A role for attentional bias in cognitive deficits in chronic pain?

<p>This thesis extends current understanding of cognitive deficits in people with chronic pain, specifically those related to attention. Researchers have proposed that attentional capacity is allocated to pain sensation, and away from current tasks and goals, leading to broad cognitive deficits (deficit-view). However, an attentional bias to pain-related information has also been observed in people with chronic pain, suggesting that attention is motivated towards information in the environment that is pain-related, and away from information that is not. Such an attentional bias away from information not related to pain may contribute to the cognitive deficits observed on tasks using neutral stimuli (motivated attention hypothesis). In testing the deficit-view and motivated attention accounts of cognitive deficits in chronic pain, I focused on how people attend to rapidly presented information (temporal attention) and the ability to control attention in the face of distraction. To assess how chronic pain affects temporal attention, I used a phenomenon known as the attentional blink, which is a failure to detect a second target that appears soon after a first. Participants viewed a stream of briefly displayed words in which two target words (indicated by their colour) were embedded, with a manipulation of the time between the first and second target. They were required to report the two targets. In one experiment the first target was either pain-related or neutral (to assess how pain-relatedness affects the induction of the blink), and in other experiments this manipulation was applied to the second target (to assess how pain-relatedness affects how targets overcome the blink). In undergraduate participants, both induction and overcoming of the attentional blink was modulated by pain-relatedness. I then compared the effects of manipulating the second target in people with and without chronic pain. If people with chronic pain have general deficits in temporal attention, a deeper attentional blink (relative to control participants) for both kinds of targets should be observed. If motivated attention describes processing in people with chronic pain, a shallower attentional blink for pain related targets than neutral targets (an attentional bias) should be observed. Critically, this bias should be larger in participants with chronic pain. Contrary to both the deficit and motivated attention views, the attentional blink in participants with chronic pain did not differ from that in controls for either pain-related or neutral targets. Furthermore, neither group showed an attentional bias for pain-related targets, and a follow-up experiment failed to replicate the attentional bias observed in undergraduate students as well. Collectively, these findings suggested that attentional bias, as assessed by modulation of the attentional blink, was not reliable. A stronger test of the deficit-view and motivated attention hypothesis was needed. I shifted focus to another attentional domain, the control of distraction. To assess how chronic pain affects attentional control, I used an emotional distraction task, in which participants identified a target letter in an array that flanked irrelevant distractor images that were either intact or scrambled. Intact images depicted either extreme threat to body-tissue, or benign scenes. Distraction is indicated by slowing on intact relative to scrambled distractor trials. If people with chronic pain have general deficits in attentional control, they should show greater distraction from both kinds of images (relative to controls). If motivated attention describes processing in people with chronic pain, greater distraction from body-threat images than neutral images (relative to controls) should be observed. While all participants were more distracted by images depicting extreme threat to body-tissue, people with chronic pain were not more distracted than control participants for either image type. Findings fail to support either a deficit or motivated attention view of attentional control in chronic pain. Although these experiments do not provide evidence that chronic pain affects attentional processing, across experiments people with chronic pain reported that they experience deficits in attention, and they showed behavioural evidence of psychomotor slowing. These findings suggest that, as is repeatedly reported in the literature, people in chronic pain feel like they have attentional deficits, and that some aspects of cognitive and/or motor processing are impacted. Careful consideration is given to what specific cognitive functions might be impaired in chronic pain. The outcome of this discussion suggests pertinent research directions to further understanding of cognition in chronic pain experience.</p>

A role for attentional bias in cognitive deficits in chronic pain?

