Lexical references to sensory modalities in verbal descriptions of people and objects by congenitally blind, late blind and sighted adults.

Abstract

BACKGROUND: Some previous studies have revealed that while congenitally blind people have a tendency to refer to visual attributes ('verbalism'), references to auditory and tactile attributes are scarcer. However, this statement may be challenged by current theories claiming that cognition is linked to the perceptions and actions from which it derives. Verbal productions by the blind could therefore differ from those of the sighted because of their specific perceptual experience. The relative weight of each sense in oral descriptions was compared in three groups with different visual experience Congenitally blind (CB), late blind (LB) and blindfolded sighted (BS) adults. METHODOLOGY/PRINCIPAL FINDINGS: Participants were asked to give an oral description of their mother and their father, and of four familiar manually-explored objects. The number of visual references obtained when describing people was relatively high, and was the same in the CB and BS groups ("verbalism" in the CB). While references to touch were scarce in all groups, the CB referred to audition more frequently than the LB and the BS groups. There were, by contrast, no differences between groups in descriptions of objects, and references to touch dominated the other modalities. CONCLUSION/SIGNIFICANCE: The relative weight of each modality varies according to the cognitive processes involved in each task. Long term memory, internal representations and information acquired through social communication, are at work in the People task, seem to favour visual references in both the blind and the sighted, whereas the congenitally blind also refer often to audition. By contrast, the perceptual encoding and working memory at work in the Objects task enhance sensory references to touch in a similar way in all groups. These results attenuate the impact of verbalism in blindness, and support (albeit moderately) the idea that the perceptual experience of the congenitally blind is to some extent reflected in their cognition.