Neural mechanisms of affective interference in schizotypy

Negatively valenced stimuli foster cognitive impairment in schizotypy and schizophrenia. To identify relevant brain mechanisms, the authors had 16 positive-schizotypy and 16 control participants perform an emotional Stroop task, judging the ink color of negative and neutral words during functional magnetic resonance imaging (fMRI) of regional brain activity. Schizotypy individuals showed increased right and decreased left activity in dorsolateral prefrontal cortex, indicating a deficit in maintenance of attentional set in the presence of negative emotional distractors. They also showed abnormal activity in ventral limbic areas, including decreased activity in nucleus accumbens and increased activity in hippocampus and amygdala, a circuit involved in the integration of cognitive and affective processes. These results indicate that aspects of emotion-cognition processes and the brain mechanisms that implement them are similar in schizotypy and schizophrenia.     

Neural and behavioral effects of interference resolution in depression and rumination

Individuals diagnosed with major depressive disorder (MDD) often ruminate about their depression and their life situations, impairing their concentration and performance on daily tasks. We examined whether rumination might be due to a deficit in the ability to expel negative information from short-term memory (STM), and fMRI was used to examine the neural structures involved in this ability. MDD and healthy control (HC) participants were tested using a directed-forgetting procedure in a short-term item recognition task. As predicted, MDD participants had more difficulty than did HCs in expelling negative, but not positive, words from STM. Overall, the neural networks involved in directed forgetting were similar for both groups, but the MDDs exhibited more spatial variability in activation in the left inferior frontal gyrus (a region critical for inhibiting irrelevant information), which may contribute to their relative inability to inhibit negative information.     

Backward inhibition as a means of sequential task-set control: evidence for reduction of task competition

Endogenously initiated transitions between tasks are associated with inhibition of the attentional set for the task preceding the transition, as demonstrated by slowed reactions to a task most recently switched away from (U. Mayr & S. W. Keele, 2000). Using an altered methodological approach, the authors found that this backward inhibition counteracts perseverative tendencies when switching to a new task in that it selectively reduces interference exerted by the preceding task set. The reduction of interference was dependent on endogenous preparation for the new task and did not occur for unpredictable task switches or for task switches that were precued without information about the identity of the new task.     

Neural mechanisms of the automatic processing of emotional information from faces and voices

Theoretical accounts suggest an increased and automatic neural processing of emotional, especially threat-related, facial expressions and emotional prosody. In line with this assumption, several functional imaging studies showed activation to threat-related faces and voices in subcortical and cortical brain areas during attentional distraction or unconscious stimulus processing. Furthermore, electrophysiological studies provided evidence for automatic early brain responses to emotional facial expressions and emotional prosody. However, there is increasing evidence that available cognitive resources modulate brain responses to emotional signals from faces and voices, even though conflicting findings may occur depending on contextual factors, specific emotions, sensory modality, and neuroscientific methods used. The current review summarizes these findings and suggests that further studies should combine information from different sensory modalities and neuroscientific methods such as functional neuroimaging and electrophysiology. Furthermore, it is concluded that the variable saliency and relevance of emotional social signals on the one hand and available cognitive resources on the other hand interact in a dynamic manner, making absolute boundaries of the automatic processing of emotional information from faces and voices unlikely.     

Spatiotemporal competition and task-relevance shape the spatial distribution of emotional interference during rapid visual processing: Evidence from gaze-contingent eye-tracking

People’s ability to perceive rapidly presented targets can be disrupted both by voluntary encoding of a preceding target and by spontaneous attention to salient distractors. Distinctions between these sources of interference can be found when people search for a target in multiple rapid streams instead of a single stream: voluntary encoding of a preceding target often elicits subsequent perceptual lapses across the visual field, whereas spontaneous attention to emotionally salient distractors appears to elicit a spatially localized lapse, giving rise to a theoretical account suggesting that emotional distractors and subsequent targets compete spatiotemporally during rapid serial visual processing. We used gaze-contingent eye-tracking to probe the roles of spatiotemporal competition and memory encoding on the spatial distribution of interference caused by emotional distractors, while also ruling out the role of eye-gaze in driving differences in spatial distribution. Spontaneous target perception impairments caused by emotional distractors were localized to the distractor location regardless of where participants fixated. But when emotional distractors were task-relevant, perceptual lapses occurred across both streams while remaining strongest at the distractor location. These results suggest that spatiotemporal competition and memory encoding reflect a dual-route impact of emotional stimuli on target perception during rapid visual processing.     

