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6,290 result(s) for "Executive Function - physiology"
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White matter plasticity in healthy older adults: The effects of aerobic exercise
White matter deterioration is associated with cognitive impairment in healthy aging and Alzheimer's disease. It is critical to identify interventions that can slow down white matter deterioration. So far, clinical trials have failed to demonstrate the benefits of aerobic exercise on the adult white matter using diffusion Magnetic Resonance Imaging. Here, we report the effects of a 6-month aerobic walking and dance interventions (clinical trial NCT01472744) on white matter integrity in healthy older adults (n = 180, 60–79 years) measured by changes in the ratio of calibrated T1- to T2-weighted images (T1w/T2w). Specifically, the aerobic walking and social dance interventions resulted in positive changes in the T1w/T2w signal in late-myelinating regions, as compared to widespread decreases in the T1w/T2w signal in the active control. Notably, in the aerobic walking group, positive change in the T1w/T2w signal correlated with improved episodic memory performance. Lastly, intervention-induced increases in cardiorespiratory fitness did not correlate with change in the T1w/T2w signal. Together, our findings suggest that white matter regions that are vulnerable to aging retain some degree of plasticity that can be induced by aerobic exercise training. In addition, we provided evidence that the T1w/T2w signal may be a useful and broadly accessible measure for studying short-term within-person plasticity and deterioration in the adult human white matter.
Coupling of functional connectivity and regional cerebral blood flow reveals a physiological basis for network hubs of the human brain
Human brain functional networks contain a few densely connected hubs that play a vital role in transferring information across regions during resting and task states. However, the relationship of these functional hubs to measures of brain physiology, such as regional cerebral blood flow (rCBF), remains incompletely understood. Here, we used functional MRI data of blood-oxygenation-level–dependent and arterial-spin–labeling perfusion contrasts to investigate the relationship between functional connectivity strength (FCS) and rCBF during resting and an N -back working-memory task. During resting state, functional brain hubs with higher FCS were identified, primarily in the default-mode, insula, and visual regions. The FCS showed a striking spatial correlation with rCBF, and the correlation was stronger in the default-mode network (DMN; including medial frontal-parietal cortices) and executive control network (ECN; including lateral frontal-parietal cortices) compared with visual and sensorimotor networks. Moreover, the relationship was connection–distance dependent; i.e., rCBF correlated stronger with long-range hubs than short-range ones. It is notable that several DMN and ECN regions exhibited higher rCBF per unit connectivity strength (rCBF/FCS ratio); whereas, this index was lower in posterior visual areas. During the working-memory experiment, both FCS–rCBF coupling and rCBF/FCS ratio were modulated by task load in the ECN and/or DMN regions. Finally, task-induced changes of FCS and rCBF in the lateral-parietal lobe positively correlated with behavioral performance. Together, our results indicate a tight coupling between blood supply and brain functional topology during rest and its modulation in response to task demands, which may shed light on the physiological basis of human brain functional connectome.
Inter- and intra-individual variability in alpha peak frequency
Converging electrophysiological evidence suggests that the alpha rhythm plays an important and active role in cognitive processing. Here, we systematically studied variability in posterior alpha peak frequency both between and within subjects. We recorded brain activity using MEG in 51 healthy human subjects under three experimental conditions — rest, passive visual stimulation and an N-back working memory paradigm, using source reconstruction methods to separate alpha activity from parietal and occipital sources. We asked how alpha peak frequency differed within subjects across cognitive conditions and regions of interest, and looked at the distribution of alpha peak frequency between subjects. In both regions we observed an increase of alpha peak frequency from resting state and passive visual stimulation conditions to the N-back paradigm, with a significantly higher alpha peak frequency in the 2-back compared to the 0-back condition. There was a trend for a greater increase in alpha peak frequency during the N-back task in the occipital vs. parietal cortex. The average alpha peak frequency across all subjects, conditions, and regions of interest was 10.3Hz with a within-subject SD of 0.9Hz and a between-subject SD of 2.8Hz. We also measured beta peak frequencies, and except in the parietal cortex during rest, found no indication of a strictly harmonic relationship with alpha peak frequencies. We conclude that alpha peak frequency in posterior regions increases with increasing cognitive demands, and that the alpha rhythm operates across a wider frequency range than the 8–12Hz band many studies tend to include in their analysis. Thus, using a fixed and limited alpha frequency band might bias results against certain subjects and conditions. •Alpha peak frequency increases with cognitive demand.•No strict harmonic relationship between alpha and beta.•Using a limited and fixed band for alpha biases against certain subjects/conditions.