<p>This thesis extends current understanding of cognitive deficits in people with chronic pain, specifically those related to attention. Researchers have proposed that attentional capacity is allocated to pain sensation, and away from current tasks and goals, leading to broad cognitive deficits (deficit-view). However, an attentional bias to pain-related information has also been observed in people with chronic pain, suggesting that attention is motivated towards information in the environment that is pain-related, and away from information that is not. Such an attentional bias away from information not related to pain may contribute to the cognitive deficits observed on tasks using neutral stimuli (motivated attention hypothesis). In testing the deficit-view and motivated attention accounts of cognitive deficits in chronic pain, I focused on how people attend to rapidly presented information (temporal attention) and the ability to control attention in the face of distraction. To assess how chronic pain affects temporal attention, I used a phenomenon known as the attentional blink, which is a failure to detect a second target that appears soon after a first. Participants viewed a stream of briefly displayed words in which two target words (indicated by their colour) were embedded, with a manipulation of the time between the first and second target. They were required to report the two targets. In one experiment the first target was either pain-related or neutral (to assess how pain-relatedness affects the induction of the blink), and in other experiments this manipulation was applied to the second target (to assess how pain-relatedness affects how targets overcome the blink). In undergraduate participants, both induction and overcoming of the attentional blink was modulated by pain-relatedness. I then compared the effects of manipulating the second target in people with and without chronic pain. If people with chronic pain have general deficits in temporal attention, a deeper attentional blink (relative to control participants) for both kinds of targets should be observed. If motivated attention describes processing in people with chronic pain, a shallower attentional blink for pain related targets than neutral targets (an attentional bias) should be observed. Critically, this bias should be larger in participants with chronic pain. Contrary to both the deficit and motivated attention views, the attentional blink in participants with chronic pain did not differ from that in controls for either pain-related or neutral targets. Furthermore, neither group showed an attentional bias for pain-related targets, and a follow-up experiment failed to replicate the attentional bias observed in undergraduate students as well. Collectively, these findings suggested that attentional bias, as assessed by modulation of the attentional blink, was not reliable. A stronger test of the deficit-view and motivated attention hypothesis was needed. I shifted focus to another attentional domain, the control of distraction. To assess how chronic pain affects attentional control, I used an emotional distraction task, in which participants identified a target letter in an array that flanked irrelevant distractor images that were either intact or scrambled. Intact images depicted either extreme threat to body-tissue, or benign scenes. Distraction is indicated by slowing on intact relative to scrambled distractor trials. If people with chronic pain have general deficits in attentional control, they should show greater distraction from both kinds of images (relative to controls). If motivated attention describes processing in people with chronic pain, greater distraction from body-threat images than neutral images (relative to controls) should be observed. While all participants were more distracted by images depicting extreme threat to body-tissue, people with chronic pain were not more distracted than control participants for either image type. Findings fail to support either a deficit or motivated attention view of attentional control in chronic pain. Although these experiments do not provide evidence that chronic pain affects attentional processing, across experiments people with chronic pain reported that they experience deficits in attention, and they showed behavioural evidence of psychomotor slowing. These findings suggest that, as is repeatedly reported in the literature, people in chronic pain feel like they have attentional deficits, and that some aspects of cognitive and/or motor processing are impacted. Careful consideration is given to what specific cognitive functions might be impaired in chronic pain. The outcome of this discussion suggests pertinent research directions to further understanding of cognition in chronic pain experience.</p>

Equivalent own name bias in autism: An EEG study of the Attentional Blink

The “Attentional Blink” refers to difficulty in detecting the second of two target stimuli presented in rapid temporal succession. Studies have shown that salient target stimuli, such as one’s own name, reduce the magnitude of this effect. Given indications that self-related processing is altered in autism, it is an open question whether this attentional self-bias is reduced in autism. To investigate this, in the current study we utilised an Attentional Blink paradigm involving one’s own and others’ names, in a group of 24 autistic adults, and 22 neurotypical adults, while measuring EEG. In line with previous studies, the Attentional Blink was reduced when the participant’s own name was the second target, with no differences between autistic and neurotypical participants. ERP results show that the effect on the Attentional Blink of one’s own name was reflected in increased N2 and P3 amplitudes, for both autistic and nonautistic individuals. This is the first event-related potential study of own-name processing in the context of the Attentional Blink. The results provide evidence of an intact attentional self-bias in autism, both at the behavioural and neural level.

Mining Temporal Dynamics With Support Vector Machine for Predicting the Neural Fate of Target in Attentional Blink

Our brains do not mechanically process incoming stimuli; in contrast, the physiological state of the brain preceding stimuli has substantial consequences for subsequent behavior and neural processing. Although previous studies have acknowledged the importance of this top-down process, it was only recently that a growing interest was gained in exploring the underlying neural mechanism quantitatively. By utilizing the attentional blink (AB) effect, this study is aimed to identify the neural mechanism of brain states preceding T2 and predict its behavioral performance. Interarea phase synchronization and its role in prediction were explored using the phase-locking value and support vector machine classifiers. Our results showed that the phase coupling in alpha and beta frequency bands pre-T1 and during the T1–T2 interval could predict the detection of T2 in lag 3 with high accuracy. These findings indicated the important role of brain state before stimuli appear in predicting the behavioral performance in AB, thus, supporting the attention control theories.