title: Relative salience of spectral and temporal features in auditory long-term memory.
abstract: In order to explore the representation of sound features in auditory long-term memory, two groups of ferrets were trained on Go vs Nogo, 3-zone classification tasks. The sound stimuli differed primarily along the spectral and temporal dimensions. In Group 1, two ferrets were trained to (i) classify tones based on their frequency (Tone-task), and subsequently learned to (ii) classify white noise based on its amplitude modulation rate (AM-task). In Group 2, two ferrets were trained to classify tones based on correlated combinations of their frequency and AM rate (AM-Tone task). Both groups of ferrets learned their tasks and were able to generalize performance along the trained spectral (tone frequency) or temporal (AM rate) dimensions. Insights into stimulus representations in memory were gained when the animals were tested with a diverse set of untrained probes that mixed features from the two dimensions. Animals exhibited a complex pattern of responses to the probes reflecting primarily the probes' spectral similarity with the training stimuli, and secondarily the temporal features of the stimuli. These diverse behavioral decisions could be well accounted for by a nearest-neighbor classifier model that relied on a multiscale spectrotemporal cortical representation of the training and probe sounds.
authors.affiliation: Neural Systems Laboratory, Institute for Systems Research, 2207 A.V. Williams Building, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Pingbo
authors.initials: P
authors.lastname: Yin
authors.affiliation: Neural Systems Laboratory, Institute for Systems Research, Electrical and Computer Engineering Department, 2203 A.V. Williams Building, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Shihab A
authors.initials: SA
authors.lastname: Shamma
authors.affiliation: Neural Systems Laboratory, Institute for Systems Research, 2207 A.V. Williams Building, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Fritz
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001303:Auditory Cortex; D001307:Auditory Perception; D007858:Learning; D057567:Memory, Long-Term