Effect of unpleasant loud noise on hippocampal activities during picture encoding: an fMRI study.
The functional link between the amygdala and hippocampus in humans has not been well documented. We examined the effect of unpleasant loud noise on hippocampal and amygdaloid activities during picture encoding by means of fMRI, and on the correct response in humans. The noise reduced activity in the hippocampus during picture encoding, decreased the correct response and increased the activity of the amygdala. A path diagram using structural equation modeling suggested that hippocampus activity might be depressed by high amygdala activity. Therefore, noise should diminish memory by reducing hippocampal activity, which might be depressed by high amygdala activity.
Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka 238-8580, Japan. yosh-hir@qa2.so-net.ne.jp
Yoshiyuki
Y
Hirano
Masafumi
M
Fujita
Kazuko
K
Watanabe
Masami
M
Niwa
Toru
T
Takahashi
Masayuki
M
Kanematsu
Yasushi
Y
Ido
Mihoko
M
Tomida
Minoru
M
Onozuka
D000328:Adult; D000679:Amygdala / Q000503:physiopathology; D005260:Female; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D009415:Nerve Net / Q000503:physiopathology; D009622:Noise / Q000009:adverse effects*; D017397:Prefrontal Cortex / Q000503:physiopathology; D014796:Visual Perception / Q000502:physiology*