Examination of emotional Stroop interference in obsessive-compulsive disorder

Previous research has produced conflicting findings on whether or not patients with subclinical or manifest obsessive-compulsive disorder (OCD) share an attentional bias for anxiety-related material. In the present study, 35 OCD patients were compared with 20 healthy controls on their performance in an emotional Stroop paradigm. Nine different stimulus conditions were compiled, including sets for depression-related and anxiety-related words as well as stimuli from two constructs with a potential relevance for the pathogenesis and maintenance of OCD symptomatology: responsibility and conscientiousness. Patients did not show enhanced interference for any of the conditions. Syndrome subtype and severity, avoidance and speed of information processing did not moderate results. The present study concurs with most prior research that OCD patients display no interference effect for general threat words. It deserves further consideration, that emotional interference effects in OCD as seen in other anxiety disorders occur when using idiosyncratic word material with a direct relation to the individual's primary concerns.     

Avoiding interference: adult attachment and emotional processing biases

The present study investigated attachment-related differences in emotional processing biases. Consistent with the proposal that avoidant individuals limit attention to potentially distressing information, attachment avoidance was associated with reductions in emotional Stroop (ES) interference for attachment-related words (e.g., intimate, loss). These biases were strongest among individuals who were currently in a romantic relationship, suggesting that being in a close relationship may activate avoidant defensive strategies. In addition, avoidant attentional biases were attenuated under cognitive load, suggesting that inhibiting attention to attachment-related information requires cognitive effort. Finally, avoidance was unrelated to ES performance for emotional, nonattachment-related words, demonstrating the specificity of these attentional biases. The present findings suggest that avoidant individuals can inhibit attention to potentially threatening information, that this ability requires cognitive effort, and that relationship status may be an important moderator of avoidant defensive strategies. The implications of these strategies for emotional functioning and well-being are discussed.     

Beyond depression: Gender differences in normal adolescents' emotional experiences

Adolescents (N=262) in the fifth, seventh, ninth, and eleventh grades reported the frequency, intensity, and duration of their experiences of 12 emotions and the situations during which they occurred. The first three scales of emotion combined to produce the emotion saliency score. Girls reported higher saliences of surprise, sad, self-hostility, shame, shy, and guilt. Boys reported higher saliency of contempt. Factor analysis of the salient emotions retained the same three factors for both genders: positive emotion, inner-passive, and outer-hostile negative emotions. The loadings for surprise, sad, and anger on each factor suggested within factor gender differences. Most salient emotions were experienced with peers; however, boys experienced both surprise and sadness more often when alone than did girls. There were gender differences in most emotion categories on the events associated with salient emotions. Boys found activities and achievement, and girls found affiliation, to be emotionally salient. These data suggest that gender differences in emotion are pervasive rather than confined to depressive emotion and include differences in the organizational properties of emotion.This study was based upon data collected for the first author's dissertation under the direction of the second author. Preliminary analyses were presented at Eastern Psychological Association, Crystal City, Maryland, 1987.     

Neural mechanisms of interference control underlie the relationship between fluid intelligence and working memory span

Fluid intelligence (gF) and working memory (WM) span predict success in demanding cognitive situations. Recent studies show that much of the variance in gF and WM span is shared, suggesting common neural mechanisms. This study provides a direct investigation of the degree to which shared variance in gF and WM span can be explained by neural mechanisms of interference control. The authors measured performance and functional magnetic resonance imaging activity in 102 participants during the n-back WM task, focusing on the selective activation effects associated with high-interference lure trials. Brain activity on these trials was correlated with gF, WM span, and task performance in core brain regions linked to WM and executive control, including bilateral dorsolateral prefrontal cortex (middle frontal gyrus; BA9) and parietal cortex (inferior parietal cortex; BA 40/7). Interference-related performance and interference-related activity accounted for a significant proportion of the shared variance in gF and WM span. Path analyses indicate that interference control activity may affect gF through a common set of processes that also influence WM span. These results suggest that individual differences in interference-control mechanisms are important for understanding the relationship between gF and WM span.     

Ambivalence over emotional expression in major depression

High ambivalence over the expression of emotions (AEE) has consistently been associated with high levels of depression in previous research. However, there is a lack of studies examining this construct and its associations in a clinical sample of patients with major depressive disorder (MDD). Therefore, the present study compared 76 MDD with 77 non-depressed controls (NC) regarding AEE. As expected, MDD reported greater AEE as compared to ND. Furthermore, levels of AEE and levels of depression were positively correlated in the MDD group. These findings extend previous work and underline the importance of AEE as a central construct in depression. Targeting AEE in treatments of depression may help to modify maladaptive interpersonal patterns of emotional expression.     