Closing the Achievement Gap through Modification of Neurocognitive and Neuroendocrine Function: Results from a Cluster Randomized Controlled Trial of an Innovative Approach to the Education of Children in Kindergarten
Effective early education is essential for academic achievement and positive life outcomes, particularly for children in poverty. Advances in neuroscience suggest that a focus on self-regulation in education can enhance children's engagement in learning and establish beneficial academic trajectories in the early elementary grades. Here, we experimentally evaluate an innovative approach to the education of children in kindergarten that embeds support for self-regulation, particularly executive functions, into literacy, mathematics, and science learning activities. Results from a cluster randomized controlled trial involving 29 schools, 79 classrooms, and 759 children indicated positive effects on executive functions, reasoning ability, the control of attention, and levels of salivary cortisol and alpha amylase. Results also demonstrated improvements in reading, vocabulary, and mathematics at the end of kindergarten that increased into the first grade. A number of effects were specific to high-poverty schools, suggesting that a focus on executive functions and associated aspects of self-regulation in early elementary education holds promise for closing the achievement gap.
Virtual training leads to physical, cognitive and neural benefits in healthy adults
Physical activity, such as high-intensity intermittent aerobic exercise (HIE), can improve executive functions. Although performing strength or aerobic training might be problematic or not feasible for someone. An experimental situation where there is no actual movement, but the body shows physiological reactions, is during the illusion through immersive virtual reality (IVR). We aimed to demonstrate whether a virtual HIE-based intervention (vHIE) performed exclusively by the own virtual body has physical, cognitive, and neural benefits on the real body. 45 healthy young adults (cross-over design) experienced HIE training in IVR (i.e., the virtual body performed eight sets of 30 s of running followed by 30 s of slow walking, while the subject is completely still) in two random-ordered conditions (administered in two sessions one week apart): the virtual body is displayed in first-person perspective (1PP) or third-person perspective (3PP). During the vHIE, we recorded the heart rate and subjective questionnaires to confirm the effectiveness of the illusion; before and after vHIE, we measured cortical hemodynamic changes in the participants’ left dorsolateral prefrontal cortex (lDLPFC) using the fNIRS device during the Stroop task to test our main hypothesis. Preliminary, we confirmed that the illusion was effective: during the vHIE in 1PP, subjects’ heart rate increased coherently with the virtual movements, and they reported subjective feelings of ownership and agency. Primarily, subjects were faster in executing the Stroop task after the vHIE in 1PP; also, the lDLPFC activity increased coherently. Clinically, these results might be exploited to train cognition and body simultaneously. Theoretically, we proved that the sense of body ownership and agency can affect other parameters, even in the absence of actual movements.
Cognitive control training with domain-general response inhibition does not change children’s brains or behavior
Cognitive control is required to organize thoughts and actions and is critical for the pursuit of long-term goals. Childhood cognitive control relates to other domains of cognitive functioning and predicts later-life success and well-being. In this study, we used a randomized controlled trial to test whether cognitive control can be improved through a pre-registered 8-week intervention in 235 children aged 6–13 years targeting response inhibition and whether this leads to changes in multiple behavioral and neural outcomes compared to a response speed training. We show long-lasting improvements of closely related measures of cognitive control at the 1-year follow-up; however, training had no impact on any behavioral outcomes (decision-making, academic achievement, mental health, fluid reasoning and creativity) or neural outcomes (task-dependent and intrinsic brain function and gray and white matter structure). Bayesian analyses provide strong evidence of absent training effects. We conclude that targeted training of response inhibition does little to change children’s brains or their behavior. Cognitive control is important for later-life success and is often targeted for interventions. Here the authors show that response inhibition training in a large sample of children over 8 weeks did not change their brains or behavior in the short or long term.
Dissociable effects of acute SSRI (escitalopram) on executive, learning and emotional functions in healthy humans
Serotonin is implicated in multiple executive functions including goal-directed learning, cognitive flexibility, response inhibition and emotional regulation. These functions are impaired in several psychiatric disorders, such as depression and obsessive–compulsive disorder. We tested the cognitive effects of the selective serotonin reuptake inhibitor escitalopram, using an acute and clinically relevant dose (20 mg), in 66 healthy male and female volunteers in a double-blind, placebo-controlled study. Participants performed a cognitive test battery including a probabilistic and reversal learning task, the CANTAB intra-dimensional/extra-dimensional shift test of cognitive flexibility, a response inhibition task with interleaved stop-signal and No-Go trials and tasks measuring emotional processing. We showed that acute escitalopram administration impaired learning and cognitive flexibility, but improved the ability to inhibit responses in stop-signal trials while leaving unaffected acute emotional processing. Our findings suggest a dissociation of effects of acute escitalopram on cognitive functions, possibly mediated by differential modulation of brain serotonin levels in distinct functional neural circuits.
