Protecting memory from misinformation: Warnings modulate cortical reinstatement during memory retrieval

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.

Keywords: cortical reinstatement; eyewitness memory; fMRI; misinformation.

Fig. 1.

Eyewitness memory paradigm used in experiments 1 and 2. Participants watched a silent video depicting a crime (witnessed event) and were then given an immediate test of recognition memory (initial memory test). Participants then listened to an audio narrative in which they were provided with postevent information that contained critical details that were either consistent, neutral, or misleading with respect to the original event. After the audio narrative, participants were given a final recognition memory test probing their memory for the original witnessed event. Participants in the no-warning group did not receive a warning about the veracity of postevent information. Participants in the prewarning group received a warning about the veracity of postevent information prior to the audio narrative. Participants in the postwarning group received a warning about the veracity of the postevent information after the audio narrative.

Fig. 2.

Behavioral results from experiments 1 and 2. (A) Results from the final memory test during the behavioral experiment (experiment 1). (B) Results from the final memory test during the fMRI experiment (experiment 2). Proportion correct refers to the proportion of trials within each trial type (consistent, neutral, misleading) that were answered correctly (i.e., the number of trials in which participants selected the correct video detail divided by the total number of trials within that trial type). Error bars indicate between-participant SEs. *P < 0.05.

Fig. 3.

Warnings increase sensory reactivation in visual processing regions during accurate memory decisions. (A) Activity in left occipital cortex (BA 18) was greater during accurate memory decisions (correct > incorrect) in participants who received a warning compared to participants who did not receive a warning. (B) Bar graph depicting mean activation (beta weights) within the occipital region of interest as a function of warning group (no-warning, prewarning, postwarning). Error bars indicate between-participant SEs. (C) Activity in the occipital cortex during accurate memory decisions was positively associated with memory performance on misleading trials (reduced misinformation effect).

Fig. 4.

Warnings decrease sensory reactivation in the auditory cortex on misleading trials. (A) Activity in the right primary auditory cortex (BA 41) was greater in participants who did not receive a warning compared to participants who did receive a warning during misleading trials (misleading > baseline). (B) Bar graph depicting mean activation (beta weights) within the auditory cortex region of interest as a function of warning group (no-warning, prewarning, postwarning). Error bars indicate between-participant SEs. (C) Activity in the auditory cortex during misleading trials was negatively associated with memory performance on misleading trials (increased misinformation effect).