Abstract:

In recent years, numerous strategies have been developed in an attempt to maintain or enhance cognitive functions in the elderly. Cognitive training (CT) has been widely implemented and is currently accepted as the most promising method to alleviate cognitive decline. Several techniques have been combined with CT to explore the synergetic effects and, recently, a beneficial effect has been shown after the combination with transcranial direct current stimulation (tDCS). In our ongoing project, we use an innovative design to further explore the synergetic effects of CT combined with tDCS to investigate neuroplasticity in older adults. Specifically, we are testing whether CT and excitatory tDCS over the left dorsolateral prefrontal cortex (lDLPFC) or right cerebellar cortex (rCC) facilitates episodic memory, compared with sham stimulation and a wait list control group. We present data from 22 healthy elderly who already completed the study (mean age=66.8, SD=4.7). Participants received either CT and sham (n=5) or excitatory tDCS over the lDLPFC (n=5) or rCC (n=5), or a wait list control group (n=5). CT was applied daily for 1 hour, after 20 minutes of tDCS, over 12 sessions. Performance on memory and other cognitive tasks was evaluated at baseline and post-intervention. Preliminary data suggest an improvement in verbal and visual episodic memory tasks in the groups receiving CT + tDCS, as well as in some language tasks (verbal fluency). Interestingly, there is a tendency for a greater improvement and consistency in the group receiving CT + tDCS in the rCC. Although such results should be interpreted with caution due to the small sample size, these preliminary data suggest that CT and neuromodulation hold promise as a means to enhance cognitive functions in healthy elderly. If proven true, greater light may be shed on the role of the cerebellar cortex in cognitive processing.