The effect of delayed auditory feedback on activity in the temporal lobe while speaking: a positron emission tomography study.
OBJECTIVE
Delayed auditory feedback is a technique that can improve fluency in stutterers, while disrupting fluency in many nonstuttering individuals. The aim of this study was to determine the neural basis for the detection of and compensation for such a delay, and the effects of increases in the delay duration.


METHODS
Positron emission tomography was used to image regional cerebral blood flow changes, an index of neural activity, and to assess the influence of increasing amounts of delay.


RESULTS
Delayed auditory feedback led to increased activation in the bilateral superior temporal lobes, extending into posterior-medial auditory areas. Similar peaks in the temporal lobe were sensitive to increases in the amount of delay. A single peak in the temporal parietal junction responded to the amount of delay but not to the presence of a delay (relative to no delay).


CONCLUSIONS
This study permitted distinctions to be made between the neural response to hearing one's voice at a delay and the neural activity that correlates with this delay. Notably, all the peaks showed some influence of the amount of delay. This result confirms a role for the posterior, sensorimotor "how" system in the production of speech under conditions of delayed auditory feedback.
Takaso
Hideki
H
Dept of Psychology, UCL. Gower Street, London WC1E 6BT.
Eisner
Frank
F
Institute of Cognitive Neuroscience, UCL, 17 Queen Square London WC1N 3AR.
Wise
Richard Js
RJ
MRC Clinical Sciences Centre, Hammersmith Hospital, Ducane Road, London W12 0NN.
Scott
Sophie K
SK
Institute of Cognitive Neuroscience, UCL, 17 Queen Square London WC1N 3AR.
D000328:Adult; D001303:Auditory Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology; D002560:Cerebrovascular Circulation; D030141:Feedback, Psychological / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology; D049268:Positron-Emission Tomography; D011932:Reading; D013060:Speech / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000502:physiology*; D013997:Time Factors