Event-related potential markers of brands false memory

Background and Aim : Electroencephalography (EEG) has been widely adopted for investigation of brain mechanism involved in different cognitive tasks such as learning and memory. In the case of memory retrieval, important role of frontal and parietal lobes for remembering of information has been indicated. However, about it is still unclear that how these regions exchange information during the memory retrieval. In this study, we tackle this question by investigation of ERP components during true and false memories of short-term autobiographical memories (STM) of brand contents. We hypothesized that frontal and parietal lobes are differently involved during true and false memory retrievals.Methods : Thirty six (12 men, 12 women, and 12children) healthy subjects voluntarily participated in this research. All the subjects performed a modified version of Deese Roediger McDermott false memory task using brands images. EEG signal was also recorded using a 32-channel amplifier while the subjects were exposed to the brands stimuli. Subsequently, ERP components of false and true memories were extracted and statistically compared with each other.Results : We found positive frontal amplitude associated with false memories is higher in the late time windows as compared to true memories. In contrast, ERP amplitude at parietal electrodes did not differ between true and false memories. Instead, parietal positivity was more pronounced during yes- compared to no-responses which could be counted as subjective reported memory by the participants. Consequently, our findings indicate that false memories differ from true memories with respect to late frontal activations.Conclusion : Contrary to findings of previous studies in the DRM paradigm, the late positive ERP component did not differ between true and false memories. This might indicate that true and false memories were associated with recollection processes to the same extent; yet, specific methodological details of this study might have contributed to this finding contradicting the literature. Regarding the stable effect of response type at the parietal ERP components, it is concluded that higher positive activities at the parietal region indicate subjectively experienced memory rather than objectively correct memory. In addition, our results indicate false memories produce higher amplitude of late positive ERP components as compare to true memories. To conclude, we assume that parietal positivity reflects subjectively experienced memory, whereas the frontal negativity is differentially associated with true and false memories. Activation over the frontal regions could incrementally hold the information and may add false information to the subjectively experienced and reported memories. As this was the first study examining the event-related potentials in the misinformation paradigm, further studies are required to replicate the findings in more application-oriented approaches. Nevertheless, the finding that true and false memories differ in patterns of frontal activation is promising, as it leads to an assumption that true and false memories can be differentiated by the amplitude of event-related potentials at the frontal regions.

Keywords:

False memory , Brain Waves , Autobiographical Memories