Perceptual Development: Intermodal Perception

History and Theory

Over 2,000 years ago, Aristotle proposed a sensus communis, or common sense, to explain how we perceive qualities common to different senses, such as number, form, and unity. Centuries later, philosophers such as John Locke and George Berkeley proposed that we needed to integrate information across separate sensory channels before perceiving a unified object or event, such as a bell ringing, rather than perceiving separate streams of light and sound. This posed a “binding” problem for perception, in that the brain would need to somehow unify separate channels of sensory information to “construct” a coherent world. This constructivist view dominated thinking throughout most of the 20th century, including Jean Piaget's well-known theory of cognitive development. Piaget proposed that integration took place gradually over the first year of life through interacting with objects and coordinating information across the senses. Prior to integration, infants were thought to perceive a world of unrelated sights, sounds, smells, and tactile impressions, much like the “blooming, buzzing confusion” described by William James in 1890.

Not until the psychologist James J. Gibson published his work on ecological perception in 1966, The Senses Considered as Perceptual Systems, was this constructivist view seriously questioned. Gibson argued that our senses work together as a unified perceptual system, and that the existence of different forms of sensory stimulation was an advantage rather than a disadvantage for perception of unified objects and events. This is because we perceive amodal (not tied to a particular sense modality) information that is redundant or identical across the senses. This includes temporal synchrony, rhythm, duration, tempo, changes in intensity, and spatial location common to audiovisual events, and shape, substance, size, and texture common to visual-tactile events. Because all events occur over time and space, all events provide amodal information.

Gibson's theory is considered a differentiation view of development. In contrast to the integration view, which holds that the senses are separate at birth, the differentiation view, articulated by Eleanor J. Gibson, proposes that the senses are unified at birth and that perceptual development is characterized as a gradual process of differentiating increasingly finer levels of sensory stimulation. From this view, now widely accepted among developmental psychologists, there is no “blooming, buzzing confusion” in early development. Rather, infants detect many general features of unified multimodal events from birth and learn to perceive increasingly more subtle differences and more complex objects and events through looking, listening, and interacting with their environment.

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