Shaping memory accuracy by left prefrontal transcranial direct current stimulation

J Neurosci. 2014 Mar 12;34(11):4022-6. doi: 10.1523/JNEUROSCI.5407-13.2014.

Abstract

Human memory is dynamic and flexible but is also susceptible to distortions arising from adaptive as well as pathological processes. Both accurate and false memory formation require executive control that is critically mediated by the left prefrontal cortex (PFC). Transcranial direct current stimulation (tDCS) enables noninvasive modulation of cortical activity and associated behavior. The present study reports that tDCS applied to the left dorsolateral PFC (dlPFC) shaped accuracy of episodic memory via polaritiy-specific modulation of false recognition. When applied during encoding of pictures, anodal tDCS increased whereas cathodal stimulation reduced the number of false alarms to lure pictures in subsequent recognition memory testing. These data suggest that the enhancement of excitability in the dlPFC by anodal tDCS can be associated with blurred detail memory. In contrast, activity-reducing cathodal tDCS apparently acted as a noise filter inhibiting the development of imprecise memory traces and reducing the false memory rate. Consistently, the largest effect was found in the most active condition (i.e., for stimuli cued to be remembered). This first evidence for a polarity-specific, activity-dependent effect of tDCS on false memory opens new vistas for the understanding and potential treatment of disturbed memory control.

Keywords: brain stimulation; dorsolateral prefrontal cortex; executive functions; false memory; memory encoding; neuroenhancement.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Artifacts
  • Executive Function / physiology*
  • Female
  • Humans
  • Male
  • Memory, Episodic*
  • Neural Pathways / physiology
  • Pattern Recognition, Visual / physiology
  • Prefrontal Cortex / anatomy & histology*
  • Prefrontal Cortex / physiology*
  • Repression, Psychology*
  • Transcranial Magnetic Stimulation / methods*
  • Young Adult