Exploring the effects of non-invasive brain stimulation on source memory: A systematic review

Diana R. Pereira1, Ana C. Teixeira-Santos1,  Alberto Lema1

1. Psychological Neuroscience Lab, CIPsi, School of Psychology, University of Minho, Braga, Portugal

OBJECTIVE: This work aimed to provide an overview of the main findings related to effects of non-invasive brain stimulation (NIBS) on source memory, i.e., our ability to remember and decide about details (e.g., stimulus color) pertaining to a study episode.

METHODS: A qualitative systematic review of the literature was conducted following the PRISMA guidelines and 17 articles published between 2006 and 2020 were included

RESULTS: Most studies used transcranial direct current stimulation (tDCS; n = 9) or transcranial magnetic stimulation (TMS; n = 5). They focused the stimulation on retrieval processes and were mainly conducted with healthy participants. Besides the methodological heterogeneity found across studies, it was possible to observe that most of them targeted prefrontal cortex sites. The findings were contradictory, including enhancing, deleterious or null effects. A more consistent modulatory role of NIBS on source memory was found for posterior parietal cortex. Also, factors such as the type of source memory task (e.g., reality monitoring vs. internal source memory) and time of day were found to influence the effects of NIBS on source memory.

CONCLUSIONS: NIBS appear to influence source memory performance under certain circumstances. Nonetheless, the conditions under which these techniques modulate or not source memory remain to be specified and require further investigation.

KEYWORDS: non-invasive brain stimulation; source memory; systematic review

ACKNOWLEDGMENTS: None

FUNDING/FINANCIAL SUPPORT: This work was supported by two Doctoral grants of the Portuguese Foundation for Science and Technology (FCT) awarded to AL (PD/BD/142821/2018) and to DRP (PD/BD/105964/2014).

DOI: https://doi.org/10.21801/ppcrj.2020.S1.34