title: A task-irrelevant stimulus attribute affects perception and short-term memory.
abstract: Selective attention protects cognition against intrusions of task-irrelevant stimulus attributes. This protective function was tested in coordinated psychophysical and memory experiments. Stimuli were superimposed, horizontally and vertically oriented gratings of varying spatial frequency; only one orientation was task relevant. Experiment 1 demonstrated that a task-irrelevant spatial frequency interfered with visual discrimination of the task-relevant spatial frequency. Experiment 2 adopted a two-item Sternberg task, using stimuli that had been scaled to neutralize interference at the level of vision. Despite being visually neutralized, the task-irrelevant attribute strongly influenced recognition accuracy and associated reaction times (RTs). This effect was sharply tuned, with the task-irrelevant spatial frequency having an impact only when the task-relevant spatial frequencies of the probe and study items were highly similar to one another. Model-based analyses of judgment accuracy and RT distributional properties converged on the point that the irrelevant orientation operates at an early stage in memory processing, not at a later one that supports decision making.
authors.affiliation: Volen Center for Complex Systems, Brandeis University, Waltham, MA 02454, USA. jiehuang@brandeis.edu
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kahana
authors.forename: Robert
authors.initials: R
authors.lastname: Sekuler
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention; D004193:Discrimination Learning; D005260:Female; D005364:Field Dependence-Independence; D006801:Humans; D007600:Judgment; D008297:Male; D008570:Memory, Short-Term; D009949:Orientation; D010364:Pattern Recognition, Visual; D011930:Reaction Time; D012684:Sensory Thresholds; D055815:Young Adult