Anodal Transcranial Direct Current Stimulation to the Left Rostrolateral Prefrontal Cortex Selectively Improves Source Memory Retrieval

Abstract

Functional neuroimaging studies have consistently implicated the left rostrolateral prefrontal cortex (RLPFC) as playing a crucial role in the cognitive operations supporting episodic memory and analogical reasoning. However, the degree to which the left RLPFC causally contributes to these processes remains underspecified. We aimed to assess whether targeted anodal stimulation—thought to boost cortical excitability—of the left RLPFC with transcranial direct current stimulation (tDCS) would lead to augmentation of episodic memory retrieval and analogical reasoning task performance in comparison to cathodal stimulation or sham stimulation. Seventy-two healthy adult participants were evenly divided into three experimental groups. All participants performed a memory encoding task on Day 1, and then on Day 2, they performed continuously alternating tasks of episodic memory retrieval, analogical reasoning, and visuospatial perception across two consecutive 30-min experimental sessions. All groups received sham stimulation for the first experimental session, but the groups differed in the stimulation delivered to the left RLPFC during the second session (either sham, 1.5 mA anodal tDCS, or 1.5 mA cathodal tDCS). The experimental group that received anodal tDCS to the left RLPFC during the second session demonstrated significantly improved episodic memory source retrieval performance, relative to both their first session performance and relative to performance changes observed in the other two experimental groups. Performance on the analogical reasoning and visuospatial perception tasks did not exhibit reliable changes as a result of tDCS. As such, our results demonstrate that anodal tDCS to the left RLPFC leads to a selective and robust improvement in episodic source memory retrieval.

Trading mental effort for confidence in the metacognitive control of value-based decision-making

“…Thus, the puzzling negative correlation between choice confidence and rRLPFC activity could be simply explained under the assumption that rRLPFC provides the neurocognitive resources that are instrumental for processing value-relevant information during decisions (and/or to compare item values). This resonates with the known involvement of rRLPFC in reasoning ( Desrochers et al, 2015 ; Dumontheil, 2014 ) or memory retrieval ( Benoit et al, 2012 ; Westphal et al, 2019 ).…”

Trading Mental Effort for Confidence in the Metacognitive Control of Value-Based Decision-Making

“…Thus, the puzzling negative correlation between choice confidence and rRLPFC activity could be simply explained under the assumption that rRLPFC provides the neurocognitive resources that are instrumental for processing value-relevant information during decisions. This resonates with the known involvement of rRLPFC in reasoning (Desrochers et al, 2015; Dumontheil, 2014) or memory retrieval (Benoit et al, 2012; Westphal et al, 2019).…”

Anodal Transcranial Direct Current Stimulation of Anterior Cingulate Cortex Modulates Subcortical Brain Regions Resulting in Cognitive Enhancement

“…Previous prefrontal tDCS studies mainly targeting the lateral prefrontal cortex (LPFC) region have reported that stimulation can influence a wide range of cognitive functions ranging from low-level attentional processes to higher-order decision making and working memory functions (Boonstra et al, 2016;Westphal et al, 2019) with some conflicting results (Berryhill et al, 2014;Tremblay et al, 2014). However, the impact of tDCS on the cingulate cortex is not clearly understood.…”