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Ksenija Marinkovic - One of the best experts on this subject based on the ideXlab platform.
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when the brain changes its mind oscillatory dynamics of conflict processing and response switching in a Flanker Task during alcohol challenge
PLOS ONE, 2018Co-Authors: Lauren E Beaton, Ksenija Marinkovic, Sheeva AzmaAbstract:Despite the subjective experience of being in full and deliberate control of our actions, our daily routines rely on a continuous and interactive engagement of sensory evaluation and response preparation streams. They unfold automatically and unconsciously and are seamlessly integrated with cognitive control which is mobilized by stimuli that evoke ambiguity or response conflict. Methods with high spatio-temporal sensitivity are needed to provide insight into the interplay between automatic and controlled processing. This study used anatomically-constrained MEG to examine the underlying neural dynamics in a Flanker Task that manipulated S-R incongruity at the stimulus (SI) and response levels (RI). Though irrelevant, Flankers evoked automatic preparation of motor plans which had to be suppressed and reversed following the target presentation on RI trials. Event-related source power estimates in beta (15–25 Hz) frequency band in the sensorimotor cortex tracked motor preparation and response in real time and revealed switching from the incorrectly-primed to the correctly-responding hemisphere. In contrast, theta oscillations (4–7 Hz) were sensitive to the levels of incongruity as the medial and ventrolateral frontal cortices were especially activated by response conflict. These two areas are key to cognitive control and their integrated contributions to response inhibition and switching were revealed by phase-locked co-oscillations. These processes were pharmacologically manipulated with a moderate alcohol beverage or a placebo administered to healthy social drinkers. Alcohol selectively decreased accuracy to response conflict. It strongly attenuated theta oscillations during decision making and partly re-sculpted relative contributions of the frontal network without affecting the motor switching process subserved by beta band. Our results indicate that motor preparation is initiated automatically even when counterproductive but that it is monitored and regulated by the prefrontal cognitive control processes under conflict. They further confirm that the regulative top-down functions are particularly vulnerable to alcohol intoxication.
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effects of alcohol intoxication on response conflict in a Flanker Task
Journal of Addiction Research and Therapy, 2013Co-Authors: Ksenija Marinkovic, Elizabeth Rickenbacher, Sheeva AzmaAbstract:Events evoke seamlessly integrated stimulus evaluation and response preparation processing streams, guided by regulative functions that change behavior flexibly in accord with the internal goals and contextual demands. The neural basis of the effects of alcohol intoxication on these processing streams is poorly understood, despite the evidence of alcohol’s deleterious effects on both attention and motor control. In an attempt to separate and examine relative susceptibility of these two dimensions, we employed a color version of the Eriksen Flanker Task that manipulated compatibility at the stimulus- and response-processing levels. Functional magnetic resonance imaging (fMRI) was performed in healthy social drinkers as they participated in both alcohol (0.6 g/kg ethanol for men, 0.55 g/kg for women) and placebo conditions in a counterbalanced design. Alcohol increased reaction times to response-level incongruity and decreased accuracy overall. Relative to the no-conflict condition, the observed brain activity was predominantly evoked by response-related conflict in medial prefrontal and lateral prefrontal cortices under placebo, in agreement with extensive evidence of their role in conflict processing. Activity evoked by response incongruity in the medial frontal cortex and insula was insignificant under alcohol, indicating its interference with response inhibition and preparation. Conversely, activity in ventrolateral prefrontal and premotor areas was relatively greater under alcohol than placebo, suggesting their compensatory engagement. This finding is consistent with the compensatory prefrontal activity increase found in studies with chronic alcoholic individuals, indicating functional reorganization with a goal of optimizing response strategy. These results delineate functional differences and selective susceptibility of a prefrontal network subserving response-level conflict processing. Our findings are incompatible with notions that moderate alcohol primarily affects attentional or stimulus-related processing and argue instead that its primary influence is on response inhibition, selection, and execution, with ramifications for the models of behavioral self-control and the inability to refrain from drinking.