Long-term effects of institutional rearing, foster care, and brain activity on memory and executive functioning
Children experiencing psychosocial deprivation as a result of early institutional rearing demonstrate many difficulties with memory and executive functioning (EF). To date, there is scant evidence that foster care placement remediates these difficulties during childhood. The current study examined longitudinal trajectories of memory and EF from childhood to adolescence in the Bucharest Early Intervention Project, a randomized controlled trial of foster care for institutionally reared children. We demonstrate that both ever- and never-institutionalized children show age-related improvements on several measures of memory and EF from age 8 to 16. Distinct patterns were observed for different domains of functioning: (i) Early-emerging disparities in attention and short-term visual memory, as well as spatial planning and problem solving, between ever- and never-institutionalized children persisted through adolescence; (ii) the gap in spatial working memory between ever- and never-institutionalized children widened by adolescence; and (iii) early difficulties in visual-spatial memory and new learning among children in foster care were mitigated by adolescence. Secondary analyses showed that higher resting EEG alpha power at age 8 predicted better EF outcomes in several domains at age 8, 12, and 16. These results suggest that early institutional rearing has enduring consequences for the development of memory and EF, with the possibility of catch-up among previously institutionalized children who start out with higher levels of problems. Finally, interindividual differences in brain activity relate to memory and EF across ages, thus highlighting one potential biological pathway through which early neglect impacts long-term cognitive functioning.
Benefit of human moderate running boosting mood and executive function coinciding with bilateral prefrontal activation
Running, compared to pedaling is a whole-body locomotive movement that may confer more mental health via strongly stimulating brains, although running impacts on mental health but their underlying brain mechanisms have yet to be determined; since almost the mechanistic studies have been done with pedaling. We thus aimed at determining the acute effect of a single bout of running at moderate-intensity, the most popular condition, on mood and executive function as well as their neural substrates in the prefrontal cortex (PFC). Twenty-six healthy participants completed both a 10-min running session on a treadmill at 50% V ˙ O 2peak and a resting control session in randomized order. Executive function was assessed using the Stroop interference time from the color-word matching Stroop task (CWST) and mood was assessed using the Two-Dimensional Mood Scale, before and after both sessions. Prefrontal hemodynamic changes while performing the CWST were investigated using functional near-infrared spectroscopy. Running resulted in significant enhanced arousal and pleasure level compared to control. Running also caused significant greater reduction of Stroop interference time and increase in Oxy-Hb signals in bilateral PFCs. Besides, we found a significant association among pleasure level, Stroop interference reaction time, and the left dorsolateral PFCs: important brain loci for inhibitory control and mood regulation. To our knowledge, an acute moderate-intensity running has the beneficial of inducing a positive mood and enhancing executive function coinciding with cortical activation in the prefrontal subregions involved in inhibitory control and mood regulation. These results together with previous findings with pedaling imply the specificity of moderate running benefits promoting both cognition and pleasant mood.
Effects of Resistance Exercise Training on Cognitive Function and Physical Performance in Cognitive Frailty: A Randomized Controlled Trial
Cognitive frailty is defined as the presence of both physical frailty and cognitive impairment (clinical dementia rating score = 0.5), in the absence of dementia. It is characterized by concurrent physical frailty and potentially reversible cognitive impairment. In this study, we sought to elucidate the effects of high-speed resistance exercise training on cognitive function and physical performance in older adults with cognitive frailty. We conducted a parallel-group, randomized controlled trial involving community-living older adults with cognitive frailty. The participants' mean age was 73.9 (± 4.3 SD) years, and 69.8% (n=30) were female. Two different 4-month interventions included high-speed resistance exercise training group (n=22) and a control group (balance and band stretching, n=23). Frailty score, cognitive function (memory, processing speed, cognitive flexibility, working memory, executive function), physical function (SPPB, TUG, gait speed), and muscle strength (grip strength, knee extension strength) were assessed at baseline, 8 weeks, and 16 weeks. Statistical analysis showed that exercise improved performance significantly in the tests for cognitive function (processing speed and executive function, both p < 0.05), physical function (SPPB, TUG, gait speed, both p < 0.05), and muscle strength (grip strength, knee extension strength, both p < 0.05). However, no significant changes in frailty score were observed between intervention and either control group (p < 0.05). In conclusion, our findings indicate that high-speed resistance exercise training approaches are effective in improving cognitive function and physical performance in older adults with cognitive frailty. This study shows that it is feasible to identify older adults with cognitive frailty in the community and primary care setting for effective intervention to reduce their level of frailty and cognitive impairment.