Region-specific reduction of auditory sensory gating in older adults.
Aging has been associated with declines in sensory-perceptual processes. Sensory gating (SG), or repetition suppression, refers to the attenuation of neural activity in response to a second stimulus and is considered to be an automatic process to inhibit redundant sensory inputs. It is controversial whether SG deficits, as tested with an auditory paired-stimulus protocol, accompany normal aging in humans. To reconcile the debates arising from event-related potential studies, we recorded auditory neuromagnetic reactivity in 20 young and 19 elderly adult men and determined the neural activation by using minimum-norm estimate (MNE) source modeling. SG of M100 was calculated by the ratio of the response to the second stimulus over that to the first stimulus. MNE results revealed that fronto-temporo-parietal networks were implicated in the M100 SG. Compared to the younger participants, the elderly showed selectively increased SG ratios in the anterior superior temporal gyrus, anterior middle temporal gyrus, temporal pole and orbitofrontal cortex, suggesting an insufficient age-related gating to repetitive auditory stimulation. These findings also highlight the loss of frontal inhibition of the auditory cortex in normal aging.
Department of Occupational Therapy and Graduate Institute of Behavioral Sciences, Chang Gung University, Taoyuan, Taiwan; Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan. Electronic address: ch.cheng@mail.cgu.edu.tw.
Chia-Hsiung
CH
Cheng
McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, Canada.
Sylvain
S
Baillet
Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Institute of Physiology, National Yang-Ming University, Taipei, Taiwan; Institute of Clinical Medicine, National Yang Ming University, Taipei, Taiwan; Brain Research Center, National Yang-Ming University, Taipei, Taiwan; Laboratory of Neurophysiology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan.
Yung-Yang
YY
Lin
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001303:Auditory Cortex / Q000502:physiology*; D001921:Brain / Q000502:physiology; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology*; D055139:Sensory Gating / Q000502:physiology*; D055815:Young Adult
Aging; Cortical inhibition; M100; Magnetoencephalography (MEG); Paired-pulse suppression; Repetition suppression