Select your language

Suggested languages for you:
Log In Start studying!
StudySmarter - The all-in-one study app.
4.8 • +11k Ratings
More than 3 Million Downloads
Free
|
|

All-in-one learning app

  • Flashcards
  • NotesNotes
  • ExplanationsExplanations
  • Study Planner
  • Textbook solutions
Start studying

Sleep and Zeitgebers

Save Save
Print Print
Edit Edit
Sign up to use all features for free. Sign up now
Sleep and Zeitgebers

You have probably noticed that your sleep quality is easily affected by factors such as light; for instance, sunlight streaming through the window into your eyes can sometimes be enough to wake you up, which is known as a zeitgeber. Research has identified a relationship between sleep and zeitgebers.

Sleep is an essential function that is needed for survival. The body can rest and recharge during sleep, ready to work at its best the next day. Lack of sleep has been linked to poor cognitive and physical performance, increased illnesses and impaired neurobehavioural functioning.

Sleep and zeitgebers in psychology

The body has mechanisms to ensure that the period of sleeping and being awake is balanced, known as homeostasis. Homeostatic balance of the sleep-wake cycle is important as it prevents people from oversleeping or not getting enough sleep.

Various factors affect the sleep-wake cycle; these are known as endogenous pacemakers and exogenous zeitgebers of sleep.

Sleep and Zeitgebers, moon covered by a blanket, StudySmarter Sleep is a famous example of a circadian rhythm, flaticon.com/premium-icon

Endogenous pacemakers and exogenous zeitgebers in psychology

Biological rhythms can vary in length, and the sleep-wake cycle is known as a circadian rhythm. Circadian rhythms are cycles of physical, mental and behavioural changes that occur once every 24 hours.

As we mentioned above, two factors affect the sleep-wake cycle:

  • Endogenous pacemakers

Endogenous pacemakers are genetically determined, internal biological mechanisms that specify biological rhythms.

An example of an endogenous pacemaker is the suprachiasmatic nucleus (SCN), nerve cells that are an internal clock suggested to keep the body in the 24-hour cycle we discussed above. The SCN resides in the hypothalamus.

It can detect light and then regulate melatonin accordingly (the hormone that helps you sleep) through the pineal gland.

  • Exogeneous zeitgebers

Exogenous zeitgebers are external factors from your surroundings that affect biological rhythms, acting as triggers or prompts to your biological rhythms.

Examples of exogenous pacemakers are the presence of light, temperature, and food.

The two work in tandem, so light, an exogenous zeitgeber, will affect the SCN, an endogenous pacemaker, to regulate your sleep-wake cycle (your biological rhythm). Let's explore that a little further.

Relationship between zeitgebers and sleep

Your endogenous pacemakers and exogenous zeitgebers work in tandem, so light, an exogenous zeitgeber, will affect the SCN, an endogenous pacemaker, to regulate your sleep-wake cycle (your biological rhythm). Let's explore that a little further.

The relationship between zeitgebers and sleep are:

Sleep and Zeitgebers: Light exposure

Light is the main exogenous zeitgeber that affects sleep. There are light-sensitive receptors in the retina (part of the eye). These receptors respond to light and send signals to the brain. For example, the signal may be to wake up. When the sun rises, there is increased light. This is the time when humans wake up and start the day.

Whereas, during and after sunset, there is decreased light. The night period is when humans usually sleep.

Another way light affects the circadian rhythm is via the release of melatonin. The pineal gland, a part of the brain, secretes melatonin. Melatonin is released when the receptors indicate low light levels within your eye (SCN).

Melatonin regulates the sleep-wake cycle. There are high levels of melatonin when you are sleeping and feeling sleepy and low levels during periods of wakefulness.

Plants also react to sunlight. When plants are exposed to increased sunlight, their leaves open to absorb more nutrients to grow healthily. When there is decreased sunlight, plants do not do this to prevent losing too much water at night.

Sleep and Zeitgebers, A plant under Sunlight, StudySmarterPlants react to sunlight to maximise their ability to absorb sunlight, flaticon.com/premium-icon

Sleep and Zeitgebers: Temperature

During sleep, the body's activity decreases, reducing the work it has to put in to maintain homeostasis.

During sleep, the heart rate is slower, there is less activity in areas such as the stomach, and the body's temperature is lower.

Core body temperature changes in a 24-hour cycle, affecting the sleep-wake cycle. Before falling asleep, the body's temperature lowers. Before waking up, the body's core temperature starts to rise.

The body is preparing for increased activity during wakefulness.

