The neural correlates of memory improvement following transcranial direct current stimulation combined with cognitive training
There is currently an urgent need for the development of an effective intervention for people at increased risk for dementia. My team has developed a novel intervention for this purpose involving the combination of mild electrical brain stimulation and targeted brain training exercises. We are currently testing the effectiveness of this intervention for improving memory in people at increased risk for dementia in an ongoing world-first randomised controlled trial. In this study we plan to use neuroimaging for the first-time to investigate the neural mechanisms associated with memory improvement following this intervention. This will be an important next step in the intervention’s development, as the results will help to inform which aspects of the intervention should be modified in order to further maximise memory improvements. If proven effective, this intervention could potentially be completed at home under medical supervision to help maintain memory functioning with normal ageing.
Currently, there is no effective intervention available for people at risk for dementia. The development of an effective intervention is therefore a national priority. In 2013, I commenced a world-first RCT to investigate the efficacy of a novel intervention for improving memory in people at increased risk for dementia; mild brain stimulation (transcranial direct current stimulation (tDCS)) combined with cognitive training (CT) (i.e., tDCS + CT). Preliminary results indicate that tDCS + CT is greater than 2-fold more effective than CT alone for improving memory in people diagnosed with amnestic mild cognitive impairment (aMCI). This RCT is due for completion in 2017. In this study, I plan to use functional magnetic resonance imaging (fMRI) for the first-time to investigate the neural mechanisms for memory improvement following tDCS+ CT. Twelve participants diagnosed with aMCI will complete a memory task during fMRI before and after completing 15 sessions of active or sham tDCS + CT. Analyses will examine neural changes following tDCS + CT and potential associations with objectively assessed memory improvement following the intervention. Results will inform which aspects of the intervention (e.g., tDCS electrode placements, CT tasks) should be modified to further enhance treatment efficacy of this promising new intervention.
Dr Martin is a post doctorate researcher and a practicing clinical neuropsychologist who conducts his research at the School of Psychiatry, University of New South Wales. Dr Martin has been investigating the cognitive enhancing effects of mild brain stimulation for over 8 years.