Effects of Anodal Transcranial Direct Current Stimulation Over the Ventrolateral Prefrontal Cortex on Episodic Memory Formation and Retrieval.

In the past decade, several studies have investigated the effects of transcranial direct current stimulation (tDCS) on episodic memory abilities. However, the specific conditions under which tDCS affects memory remain largely unclear. Here, we report data from 4 experiments aimed at investigating the effects of anodal tDCS over the left ventrolateral prefrontal cortex (VLPFC) on verbal episodic memory. We evaluated tDCS-induced effects as a function of time of administration, nature of the memory encoding task, and age of the participants. A robust enhancement of memory performance was only found when anodal tDCS was delivered during intentional memorization. This enhancement was evident in young and older adults. tDCS applied during incidental memorization or during retrieval did not induce any modulation of memory performance, and memory was unaffected by offline administration before encoding or retrieval. These results show that the modulation of episodic memory functions by anodal tDCS over the left VLPFC is dependent upon the time of administration and the nature of the memory task. The findings may help profile the optimal stimulation protocols for neurorehabilitation interventions on individuals with memory decline.

Learning facts during aging: the benefits of curiosity.

Background/study context: Recent studies have shown that young adults better remember factual information they are curious about. It is not entirely clear, however, whether this effect is retained during aging. Here, the authors investigated curiosity-driven memory benefits in young and elderly individuals. METHODS: In two experiments, young (age range 18-26) and older (age range 65-89) adults read trivia questions and rated their curiosity to find out the answer. They also attended to task-irrelevant faces presented between the trivia question and the answer. The authors then administered a surprise memory test to assess recall accuracy for trivia answers and recognition memory performance for the incidentally learned faces. RESULTS: In both young and elderly adults, recall performance was higher for answers to questions that elicited high levels of curiosity. In Experiment 1, the authors also found that faces presented in temporal proximity to curiosity-eliciting trivia questions were better recognized, indicating that the beneficial effects of curiosity extended to the encoding of task-irrelevant material. CONCLUSIONS: These findings show that elderly individuals benefit from the memory-enhancing effects of curiosity. This may lead to the implementation of learning strategies that target and stimulate curiosity in aging.

Brain indices of disagreement with one's social values predict EU referendum voting behavior.

Pre-electoral surveys typically attempt, and sometimes fail, to predict voting behavior on the basis of explicit measures of agreement or disagreement with a candidate or political position. Here, we assessed whether a specific brain signature of disagreement with one's social values, the event-related potential component N400, could be predictive of voting behavior. We examined this possibility in the context of the EU referendum in the UK. In the 5 weeks preceding the referendum, we recorded the N400 while participants with different vote intentions expressed their agreement or disagreement with pro- and against-EU statements. We showed that the N400 responded to statements incongruent with one's view regarding the EU. Crucially, this effect predicted actual voting behavior in decided as well as undecided voters. The N400 was a better predictor of voting choice than an explicit index of preference based on the behavioral responses. Our findings demonstrate that well-defined patterns of brain activity can forecast future voting behavior.