The role of the prefrontal cortex in accuracy of judgments of learning
Alexandra M. Gaynor1, Elizabeth F. Chua1,2; 1The Graduate Center, The City University of New York, 2Brooklyn College, The City University of New York
Accurate awareness of one’s memory is crucial for effective control of learning. When individuals make confidence judgments at study about their ability to remember information at later test, known as Judgments of Learning (JOLs), they often base JOLs on cues that are not predictive of memory accuracy, such as encoding fluency, while disregarding cues such as depth of encoding, which do influence memory accuracy. Neuroimaging studies suggest the anterior prefrontal cortex (aPFC) is involved in JOL accuracy, and the dorsolateral prefrontal cortex (DLPFC) is associated with the magnitude of JOL ratings; however, no studies have tested the roles of these regions in JOLs that are based on different cues. We applied high-definition transcranial direct current stimulation (HD-tDCS) over the aPFC, DLPFC, and sham stimulation while participants studied and gave JOLs to high-frequency and low-frequency words, presented upright or inverted 180°. Participants took an old/new recognition test 24 hours later. Results demonstrated that participants gave higher JOLs to high-frequency words (p<0.01) but had better memory for low-frequency words (p<0.001). They gave marginally higher JOLs to upright words (p=0.08) but had better memory for inverted words (p<0.001). There was a marginally significant interaction (p=0.07) between the effects of stimulation and frequency on JOL accuracy: while JOL accuracy was similar for high- and low-frequency words under both sham and DLPFC stimulation, aPFC stimulation significantly improved JOL accuracy for low-frequency words. Results suggest the role of the aPFC in JOL accuracy may vary with the cues on which JOLs are based.
Topic Area: LONG-TERM MEMORY: Episodic