Search

This study investigated the role of arousal and effort costs in the cognitive benefits of alternating between sitting and standing postures using a sit‐stand desk, while measuring executive functions, self‐reports, physiology, and neural activity in a 2‐h laboratory session aimed to induce mental fatigue. Two sessions were conducted with a one‐week gap, during which participants alternated between sitting and standing postures each 20‐min block in one session and remained seated in the other. In each block, inhibition, switching, and updating were assessed. We examined effects of time‐on‐task, acute (local) effects of standing versus sitting posture, and cumulative (global) effects of a standing posture that generalize to the subsequent block in which participants sit. Results (N = 43) confirmed that time‐on‐task increased mental fatigue and decreased arousal. Standing (versus sitting) led to acute increases in arousal levels, including self‐reports, alpha oscillations, and cardiac responses. Standing also decreased physiological and perceived effort costs. Standing enhanced processing speed in the flanker task, attributable to shortened nondecision time and speeded evidence accumulation processes. No significant effects were observed on higher‐level executive functions. Alternating postures also increased heart rate variability cumulatively over time. Exploratory mediation analyses indicated that the positive impact of acute posture on enhanced drift rate was mediated by self‐reported arousal, whereas decreased nondecision time was mediated by reductions in alpha power. In conclusion, alternating between sitting and standing postures can enhance arousal, decrease effort costs, and improve specific cognitive and physiological outcomes. [ABSTRACT FROM AUTHOR]

In natural languages, two negating elements that cancel each other out (as innot impossible) are logically equivalent to the non-negated word form (in this case,possible). It has been proposed that the function of sentential double negation is to create coherence between sentences containing opposing information. Thus,not impossibleis functionally different frompossible. The present ERP study tested this hypothesis in Dutch. Native speakers read sentences in which evoked negative expectations are cancelled by a second sentence including either a double negation or the corresponding non-negated word form. Results showed that non-negated word forms, such aspossible, elicited a larger N400 effect than double negations, such asnot impossible. We suggest that canceling out a negative expectation by a double negation compared to the non-negated word form, makes it easier for the reader to integrate the two sentences semantically and connect them to the present discourse. [ABSTRACT FROM PUBLISHER]

Rationale: The P3 is a ubiquitous component of stimulus-driven neural activity that can be observed in scalp electrophysiological recordings. Multiple lines of evidence suggest an important role for the noradrenergic system in the generation of the P3. However, pharmacological studies of the P3 using noradrenergic manipulations have so far been limited to agents that affect α2-receptor signaling. Objectives: The present study investigated whether β-adrenergic receptors are involved in the generation of the P3 and the error positivity (Pe), a component of the event-related potential that is elicited by errors and that bears many similarities to the P3. Methods: We used a double-blind, placebo-controlled, crossover design in which we examined in human participants ( N = 16) the effect of a single dose of propranolol (80 mg) on the amplitudes of the P3 observed in visual and auditory oddball tasks and the Pe observed in a flanker task. Results: We found that P3s to auditory stimuli were increased in amplitude following treatment with propranolol. Propranolol also modulated the P3 to visual stimuli, but in a direction dependent on participants' level of trait anxiety: In participants with lower trait anxiety, propranolol resulted in a (non-significant) decrease in P3 amplitudes; in participants with higher trait anxiety, propranolol significantly enhanced P3 amplitude. Propranolol did not modulate the amplitude of the Pe or behavioral measures of conflict/error-related performance adjustments. Conclusions: These results provide the first evidence for involvement of β-adrenergic receptors in P3 generation. We speculate that propranolol affected the P3 through actions at β2-receptors in the locus coeruleus. [ABSTRACT FROM AUTHOR]

This study investigated the role of arousal and effort costs in the cognitive benefits of alternating between sitting and standing postures using a sit-stand desk, while measuring executive functions, self-reports, physiology, and neural activity in a 2-h laboratory session aimed to induce mental fatigue. Two sessions were conducted with a one-week gap, during which participants alternated between sitting and standing postures each 20-min block in one session and remained seated in the other. In each block, inhibition, switching, and updating were assessed. We examined effects of time-on-task, acute (local) effects of standing versus sitting posture, and cumulative (global) effects of a standing posture that generalize to the subsequent block in which participants sit. Results (N = 43) confirmed that time-on-task increased mental fatigue and decreased arousal. Standing (versus sitting) led to acute increases in arousal levels, including self-reports, alpha oscillations, and cardiac responses. Standing also decreased physiological and perceived effort costs. Standing enhanced processing speed in the flanker task, attributable to shortened nondecision time and speeded evidence accumulation processes. No significant effects were observed on higher-level executive functions. Alternating postures also increased heart rate variability cumulatively over time. Exploratory mediation analyses indicated that the positive impact of acute posture on enhanced drift rate was mediated by self-reported arousal, whereas decreased nondecision time was mediated by reductions in alpha power. In conclusion, alternating between sitting and standing postures can enhance arousal, decrease effort costs, and improve specific cognitive and physiological outcomes., (© 2024 The Author(s). Psychophysiology published by Wiley Periodicals LLC on behalf of Society for Psychophysiological Research.)

Tai Chi Chuan (TCC) is a promising intervention against age-related decline. Though previous studies have shown benefits in motoric and cognitive domains, it is unclear how these effects are functionally related. Therefore, a randomized controlled trial was conducted in an aging population (53-85). Two measures of motor functioning - motor speed and functional balance - and three cognitive control measures - shifting, updating and inhibition - were included. The TCC condition consisted of an online 10 week 20 lessons video program of increasing level and control condition of educational videos of similar length and frequency. All analyses were done with Bayesian statistics. Counter to expectation no differences were found in cognition between TCC and control pre-to-posttest. However, there was extreme evidence for TCC benefits on functional balance and moderate evidence for increased motoric speed. After weighing the evidence and limitations of the intervention we conclude that TCC does not enhance cognitive control.