| Title |
Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training
|
|---|---|
| Published in |
Psychopharmacology, September 2002
|
| DOI | 10.1007/s00213-002-1217-9 |
| Pubmed ID | |
| Authors |
Harris R. Lieberman, William J. Tharion, Barbara Shukitt-Hale, Karen L. Speckman, Richard Tulley |
| Abstract |
When humans are acutely exposed to multiple stressors, cognitive performance is substantially degraded. Few practical strategies are available to sustain performance under such conditions. This study examined whether moderate doses of caffeine would reduce adverse effects of sleep deprivation and exposure to severe environmental and operational stress on cognitive performance. Volunteers were 68 U.S. Navy Sea-Air-Land (SEAL) trainees, randomly assigned to receive either 100, 200, or 300 mg caffeine or placebo in capsule form after 72 h of sleep deprivation and continuous exposure to other stressors. Cognitive tests administered included scanning visual vigilance, four-choice visual reaction time, a matching-to-sample working memory task and a repeated acquisition test of motor learning and memory. Mood state, marksmanship, and saliva caffeine were also assessed. Testing was conducted 1 and 8 h after treatment. Sleep deprivation and environmental stress adversely affected performance and mood. Caffeine, in a dose-dependent manner, mitigated many adverse effects of exposure to multiple stressors. Caffeine (200 and 300 mg) significantly improved visual vigilance, choice reaction time, repeated acquisition, self-reported fatigue and sleepiness with the greatest effects on tests of vigilance, reaction time, and alertness. Marksmanship, a task that requires fine motor coordination and steadiness, was not affected by caffeine. The greatest effects of caffeine were present 1 h post-administration, but significant effects persisted for 8 h. Even in the most adverse circumstances, moderate doses of caffeine can improve cognitive function, including vigilance, learning, memory, and mood state. When cognitive performance is critical and must be maintained during exposure to severe stress, administration of caffeine may provide a significant advantage. A dose of 200 mg appears to be optimal under such conditions. |
X Demographics
The data shown below were collected from the profiles of 23 X users who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United States | 11 | 48% |
| Russia | 1 | 4% |
| Romania | 1 | 4% |
| Canada | 1 | 4% |
| France | 1 | 4% |
| Unknown | 8 | 35% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 20 | 87% |
| Practitioners (doctors, other healthcare professionals) | 2 | 9% |
| Scientists | 1 | 4% |
Mendeley readers
The data shown below were compiled from readership statistics for 618 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United States | 5 | <1% |
| Sweden | 2 | <1% |
| France | 1 | <1% |
| Austria | 1 | <1% |
| Malaysia | 1 | <1% |
| Uganda | 1 | <1% |
| India | 1 | <1% |
| Canada | 1 | <1% |
| Australia | 1 | <1% |
| Other | 4 | <1% |
| Unknown | 600 | 97% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Bachelor | 140 | 23% |
| Student > Master | 98 | 16% |
| Student > Ph. D. Student | 67 | 11% |
| Researcher | 56 | 9% |
| Student > Postgraduate | 26 | 4% |
| Other | 102 | 17% |
| Unknown | 129 | 21% |
| Readers by discipline | Count | As % |
|---|---|---|
| Psychology | 131 | 21% |
| Sports and Recreations | 62 | 10% |
| Medicine and Dentistry | 62 | 10% |
| Agricultural and Biological Sciences | 58 | 9% |
| Nursing and Health Professions | 25 | 4% |
| Other | 128 | 21% |
| Unknown | 152 | 25% |
Attention Score in Context
This research output has an Altmetric Attention Score of 361. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 20 February 2024.
All research outputs
#89,913
of 26,017,215 outputs
Outputs from Psychopharmacology
#26
of 5,442 outputs
Outputs of similar age
#45
of 50,768 outputs
Outputs of similar age from Psychopharmacology
#1
of 24 outputs
Altmetric has tracked 26,017,215 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 99th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 5,442 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 12.1. This one has done particularly well, scoring higher than 99% of its peers.
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We're also able to compare this research output to 24 others from the same source and published within six weeks on either side of this one. This one has done particularly well, scoring higher than 95% of its contemporaries.