Haptic recognition in severe low-vision infants as assessed by a familiarization procedure

Despite the probable significance of tactile or haptic (Gibson, 1966) capacities in the early development of children who are blind or have low vision (Bigelow, 1990; Fraiberg, 1977; Hatwell, 1978), there are still many unanswered questions regarding the emergence of such capacities. A centraI issue in this respect is the nature and extent of children's memory of haptic features. Although there is evidence that blind preschoolers (Ungar, Blades, Spencer, & Morsley, 1994) and older children (Pathak & Pring, 1989) are able to retain information from tactile maps and two-dimensional displays, there has been little research on the age at which such memory abilities begin in children who are blind or have low vision and few studies of memory for three-dimensional objects. There is evidence that blind infants show a poor spontaneous response to such objects in the naturalistic environment (Fraiberg, 1977), but this does not necessarily mean that the haptic features of objects could not be retained if infants were to engage in exploratory behavior. A promising tool for addressing these issues is habituation or familiarization, a procedure that has been successfully used to investigate haptic memory in sighted infants (Catherwood, 1993a, 1993b; Gottfried & Rose, 1980; Streri & P echeux, 1986). Variants of this procedure have been used to confirm that infants as young as 4 months are able to recognize objects on the basis of features, such as shape or texture, that have been experienced only through haptic means. In such procedures, infants are either repeatedly presented with or allowed to explore one item and then presented with "test" trials involving the re-presentation of this familiar item, as well as "novel" items that differ in one or more features from the familiar item. The essential premise is that if the infants display more exploratory interest in the novel items than in the familiar item (in terms of longer manipulation time), it suggests that the familiar item has been discriminated from the novel items or recognized on the basis of the feature or features in which the novel and familiar items differ (given that all other factors have been accounted for). These procedures would seem particularly suited to the study of recognition abilities in infants who are blind or have low vision, but they have not yet been applied in such research. The present investigation involved a pilot assessment of such procedures over two test sessions with two infants with severe low vision.