title: Differences of cerebral activation between superior and inferior learners during motor sequence encoding and retrieval.
abstract: Cerebral activation during memory encoding and retrieval might depend on subjects' learning capacity, either by corresponding to better performance in superior learners or by reflecting increased effort in inferior learners. To investigate these alternative hypotheses, the study compared cerebral activation during encoding and retrieval of a motor sequence in groups of subjects with superior and inferior learning performances. Ten healthy subjects underwent functional magnetic resonance imaging (fMRI) while performing a motor sequence encoding paradigm (i.e. finger tapping sequence) and a retrieval paradigm (i.e. reproduction of the learned sequence). Subjects were divided into superior and inferior learners according to the correctness of sequence reproduction during retrieval. During encoding, there was strong bilateral activation in the middle frontal gyrus, the supplementary motor area (SMA), the lateral parietal lobe and the cerebellum. During retrieval, again strong activation was found in identical areas of the prefrontal cortex, the parietal lobe and the cerebellum. During encoding, inferior learners showed more left-sided activations in the left middle frontal and inferior parietal gyri. Superior learners showed increased activation in the corresponding right-sided brain areas during encoding as well as during retrieval. Differences of cerebral activations in the prefrontal and parietal cortex during encoding and retrieval were found to be related to retrieval performance, i.e. success and effort. Further intervention studies are needed to assess whether these interindividual differences are the cause or the consequence of differences in memory performance.
authors.affiliation: Department of Psychiatry, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany. heun@uni-bonn.de
authors.forename: Reinhard
authors.initials: R
authors.lastname: Heun
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Freymann
authors.forename: Dirk Oliver
authors.initials: DO
authors.lastname: Granath
authors.forename: Christian Paul
authors.initials: CP
authors.lastname: Stracke
authors.forename: Frank
authors.initials: F
authors.lastname: Jessen
authors.forename: Katrin
authors.initials: K
authors.lastname: Barkow
authors.forename: Jürgen
authors.initials: J
authors.lastname: Reul
mesh_terms: D000124:Achievement; D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007858:Learning; D008279:Magnetic Resonance Imaging; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time