Article

Dissociable contributions of left and right dorsolateral prefrontal cortex in planning.

Department of Neurology, University Medical Center, University of Freiburg, Germany.
Cerebral Cortex (impact factor: 6.54). 02/2011; 21(2):307-17. DOI:10.1093/cercor/bhq096 pp.307-17
Source: PubMed

ABSTRACT It is well established that the mid-dorsolateral prefrontal cortex (dlPFC) plays a critical role in planning. Neuroimaging studies have yielded predominantly bilateral dlPFC activations, but the existence and nature of functionally specific contributions of left and right dlPFC have remained elusive. In recent experiments, 2 independent parameters have been identified which substantially determine planning: 1) the degree of interdependence between consecutive steps (search depth) and 2) the degree to which the configuration of the goal state renders the order of single steps either clearly evident or ambiguous (goal hierarchy). Thus, search depth affects the actual mental generation and evaluation of action sequences, whereas goal hierarchy reflects the extraction of goal information from an encountered problem. Here, both parameters were independently manipulated in an event-related functional magnetic resonance imaging study using the Tower of London task. Results revealed a double dissociation as indicated by a significant crossover interaction of hemisphere and task parameter: in left dlPFC, activations were stronger for higher demands on goal hierarchy than on search depth, whereas the reversed result emerged in right dlPFC. In conclusion, often observed bilateral patterns of dlPFC activation in complex tasks may reflect the concomitant operation of specific cognitive processes that show opposing lateralizations.

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Keywords

actual mental generation
 
bilateral dlPFC activations
 
bilateral patterns
 
complex tasks
 
concomitant operation
 
critical role
 
dlPFC
 
dlPFC activation
 
double dissociation
 
event-related functional magnetic resonance imaging study
 
functionally specific contributions
 
goal hierarchy
 
goal information
 
goal state renders
 
higher demands
 
mid-dorsolateral prefrontal cortex
 
Neuroimaging studies
 
recent experiments
 
search depth
 
significant crossover interaction