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neural dynamics of alcohol effects on cognitive control eriksen Flanker Task
2010Co-Authors: Ksenija Marinkovic, Sheeva AzmaAbstract:Alcohol intoxication interferes with the capacity to inhibit maladaptive reactions and execute correct responses. In order to investigate alcohol’s effects on cognitive control, a group of healthy subjects (N = 20, 9 women) participated in both alcohol (0.6 g/kg ethanol) and placebo conditions in a color version of the Eriksen Flanker Task. MEG signal was recorded from the whole head and the noise-normalized minimum norm inverse estimates were anatomically constrained to each person’s cortical surface reconstructed from MRI. Alcohol increased error rates in the response-conflict condition. Under placebo, the anterior cingulate (AC) was sensitive to the level of conflict, supporting an optimized response strategy. Alcohol blunted this conflict-induced differentiation in AC activity. This suggests that alcohol impairs cognitive control by affecting top-down regulation of response preparation and execution. Alcohol-induced impairment of executive functions may result in poor self-control, expressed as socially-inappropriate behavior and an inability to refrain from drinking.
Denise A Hien - One of the best experts on this subject based on the ideXlab platform.
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neural and behavioral correlates of attentional inhibition training and perceptual discrimination training in a visual Flanker Task
Frontiers in Human Neuroscience, 2018Co-Authors: Robert D Melara, Shalini Singh, Denise A HienAbstract:ABSTRACT Two groups of healthy young adults were exposed to three weeks of cognitive training in a modified version of the visual Flanker Task, one group trained to discriminate the target (discrimination training) and the other group to ignore the Flankers (inhibition training). Inhibition training, but not discrimination training, led to significant reductions in both Garner interference, indicating improved selective attention, and in Stroop interference, indicating more efficient resolution of stimulus conflict. The behavioral gains from training were greatest in participants who showed the poorest selective attention at pretest. Electrophysiological recordings revealed that inhibition training increased the magnitude of Rejection Positivity (RP) to incongruent distractors, an ERP component associated with inhibitory control. Source modeling of RP uncovered a dipole in the medial frontal gyrus for those participants receiving inhibition training, but in the cingulate gyrus for those participants receiving discrimination training. Results suggest that inhibitory control is plastic; inhibition training improves conflict resolution, particularly in individuals with poor attention skills.
Ronald Hubner - One of the best experts on this subject based on the ideXlab platform.
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conflict resolution in the eriksen Flanker Task similarities and differences to the simon Task
PLOS ONE, 2019Co-Authors: Ronald Hubner, Lisa TobelAbstract:: In the Eriksen Flanker Task as well as in the Simon Task irrelevant activation produces a response conflict that has to be resolved by mental control mechanisms. Despite these similarities, however, the Tasks differ with respect to their delta functions, which express how the congruency effects develop with response time. The slope of the delta function is mostly positive for the Flanker Task, but negative for the Simon Task. Much effort has been spent to explain this difference and to investigate whether it results from Task-specific control. A prominent account is that the temporal overlap between irrelevant and relevant response activation is larger in the Flanker Task than in the Simon Task. To test this hypothesis, we increased the temporal distance in a Flanker Task by presenting the Flankers ahead of the target. This not only produced negatively sloped delta functions but also caused reversed congruency effects. We also conducted a Simon-Task experiment in which we varied the proportion of congruent stimuli. As a result, the delta function was negatively sloped only if the proportion was low. These results demonstrate that a long temporal distance is necessary but not sufficient for observing negatively sloped delta functions. Finally, we modeled the data with drift-diffusion models. Together, our results show that differently sloped delta functions can be produced with both Tasks. They further indicate that activation suppression is an important control mechanism that can be adapted rather flexibly to the control demands.
