Perceptual dependence for shape and texture during haptic processing.

Perceptual dependence--the existence of perceptual interactions between the component dimensions of the same stimulus--was investigated for shape and texture during haptic processing. The haptic system combines tactual and kinesthetic information. Previous research has demonstrated that haptic exploration influences the extent to which object properties are integrated. Conditions designed to promote and impede the integration of shape and texture were compared. Perceptual independence was assessed by the use of a speeded-classification paradigm and quantitative tests developed by Ashby and Maddox. Results indicate that shape and texture are perceptually dependent for both conditions. Hand-movement analysis show simultaneous exploration for both dimensions. The tendency to process dimensions dependently is discussed in terms of a limited-capacity model of haptic-information processing.