Richard K. Davenport

Intermodal equivalence of stimuli in apes.

Orang-utans and chimpanzees can discriminate between two objects on the basis of tactile cues and select the one that matches a visually presented sample.

CROSS-MODAL PERCEPTION IN APES*

I should like to describe some experiments in cross-modal perception with apes and monkeys and to attempt to relate this phenomenon to the origins of speech and language. The sensory modalities of most human adults operate in concert as an integrated system of systems. Information received via one modality is coordinated in some manner with information from other modalities, and much of adaptive behavior, including language, presumably depends to a large extent on this intermodality integration. The existence of cross-modal perception and the unity of the senses in humans was graphically testified to by von Hornbostel when he said, “It matters little through which sense I realize that in the dark I have blundered into a pigsty.”’ In routine activities, we are seldom aware of the marked discrepancies in information originating in the several sensory modalities. The extent to which this capacity is shared with psychologically and neurologically unusual humans, infants, and other animals is not entirely clear. The interrelatedness of the senses, variously termed intermodal or cross-modal transfer, intermodal integration or generalization, cross-modal perception. and the like has a long philosophical history, extending a t least as far back as the early 1700s with Locke and Berkeley, but a relatively brief clinical and experimental history. Neurological case studies of the late 1800s provided some interesting data, and von Senden’s observations published in 1932 on early-blinded people whose sight was restored in adulthood were more directly relevant. Experimental work with humans, including the blind, deaf, neurologically damaged, very young children, and normal adults, has accelerated in the past few years (see reviews by Freidesz and Gibson3). Experimental investigations with nonhuman animals aimed directly a t cross-modal perception are recent and still rather few in number. There are a number of fundamental issues regarding cross-modal perception which require clarification: I . What are the roles of maturation and experience in its expression? 2. What are the neurological requisites for the phenomenon and in what manner d o neuroanatomical characteristics facilitate cross-modal perception (in part a phylogenetic issue)? 3. What is the nature of the information processing that permits integration of information among the several modalities? 4. To what extent d o other behavioral capacities such as language mediate or facilitate perceptual integration? 5 . To what extent d o cross-modal capabilities contribute to adaptive behavior in general, and cognitive processes and language in particular? 6. In what manner and to what extent d o intramodality characteristics or limitations in and of themselves contribute to cross-modal functioning?

Reading Comprehension and Perception of Sequentially Organized Patterns: Intramodal and Cross-Modal Comparisons

The ability to make sameness or difference judgments of pairs of Morse code-like patterns was measured when stimuli were presented intramodally or crossmodally. Visual, auditory, and tactual modalities were compared. Performance was compared in three groups of children — (1) a group poor in Reading Comprehension (group PR), grade levels 3 to 6; (2) a group matched with group PR on Vocabulary, sex, and age but at grade level on Comprehension; and (3) a group approximately two years younger than Group PR but matched with it on Comprehension scores. The younger group showed poorest overall performance on the experimental task. Overall, as a main effect, accuracy in the intramodal conditions was better than in the cross-modal conditions. When the first pattern of a pair was auditory, performance was better than when it was visual or tactual, while tactual performance was better than visual. Any comparison, however, in which the first pattern was auditory discriminated between the group poor in Reading Comprehension and the group of normal readers matched with it on Vocabulary. A deficit in auditory memory rather than cross-modal perception appears to be a factor in poor Reading Comprehension.

chapter 3 – Cross-Modal Perception: A Basis for Language?

Publisher Summary This chapter discusses the significance of cross-modal perception. The importance of further research to the understanding of cross-modal functioning seems clear. A number of fundamental issues regarding cross-modal perception still require clarification. An increased knowledge of cross-modal perception could provide a powerful tool to study the historically important and difficult question of central information processing in animals. However, what evolutionary occurrences could have accounted for this central elaboration is not yet known. On the basis of Geshwinds extensive neurological and theoretical work, he has stated that it cannot be argued that the ability to form cross-modal associations depends on already having speech, rather the ability to acquire speech has as a prerequisite the ability to form cross-modal associations and the ability to form cross-modal linkages was a necessary condition for the acquisition of language. The cross-modal perception of equivalence requires the derivation of a modality-independent representation, cognition, or the concept of a stimulus or event. Animals that can have the same or similar representation, regardless of the means of peripheral reception, possess a great advantage in coping with the complex demands of living, especially in unusual circumstances in which one modality may be operating suboptimally when precise and accurate response is necessary on the basis of limited information or when cognitive manipulation is required.