Selecting an appropriate control group for studying the effects of exercise on cognitive performance.

Differences in expectations between experimental and control groups can influence the outcomes of exercise interventions, emphasizing the need to match expectations across study groups. This online study examined whether the expectations to improve the performance of different cognitive tasks differ between various activities commonly used in research on the effects of exercise and cognitive function. Two hundred and five middle-aged adults performed two reaction-time tasks and one memory task. They were then asked to rate, on a 1-5 Likert scale, their expectations to improve performance in those tasks should they engage in six types of activities for three months: brisk walking, resistance exercise, stretching and balance exercises, watching videos with lectures on art, history, and science, a program of relaxation techniques, and yoga/tai chi/meditation. Results revealed that the highest expectations for improvement were associated with relaxation techniques and yoga/tai chi/meditation. Some activities, such as brisk walking and stretch and balance exercises, shared similar expectations. Previous knowledge of the possible beneficial effects of exercise on cognitive performance also led to higher expectations. To establish causal relationships, researchers should strive to use activities that share similar expectations to improve performance for the experimental and control groups. The findings of this study provide such activity pairs. Finally, researchers should also try to match participants with and without prior knowledge of the benefits of exercise to cognitive function between experimental and control groups.

Is There a Preferred Mode of Exercise for Cognition Enhancement in Older Age?-A Narrative Review.

The aim of this review is to examine the moderating effect of the mode of exercise on the exercise-cognition relationship. Is one mode of exercise more efficient in enhancing cognition than the other? For example, is aerobic exercise preferable over balance training? Based on official guidelines for old age, exercise modes include aerobic activity, strength (resistance) training, flexibility, balance, and coordination. In relation to cognition, these exercise modes are further divided into two categories: physical training-aerobic and strength, and motor training-balance, coordination, and flexibility. The physical training activities are repetitive and automatic in nature, and require high metabolic energy and relatively low neuromuscular effort. The motor activities involve high neuromuscular demands and relatively low metabolic demands. In addition, there are specific movement skills that require more neuromuscular effort (e.g., Tai Chi), and sometimes also greater metabolic demands (e.g., tennis). Selected studies examining the effect of various modes of exercise on cognition contend that both training categories affect neuroplasticity, and consequently cognitive functioning. However, there are two main differences between them: (1) Physical training affects cognition via improvement in cardiovascular fitness, whereas motor training affects cognition directly; (2) Physical training affects neuroplasticity and cognition in a global manner, while motor training is task-specific in increasing brain neuroplasticity and in affecting cognition. Examining the underpinnings of these pathways reveals that there is a difference in the underlying forces behind the two training categories. In the physical training category, it is the intensity of training that enhances neuroplasticity and consequently improves cognition, while in the motor activities it is the task complexity that increases neuroplasticity, which improves cognition. Dual-task training, which includes cognitive demands in addition to physical or motor activity, has proven more effective in improving cognitive functioning than a single task. The implications are that if all training components traditionally recommended by official bodies-physical as well as motor training-are efficient in enhancing cognition, then we merely have to emphasize the inclusion of all exercise modes in our routine exercise regimen for physical as well as cognitive health in advanced age.

Clinical Effects of a Commercial Supplement of Ophiocordyceps sinensis and Ganoderma lucidum on Cognitive Function of Healthy Young Volunteers.

Ophiocordyceps sinensis (= Cordyceps sinensis) and Ganoderma lucidum are medicinal mushrooms used in traditional Chinese medicine. The effects of O. sinensis and G. lucidum on cognitive function have been evaluated through the use of animal models and in vitro studies, which indicated beneficial effects. The purpose of this study was to evaluate the effects of treatment with a commercially available supplement of O. sinensis and G. lucidum on cognitive function in young, healthy human participants. Physical education students (n = 96 [53 men, 43 women]; mean ± standard deviation age, 26.3 ± 3.21 years) were randomly divided into 3 treatment groups: highdose supplement (HD) group, low-dose supplement (LD) group, and a placebo (PL) group. Each group received the treatment, administered by a technician blinded to supplements/placebo, for 30 days. Participants were evaluated for various cognitive functions before and immediately after treatment. Evaluation of cognitive function domains-global cognitive score, memory, executive function, attention, information processing speed, visuospatial ability, verbal function, and motor skills-showed no significant differences between groups. These results indicate that a combination of O. sinensis and G. lucidum supplements for 30 days did not enhance cognitive function domains in young healthy participants.

Age-related differences in human corticospinal excitability during simple reaction time.

Age-related declines in central processing may delay the facilitation of corticospinal (CS) tracts that underlie emergence of voluntary responses to external stimuli. To explore this effect, single pulse transcranial magnetic stimulation (TMS) was applied to the left motor cortex at different latencies from the go-signal (auditory tone) during a simple reaction time (SRT) task with the right or left thumb [i.e. right (RHM) or left hand move (LHM)]. Motor evoked potentials (MEPs) in the right abductor pollicis brevis (APB) were recorded from eleven healthy right-handed participants (aged 22-65; six young adults and five old adults). Both age groups showed significant facilitation of CS excitability approximately 100-120 ms from the onset of the go-signal in the RHM SRT that occurred before the onset of EMG voluntary burst, with no evidence for motor slowing in old adults. Old adults demonstrated a significant facilitation of MEPs in the time that preceded the go-signal for RHM SRT and a marked depression of CS excitability in preparation for the LHM SRT that was sustained up to 80 ms after the onset of the go-signal. Both effects were not seen in young adults. While the small number of participants may hinder the generality of the present observations, this pilot study suggests for the first time that old adults implemented selective tuning of CS excitability prior to the onset of the go command to speed up their response generation.

Mood alterations in mindful versus aerobic exercise modes.

The results of most recent studies have generally indicated an improvement in mood after participation in aerobic exercise. However, only a few researchers have compared mindful modes of exercise with aerobic exercise to examine the effect of 1 single session of exercise on mood. In the present study, the authors assessed state anxiety, depressive mood, and subjective well-being prior to and following 1 class of 1 of 4 exercise modes: yoga, Feldenkrais (awareness through movement), aerobic dance, and swimming; a computer class served as a control. Participants were 147 female general curriculum and physical education teachers (mean age = 40.15, SD = 0.2) voluntarily enrolled in a 1-year enrichment program at a physical education college. Analyses of variance for repeated measures revealed mood improvement following Feldenkrais, swimming, and yoga but not following aerobic dance and computer lessons. Mindful low-exertion activities as well as aerobic activities enhanced mood in 1 single session of exercise. The authors suggest that more studies assessing the mood-enhancing benefits of mindful activities such as Feldenkrais and yoga are needed.