How brains beware: neural mechanisms of emotional attention

Emotional processes not only serve to record the value of sensory events, but also to elicit adaptive responses and modify perception. Recent research using functional brain imaging in human subjects has begun to reveal neural substrates by which sensory processing and attention can be modulated by the affective significance of stimuli. The amygdala plays a crucial role in providing both direct and indirect top-down signals on sensory pathways, which can influence the representation of emotional events, especially when related to threat. These modulatory effects implement specialized mechanisms of 'emotional attention' that might supplement but also compete with other sources of top-down control on perception. This work should help to elucidate the neural processes and temporal dynamics governing the integration of cognitive and affective influences in attention and behaviour.     

The lateralized emotional stroop task: left visual field interference in women

In a visual hemifield emotional Stroop task, 54 women were asked to name the color of laterally flashed emotional and neutral words while ignoring their semantic content. Vocal reaction times for color naming were recorded. The participants exhibited significant emotional interference effects in the left visual field, which tended to be larger for negative words than for positive words. Participants with higher trait anxiety scores exhibited larger interference for positive words in the left relative to the right visual field. The outcome indicates that, in women, emotional Stroop interference arises in the right rather than in the left hemisphere, with a larger impact of negative than of positive words, and with trait anxiety modulating the lateralized interference for positive words.     

Neural correlates of emotional intelligence in adolescent children

The somatic marker hypothesis posits a key role for the ventromedial prefrontal cortex, amygdala, and insula in the ability to utilize emotions to guide decision making and behavior. However, the relationship between activity in these brain regions and emotional intelligence (EQ) during adolescence, a time of particular importance for emotional and social development, has not been studied. Using functional magnetic resonance imaging (fMRI), we correlated scores from the Bar-On Emotional Quotient Inventory, Youth Version (EQ-i:YV) with brain activity during perception of fearful faces in 16 healthy children and adolescents. Consistent with the neural efficiency hypothesis, higher EQ correlated negatively with activity in the somatic marker circuitry and other paralimbic regions. Positive correlations were observed between EQ and activity in the cerebellum and visual association cortex. The findings suggest that the construct of self-reported EQ in adolescents is inversely related to the efficiency of neural processing within the somatic marker circuitry during emotional provocation.     

Neural correlates of rumination in depression

Rumination, or recursive self-focused thinking, has important implications for understanding the development and maintenance of depressive episodes. Rumination is associated with the worsening of negative mood states, greater affective responding to negative material, and increased access to negative memories. The present study was designed to use fMRI to examine neural aspects of rumination in depressed and healthy control individuals. We used a rumination induction task to assess differences in patterns of neural activation during ruminative self-focus as compared with a concrete distraction condition and with a novel abstract distraction condition in 14 participants who were diagnosed with major depressive disorder and 14 healthy control participants. Depressed participants exhibited increased activation in the orbitofrontal cortex, subgenual anterior cingulate, and dorsolateral prefrontal cortex as compared with healthy controls during rumination versus concrete distraction. Neural activity during rumination versus abstract distraction was greater for depressed than for control participants in the amygdala, rostral anterior cingulate/medial prefrontal cortex, dorsolateral prefrontal cortex, posterior cingulate, and parahippocampus. These findings indicate that ruminative self-focus is associated with enhanced recruitment of limbic and medial and dorsolateral prefrontal regions in depression. Supplemental materials for this article may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.     

Neural mechanisms of timing

A crucial step in timing research is to isolate clock components from other sources of temporal variability. Significant progress has been made both behaviorally and neurologically, using elaborate experimental designs that separate timing mechanisms from motoric sensory and mnemonic processes. Marked similarities between the temporal characteristics of the clock in perception and production tasks implicate a common timing system. Similar conclusions can be reached from clinical studies, indeed individuals with neocerebellar damage are impaired at discriminating and reproducing short intervals. However, other patient populations, especially those with disorders affecting the basal ganglia, also exhibit deficits in timing tasks. It therefore appears that temporal computation may be distributed throughout the brain with specific roles for different neural structures.     

Response competition: A major source of interference in a tactile identification task

Two experiments investigated the ability of subjects to identify a moving, tactile stimulus. In both experiments, the subjects were presented with a target to their left index fingerpad and a nontarget (also moving) to their left middle fingerpad. Subjects were instructed to attend only to the target location and to respond “1” if the stimulus moved either to the left or up the finger, and to respond “2” if the stimulus moved either right or down the finger. The results showed that accuracy was better and reaction times were faster when the target and nontarget moved in the same direction than when they moved in different directions. When the target and nontarget moved in different directions, accuracy was significantly better and reaction times were significantly faster when the two stimuli had the same assigned response than when they had different responses. The results provide support for the conclusion that movement information is processed across adjacent fingers to the level of incipient response activation, even when subjects attempt to focus their attention on one location on the skin.