Key evidence an nummers
| Evidence | Quantitative result | Limit |
|---|---|---|
| Chronic sleep restriction experiment | 4, 6 or 8 oors in bed fur 14 nichts | Controlled conditions in healthy adults |
| Short-term total-deprivation meta-analysis | 70 airticles, 147 cognitive tests | Different fae chronic pairtial restriction |
| Simple-attention lapses in that synthesis | Hedges' g = −0.776; 95% CI −0.96 to −0.60 | Standardised impairment, no milliseconds |
The restriction experiment haed 48 healthy adults aged 21–38 across its experimental conditions. Time in bed is a chance tae sleep, no a measured promise that ilka pairticipant slept that lang. Its growin deficits are evidence against assummin that feelin uised tae a short nicht means performance isnae affectit. Van Dongen et al., 2003
The meta-analysis keekit at short-term total sleep deprivation, unner 48 oors, an separated cognitive domains. Its muckle effect on simple-attention lapses cannae be turnt intae a fixed percentage slowin or an equivalent nummer o IQ pynts. The sign means poorer performance wi deprivation, no a negative nummer o real-warl lapses. Lim et al., 2010
Hou a guid fastest response can miss the problem
Somebody can respond quickly on mony trials yet hae the odd gey slow response. Sustained psychomotor vigilance tasks are designed tae pick up that pattern. Basner and Dinges fand that the choice o outcome haed a strang effect on sensitivity tae sleep loss; response-speed an lapse measures wur mair uissfu than relyin on the mean or median reaction time alane. Basner et al., 2011
A brief visual gemme samples juist a wee pairt o this behaviour. Woods an colleagues' calibrated simple-reaction procedure is a different experiment, wi different timin an scorin. Its average isnae a conversion table fae rested tae sleep-deprived fur yer browser. Woods et al., 2015
Whit affects it?
Age, sleep history an context maitter
The chronic restriction study's young-adult sample disnae gie penalties fur ilka age or sex fur everybody. Hou lang somebody's been waukin, sleep on previous nichts an the cognitive task aa affect the comparison. The meta-analysis fand differences atween domains, an that's anither raison yin solved puzzle or yin quick response cannae prove that sleep loss disnae hae an effect. Van Dongen et al., 2003 Lim et al., 2010
Device an saftware timin are ither sources o variation. A chynged input device can shift a score on its ain, separate fae sleep. When ye're makin an informal comparison atween days, uise the same set-up an dinnae read a wee, ane-off difference as a precise sleep effect. Anwyl-Irvine et al., 2020
Whit's backed up in practice?
The adult sleep consensus recommends regularly gettin at least seven oors o sleep fur adults aged 18–60, while adaein that fowk vary. That's health guidance fur the population, no a checked nummer o oors needed tae beat a reaction-time record. A short gemme cannae certify that ye're fit tae drive or dae safety-critical wark either. Watson et al., 2015 Basner et al., 2011
Caffeine can chynges baith alertness an sleep later on. A meta-analysis fand an average reduction in the total time slept efter it, an a controlled evenin study fand disruption even whan a substantial dose o caffeine wis taen hours afore bed. Neither result backs up swapin sleep fur caffeine tae get a reassurin browser score. Gardiner et al., 2023 Drake et al., 2013
Fur watchin yersel, write doon yer chance tae sleep alangside repeated results, an treat ony link atween them as an experiment. Dinna deliberately cut doun on sleep tae mak a afore-an-efter demonstration. The usefu scientific comparison comes fae controlled studies, no frae treatin yin unusually guid or ill gemme as a diagnosis. Lim et al., 2010 Van Dongen et al., 2003
Gie the related free test a try
Reaction time test
Uise the reaction time test tae keek at consistency as weel as speed, in yer usual safe conditions. Keep yer device an input method the same. It's no the laboratory psychomotor vigilance test, an it disnae clear ye fur drivin, shift wark or ony ither safety-critical activity.
Common questions
Can I feel fine while performance gets waur?
Aye. In the chronic restriction study, how sleepy fowk felt didnae closely track the growin performance deficits. Van Dongen et al., 2003
Hou mony milliseconds does yin bad nicht add?
The evidence cited disnae back up yin value fur everybody. The task, yer sleep history an whether ye keek at lapses or central response time aa chynges the answer. Lim et al., 2010 Basner et al., 2011
Does a fast score mean I got eneuch sleep?
Naw. A brief fast response disnae catch aw failures in sustained attention or measure whether ye got eneuch sleep. Basner et al., 2011
Sources
- Van Dongen et al. (2003). The Cumulative Cost of Additional Wakefulness: Dose-Response Effects on Neurobehavioral Functions and Sleep Physiology From Chronic Sleep Restriction and Total Sleep Deprivation.
- Basner et al. (2011). Maximizing Sensitivity of the Psychomotor Vigilance Test (PVT) to Sleep Loss.
- Lim et al. (2010). A meta-analysis of the impact of short-term sleep deprivation on cognitive variables..
- Woods et al. (2015). Factors influencing the latency of simple reaction time.
- Anwyl-Irvine et al. (2020). Realistic precision and accuracy of online experiment platforms, web browsers, and devices.
- Watson et al. (2015). Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society.
- Gardiner et al. (2023). The effect of caffeine on subsequent sleep: A systematic review and meta-analysis.
- Drake et al. (2013). Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed.
Cite this page: Hou muckle does lack o sleep slow doon reaction time?. Helibrain. 2026. https://helibrain.com/sco/answers/sleep-deprivation-and-reaction-time. CC BY 4.0.
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