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does attentional selectivity in the Flanker Task improve discretely or gradually
Frontiers in Psychology, 2012Co-Authors: Ronald Hubner, Lisa TobelAbstract:An important question is whether attentional selectivity improves discretely or continuously during stimulus processing. In a recent study, Hubner, et al. (2010) found that the discrete DSTP model accounted better for Flanker-Task data than various continuous improvement models. However, in a subsequent study, White, et al. (2011) introduced the continuous SSP model and showed that it was superior to the DSTP model. From this result they concluded that attentional selectivity improves continuously rather than discretely. Because different stimuli and procedures were used in these two studies, though, we questioned that the superiority of the SSP model holds generally. Therefore, we fit the SSP model to Hubner et al.’s data and found that the DSTP model was again superior. A series of four experiments revealed that model superiority depends on the response-stimulus interval (RSI). Together, our results demonstrate that methodological details can be crucial for model selection, and that further comparisons between the models are needed before it can be decided whether attentional selectivity improves continuously or discretely.
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monetary reward increases attentional effort in the Flanker Task
Psychonomic Bulletin & Review, 2010Co-Authors: Ronald Hubner, Jan SchlosserAbstract:An important question is whether monetary reward can increase attentional effort in order to improve performance. Up to now, evidence for a positive answer is weak. Therefore, in the present study, the Flanker Task was used to examine this question further. Participants had to respond sooner than a certain deadline in a Flanker Task. One group of participants received a performance-contingent monetary reward, whereas the other group earned a fixed amount of money. As a result, monetary reward significantly improved performance in comparison with the control group. The analysis of speed-accuracy trade-off functions revealed that monetary reward increased attentional effort, leading to an enhanced quality of stimulus coding. Little evidence was found that reward also improved selective spatial attention.
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on the fly adaptation of selectivity in the Flanker Task
Psychonomic Bulletin & Review, 2008Co-Authors: Carola Lehle, Ronald HubnerAbstract:The processing selectivity in the Flanker Task has been shown to depend on the ratio of congruent trials to incongruent trials in a Task (Gratton, Coles, & Donchin, 1992). If congruent trials are more frequent than incongruent ones, the Flankers are more attended and, consequently, the Flanker congruency effect is increased. Recent results suggest that participants can even allocate attention on the fly to the Flankers—that is, in a highly flexible way after stimulus onset—depending on the frequency of incongruent trials on a certain stimulus location. Because location plays a unique role in stimulus selection, we investigated in two experiments whether selectivity can also be adjusted on the fly depending on stimulus color. The results demonstrate that color can be used for such an adjustment, but only if the association between color and frequency has been previously learned under blocked conditions
Peter Kuppens - One of the best experts on this subject based on the ideXlab platform.
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a diffusion model account of the relationship between the emotional Flanker Task and rumination and depression
Emotion, 2013Co-Authors: Joachim Vandekerckhove, Peter KuppensAbstract:Although there exists a consensus that depression is characterized by preferential processing of negative information, empirical findings to support the association between depression and rumination on the one hand and selective attention for negative stimuli on the other hand have been elusive. We argue that one of the reasons for the inconsistent findings may be the use of aggregate measures of response times and accuracies to measure attentional bias. Diffusion model analysis allows to partial out the information processing component from other components that comprise the decision-making process. In this study, we applied a diffusion model to an emotional Flanker Task. Results revealed that when focusing on a negative target, both rumination and depression were associated with facilitated processing due to negative distracters, whereas only rumination was associated with less interference by positive distracters. After controlling for depression scores, rumination still predicted attentional bias for negative information, but depression scores were no longer predictive after controlling for rumination. Consistent with elusive findings in the literature, we did not find this pattern of results when using accuracy scores or mean response times. Our results suggest that rumination accounts for the attentional bias for negative information found in depression. © 2013 American Psychological Association.
