چکیده (انگلیسی):

Background: Transcranial direct current stimulation (tDCS) is a technique that can systematically modify behaviour
by inducing changes in the underlying brain function. In order to better understand the neuromodulatory effect of
tDCS, the present study examined the impact of tDCS on performance in a working memory (WM) task and its
underlying neural activity. In two experimental sessions, participants performed a letter two-back WM task after
sham and either anodal or cathodal tDCS over the left dorsolateral prefrontal cortex (DLPFC).
Results: Results showed that tDCS modulated WM performance by altering the underlying oscillatory brain activity
in a polarity-specific way. We observed an increase in WM performance and amplified oscillatory power in the
theta and alpha bands after anodal tDCS whereas cathodal tDCS interfered with WM performance and decreased
oscillatory power in the theta and alpha bands under posterior electrode sides.
Conclusions: The present study demonstrates that tDCS can alter WM performance by modulating the underlying
neural oscillations. This result can be considered an important step towards a better understanding of the
mechanisms involved in tDCS-induced modulations of WM performance, which is of particular importance, given
the proposal to use electrical brain stimulation for the therapeutic treatment of memory deficits in clinical settings.