Behavioral observations of sensory substitution in neonate macaques (Macaca arctoides)

The ability of neonate macaque monkeys to learn to respond to artificial spatial sensory information was studied through the use of compact, head-worn, electronic spatial sonars with audible displays, which translate spatial information into auditory dimensions specifying distance, direction, and surface characteristics. Three animals were born in the dark and raised without vision for 1 to 3 months while wearing either the Binaural Sensory Aid (Animal 1; Kay, 1974) or the Trisensor (Animals 2 and 3; Easton & Jackson, 1983) airborne sonars. Each animal demonstrated alertness to information transmitted by the devices in spontaneous reaching or reinforced discrimination tasks, and more device-related, perceptual-motor activities were observed when the sensors were switched on than when they were switched off. The results show that neonate monkeys can learn effective use of information obtained from sensory substitution devices through unstructured interaction with the environment.