OS_04. Executive control
Friday, September 30th, 2011 [10:50 - 11:50]
OS_04.1 - Neural correlates of executive control training
Karbach, J. & Brieber, S.
Department of Psychology. Saarland University. Saarbrücken, Germany
Although a number of behavioral studies have shown that executive control training can transfer to new untrained tasks, little is known about the underlying mechanisms and the associated changes in functional brain activity. Previous studies have yielded mixed results, including patterns of increases, decreases, and functional reorganization of regional activations after training. The aim of this study was to investigate qualitative and quantitative changes in neural activity associated with the transfer of task-switching training. We assessed 31 young adults in a pretest-training-posttest design. Both pretest and posttest included functional neuroimaging (fMRI) while participants performed task switching and working memory tasks. After the pretest, participants were randomly assigned to a training condition (n=16) or an inactive control condition (n=15). The training group performed five sessions of task-switching training. Behavioral data showed training-related benefits on the switching task as well as transfer of training to a similar new switching task and a working memory task. Neuroimaging data revealed reduced activity in prefrontal and superior parietal areas after the training, pointing to increased neural efficiency. Consistent with previous findings, the training also resulted in increased activity in the striatum, suggesting that it plays an important role in mediating learning and transfer effects.
OS_04.2 - A TMS study of the role of right intraparietal sulcus in advance task-set preparation
Stevens, T. & Monsell, S.
School of Psychology. University of Exeter. Exeter, UK.
Imaging studies suggest that the right intraparietal sulcus (rIPS) is activated during advance preparation for a task-switch, but little or no rIPS activation is seen in experiments that do not allow time for preparation. We examined the role of rIPS using TMS with a task-cuing paradigm. The tasks were to classify the colour or the shape of a stimulus with a left or right key press. An auditory task cue preceded the stimulus by an interval of 100 ms (short CSI) or 750 ms (long CSI). In Experiment 1, we applied 3 TMS pulses at 20 Hz over rIPS, or over a control site, from 250 ms before the stimulus onset: i.e. during preparation with a long CSI, or before the cue with a short CSI. When the control site was stimulated, the usual reduction in behavioural switch cost with increasing CSI was observed. Stimulation of rIPS significantly attenuated this reduction. In Experiment 2, TMS applied 300 ms after stimulus onset had no impact on switch costs. This result suggests that rIPS plays a critical role in advance task-set preparation rather than in task-set reconfiguration more generally.
OS_04.3 - Genes implicated in executive functioning during neuropsychological testing and in daily life
Alfimova, M. , Korovaitseva, G. , Lezheiko, T. & Golimbet, V.
Mental Health Research Center RAMS
The objective of this study was to investigate whether the same sets of genes influence executive functioning during neuropsychological testing and in everyday behavior. Overlapping samples of healthy individuals completed neuropsychological tests measuring executive functions (n=150) and the Self Report form of the Behavioral Rating Inventory of Executive Function - Adult version (BRIEF-A) (n=100). The samples were genotyped for genes involved in dopaminergic neurotransmission (DRD4, COMT, MAOA) and neuroplasticity (BDNF, SNAP-25, NRG1). We failed to reveal strong relations between the BRIEF-A and standardized neuropsychological tests of executive functions. Neuropsychological measures showed specific associations with both dopamine system and neuroplasticity genes. A BRIEF-A score correlated only with dopaminergic genes, different alleles of DRD4, COMT, and MAOA being related to higher subjective rating of everyday executive functioning in men and women. The results suggest that dopaminergic system genes plays a critical role in everyday executive functions/self-regulation, while pure cognitive executive functions are influenced by a larger number of gene sets involved in different types of CNS processes.