EFFECTS OF SPATIAL ATTENTION ON TACTILE PROCESSING: A SPEED-ACCURACY ANALYSIS
Does attention to spatial cues affect tactile processing? Subjects received 60-Hz mechanical sinusoids at levels near 15 dB SL, delivered with equal probabilities to the left and right hands. Spatial attention was directed by a visual cue: an arrow that pointed left or right. The cue was valid (pointed in the direction of the hand that would receive the stimulus) on 75% of the trials, invalid on 25%. The subjectsâ€™ task was to identify, as quickly as possible, the intensity of the stimulus â€“ as low (press one pedal with left foot) or high (press another pedal with right foot). Latency operating characteristics (LOCs) for each subject quantified the trade-off between response time and accuracy. Seven of the eight subjects accumulated information more rapidly on valid compared to invalid trials (slopes of LOC were greater), thereby indicating the benefits of directed spatial attention.