Physiological parallels with perception

Signal detection theory (SDT) lends itself to comparison among perceptual and physiological results in humans and other animals. In physiological recordings, trial-by-trial distributions of single-unit spike counts or of event-related-potentials typically yield non-normal distributions, calling for non-parametric tests. An empirical receiver operating characteristic (ROC) curve can compare distributions of physiological measures between pairs of stimulus conditions. The area under the ROC curve is a non-parametric measure of sensitivity, yielding the proportion correct and, thence, the sensitivity index, d’. The d’ cumulated over a succession of the increasing values of a stimulus parameter provides a measure of the growth of response over that parameter range. I will present examples from several ongoing projects including: (1) studies of activation of the central auditory pathway by cochlear implants and by a penetrating auditory nerve electrode, with single-unit recordings from the inferior colliculus; (2) comparisons of spatial stream segregation among 2-alternative forced choice in humans, hold-response measures in cats, and cortical single-unit recording in cats; and (3) studies of frequency sensitivity using the auditory change complex and masked onset responses. In general, these techniques derived from SDT yield a satisfying agreement among perceptual measures and their physiological underpinnings.Signal detection theory (SDT) lends itself to comparison among perceptual and physiological results in humans and other animals. In physiological recordings, trial-by-trial distributions of single-unit spike counts or of event-related-potentials typically yield non-normal distributions, calling for non-parametric tests. An empirical receiver operating characteristic (ROC) curve can compare distributions of physiological measures between pairs of stimulus conditions. The area under the ROC curve is a non-parametric measure of sensitivity, yielding the proportion correct and, thence, the sensitivity index, d’. The d’ cumulated over a succession of the increasing values of a stimulus parameter provides a measure of the growth of response over that parameter range. I will present examples from several ongoing projects including: (1) studies of activation of the central auditory pathway by cochlear implants and by a penetrating auditory nerve electrode, with single-unit recordings from the inferior colliculus;...