title: False memory for face in short-term memory and neural activity in human amygdala.
abstract: Human memory is often inaccurate. Similar to words and figures, new faces are often recognized as seen or studied items in long- and short-term memory tests; however, the neural mechanisms underlying this false memory remain elusive. In a previous fMRI study using morphed faces and a standard false memory paradigm, we found that there was a U-shaped response curve of the amygdala to old, new, and lure items. This indicates that the amygdala is more active in response to items that are salient (hit and correct rejection) compared to items that are less salient (false alarm), in terms of memory retrieval. In the present fMRI study, we determined whether the false memory for faces occurs within the short-term memory range (a few seconds), and assessed which neural correlates are involved in veridical and illusory memories. Nineteen healthy participants were scanned by 3T MRI during a short-term memory task using morphed faces. The behavioral results indicated that the occurrence of false memories was within the short-term range. We found that the amygdala displayed a U-shaped response curve to memory items, similar to those observed in our previous study. These results suggest that the amygdala plays a common role in both long- and short-term false memory for faces. We made the following conclusions: First, the amygdala is involved in detecting the saliency of items, in addition to fear, and supports goal-oriented behavior by modulating memory. Second, amygdala activity and response time might be related with a subject's response criterion for similar faces.
authors.affiliation: Nagoya University, Graduate School of Medicine, Department of Psychiatry, 65 Tsurumai, Showa, Nagoya, Aichi 466-8550, Japan. Electronic address: iidaka@med.nagoya-u.ac.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Iidaka
authors.affiliation: National Institute for Physiological Sciences, Division of Cerebral Integration, 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan.
authors.forename: Tokiko
authors.initials: T
authors.lastname: Harada
authors.affiliation: National Institute for Physiological Sciences, Division of Cerebral Integration, 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Sadato
mesh_terms: D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000502:physiology*; D005145:Face / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011930:Reaction Time; D055815:Young Adult
keywords: Illusory memory; Motivation; Prefrontal cortex; Reaction time; Salience