title: Participation of the classical speech areas in auditory long-term memory.
abstract: Accumulating evidence suggests that storing speech sounds requires transposing rapidly fluctuating sound waves into more easily encoded oromotor sequences. If so, then the classical speech areas in the caudalmost portion of the temporal gyrus (pSTG) and in the inferior frontal gyrus (IFG) may be critical for performing this acoustic-oromotor transposition. We tested this proposal by applying repetitive transcranial magnetic stimulation (rTMS) to each of these left-hemisphere loci, as well as to a nonspeech locus, while participants listened to pseudowords. After 5 minutes these stimuli were re-presented together with new ones in a recognition test. Compared to control-site stimulation, pSTG stimulation produced a highly significant increase in recognition error rate, without affecting reaction time. By contrast, IFG stimulation led only to a weak, non-significant, trend toward recognition memory impairment. Importantly, the impairment after pSTG stimulation was not due to interference with perception, since the same stimulation failed to affect pseudoword discrimination examined with short interstimulus intervals. Our findings suggest that pSTG is essential for transforming speech sounds into stored motor plans for reproducing the sound. Whether or not the IFG also plays a role in speech-sound recognition could not be determined from the present results.
authors: National Institute of Mental Health, Bethesda, Maryland, United Sates of America; Danish Research Center for Magnetic Resonance, Hvidovre, Denmark; National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United Sates of America.
authors: Anke Ninija
authors: AN
authors: Karabanov
authors: National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United Sates of America.
authors: Rainer
authors: R
authors: Paine
authors: National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United Sates of America; Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.
authors: Chi Chao
authors: CC
authors: Chao
authors: Institute of Child Health, University College London, London, United Kingdom.
authors: Katrin
authors: K
authors: Schulze
authors: National Institute of Mental Health, Bethesda, Maryland, United Sates of America.
authors: Brian
authors: B
authors: Scott
authors: National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United Sates of America.
authors: Mark
authors: M
authors: Hallett
authors: National Institute of Mental Health, Bethesda, Maryland, United Sates of America.
authors: Mortimer
authors: M
authors: Mishkin
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D004058:Diffusion; D005260:Female; D006801:Humans; D008297:Male; D057567:Memory, Long-Term; D017397:Prefrontal Cortex / Q000502:physiology; D013060:Speech / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology; D050781:Transcranial Magnetic Stimulation