Psychophysical spectro-temporal receptive fields in an auditory task.
Psychophysical relative weighting functions, which provide information about the importance of different regions of a stimulus in forming decisions, are traditionally estimated using trial-based procedures, where a single stimulus is presented and a single response is recorded. Everyday listening is much more "free-running" in that we often must detect randomly occurring signals in the presence of a continuous background. Psychophysical relative weighting functions have not been measured with free-running paradigms. Here, we combine a free-running paradigm with the reverse correlation technique used to estimate physiological spectro-temporal receptive fields (STRFs) to generate psychophysical relative weighting functions that are analogous to physiological STRFs. The psychophysical task required the detection of a fixed target signal (a sequence of spectro-temporally coherent tone pips with a known frequency) in the presence of a continuously presented informational masker (spectro-temporally random tone pips). A comparison of psychophysical relative weighting functions estimated with the current free-running paradigm and trial-based paradigms, suggests that in informational-masking tasks subjects' decision strategies are similar in both free-running and trial-based paradigms. For more cognitively challenging tasks there may be differences in the decision strategies with free-running and trial-based paradigms.
Shub
Daniel E
DE
Department of Psychology, University of Pennsylvania, 3451 Walnut St., Philadelphia, PA 19104, USA. dshub@sas.upenn.edu
Richards
Virginia M
VM
D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D003657:Decision Making / Q000502:physiology; D006801:Humans; D010470:Perceptual Masking; D011571:Psychoacoustics; D011601:Psychophysics; D013018:Sound Spectrography; D055815:Young Adult