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.
Hirano
Yoshiyuki
Y
Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka 238-8580, Japan. yosh-hir@qa2.so-net.ne.jp
Fujita
Masafumi
M
Watanabe
Kazuko
K
Niwa
Masami
M
Takahashi
Toru
T
Kanematsu
Masayuki
M
Ido
Yasushi
Y
Tomida
Mihoko
M
Onozuka
Minoru
M
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*