By: Phillip DeRenzo Grade 11 Pittsburgh Central Catholic High School

Introduction Over 20% of adults suffer from some form of sleep deprivation. Sleep deprivation and reaction time go hand in hand. So, what effects does sleep deprivation have on reaction time of human senses? Three senses were tested in this experiment: Sight Hearing Touch

Sleep Deprivation A shortage of the essential amount of sleep. A situation where somebody does not get the required amount of sleep and it effects aspects of their life. May result in blurred vision, drowsiness, dizziness, fainting, and slow reaction time.

Sleep Requirements Average Total Amount of Sleep Required (hours/day) Human Infant16 Human Adolescent9 Human Adult8

Background of Sleep Deprivation vs. Reaction Time Studies show that those who lack enough sleep will see a significant effect on their physical and mental abilities. Through studies, scientists have found that the reactions of someone who is significantly deprived of sleep are similar to the reactions of those who have consumed a considerable amount of alcohol.

Sleep Deprivation and the Brain The thalamus (in the brain) is more highly activated when an individual is sleep deprive, but the thalamus is more highly activated during problematic tasks when in a state of rested wakefulness and not when deprived of sleep. When the thalamus is highly activated, there’s a decrease in parietal, prefrontal, and cingulate cortex activation, which weakens visual awareness and performance. Sleep deprivation causes lowered perceptual attentiveness, resulting in a lessening of auditory attention.

Purpose To take scientific studies one step further and determine how sleep deprivation affects the individual reaction times of three senses: Sight Hearing Touch Also, at what point is one deprived enough of sleep to see an effect on the reaction time of their senses?

Materials Meter stick Human subject Pencil Paper Flat surface (wall)

Hypotheses Null Hypothesis : Sleep deprivation will not affect the reaction times of sight, hearing, or touch. Alternate Hypothesis : Sleep deprivation will cause a decrease in the reaction times of sight, hearing, and touch.

Procedure 1. A meter stick was held against a wall. 2. The subject placed the bottom of his hand approximately 1 centimeter away from the meter stick directly at the 0 centimeter mark. 3. First, the subject’s reflex time for sight was tested. The meter stick was dropped while the subject’s eyes were open and he was to catch the falling meter stick as quickly as possible. 4. His reaction time was measured by the cm. mark where the bottom of his hand was located when he caught the stick. 5. Steps 1 – 4 were repeated 6 times.

Procedure (Continued) 6. Second, the subject’s reaction time for touch was tested. Steps 1 – 5 were repeated; however the meter stick was dropped while the subject had his eyes closed. At the exact time that the meter stick was dropped, the subject was touched on the shoulder, informing him that the stick was dropped. 7. Third, the subject’s reaction time for hearing was tested. Steps 1 – 5 were repeated; however the meter stick was dropped while the subject had his eyes closed. At the exact time that the meter stick was dropped, “NOW!” was yelled, informing the subject that the stick was dropped. 8. The results were written down and the data was analyzed for conclusions to be made.

Effects on Reaction Time of Sight Hours Without Sleep Inverse Reaction Time (cm. dropped) p-value = 8.83E-06

Effects on Reaction Time of Touch Hours Without Sleep Inverse Reaction Time (cm. dropped) p-value = 5.04E-06

Effects on Reaction Time of Hearing Hours Without Sleep Inverse Reaction Time (cm. dropped) p-value = 5.68E-05

Dunnetts’ Test (Sight) VariableT ValueInterpretation 6 Hours0.99Insignificant (Accept Null) 12 Hours0.25Insignificant (Accept Null) 18 Hours2.03Insignificant (Accept Null) 24 Hours3.61Significant (Reject Null) 30 Hours5.58Significant (Reject Null) T-Crit = 3.39

Dunnetts’ Test (Touch) VariableT ValueInterpretation 6 Hours0.28Insignificant (Accept Null) 12 Hours0.51Insignificant (Accept Null) 18 Hours3.38Insignificant (Accept Null) 24 Hours4.54Significant (Reject Null) 30 Hours5.09Significant (Reject Null) T-Crit = 3.39

Dunnetts’ Test (Hearing) VariableT ValueInterpretation 6 Hours0.32Insignificant (Accept Null) 12 Hours1.46Insignificant (Accept Null) 18 Hours1.55Insignificant (Accept Null) 24 Hours3.64Significant (Reject Null) 30 Hours5.24Significant (Reject Null) T-Crit = 3.39

Anova (Sight) Anova: Single Factor SUMMARY GroupsCountSumAverageVariance Column Column Column Column Column Column ANOVA Source of VariationSSdfMSFP-valueF crit Between Groups E Within Groups Total

Anova (Hearing) Anova: Single Factor SUMMARY GroupsCountSumAverageVariance Column Column Column Column Column Column ANOVA Source of VariationSSdfMSFP-valueF crit Between Groups E Within Groups Total

Anova (Touch) Anova: Single Factor SUMMARY GroupsCountSumAverageVariance Column Column Column Column Column Column ANOVA Source of VariationSSdfMSFP-valueF crit Between Groups E Within Groups Total

Conclusion The null hypothesis that sleep deprivation will not affect the reaction times of sight, hearing, or touch was accepted for 6, 12, and 18 hours without sleep. The null hypothesis that sleep deprivation will not affect the reaction times of sight, hearing, or touch was rejected for 24 and 30 hours without sleep.

Limitations and Extensions The subject may not have been touched at the exact time that the meter stick was dropped. “NOW!” may not have been yelled at the exact time that the meter stick was dropped. Human error in calculating the exact measurement in centimeters on the meter stick. Test numerous subjects to get more evidence of the results. Compare the effects of sleep derivation on each sense to each other in order to determine which sense is affected the most. Extended length of number of hours without sleep

Sources deprivation.html deprivation.html deprivation-effect-reaction-19 deprivation-effect-reaction-19 o-sleep.htm o-sleep.htm