Barbara Drueke

When response inhibition is followed by response reengagement: An event-related fMRI study

In the course of daily living, changing environmental demands often make our actions, once initiated, unnecessary or even inappropriate. Under such circumstances, the ability to inhibit the obsolete action and to update behavior can be of vital importance. Previous lesion and neuroimaging studies have shown that the right prefrontal cortex and the basal ganglia seem to play an important role in the inhibition of already initiated motor responses. The present study was designed to investigate whether the neural activity of inhibitory motor control was altered if the inhibition process was succeeded by an additional process, namely the reengagement into an alternative action. Therefore, cerebral blood oxygenation during performance of a stop‐change paradigm was registered in 15 male participants using event‐related functional magnetic resonance imaging. Data analysis showed, that during successful and failed stopping and changing (response inhibition and subsequent response reengagement) of initiated motor responses a very similar network was activated including primarily the right inferior frontal cortex (IFC). Besides, stopping‐related activation in right IFC was significantly greater for fast inhibitors than for slow ones. Results of the present study thus further underline the important role of right IFC in response inhibition and suggest that the inhibition process functions similarly regardless whether changing task demands require the complete suppression of an already initiated motor response or its suppression and a subsequent response reengagement into an alternative action. Hum Brain Mapp, 2010.

Stop or stop-change — Does it make any difference for the inhibition process?

In the course of daily living altering environmental conditions or changing internal states often cause us to abandon obsolete planned or initiated actions and force us to update our behavior. The stop-change paradigm, an extension of the very popular stop-signal paradigm, allows the investigation of response inhibition and response re-engagement in a laboratory setting. This is very important as everyday life rarely calls for the complete suppression of actions without subsequent behavioral adjustment. The present review first gives a short overview on stop-signal inhibition and its behavioral and neural models before summarizing the findings in the stop-change domain. In doing so, this review shall contribute to a better understanding of the functional and neural architecture of response inhibition and re-engagement. Moreover, the question is raised whether the same or different inhibition process(es) are involved in stop-signal- and stop-change inhibition.

Serotonergic modulation of response inhibition and re‐engagement? Results of a study in healthy human volunteers

Cognitive functions dependent on the prefrontal cortex, such as the ability to suppress behavior (response inhibition) and initiate a new one (response re‐engagement) is important in the activities of daily life. Central serotonin (5‐HT) function is thought to be a critical component of these cognitive functions. In recent studies, 5‐HT failed to affect stop‐signal reaction time (SSRT), a fundamental process in behavioral inhibition. We were interested if response inhibition and re‐engagement are influenced through central 5‐HT activity as mediated via the 5‐HT transporter.

The role of 5-HT in response inhibition and re-engagement

In animal and human research, the neurotransmitter serotonin (5-HT) has been implicated in inhibitory control. Using functional magnetic resonance imaging (fMRI), the present study investigated the acute effects of pharmacological modulation of the serotonergic system on brain activation during response inhibition and re-engagement in healthy human volunteers. In a randomized double-blind placebo-controlled cross-over design 14 men received either a single oral dose of the selective serotonin reuptake inhibitor (SSRI) escitalopram (10mg) or a placebo. At the time of the expected plasma peak concentration, participants performed a stop-change task during fMRI. Escitalopram did not affect behavioural performance, since the main effect did not reveal significant differences between reaction times of go-, stop- or change-trials. During successful response inhibition, escitalopram, however, was associated with enhanced brain activation in right prefrontal cortex, right supplementary/pre-motor and bilateral cingulate cortex, and subcortical regions. During inhibition failures, escitalopram also modulated a broad network of brain regions, including anterior cingulate, right parietal cortex, right orbitofrontal cortex, and areas in right temporal cortex and subcortical regions. During response re-engagement escitalopram increased brain activation in right inferior frontal gyrus and precuneus as well as in left middle temporal gyrus. The results implicate the involvement of 5-HT in neural regulation of response inhibition and re-engagement. This study also provides evidence that 5-HT affects both action restraint and action cancellation through modulation of activation of brain areas. The results support the view for a fronto-striatal circuitry for response inhibition in conjunction with serotonin.

Can executive control be influenced by performance feedback? Two experimental studies with younger and older adults

Executive control describes a wide range of cognitive processes which are critical for the goal-directed regulation of stimulus processing and action regulation. Previous studies have shown that executive control performance declines with age but yet, it is still not clear whether different internal and external factors—as performance feedback and age—influence these cognitive processes and how they might interact with each other. Therefore, we investigated feedback effects in the flanker task in young as well as in older adults in two experiments. Performance feedback significantly improved executive performance in younger adults at the expense of errors. In older adults, feedback also led to higher error rates, but had no significant effect on executive performance which might be due to stronger interference. Results indicate that executive functions can be positively influenced by performance feedback in younger adults, but not necessarily in older adults.

