No abstract

Exposure to even subtle forms of misleading information can significantly alter memory for past events. Memory distortion due to misinformation has been linked to faulty reconstructive processes during memory retrieval and the reactivation of brain regions involved in the initial encoding of misleading details (cortical reinstatement). The current study investigated whether warning participants about the threat of misinformation can modulate cortical reinstatement during memory retrieval and reduce misinformation errors. Participants watched a silent video depicting a crime (original event) and were given an initial test of memory for the crime details. Then, participants listened to an auditory narrative describing the crime in which some original details were altered (misinformation). Importantly, participants who received a warning about the reliability of the auditory narrative either before or after exposure to misinformation demonstrated less susceptibility to misinformation on a final test of memory compared to unwarned participants. Warned and unwarned participants also demonstrated striking differences in neural activity during the final memory test. Compared to participants who did not receive a warning, participants who received a warning (regardless of its timing) demonstrated increased activity in visual regions associated with the original source of information as well as decreased activity in auditory regions associated with the misleading source of information. Stronger visual reactivation was associated with reduced susceptibility to misinformation, whereas stronger auditory reactivation was associated with increased susceptibility to misinformation. Together, these results suggest that a simple warning can modulate reconstructive processes during memory retrieval and reduce memory errors due to misinformation.

No abstract

Previous studies have reported greater activity in the parahippocampal cortex during true memory than false memory, which has been interpreted as reflecting greater sensory processing during true memory. However, in these studies, sensory detail and contextual information were confounded. In the present fMRI study, we employed a novel paradigm to dissociate these factors. During encoding, abstract shapes were presented in one of two contexts (i.e., moving or stationary). During retrieval, participants classified shapes as previously "moving" or "stationary." Critically, contextual processing was relatively greater during false memory ("moving" responses to stationary items), while sensory processing was relatively greater during true memory ("moving" responses to moving items). Within the medial temporal lobe, false memory versus true memory produced greater activity in the parahippocampal cortex, whereas true memory versus false memory produced greater activity in the hippocampus. The present results indicate that the parahippocampal cortex mediates contextual processing rather than sensory processing.

No abstract