2014 年 3 巻 2 号 p. 155-161
Episodic memory is often impaired by the effect of aging. There are two main forms of age-related decline in episodic memory: increased forgetting of experienced events and remembering of events that have not been experienced. Neural correlates of the former types of memory disturbance have been investigated carefully in several previous fMRI studies, but evidence with regard to the latter remains scarce. This review article summarizes previous fMRI findings associated with false memory retrieval and effect of aging on it, and proposes frameworks for understanding the underlying mechanisms. Previous fMRI studies of false memories in young adults have shown significant activation related to false remembering in the lateral prefrontal cortex (PFC), medial PFC including the anterior cingulate cortex (ACC), and superior/inferior parietal cortices. The findings suggest that incompatible interaction between these regions could contribute to the retrieval of false memories related to failure of the process of monitoring retrieved memories. An age-related decrease in activation associated with false remembering has been identified in the lateral PFC, ACC and visual cortices such as the precuneus or occipital lobe. Decreasing activation in these regions in older adults indicates that the age-related increase of false remembering could be caused by decreased interaction between the monitoring and remembering systems in older adults compared to young adults. Future fMRI research into false memories should include further investigation of how the processing of false memories is correlated with other cognitive functions such as “lying” or “confabulation”.