Measuring decentering in self-reports: Psychometric properties of the Experiences Questionnaire in a German sample

Abstract Decentering is described as referring to ones current mental experiences from an objective perspective. This study presents a psychometric evaluation of a German version of the Experiences Questionnaire (EQ-D), a self-report instrument designed to measure decentering. Confirmatory factor analysis on a sample of 506 university students indicates acceptable-to-good model fit (χ 2=58.3; TLI=.92; CFI=.95; RMSEA=.067) for a second-order factor Overall Decentering comprising the two first-order factors Accepting Self-Perception and Distanced Perspective. Preliminary evidence for the validity of the EQ-D was demonstrated via negative correlations with measures of depression and depressive rumination. The present results stress the multidimensional nature of decentering and provide important suggestions for future research on how to investigate and operationalize the decentering construct.

Does cognitive behavior therapy alter emotion regulation in inpatients with a depressive disorder

Introduction Emotion regulation plays an important role in the development and treatment of depression. The present study investigated whether the emotion regulation strategies, expressive suppression (ES) and cognitive reappraisal (CR) change in the course of cognitive behavior therapy (CBT) of depressive inpatients. Furthermore, it also examined whether changes in CR and ES correlated with positive treatment outcomes. Methods Forty-four inpatients from a psychotherapeutic hospital who suffered from a depressive disorder (mean age =36.4 years, standard deviation =13.4 years; 63.6% female) filled in the Emotion Regulation Questionnaire and the Beck Depression Inventory at admission and discharge. To detect changes in emotion regulation, and depression across treatment, data were analyzed using multivariate analyses of variance (MANOVA) for repeated measures, effect sizes, and Spearman correlations. A P-value of ≤0.05 was considered statistically significant. Results Depression severity (F[1]=10.42, P=0.003; η2=0.22) and CR (F[1]=4.71, P=0.04; η2=0.11) changed significantly across CBT treatment. ES remained virtually stable. Post-treatment scores of CR were also positively correlated with reduction in depressive symptoms across treatment (ρ=0.30, P=0.05). Conclusion The results suggest that CBT affects emotion regulation in depressive inpatients only for CR and that higher post-treatment scores in CR were related to greater reduction in depressive symptoms across treatment.

Neural correlates of positive and negative performance feedback in younger and older adults

BackgroundRecent studies with younger adults have shown that performance feedback can serve as a reward, and it elicits reward-related brain activations. This study investigated whether performance feedback is processed similarly in younger and older adults and whether there are differential aging effects for positive and negative performance feedback.MethodsWe used event-related fMRI in a choice reaction-time task and provided performance feedback after each trial.ResultsAlthough younger and older adults differed in task-related activation, they showed comparable reward-related activation. Positive performance feedback elicited the strongest striatal and amygdala activation, which was reflected behaviorally in slightly faster reaction times.ConclusionsThese results suggest that performance feedback serves as a reward in both younger and older adults.

Metacognitive monitoring of attention performance and its influencing factors

Metacognitive monitoring is a central element of metacognitive processing exerting widespread influences on information processing. Albeit being subject to numerous empirical investigations referring to memory performance, there is little research investigating metacognitive monitoring in other cognitive domains. The present study investigated in 45 healthy students whether factors that are known to influence monitoring of memory performance, i.e. task difficulty, time of assessment, and practice, also exhibit a significant impact on monitoring of attention performance. A multivariate analysis of variance with three within-subject repeated measures factors on two dependent variables (monitoring of (a) time, and (b) errors in an attention task) was conducted. Results showed that monitoring ability significantly decreased with increasing task difficulty, was significantly better for post than for pre-assessment, and significantly increased with practice. Therefore, results suggest that the examined factors influenced monitoring of attention performance equivalent to the influence of these factors found in metamemory research.

Exploring the relationship of decentering to health related concepts and cognitive and metacognitive processes in a student sample

BackgroundDecentering, a central change strategy of Mindfulness-Based Cognitive Therapy, is a process of stepping outside of one’s own mental events leading to an objective and non-judging stance towards the self. The study aimed at investigating associated mechanisms of decentering.MethodThe present study investigated the relation of decentering, operationalized by means of the German Version of the Experiences Questionnaire, to severity of depressive symptoms, assessed by the adaptive Rasch-based depression screening, and self-focussed attention, assessed by the Questionnaire of Dysfunctional and Functional Self-Consciousness. Furthermore, the relationship between decentering and a) the ability to shift and allocate attention by means of the Stroop test, and b) metacognitive monitoring, i.e. the absolute difference between judged and real task performance, was investigated. These relationships were examined in 55 healthy students using Pearson’s correlations.ResultsIn line with our assumptions, higher decentering scores were significantly associated with lower scores on severity of depressive symptoms, with higher functional- and lower dysfunctional self-focussed attention. Contrary to our expectations, results neither indicated a relationship between decentering and attention ability, nor between decentering and metacognitive monitoring.ConclusionsThe present results suggest that decentering is associated with concepts of mental health (i.e. less severity of depressive symptoms and higher functional self-focussed attention). Overall, the concept decentering seems to be mainly composed of self-focussed aspects when investigated in a healthy sample without intervention. Further investigations of associated concepts of decentering should consider aspects of self-relevance and emotional valence.