Acute moderate-intensity exercise improves 24-h sleep deprivation-induced cognitive decline and cerebral oxygenation: A near-infrared spectroscopy study

Background: Shift working is associated with a profound desynchronization of circadian rhythm and in particular, night-shift work disrupts normal circadian physiology. Sleep deprivation affects the functioning of certain brain areas and thus impairs cognitive performance. The purpose of this study was to investigate the effects of the night shift on cognitive performance and cerebral oxygenation/haemodynamics. Methods: A prospective, observational, comparative, randomized and cross-over study was carried out. A total of 74 intensive care unit nurses in Spain were included in the study. The following variables were measured: sociodemographic, burnout, anxiety, baseline cerebral oxygenation levels on night and day shift using a near-infrared spectroscopy system and cognitive task performance during a verbal fluency task to evaluate the alterations in the prefrontal cortex, assessed as changes in regional saturation index. Results: The average regional saturation index decreased significantly in the night shift (r = 0.560, p < 0.001). The ICU nurses showed a significant decrease in the verbal fluency test on average (8.53 ± 8.49, p < 0.001) and, in general, there was also a significant increase in anxiety score (3.17 ± 7.56, p = 0.001). Conclusions: Sleep deprivation during the night shift was considered to be related to decreased dorsolateral PFC reactivity. After the night shift, the nurses showed a decrease in prefrontal cortex activity and in cognitive performance.

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Imagery Use and Affective Responses During Exercise: An Examination of Cerebral Hemodynamics Using Near-Infrared Spectroscopy

Journal of Sport and Exercise Psychology ◽

10.1123/jsep.35.5.503 ◽

2013 ◽

Vol 35 (5) ◽

pp. 503-513 ◽

Cited By ~ 12

Author(s):

Gavin Tempest ◽

Gaynor Parfitt

Keyword(s):

Infrared Spectroscopy ◽

Frontal Cortex ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Ventilatory Threshold ◽

Cerebral Hemodynamics ◽

Affective Responses ◽

Moderate Intensity ◽

Moderate Intensity Exercise ◽

Control Activity

Imagery, as a cognitive strategy, can improve affective responses during moderate-intensity exercise. The effects of imagery at higher intensities of exercise have not been examined. Further, the effect of imagery use and activity in the frontal cortex during exercise is unknown. Using a crossover design (imagery and control), activity of the frontal cortex (reflected by changes in cerebral hemodynamics using near-infrared spectroscopy) and affective responses were measured during exercise at intensities 5% above the ventilatory threshold (VT) and the respiratory compensation point (RCP). Results indicated that imagery use influenced activity of the frontal cortex and was associated with a more positive affective response at intensities above VT, but not RCP to exhaustion (p < .05). These findings provide direct neurophysiological evidence of imagery use and activity in the frontal cortex during exercise at intensities above VT that positively impact affective responses.

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