Haptic Exploration and Mental Estimation of Distances on a Fictitious Island: From Mind's Eye to Mind's Hand

This study replicated Kosslyn, Ball, and Reiser's (1978) well-known experiment of a fictitious island that was specifically designed to demonstrate that visual images preserve metric information used in the resolution of spatial tasks. The participants had to memorize a visual map of an island and then mentally scan the distances between the objects on the island. Kosslyn et al. took the high correlations found between linear distances and mental estimates of distances as evidence to support their hypothesis. In this replication of the experiment, the performances of participants who were sighted and blind were compared by using a raised model of the island. The aim was to test whether the same results would occur when the task was carried out by participants who were blind. If this were the case, Kosslyn's et al.'s interpretation would have to be revised. The pattern of performance of people who are blind in several spatial tasks is not different from that of blindfolded sighted participants, although the former usually take more time in each trial (Carpenter & Eisenberg, 1978; Hollins, 1986). However, Millar (1990) pointed out that it is difficult to ascertain what problemsolving strategies are used by merely looking at the outcome of a task. Rather, both people who are blind and those who are sighted are able to use spatial strategies that display different patterns of performance compatible with the sensorial (experiential) modality. In summary, following Millar's results and arguments, the authors considered that if blind participants could perform as well as blindfolded participants in the island task, it would be difficult to sustain the view that visual images are the processing code for spatial tasks like the fictitious island.