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a diffusion model account of the relationship between the emotional Flanker Task and rumination and depression
Emotion, 2013Co-Authors: Joachim Vandekerckhove, Peter KuppensAbstract:Although there exists a consensus that depression is characterized by preferential processing of negative information, empirical findings to support the association between depression and rumination on the one hand and selective attention for negative stimuli on the other hand have been elusive. We argue that one of the reasons for the inconsistent findings may be the use of aggregate measures of response times and accuracies to measure attentional bias. Diffusion model analysis allows to partial out the information processing component from other components that comprise the decision-making process. In this study, we applied a diffusion model to an emotional Flanker Task. Results revealed that when focusing on a negative target, both rumination and depression were associated with facilitated processing due to negative distracters, whereas only rumination was associated with less interference by positive distracters. After controlling for depression scores, rumination still predicted attentional bias for negative information, but depression scores were no longer predictive after controlling for rumination. Consistent with elusive findings in the literature, we did not find this pattern of results when using accuracy scores or mean response times. Our results suggest that rumination accounts for the attentional bias for negative information found in depression.
Koviljka Barisnikov - One of the best experts on this subject based on the ideXlab platform.
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neural functional correlates of the impact of socio emotional stimuli on performances on a Flanker Task in children aged 9 11 years
Neuropsychologia, 2018Co-Authors: Morgane Reveillon, Francois Lazeyras, Laurens Van Calster, Yann Cojan, David Sander, Petra Susan Huppi, Koviljka BarisnikovAbstract:Abstract Immature cognition is susceptible to interference from competing information, and particularly in affectively charged situations. Several studies have reported activation in the anterior cingulate cortex, prefrontal cortex and amygdala associated with emotional conflict processing in adults but literature is lacking regarding children. Moreover, studies in children and adolescents still disagree regarding the functional activation of amygdala related to facial stimuli. In the purpose of investigating both the effect of socio-emotional stimuli and its interaction with interference control, we designed a Flanker Task associated with an event-related fMRI paradigm in 30 healthy children ages 9–11. In addition to happy, angry and neutral faces, we presented scrambled stimuli to examine a potential effect of faces. Regarding both brain and behavior results, no effect of emotional valence was observed. However, both results evidenced an emotional effect of faces compared with scrambled stimuli. This was expressed by faster RTs associated with increased amygdala activity and activation of the ventral ACC, in congruent trials only. When scrambled were inversely compared to faces, increased activity was observed within the lateral prefrontal cortex. Regarding the amygdala, the results suggest that in late school age children, activity in the amygdala seemed to underlie the socio-emotional effect induced by faces but not the emotional conflict. Studying brain regions involved in emotion regulation is important to further understand neurodevelopmental disorders and psychopathologies, particularly in late childhood and adolescence.
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Neural functional correlates of the impact of socio-emotional stimuli on performances on a Flanker Task in children aged 9–11 years
Neuropsychologia, 2018Co-Authors: Morgane Reveillon, Francois Lazeyras, Laurens Van Calster, Yann Cojan, David Sander, Petra Susan Huppi, Koviljka BarisnikovAbstract:Abstract Immature cognition is susceptible to interference from competing information, and particularly in affectively charged situations. Several studies have reported activation in the anterior cingulate cortex, prefrontal cortex and amygdala associated with emotional conflict processing in adults but literature is lacking regarding children. Moreover, studies in children and adolescents still disagree regarding the functional activation of amygdala related to facial stimuli. In the purpose of investigating both the effect of socio-emotional stimuli and its interaction with interference control, we designed a Flanker Task associated with an event-related fMRI paradigm in 30 healthy children ages 9–11. In addition to happy, angry and neutral faces, we presented scrambled stimuli to examine a potential effect of faces. Regarding both brain and behavior results, no effect of emotional valence was observed. However, both results evidenced an emotional effect of faces compared with scrambled stimuli. This was expressed by faster RTs associated with increased amygdala activity and activation of the ventral ACC, in congruent trials only. When scrambled were inversely compared to faces, increased activity was observed within the lateral prefrontal cortex. Regarding the amygdala, the results suggest that in late school age children, activity in the amygdala seemed to underlie the socio-emotional effect induced by faces but not the emotional conflict. Studying brain regions involved in emotion regulation is important to further understand neurodevelopmental disorders and psychopathologies, particularly in late childhood and adolescence.
