Effects of Ai-Chi Practice on Balance and Left Cerebellar Activation during High Working Memory Load Task in Older People: A Controlled Pilot Trial

Background: Normal aging is associated with balance and working memory decline. From a neurobiological standpoint, changes in cerebellar functional plasticity may mediate the decline in balance and working memory for older adults. Mounting evidence suggests that physical activity is beneficial for decreasing aging effects. Previous studies have focused on land-based physical activity and research concerning the aquatic environment is scarce. This study investigated the effectiveness of Ai-Chi on balance abilities and cerebral activation during a high working memory load task among community-dwelling older people. Methods: A total of 19 people aged 65–86 years were allocated to receive Ai-Chi practice (n = 6), structured on-land Ai-Chi practice (n = 7) or guided-imagery of Ai-Chi practice (n = 6) for a bi-weekly, 30-min exercise session for 12 weeks. Balance was measured by the Tinetti balance sub-test and working memory was measured by the N-back test during functional-MRI scan. Results: The Ai-Chi practice group presented a significant change in balance between pre and post intervention (balance t = −4.8, p < 0.01). In the whole-brain analysis, during high working memory load task, the Ai-Chi practice group presented a decrease in left cerebellar activation. Region of interest analyses yielded similar results by which pre-cerebellar activation was higher than post-intervention (t = 2.77, p < 0.05). Conclusions: Ai-Chi is an available, non-invasive intervention method that may serve as a tool to improve cerebellar activation that in turn might improve balance. In addition, our findings may provide new insights into the neuronal mechanisms that underlie both motor and cognitive abilities.

Investigating the Role of Executive Resources across Aesthetic and Non-Aesthetic Judgments

Aesthetic judgments dominate much of daily life by guiding how we evaluate objects, people, and experiences in our environment. One key question that remains unanswered is the extent to which more specialised or largely general cognitive resources support aesthetic judgments. To investigate this question in the context of executive resources, we examined the extent to which a central working memory load produces similar or different reaction time interference on aesthetic compared to non-aesthetic judgments. Across three pre-registered experiments that used Bayesian multi-level modelling approaches (N&gt;100 per experiment), we found clear evidence that a central working memory load produces similar reaction time interference on aesthetic judgments relative to non-aesthetic (motion) judgments. We also showed that this similarity in processing across aesthetic versus non-aesthetic judgments holds across variations in the form of art (people vs landscape; Exps. 1-3), medium type (artwork vs photographs; Exp. 2) and load content (art images vs letters; Exps. 1-3). These findings suggest that across a range of experimental contexts, as well as different processing streams in working memory (e.g., visual vs verbal), aesthetic and motion judgments commonly rely on a domain-general executive system, rather than a system that is more specifically tied to aesthetic judgments. In doing so, these findings shine new light on the cognitive architecture that supports aesthetic judgments, as well as how domain-general executive systems operate more generally in cognition.

Neuroanatomical correlates of working memory performance in Neurofibromatosis 1

Background: Neurofibromatosis 1 (NF1) is a single-gene neurodevelopmental disorder associated with cognitive and behavioural impairments, particularly with deficits in working memory. This study investigates the cerebral volumetric differences in adolescents with NF1 as compared to typically developing controls and how working memory task performance is associated with these differences. Methods: 31 adolescents aged 11-17 years were compared to age and sex-matched controls. NF1 subjects were assessed using detailed multimodal measurement of working memory at baseline followed by a 3T MR scan. A voxel-based morphometry approach was used to estimate the total and regional gray matter(GM) volumetric differences between the NF1 and control groups. The working memory metrics were subjected to a principal component analysis (PCA) approach. Finally, we examined how the components derived from PCA correlated with the changes in GM volume in the NF1 group, after adjusting for age, sex and total intracranial volume. Results: The NF1 cohort showed increased GM volumes in the thalamus, globus pallidus, caudate, putamen, dorsal midbrain and cerebellum bilaterally as compared to controls. The PCA yielded three independent behavioural components reflecting high memory load, low memory load and auditory working memory. Correlation analyses revealed that increased volume of the inferior lateral parietal cortex was associated with poorer performance on the high working memory load tasks. Increased volume of posterior cingulate cortex, a key component of the default mode network (DMN) was significantly associated with poorer performance on low working memory load tasks. Discussion: This is the first study to examine the neuroanatomical correlates of working memory in NF1 adolescents. Consistent with prior literature we show larger subcortical brain volumes in in the NF1 cohort. The strong association between posterior cingulate cortex volume and performance on low memory load conditions supports previously suggested hypotheses of deficient DMN structural development, which in turn may contribute to the cognitive impairments in NF1.