ATTENTION AND THE DETECTABILITY OF WEAK TASTE STIMULI

Subjects detected weak solutions of sucrose or citric acid under condi tions in which attention was directed toward one of the tastants or th e other. Detection thresholds were measured using an adaptive, forced- choice procedure, with a three-down one-up rule, which computer simula tions suggest should be more reliable than the popular two-down one-up rule. The thresholds were modestly but systematically lower for atten ded tastants than for unattended ones. Similar results have been repor ted in other sense modalities, including vision (greater sensitivity t o stimuli presented to attended versus unattended spatial locations) a nd hearing (greater sensitivity to stimuli presented at attended versu s unattended sound frequencies). Taken together, the findings are cons istent with a general hypothesis regarding attention in sensory system s: gains or losses in detectability occur when a central attentional m echanism (or, conceivably, a preattentive mechanism) selectively and p referentially monitors signals arising from particular subsets of peri pheral neural inputs.