emotional distraction can be effectively proactively controlled. In this thesis, I used EEG to measure pre-stimulus indices of proactive control in order to determine whether proactive control is responsible for the effective control of emotional and neutral distraction in the high distractor frequency condition, as well asto examine whether proactive control differs according whether a neutral or emotional distraction is anticipated.In addition to replicating the previous behavioural findings, posterior EEG alpha was found to be tonically suppressed in the high compared to low distractor frequency condition, strongly supporting the hypothesis that proactive control was engaged in the high distractor frequency condition. By contrast, there was no difference in phasic alpha suppression (i.e., the drop in alpha in response to fixation onset) between conditions, indicating that the more effective control of distraction in the high frequency distractor conditions was due to a sustained proactive control strategy, rather than greater trial-by-trial preparation to attend to the target. In addition, no alpha lateralisation was found, indicating the mechanisms by which distraction was proactively controlled did not include the preparatory suppression of expected distractor locations. Finally, tonic alpha did not differ according to the expected distractor valence, but phasic alpha suppression was more pronounced when negative, compared to neutral or positive, distractors were expected, independent of distractor frequency condition. This suggests proactive control was also used to some extent in the low distractor frequency condition, but more importantly also provides initial evidence that the proactive control of negative distraction may be unique. Taken together, my findings provide compelling evidence that emotional distraction can be effectively proactively controlled. Future research is needed to determine the mechanisms by which this occurs, and whether the proactive control of emotional distraction is particularly effortful.</p>

Proactive Control of Emotional Distraction: An ERP Investigation

<p>According to the Dual Mechanisms of Control (DMC) framework (Braver, 2012) distraction can be controlled either proactively (i.e., before the onset of a distractor) or reactively (i.e., after the onset of a distractor). Research clearly indicates that, when distractors are emotionally neutral, proactive mechanisms are more effective at controlling distraction than reactive mechanisms. However, whether proactive control mechanisms can control irrelevant emotional distractions as effectively as neutral distraction is not known. In the current thesis I examined cognitive control over emotional distraction. In Experiment 1, I tested whether proactive mechanisms can control emotional distraction as effectively as neutral distraction. Participants completed a distraction task. On each trial, they determined whether a centrally presented target letter (embedded amongst a circle of ‘o’s) was an ‘X’ or an ‘N’, while ignoring peripheral distractors (negative, neutral, or positive images). Distractors were presented on either a low proportion (25%) or a high proportion (75%) of trials, to evoke reactive and proactive cognitive control strategies, respectively. Emotional images (both positive and negative) produced more distraction than neutral images in the low distractor frequency (i.e., reactive control) condition. Critically, emotional distraction was almost abolished in the high distractor frequency condition; emotional images were only slightly more distracting than neutral images, suggesting that proactive mechanisms can control emotional distraction almost as effectively as neutral distraction. In Experiment 2, I replicated and extended Experiment 1. ERPs were recorded while participants completed the distraction task. An early index (the early posterior negativity; EPN) and a late index (the late positive potential; LPP) of emotional processing were examined to investigate the mechanisms by which proactive control minimises emotional distraction. The behavioural results of Experiment 2 replicated Experiment 1, providing further support for the hypothesis that proactive mechanisms can control emotional distractions as effectively as neutral distractions. While proactive control was found to eliminate early emotional processing of positive distractors, it paradoxically did not attenuate late emotional processing of positive distractors. On the other hand, proactive control eliminated late emotional processing of negative distractors. However, the early index of emotional processing was not a reliable index of negative distractor processing under either reactive or proactive conditions. Taken together, my findings show that proactive mechanisms can effectively control emotional distraction, but do not clearly establish the mechanisms by which this occurs.</p>

Understanding the cognitive differences in psychopathy: Emotional distraction across psychopathic traits

