title: Is there "neural efficiency" during the processing of visuo-spatial information in male humans? An EEG study.
abstract: More intelligent persons (high IQ) typically present a higher cortical activity during tasks requiring the encoding of visuo-spatial information, namely higher alpha (about 10 Hz) event-related desynchronization (ERD; Doppelmayr et al., 2005). The opposite is true ("neural efficiency") during the retrieval of the encoded information, as revealed by both lower alpha ERD and/or lower theta (about 5 Hz) event-related synchronization (ERS; Grabner et al., 2004). To reconcile these contrasting results, here we evaluated the working hypothesis that more intelligent male subjects are characterized by a high cortical activity during the encoding phase. This deep encoding would explain the relatively low cortical activity for the retrieval of the encoded information. To test this hypothesis, electroencephalographic (EEG) data were recorded in 22 healthy young male volunteers during visuo-spatial information processing (encoding) and short-term retrieval of the encoded information. Cortical activity was indexed by theta ERS and alpha ERD. It was found that the higher the subjects' total IQ, the stronger the frontal theta ERS during the encoding task. Furthermore, the higher the subjects' total IQ, the lower the frontal high-frequency alpha ERD (about 10-12 Hz) during the retrieval task. This was not true for parietal counterpart of these EEG rhythms. These results reconcile previous contrasting evidence confirming that more intelligent persons do not ever show event-related cortical responses compatible with "neural efficiency" hypothesis. Rather, their cortical activity would depend on flexible and task-adapting features of frontal activation.
authors: ITAB e Dipartimento di Scienze Cliniche e Bioimmagini, Università G. D'Annunzio, Chieti, Italy.
authors: Paolo
authors: P
authors: Capotosto
authors: M Gianni
authors: MG
authors: Perrucci
authors: Marcella
authors: M
authors: Brunetti
authors: Cosimo
authors: C
authors: Del Gratta
authors: Michael
authors: M
authors: Doppelmayr
authors: Roland H
authors: RH
authors: Grabner
authors: Wolfgang
authors: W
authors: Klimesch
authors: Aljoscha
authors: A
authors: Neubauer
authors: Christa
authors: C
authors: Neuper
authors: Gert
authors: G
authors: Pfurtscheller
authors: Gian Luca
authors: GL
authors: Romani
authors: Claudio
authors: C
authors: Babiloni
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003344:Cortical Synchronization; D004569:Electroencephalography; D005071:Evoked Potentials; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D007361:Intelligence Tests; D008297:Male; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology*; D013826:Theta Rhythm; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult