Biomedical subjects

Kristine M Knutson

Publications and source records attributed to Kristine M Knutson.

3 recordsLinked to original sources

PubMed2005

Representation of attitudinal knowledge: role of prefrontal cortex, amygdala and parahippocampal gyrus.

It has been proposed that behavior is influenced by representations of different types of knowledge: action representations, event knowledge, attitudes and stereotypes. Attitudes (representations of a concept or object and its emotional evaluation) allow us to respond quickly to a given stimulus. In this study, we explored the representation and inhibition of attitudes. We show that right dorsolateral prefrontal cortex mediates negative attitudes whereas left ventrolateral prefrontal cortex mediates positive attitudes. Parahippocampal regions and amygdala mediate evaluative processing. Furthermore, anxiety modulates right dorsolateral prefrontal activation during negative attitude processing. Inhibition of negative attitudes activates left orbitofrontal cortex: a region that when damaged is associated with socially inappropriate behavior in patients. Inhibition of positive attitudes activates a brain system involving right inferior frontal gyrus and bilateral anterior cingulate. Thus, we show that there are dissociable networks for the representation and inhibition of attitudes.

Adult↗

PubMed2004

Psychological structure and neural correlates of event knowledge.

Humans are capable of storing and retrieving sequences of complex structured events. Here we report a study in which we establish the psychological structure of event knowledge and then use parametric event-related functional magnetic resonance imaging to identify its neural correlates. We demonstrate that event knowledge is organized along dissociable dimensions that are reflected in distinctive patterns of neural activation: social valence (amygdala and right orbitofrontal cortex), experience (medial prefrontal cortex) and engagement (left orbitofrontal cortex). Our study affirms the importance and uniqueness of the human prefrontal cortex in representing event knowledge.

Adaptation, Psychological↗

PubMed2004

Brain activation in processing temporal sequence: an fMRI study.

Structured event complexes (SECs) are stored representations of sequential event knowledge, and represent sequences of activities that have been described elsewhere as scripts or schemas. Previous studies have shown that the prefrontal cortex is involved in temporal sequencing. The present study investigates the involvement of the prefrontal cortex in temporal order and membership judgments of script and category items by using functional magnetic resonance imaging. In this experiment, stimuli were either script events or category items. In experimental trials, subjects classified stimuli according to temporal order or membership category. Results show that the script order task and the chronological order task (relative to their respective memberships tasks) were associated with different patterns of PFC activation. Both order tasks activated the middle frontal gyrus bilaterally; however, script order tasks showed additional activation in right inferior frontal gyrus, and the chronological order tasks in left inferior frontal gyrus. These results suggest that while the middle frontal gyri are activated bilaterally in both script and chronological temporal ordering tasks, there are different, though largely overlapping, neural substrates for script and chronological representations during temporal ordering.

Adult↗