Biomedical subjects

Vincent van Veen

Publications and source records attributed to Vincent van Veen.

4 recordsLinked to original sources

PubMed2005

Separating semantic conflict and response conflict in the Stroop task: a functional MRI study.

Attentive behavior requires the ability to perform in the face of distraction. Distracting information can cause conflict at any level along the information processing stream. However, it is not yet known whether the brain has distinct subsystems dedicated to detecting and resolving these different forms of distraction. Although previous studies have localized brain activity during semantic and response conflict, no prior study has specifically determined whether these activations occur in distinct or overlapping regions. We used a modified version of the Stroop color-word task, by which we were able to separate semantic from response conflict. Behavioral data indicate that these two kinds of conflict both contribute to the overall Stroop interference effect, while fMRI data indicate that they elicit non-overlapping activation in anterior cingulate, prefrontal, and parietal brain regions. These results suggest that the brain has distinct but parallel attentional mechanisms for resolving these different forms of cognitive interference.

Adult↗

PubMed2004

Errors without conflict: implications for performance monitoring theories of anterior cingulate cortex.

Recent theories of the neural basis of performance monitoring have emphasized a central role for the anterior cingulate cortex (ACC). Replicating an earlier event-related potential (ERP) study, which showed an error feedback negativity that was modeled as having an ACC generator, we used event-related fMRI to investigate whether the ACC would differentiate between correct and incorrect feedback stimuli in a time estimation task. The design controlled for response conflict and frequency and expectancy effects. Although participants in the current study adjusted their performance following error feedback, we did not observe error feedback-evoked ACC activity. In contrast, we did observe ACC activity while the same subjects performed the Stroop task, in which an area of the ACC activated during both conflict and error trials. These findings are inconsistent with previous dipole models of the error feedback negativity, and suggest the ACC may not be involved in the generation of this ERP component. These results question involvement of the ACC in the detection of errors per se when controlling for conflict.

Adult↗

PubMed2002

Neural mechanisms of planning: a computational analysis using event-related fMRI.

To investigate the neural mechanisms of planning, we used a novel adaptation of the Tower of Hanoi (TOH) task and event-related functional MRI. Participants were trained in applying a specific strategy to an isomorph of the five-disk TOH task. After training, participants solved novel problems during event-related functional MRI. A computational cognitive model of the task was used to generate a reference time series representing the expected blood oxygen level-dependent response in brain areas involved in the manipulation and planning of goals. This time series was used as one term within a general linear modeling framework to identify brain areas in which the time course of activity varied as a function of goal-processing events. Two distinct time courses of activation were identified, one in which activation varied parametrically with goal-processing operations, and the other in which activation became pronounced only during goal-processing intensive trials. Regions showing the parametric relationship comprised a frontoparietal system and include right dorsolateral prefrontal cortex [Brodmann's area (BA 9)], bilateral parietal (BA 40/7), and bilateral premotor (BA 6) areas. Regions preferentially engaged only during goal-intensive processing include left inferior frontal gyrus (BA 44). The implications of these results for the current model, as well as for our understanding of the neural mechanisms of planning and functional specialization of the prefrontal cortex, are discussed.

Adult↗

PubMed2002

The anterior cingulate as a conflict monitor: fMRI and ERP studies.

We propose that the anterior cingulate cortex (ACC) contributes to cognition by detecting the presence of conflict during information processing, and to alert systems involved in top-down control to resolve this conflict. Here, we review several functional magnetic resonance imaging (fMRI) and event-related potential (ERP) studies that have used simple response interference tasks, and propose that ACC activity is activated prior to the response during correct conflict trials and reflected in the frontocentral N2, and immediately following error trials and reflected in the error-related negativity (ERN). Furthermore, we suggest that certain disturbances in cognition and behavior in common mental disorders such as schizophrenia and obsessive-compulsive disorder (OCD) can be understood as resulting from alteration in performance monitoring functions associated with this region of the brain.

Animals↗