High‐gamma power changes after cognitive intervention: preliminary results from twenty‐one senior adult subjects

Abstract

IntroductionBrain‐imaging techniques have begun to be popular in evaluating the effectiveness of cognitive intervention training. Although gamma activities are rarely used as an index of training effects, they have several characteristics that suggest their potential suitability for this purpose. This pilot study examined whether cognitive training in elderly people affected the high‐gamma activity associated with attentional processing and whether high‐gamma power changes were related to changes in behavioral performance.MethodsWe analyzed (MEG) magnetoencephalography data obtained from 35 healthy elderly subjects (60–75 years old) who had participated in our previous intervention study in which the subjects were randomly assigned to one of the three types of intervention groups: Group V trained in a vehicle with a newly developed onboard cognitive training program, Group P trained with a similar program but on a personal computer, and Group C was trained to solve a crossword puzzle as an active control group. High‐gamma (52–100 Hz) activity during a three‐stimulus visual oddball task was measured before and after training. As a result of exclusion in the MEG data analysis stage, the final sample consisted of five subjects in Group V, nine subjects in Group P, and seven subjects in Group C.ResultsResults showed that high‐gamma activities were differently altered between groups after cognitive intervention. In particular, members of Group V, who showed significant improvements in cognitive function after training, exhibited increased high‐gamma power in the left middle frontal gyrus during top‐down anticipatory target processing. High‐gamma power changes in this region were also associated with changes in behavioral performance.ConclusionsOur preliminary results suggest the usefulness of high‐gamma activities as an index of the effectiveness of cognitive training in elderly subjects.

Cognitive and neural plasticity in old age: A systematic review of evidence from executive functions cognitive training

“…Although Mozolic et al (2010) did not observe any structural changes after 8 hours of training, training-related functional increases in cerebral blood flow were found. Similarly, significant increases in frontal activation were observed in two other studies after 8 hours of cognitive training (Akimoto et al, 2016;Gaál and Czigler, 2018). Decreased frontal and parietal activation was observed after 9 to 12 hours training (Brehmer et al, 2011;Heinzel et al, 2016;Kühn et al, 2017), and increased activation in subcortical regions after 10 hours training (Brehmer et al, 2011).…”

“…Exploration of training dose indicated that 8 hours of multidomain training did not promote transfer (Akimoto et al, 2016). However, studies employing 8 hours of singledomain training demonstrated cognitive transfer, though improvements were limited and generally restricted to trained and near-transfer tasks (Gaál and Czigler, 2018;Mozolic et al, 2010).…”

“…Of these studies, three reported positive correlations, indicating that larger cognitive improvements were associated with increases in theta power along midline frontal regions (Anguera et al, 2013), as well as increased centroparietal CNV amplitudes (Niu et al, 2016), and P3 amplitudes (Tusch et al, 2016). Similarly, one study found that reductions in reaction time (better performance) were associated with larger increases of high-gamma power within the left medial frontal gyrus and intraparietal sulcus (Akimoto et al, 2016). Gajewski and Falkenstein 2012…”

“…One study utilized magnetoencephalography (MEG), reporting training-related increases in high-gamma power within the left medial frontal gyrus (target condition) and left thalamus (non-target condition) compared to an active control group (Akimoto et al, 2016).…”

“…One study demonstrated training-related gains on a composite measure of global cognition which included a combination of memory, speed, and EF measures (Lampit et al, 2015). For the attention domain, training-related improvements were only reported for the Test of Variables of Attention, but not for the Useful Field of View task (Anguera et al, 2013), or the Oddball task (Akimoto et al, 2016;O'Brien et al, 2017). Improvements were observed for untrained working memory tasks (Anguera et al, 2013;Gajewski and Falkenstein, 2018), as well as episodic memory assessed using the Verbal Paired Associates (recognition) task (Kim et al, 2017).…”