INTRADIMENSIONAL AND EXTRADIMENSIONAL SHIFTS IN MONKEY WITHIN AND ACROSS SENSORY MODALITIES

After learning a series of successive tactual reversals in which 1 dimension (form or size) was relevant, 8 monkeys received intradimensional (ID) or extradimensional (ED) shifts within and across sensory modalities. Within the tactual modality, reversals were characterized by a flattening or reversal midplateau and ID was superior to ED. Across modalities (tactual-visual), no difference was found between ID and ED shifts. The results give evidence for the existence of stimulus analyzing mechanisms in a nonvisual modality and provide support for a 2-stage chaining model of discrimination learning. The results of the cross-modal shifts suggest, however, that tactual and visual analyzers are modality specific. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1968 American Psychological Association.