tDCS effects on task-related activation and working memory performance in traumatic brain injury: A within group randomized controlled trial

ABSTRACT

Non-invasive transcranial direct current stimulation (tDCS) has been reported to facilitate working memory in normal adults. There is some evidence in people with Traumatic Brain Injury (TBI) but overall evidence is mixed. This study aimed to address shortcomings of prior study designs in TBI to examine whether a single dose of tDCS would lead to benefits in working memory. Thirty people with severe, chronic TBI were administered a single session of either anodal tDCS (2 mA for 20 min) or sham tDCS (2 mA for 30 s), in a counterbalanced order, over the left parietal cortex while performing 1-back and 2-back working memory tasks. Skin conductance levels were examined as a measure of task activated arousal, a possible functional analogue of cortical excitability. We found that tDCS led to no improvements in accuracy on the working memory tasks. A slight increase in variability and reaction time with tDCS was related to decreased task activated arousal. Overall, this study yielded no evidence that a single session of tDCS can facilitate working memory for people with TBI.

KEYWORDS:

• Transcranial direct current stimulation (tDCS)
• Traumatic brain injury (TBI)
• Working memory
• Treatment
• Arousal

Acknowledgements

We are indebted to the people with brain injuries who participated in this research and to NHMRC for funding this trial.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Australian National Health and Medical Research Council (NHMRC) [grant number 1081923].