1. Transcranial direct current stimulation facilitates episodic memory encoding
Kevin Jones, Filiz Gözenman, & Marian Berryhill
Cognitive & Brain Sciences, University of Nevada
Introduction
The parietal lobe is involved in LTM, however the exact role is still being debated via various models.
(Subjective experience: Davidson 2008, CoBRA: Shimamura 2011, internal representations/output buffer/ mnemonic accumulator: Wagner 2005)
Question
Is the parietal lobe more involved in LTM at encoding or consolidation?
If encoding, tDCS should improve learning rate when applied during word-list learning.
Experiment 1
If consolidation, tDCS should improve long delay free-recall when applied during consolidation period.
Experiment 2
Methods
15 minutes of P3 tDCS (1.5 mA) during encoding of California Verbal Learning Task (CVLT)
CVLT is a test of learning, consolidation, and retrieval of word lists
Spatial 2-back
N = 16
15 minutes of P3 tDCS (1.5 mA) during consolidation
Dropped second 2-back and FC recognition tasks
Maybe switch learning rate for sdfr in exp 2
Experimental Design
Main Findings
Posterior parietal lobe is involved in encoding of new long-term memories
 Experiment 1: PPC TDCS improved learning rate of word lists as compared to sham stimulation
 Experiment 2: No benefit of stimulation after list learning during delay period
Conclusions
PPC sensitive to tDCS stimulation during encoding
PPC less relied upon during consolidation period
Kevin Jones:
Dr. Marian Berryhill:
Cognitive and Brain Sciences
Department of Psychology, MS 296
University of Nevada
Reno, NV 89557
References
Davidson, P.S., Anaki,D., Ciaramelli, E., Cohn, M., Kim, A.S., Murphy, K. J., Troyer, A.K., Moscovitch,M., and Levine,B.(2008) .Doeslateral parietal cortex support episodic memory?Evidence from focal lesion patients. Neuropsychologia 46, 1743 – 1755.
Shimamura, A.P. (2011). Episodic retrieval and the cortical binding of relational activity. Cogn. Affect. Behav. Neurosci. 11, 277–291.
Wagner, A.D., Shannon, B.J., Kahn,I., and Buckner, R.L.(2005). Parietal lobe contributions to episodic memory retrieval. Trends Cogn.Sci. 9, 445–453.
Experiment 1 – tDCS during encoding
Faster Learning!
Experiment 2 – tDCS during consolidation