Separate contributions of enhanced and suppressed sensitivity to the auditory attentional filter

• Published in: Hearing research 2008-07, Vol.241 (1), p.18-25
• Main Authors: Tan, Michael N., Robertson, Donald, Hammond, Geoffrey R.
• Format: Article
• Language: English
• Subjects: Acoustic Stimulation; Antimasking; Attention; Auditory; Auditory Pathways - physiology; Auditory Perception; Auditory Threshold; Biological and medical sciences; Cochlear Nucleus - physiology; Cues; Cuing; Detection; Drug toxicity and drugs side effects treatment; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Medical sciences; Olivary Nucleus - physiology; Olivocochlear; Perceptual Masking; Pharmacology. Drug treatments; Psychoacoustics; Toxicity: respiratory system, ent, stomatology; Vertebrates: nervous system and sense organs
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/j.heares.2008.04.003

Three experiments used a probe-signal method to determine the extent to which exposure-related changes in sensitivity result from an immediate effect of stimulation and from a cumulative effect of repeated stimulation. In the first experiment, a fixed-frequency cue was followed by a same-frequency target (on 75% of trials) or a different-frequency probe (on 25% of trials). In the second experiment, a cue frequency selected randomly from a set of five was followed by a same-frequency target, or one of four different-frequency probes. Targets and probes were randomly selected independently of the cue frequency and all were equiprobable (20%). Target detection showed an average 3.4 dB advantage over probe detection. In the third experiment, tones with a randomly selected frequency were detected better when cued by a tone of the same-frequency than when presented without a prior cue. The cued tones showed an average 2.6 dB advantage over the uncued tones. Together, these results suggest that two mechanisms contribute to changes in sensitivity following auditory stimulation: first, an immediate enhancement of target detection produced by an auditory cue and second, a suppression of non-target frequencies caused by the expectation of a target.