Abstract
To better understand the effects of emotional valence on autobiographical memory (AM), the present study compared behavioral performance and neural activation in positive and negative AMs at different levels of remoteness (the time-interval between encoding and retrieving) in a sample of Chinese older females. The behavioral results revealed that older females held a positivity bias in emotional AM in the form of an obvious trend of higher level of vividness when retrieving positive AMs compared with negative AMs. At the neural level, a de-lateralized neural network, covering the core AM system and the affect processing system, was found to be associated with emotional AM. Within the network, increased activation of a prefrontal cortex/anterior cingulate cortex (PFC/ACC) control system was found when processing negative recent AMs compared with positive recent AMs; increased activation of the somatosensory area was found with positive remote AMs compared with negative remote AMs. On the basis of these results, we suggest that the positivity bias of the older adults in recent AMs may be due to the use of an emotion regulation or control system (involving PFC/ACC) against negative AMs; in contrast, for remote AMs, the positivity bias may be due to better access to the positive remote memory details than the negative remote memory details.