Categorization behaviour in adults,adolescents, and attention-deficit/hyperactivity disorder adolescents: A comparative investigation

Although significant progress has been made with respect to our understanding of categorization and concept learning behaviour in adults, much less is known about how this key capacity plays out with respect to more restrictive populations. This is unfortunate because much may be revealed about the nature of concept learning by examining the limits exhibited by special populations. With this tenet in mind, in what follows, we investigated key aspects of concept learning in terms of the unexplored comparative performance of three populations—adults, adolescents, and adolescents with attention-deficit/hyperactivity disorder (ADHD). To do so, we employed a novel parainformative experimental task involving categorical stimuli with four objects defined over three dimensions. The learning difficulty ordering for these types of three-dimensional stimuli has proven robust and has been replicated by several researchers. Indeed, in our experiment, we observed the same concept learning ordering in adults and adolescents, but not in ADHD adolescents: For example, the latter group showed greatly impaired categorization performance on stimuli characterized by an “exclusive-or” rule. However, categorization performance on such type of stimuli indicated good reliability in discriminating between adolescents with and without ADHD (receiver-operating characteristic, ROC?=?.82). We accurately predicted and accounted for these results using generalized invariance structure theory (GIST; Vigo, 2013. The GIST of concepts. Cognition, 129, 138–162), which posits that organisms detect invariance patterns in stimuli that are necessary precursors to concept formation.     

Task instructions determine the visuospatial and verbal–spatial nature of number–space associations

Evidence for number–space associations comes from the spatial–numerical association of response codes (SNARC) effect, consisting in faster reaction times to small/large digits with the left/right hand, respectively. Two different proposals are commonly discussed concerning the cognitive origin of the SNARC effect: the visuospatial account and the verbal–spatial account. Recent studies have provided evidence for the relative dominance of verbal–spatial over visuospatial coding mechanisms, when both mechanisms were directly contrasted in a magnitude comparison task. However, in these studies, participants were potentially biased towards verbal–spatial number processing by task instructions based on verbal–spatial labels. To overcome this confound and to investigate whether verbal–spatial coding mechanisms are predominantly activated irrespective of task instructions, we completed the previously used paradigm by adding a spatial instruction condition. In line with earlier findings, we could confirm the predominance of verbal–spatial number coding under verbal task instructions. However, in the spatial instruction condition, both verbal–spatial and visuospatial mechanisms were activated to an equal extent. Hence, these findings clearly indicate that the cognitive origin of number–space associations does not always predominantly rely on verbal–spatial processing mechanisms, but that the spatial code associated with numbers is context dependent.     

Do emotions have distinct vocal profiles? A study of idiographic patterns of expression

Research on vocal expressions of emotion indicates that persons can identify emotions from voice with relatively high accuracy rates. In addition, fairly consistent vocal profiles for specific emotions have been identified. However, important methodological issues remain to be addressed. In this paper, we address the issue of whether there are individual differences in the manner in which particular emotions may be expressed vocally and whether trained speakers’ portrayals of emotion are in some sense superior to untrained speakers’ portrayals. Consistent support was found for differences across speakers in the manner in which they expressed the same emotions. No accompanying relationship was found between differences in expression and accuracy of identification of those expressions. Little evidence for the superiority of trained speakers was found. Implications of these findings for future studies of vocal expressions of emotion, as well as our understanding of emotions in general, are discussed.     

Emotion regulation in depression: Examining the role of cognitive processes

Sustained negative affect is a hallmark feature of depressive episodes. The ability to regulate emotional responses to negative events may therefore play a critical role in our understanding of this debilitating disorder. Individual differences in cognitive processes such as attention, memory, and interpretation may underlie difficulties in emotion regulation and numerous studies have identified cognitive biases and deficits that characterise depressed people. Few studies, however, have explicitly linked these biases to the difficulties in emotion regulation that are associated with depression. In this paper we discuss relations among cognitive processes and emotion regulation and review the depression literature to identify cognitive biases and deficits that may underlie maladaptive responses to negative events and mood states. Our review suggests that difficulties in the disengagement from negative material, memory biases, and deficits in cognitive control are frequently observed in depressive disorders and may be associated with the use of maladaptive emotion regulation strategies, such as rumination. These biases may also be related to difficulties implementing strategies that are effective for non-depressed people, such as recall of mood-incongruent material and reappraisal. Our review also suggests, however, that empirical studies linking cognitive biases and emotion regulation in depression are still largely missing and would present an important goal for future research in this area.     

Reappraisal and expected value modulate risk taking

Decision making is informed by appraisals of appetitive cues and their associated opportunities for rewards. Such appraisals can be modulated by cognitive regulation strategies in order to promote goal-directed choices. Little is known about how cognitive regulation strategies, especially reappraisal, alter risk taking during decision making. To characterise the effect of reappraisal on risk taking, we systematically varied both the goal of regulation and the value of the decision options. Participants engaged in two reappraisal strategies with opposite goals, to increase (“emphasise”) or decrease (“de-emphasise”) the importance of an upcoming decision, during the presentation of cues signalling monetary decisions. The expected value of taking a risk was systematically varied across decisions such that a risky choice could be beneficial or disadvantageous. Reappraisal strategies increased or decreased risk taking in accordance both with regulation goals and expected value information. These results suggest that reappraisal can be used to flexibly alter behaviour associated with appetitive cues while maintaining value information.     

