Implicit emotion during recollection of past events: a nonverbal fMRI study

Faces of other significant people are highly self-relevant and close to our everyday way of recollecting past events. We chose such stimuli to probe the emotional component of autobiographical memory retrieval. Photographs were collected from family members without the participant's involvement, thereby avoiding refreshment of the memory trace prior to the scanning session. We asked the subjects to spontaneously evoke a unique autobiographical episode following the presentation of relatives' and friends' faces. Famous faces recognition was used as a semantic memory control task. We carried out a post-fMRI debriefing session to collect participants' memories and their emotional intensity. The post-scanning behavioural data together with the neuroimaging data provided evidence that emotional aspects were implicitly involved during recollections. Our findings suggest that the use of highly self-relevant stimuli and the collection of data with no previous refreshment of the memory trace influence the right lateralisation of activations in the medial temporal lobe (MTL).