Orienting of attention in deafferented patients.

Visual attentional processes were compared in two deafferented patients and 11 normal subjects. Two consecutive stimuli were presented in rapid succession in one of two locations. A peripheral cue first oriented attention to one location where a response was requested. After 100 msec, a second response was required at either the same or opposite location (valid vs invalid cue). Four probabilities of valid cue occurrence were presented: 100, 80, 50 and 20%. Results showed (1) faster reaction times for the second response on cued than on uncued signals; (2) greater attentional effects with increased cue probability; (3) smaller attentional effects in patients. These findings suggest that the patients adopted a cost-minimizing strategy.