Improving attention control in dysphoria through cognitive training: Transfer effects on working memory capacity and filtering efficiency

Impaired filtering of irrelevant information from working memory is thought to underlie reduced working memory capacity for relevant information in dysphoria. The current study investigated whether training‐related gains in working memory performance on the adaptive dual n‐back task could result in improved inhibitory function. Efficacy of training was monitored in a change detection paradigm allowing measurement of a sustained event‐related potential asymmetry sensitive to working memory capacity and the efficient filtering of irrelevant information. Dysphoric participants in the training group showed training‐related gains in working memory that were accompanied by gains in working memory capacity and filtering efficiency compared to an active control group. Results provide important initial evidence that behavioral performance and neural function in dysphoria can be improved by facilitating greater attentional control.     

Understanding depressive rumination from a cognitive science perspective: The impaired disengagement hypothesis

Persisting negative thoughts are considered a hallmark of depression. Recent information-processing approaches have begun to uncover underlying mechanisms of depressive rumination. Despite marked advances in this area, there is a lack of integration between psychopathology and cognitive (neuro) science research. We propose the ‘impaired disengagement’ hypothesis as a unifying framework between both approaches. The core tenet of our model is that prolonged processing of self-referent material is due to impaired attentional disengagement from negative self-referent information. We discuss empirical evidence for this framework and outline future ways in which the causal predictions of this model can be tested. The proposed framework can account for effectiveness of various treatments for depression and may aid in devising new interventions to target depressive cognition.     

The neural correlates of cognitive effort in anxiety: effects on processing efficiency

We investigated the neural correlates of cognitive effort/pre-target preparation (Contingent Negative Variation activity; CNV) in anxiety using a mixed antisaccade task that manipulated the interval between offset of instructional cue and onset of target (CTI). According to attentional control theory (Eysenck et al., 2007) we predicted that anxiety should result in increased levels of compensatory effort, as indicated by greater frontal CNV, to maintain comparable levels of performance under competing task demands. Our results showed that anxiety resulted in faster antisaccade latencies during medium compared with short and long CTIs. Accordingly, high-anxious individuals compared with low-anxious individuals showed greater levels of CNV activity at frontal sites during medium CTI suggesting that they exerted greater cognitive effort and invested more attentional resources in preparation for the task goal. Our results are the first to demonstrate the neural correlates of processing efficiency and compensatory effort in anxiety and are discussed within the framework of attentional control theory.     

Molecular characterization of p16‐immunopositive but HPV DNA‐negative oropharyngeal carcinomas

Recent studies have reported that p16 protein overexpression qualifies as a surrogate marker identifying an oncogenic human papillomavirus (HPV) infection in oropharyngeal squamous cell carcinoma (OPSCC). However, there is still a percentage of OPSCCs that are positive for p16 immunohistochemistry (p16 IHC) but lack HPV DNA. The objective of this study was to characterize this group at the molecular level by performing sensitive HPV DNA‐ and RNA‐based PCR methods and genetic profiling. All patients diagnosed with an OPSCC in the period 2000–2006 in two Dutch university medical centers were included (n = 841). The presence of HPV in a tumor sample was tested by p16 IHC followed by an HPV DNA GP5+/6+ PCR. p16 IHC scored positive in 195 samples, of which 161 were HPV DNA‐positive and 34 (17%) HPV DNA‐negative. In the latter group, a SPF₁₀‐LiPA25 assay, an HPV16 type‐specific E7 PCR and an E6 mRNA RT‐PCR were performed. Next, ten of these cases were further analyzed for loss of heterozygosity (LOH) of 15 microsatellite markers at chromosome arms 3p, 9p and 17p. Of the 34 p16‐positive but PCR‐negative OPSCCs, two samples tested positive by SPF₁₀ assay, HPV16 E7 PCR and HPV16 E6 mRNA RT‐PCR. Three samples tested positive by SPF₁₀ assay but negative by the HPV16‐specific assays. Nine of ten cases that were tested for LOH showed a genetic pattern comparable to that of HPV‐negative tumors. This study categorizes p16‐positive but HPV DNA‐negative OPSCCs as HPV‐negative tumors based on genetic profiling. This study highlights the importance of performing HPV testing in addition to p16 IHC for proper identification of HPV‐associated OPSCCs.     

Trait anxiety modulates the electrophysiological indices of rapid spatial orienting towards angry faces

We investigated the electrophysiological markers of attentional bias for threat in anxiety. Low-anxiety and high-anxiety individuals performed a spatial-cueing task, in which an emotional facial expression (angry or happy) was presented alongside a neutral expression. Results revealed that angry expressions elicited an enhanced N2pc component, but that this was true only for those reporting high levels of trait anxiety. These results confirm the early capture of spatial attention by threat-related stimuli, and demonstrate that this early bias is modulated by trait anxiety. Enhanced P1 amplitudes to targets after presentations of angry expressions were also found; however, this effect was not modulated by trait anxiety levels. Our findings indicate that individual differences in temperament are an important determinant of the early neural response to threat.     

Attentional control in dysphoria: an investigation using the antisaccade task

We examined inhibitory mechanisms in dysphoria using direct measures of attentional control. Dysphoric and non-dysphoric participants performed standard and delayed versions of the antisaccade and prosaccade tasks with facial expressions as stimuli. Results showed higher error rates in the standard antisaccade task than in the delayed tasks, with the dysphoric group having higher error rates in response to emotional facial expressions, in particular happy expressions. Our findings indicate impaired attentional processing in response to emotional facial expressions, in particular happy expressions, in dysphoria. Implications for understanding the mechanisms underlying attentional control in dysphoria are discussed.     

The neural correlates of impaired inhibitory control in anxiety

According to Attentional Control Theory (Eysenck et al., 2007) anxiety impairs the inhibition function of working memory by increasing the influence of stimulus-driven processes over efficient top-down control. We investigated the neural correlates of impaired inhibitory control in anxiety using an antisaccade task. Low- and high-anxious participants performed anti- and prosaccade tasks and electrophysiological activity was recorded. Consistent with previous research high-anxious individuals had longer antisaccade latencies in response to the to-be-inhibited target, compared with low-anxious individuals. Central to our predictions, high-anxious individuals showed lower ERP activity, at frontocentral and central recording sites, than low anxious individuals, in the period immediately prior to onset of the to-be-inhibited target on correct antisaccade trials. Our findings indicate that anxiety interferes with the efficient recruitment of top-down mechanisms required for the suppression of prepotent responses. Implications are discussed within current models of attentional control in anxiety ( [Bishop, 2009] and [Eysenck et al., 2007]).     

The combined cognitive bias hypothesis in depression

Drawing from substantial evidence demonstrating cognitive biases in depression at various stages of information processing (i.e., attention, interpretation, memory, cognitive control), we argue for an approach that considers the interplay among these processes. This paper attempts to apply the combined cognitive bias hypothesis (Hirsch, Clark, & Mathews, 2006) to depression research and reviews competing theoretical frameworks that have guided research in this area. We draw on current findings from behavioral studies on the interplay between depression-related processing biases. These data indicate that various cognitive biases are associated. However, it is not clear whether single or multiple biases are most predictive of depressive symptoms. We conclude this article with theoretical and clinical implications of the current state of research in this field and propose a number of ways in which research on the combined cognitive bias hypothesis can be advanced.     

Impaired filtering of irrelevant information in dysphoria: an ERP study

Behavioural findings have led to proposals that difficulties in attention and concentration in depression may have their roots in fundamental inhibitory impairments for irrelevant information. These impairments may be associated with reduced capacity to actively maintain relevant information to facilitate goal-directed behaviour. In light of mixed data from behavioural studies, the current study using direct neural measurement, examines whether dysphoric individuals show poor filtering of irrelevant information and reduced working memory (WM) capacity for relevant information. Consistent with previous research, a sustained event-related potential (ERP) asymmetry, termed contra-lateral delay activity (CDA), was observed to be sensitive to WM capacity and the efficient filtering of irrelevant information from visual WM. We found a strong positive correlation between the efficiency of filtering irrelevant items and visual WM capacity. Specifically, dysphoric participants were poor at filtering irrelevant information, and showed reduced WM capacity relative to high capacity non-dysphoric participants. Results support the hypothesis that impaired inhibition is a central feature of dysphoria and are discussed within the framework of cognitive and neurophysiological models of depression.