The Effect of Sleep Deprivation on Passive and Active Functions and Distance Modulation of the Vestibulo-Ocular Reflex

The study will include two sleep protocols: Normal sleep and 24h sleep deprivation. The participants will be informed and will sign a consent form. Participants will then be randomly divided to begin with one of the sleep protocols. To avoid major changes in participants lifestyle, that might intervene with the basic measurements, both nights will take place within a maximum of one month and a minimum of one week for recovery between them. One week prior to each condition, participants will fill a sleep diary which will include their sleep duration to ensure that a routine sleep pattern will be maintained prior to each of the tests. Participants will be instructed not to consume alcoholic drinks or mind-altering substances for 24h prior, and during both conditions, and caffeine for 12h prior and during both conditions.

To enable normal sleep as possible, the normal sleep protocol will take place in each of the participants home. Matching environmental conditions will be kept to those of the clinic (lighting, white background) where the sleep deprivation protocol will be held. The participants will be tested using the Video Head Impulse test (vHIT) and the Computerized Dynamic Visual Acuity test (c-DVA) during both nights. The participants will be equipped with an ActiGraph watch wGT3X-BT to assure sleeping conditions.

Inclusion criteria

• Age 30-60 years old
• Healthy
• Persons who are not night shift workers
• Persons who are not used to but can keep awake for 24 hours

Exclusion criteria

• Night shift workers
• Vestibular system deficiency in vHIT test
• Active neurological disease
• Any orthopedic deficit in the cervical area preventing a proper vHIT examination
• A diagnosed sleep disorder or >5 score in the Pittsburgh sleep quality questionnaire Hebrew version (PSQI)