ON THE DISTINGUISHABILITY OF CONCEPTUAL A ND IMAGINAL REPRESENTATIONSIN ELEMENTARY THINKING

The topic focuses on the distinguishability between conceptual and ima ginal representations in elementary cognitive tasks. First results of advantage and disadvantage of a new method dealing with the distinguis hability of conceptual and imaginal representation by means of an adap tive EEG-coherence analysis are presented. Subjects had to decide whet her two letters, a capital letter and a small one, had the identical n ame (Posner-Mitchell-paradigm, respectively whether two Garner-pattern s are identical. The increased decision time in concept activation in contrast to pattern comparison is accompanied by an increased (60-80 m s) coherence duration (coherence > 0.80) in the left parietotemporal c ortex but not in the right parietotemporal one. This coherence duratio n difference is additionally observed when tile decision time differen ce of both tasks is zero. A different decision time in case of equal m odalities in both situations (pattern comparison only) is accompanied by a difference in the duration of high coherence in the right parieto temporal cortex but not in the left one, The results were discussed in the context of the distinguishability of modalities by means of EEG-c oherence analysis. The presented investigation method is restricted to elementary comparison tasks which are identical in cognitive operatio ns. This method allows new possibilities in the component analysis of cognitive processes without the presupposition of the linearity.