Health anxiety,anxiety sensitivity,and attentional biases for pictorial and linguistic health‐threat cues

The study investigated attentional biases for pictorial and linguistic health‐threat stimuli in high and low health anxious individuals, who were selected from the upper and lower quartile ranges of a normal sample using a screening measure of health anxiety. Attentional bias was assessed using a visual probe task which presented health‐threat and neutral pictures and words at two exposure durations, 500 ms and 1250 ms. The prediction that the high health anxious group would show a greater attentional bias for health‐threat cues than the low health anxious group was not supported despite the groups being well‐differentiated on a general measure of health anxiety, the Illness Attitudes Scale (IAS). Instead, the results indicated that individuals with high levels of anxiety sensitivity showed a significantly greater initial attentional bias for threat pictures compared with those with low anxiety sensitivity, as assessed by the Anxiety Sensitivity Index (ASI).     

Depressive symptoms and cognitive control in a mixed antisaccade task: Specific effects of depressive rumination

Growing empirical evidence suggests that cognitive and affective problems in depression may be a reflection of cognitive control impairments. However, to date, the nature of such impairments is still poorly understood and further investigation of this topic is required to advance current knowledge on the underlying vulnerability factors for depression. Using a mixed antisaccade paradigm, the present study examined if depressive symptoms in general, and more specifically rumination, are related to impairments in cognitive control functions such as inhibition and switching. The results on antisaccade latency and error rates indicated that depressive symptoms in general were not related to impairments in inhibition and switching. However, rumination was associated with impaired inhibition such that high, compared to low, ruminators had slower antisaccade latencies. No group differences were observed on antisaccade error rates. Implications for understanding the underlying vulnerability factors for the development of depressive symptoms are discussed.     

Effects of traumatic stress and perceived stress on everyday cognitive functioning

Stressful or traumatic events have been shown to impair cognitive functioning on laboratory-based tasks due to stress-related intrusive thoughts and avoidance. However, research on the effects of stress on everyday cognitive functioning has been lacking. A sample of 909 undergraduates completed measures of perceived stress, PTSD symptoms, and everyday cognitive failures. The results revealed that both perceived stress and PTSD symptoms uniquely predicted cognitive failures, even after controlling for a number of potentially confounding variables. Additionally, there was a significant interaction. Participants with low scores on both measures of stress reported the fewest occurrences of everyday cognitive failures. In contrast, participants with elevated scores on either measure of stress reported higher levels of cognitive failures. These results suggest that there are unique negative effects of perceived stress and PTSD symptoms on everyday cognitive functioning and sharpen our understanding of the relationship between stress and cognition.     

Depression reduces perceptual sensitivity for positive words and pictures

There is evidence of maladaptive attentional biases for lexical information (e.g., Atchley, Ilardi, & Enloe, 2003; Atchley, Stringer, Mathias, Ilardi, & Minatrea, 2007) and for pictographic stimuli (e.g., Gotlib, Krasnoperova, Yue, & Joormann, 2004) among patients with depression. The current research looks for depressotypic processing biases among depressed out-patients and non-clinical controls, using both verbal and pictorial stimuli. A d′ measure (sensitivity index) was used to examine each participant's perceptual sensitivity threshold. Never-depressed controls evidenced a detection bias for positive picture stimuli, while depressed participants had no such bias. With verbal stimuli, depressed individuals showed specific decrements in the detection of positive person-referent words (WINNER), but not with positive non-person-referent words (SUNSHINE) or with negative words. Never-depressed participants showed no such differences across word types. In the current study, depression is characterised both by an absence of the normal positivistic biases seen in individuals without mood disorders (consistent with McCabe & Gotlib, 1995), and by a specific reduction in sensitivity for person-referent positive information that might be inconsistent with depressotypic self-schemas.     

Evidence for a cognitive control network for goal-directed attention in simple sustained attention

The deterioration of performance over time is characteristic for sustained attention tasks. This so-called “performance decrement” is measured by the increase of reaction time (RT) over time. Some behavioural and neurobiological mechanisms of this phenomenon are not yet fully understood. Behaviourally, we examined the increase of RT over time and the inter-individual differences of this performance decrement. On the neurophysiological level, we investigated the task-relevant brain areas where neural activity was modulated by RT and searched for brain areas involved in good performance (i.e. participants with no or moderate performance decrement) as compared to poor performance (i.e. participants with a steep performance decrement). For this purpose, 20 healthy, young subjects performed a carefully designed task for simple sustained attention, namely a low-demanding version of the Rapid Visual Information Processing task. We employed a rapid event-related functional magnetic resonance imaging (fMRI) design. The behavioural results showed a significant increase of RT over time in the whole group, and also revealed that some participants were not as prone to the performance decrement as others. The latter was statistically significant comparing good versus poor performers. Moreover, high BOLD-responses were linked to longer RTs in a task-relevant bilateral fronto-cingulate-insular-parietal network. Among these regions, good performance was associated with significantly higher RT-BOLD correlations in the pre-supplementary motor area (pre-SMA). We concluded that the task-relevant bilateral fronto-cingulate-insular-parietal network was a cognitive control network responsible for goal-directed attention. The pre-SMA in particular might be associated with the performance decrement insofar that good performers could sustain activity in this brain region in order to monitor performance declines and adjust behavioural output.