<p>Emotional stimuli naturally draw our attention. In emotional distraction paradigms, such stimuli can interrupt performance on a simple cognitive task. There are, however, individual differences in the extent to which emotional distractors impact performance. Previous research has found that highly psychopathic people perform better than others in these tasks, indicating that they are less distracted by emotional stimuli. We tested two separate accounts of the cognitive differences in psychopathy. Emotional processing accounts believe the deficit is specific to processing of aversive stimuli. Conversely, the Attention deficit accounts suggest the deficit is rather ineffective processing of peripheral information. To tease these hypotheses apart we investigated emotional distraction using positive and negative peripheral distractors. Negative distraction but not positive distraction should be reduced if emotional processing accounts are correct; all types of distraction should be reduced for Attention-deficit accounts. The current study employs an emotional distraction paradigm that includes peripheral task-irrelevant distractors that vary in valence and arousal. We measured trait psychopathy using the Psychopathic Personality Inventory in a university sample and grouped participants into low, intermediate, or high Fearless Dominance groups. Participants (N = 83) were instructed to ignore distracting images (positive, negative, or neutral) in the periphery while completing a simple perceptual task at fixation. Participants low in Fearless Dominance showed greater distraction by emotional stimuli than neutral stimuli. In contrast, those high in Fearless Dominance showed no greater distraction by emotional than neutral stimuli. The findings suggest there is no fear-specific deficit in psychopathy, instead, we see an overall decrease in emotional distraction for those high in Fearless Dominance. This finding also supports attention-deficit accounts, however, distraction by neutral stimuli was not associated with Fearless Dominance indicating the reduced distraction is specific to emotional stimuli.</p>

Understanding the cognitive differences in psychopathy: Emotional distraction across psychopathic traits

<p>Emotional stimuli naturally draw our attention. In emotional distraction paradigms, such stimuli can interrupt performance on a simple cognitive task. There are, however, individual differences in the extent to which emotional distractors impact performance. Previous research has found that highly psychopathic people perform better than others in these tasks, indicating that they are less distracted by emotional stimuli. We tested two separate accounts of the cognitive differences in psychopathy. Emotional processing accounts believe the deficit is specific to processing of aversive stimuli. Conversely, the Attention deficit accounts suggest the deficit is rather ineffective processing of peripheral information. To tease these hypotheses apart we investigated emotional distraction using positive and negative peripheral distractors. Negative distraction but not positive distraction should be reduced if emotional processing accounts are correct; all types of distraction should be reduced for Attention-deficit accounts. The current study employs an emotional distraction paradigm that includes peripheral task-irrelevant distractors that vary in valence and arousal. We measured trait psychopathy using the Psychopathic Personality Inventory in a university sample and grouped participants into low, intermediate, or high Fearless Dominance groups. Participants (N = 83) were instructed to ignore distracting images (positive, negative, or neutral) in the periphery while completing a simple perceptual task at fixation. Participants low in Fearless Dominance showed greater distraction by emotional stimuli than neutral stimuli. In contrast, those high in Fearless Dominance showed no greater distraction by emotional than neutral stimuli. The findings suggest there is no fear-specific deficit in psychopathy, instead, we see an overall decrease in emotional distraction for those high in Fearless Dominance. This finding also supports attention-deficit accounts, however, distraction by neutral stimuli was not associated with Fearless Dominance indicating the reduced distraction is specific to emotional stimuli.</p>

Emotional Distraction by Constant Finger Tapping

This study examined the effects of emotional distraction in the context of recalling stressful interpersonal events in daily life. Previous studies have revealed that distraction decreases unpleasant emotions. In this study, we examined whether distraction tasks decrease unpleasant task-related thoughts in addition to unpleasant emotions. Furthermore, to investigate the implicit effects of emotional changes, we examined changes in pupil size in relation to unpleasant emotions and task-unrelated thoughts (TUT). The behavioral tasks were administered to 21 university students ( Mage = 21.24 ± 2.93 years; range: 18–30 years). After excluding participants for poor data quality, 16 (21.31 ± 3.34 years; 18–30 years) were included for further pupil data analysis. As an emotion induction procedure, participants were asked to freely recall memories of stressful interpersonal events in their daily lives and were given a series of questions about their recalled memories, which were presented on the monitor. In the following distraction experiment, questions during the emotion induction procedure were represented as emotional stimulation; a distraction task (non-constant or constant finger tapping) or rest condition was then performed; subsequently, ratings were given for attentional state, thought types conceived during the tasks, and emotional state. Upon analysis, differences in the ratings for unpleasant emotion and TUT were non-significant between all conditions. Nevertheless, pupil dilation in the non-constant and constant conditions was associated with decreased unpleasant emotions ( p < .05; p < .05 to .01). More importantly, pupil dilation was associated with decreased unpleasant TUT ( p < .05) only in the constant condition. Although the observed effects were subtle, we found that constant finger tapping decreased unpleasant emotions and TUT. It is expected for a future emotion regulation study to further investigate the effects in the relationships among emotions, thoughts, and physiological states, which can help in coping with unpleasant emotions.