This can be considered an endogenous pacemaker and exogenous zeitgeber as it is affected by internal and external influences.

Sleep and Zeitgebers: Food

The sleep-wake cycle is affected by mealtimes, also known as social cues. As previously mentioned, the body's activity decreases when sleeping. After eating a meal, the digestive system works hard to digest the food. Therefore, during this period, it is difficult to sleep.

When hungry, the stomach sends a signal to the brain telling the body that it needs to wake up so that the body can be fueled.

Sleep and Zeitgebers, Dream icon of food, StudySmarterFood can affect the sleep-wake cycle, flaticon.com

Psychological effects of sleep deprivation

Just as exogenous zeitgebers regulate the sleep-wake cycle, they can just as easily disrupt them.

Someone may start sleeping later or for shorter periods if they eat too much or too close to when they fall asleep.

Other external factors can disrupt the sleep-wake cycle; these include:

  • Jet lag – when travelling to a new time zone, the sleep-wake cycle is disrupted and is no longer synchronised to the external environment (light)

  • Shift work – jobs that require early morning shifts or late night shifts can disrupt the circadian rhythm, leading to the sleep-wake cycle not being synchronised with endogenous zeitgebers.

The disruption of the sleep-wake cycle can lead to sleep deprivation; the psychological effects of sleep deprivation are:

  • Mood issues – anxiety, irritability, low mood, mood swings, and in extreme cases, it can cause psychosis episodes

  • Impaired cognitive abilities – memory, perception, attention

  • The onset of sleep illnesses, which can also impact mental illnesses such as anxiety or depression.


Sleep and Zeitgebers - Key takeaways

  • Sleep is an essential function needed for survival, and the sleep-wake cycle is an example of a circadian rhythm, occurring once every 24-hours.
  • Biological rhythms, such as the circadian rhythm, are affected by internal and external influences. Internal factors are endogenous pacemakers and are genetically determined biological mechanisms. External factors are exogenous zeitgebers, which act as triggers to biological mechanisms.
  • An example of an endogenous pacemaker is the suprachiasmatic nucleus, which can detect light and regulate melatonin secretion by the pineal gland.
  • An example of an exogenous zeitgeber is light, as it prompts biological mechanisms depending on the levels of light present.
  • Both factors can help regulate and disrupt the sleep-wake cycle, and disrupted sleep can negatively affect psychological and physiological health.

Frequently Asked Questions about Sleep and Zeitgebers

Some examples of zeitgebers are:

  • Light 
  • Temperature 
  • Food

The four stages of sleep in psychology are:

  • Stage 1 non-rapid eye movement 
  • Stage 2 non-rapid eye movement 
  • Stage 3 non-rapid eye movement 
  • Rapid eye movement stage

The role of zeitgebers in the circadian rhythm is to make sure that the biological clock is synchronised with the individual's environment. Disruption can manifest in psychological effects of sleep deprivation, such as impaired cognitive functioning. 

Sleep is an example of a circadian rhythm rather than something that affects it. Circadian rhythms occur once every 24-hours and are affected by endogenous pacemakers and exogenous zeitgebers. 

Light intensity during sleep, time of meals and temperature are examples of zeitgebers that influence the sleep-wake cycle. 


For example, we know to wake up when it is bright and sleep when it is dark outside. 

Final Sleep and Zeitgebers Quiz

Question

What is the definition of exogeneous zeitgebers? 

Show answer

Answer

Exogenous zeitgebers are external factors from your surroundings that affect biological rhythms, acting as triggers or prompts to your biological mechanisms. 

Show question

Question

________ zeitgebers are external factors from your surroundings that affect biological rhythms, acting as triggers or prompts to your biological mechanisms. 

Show answer

Answer

Endogeneous 

Show question

Question

What are three examples of exogeneous pacemakers?

Show answer

Answer

Three examples of exogenous pacemakers are light, temperature, and food.

Show question

Question

What two factors can lead to the disruption of the sleep-wake cycle? 

Show answer

Answer

Two factors that can lead to the disruption of the sleep-wake cycle are:

  • jet lag 
  • shift work

Show question

Question

What are the psychological effects of sleep deprivation? 

Show answer

Answer

The psychological effects of sleep deprivation are:

  • cause low moods
  • impair cognitive abilities 
  • cause the onset of sleep illnesses

Show question

Question

Which of the following is an example of an endogenous pacemaker and exogenous zeitgeber? 

Show answer

Answer

Temperature 

Show question

Question

What type of rhythm is the sleep-wake cycle?

Show answer

Answer

Circadian rhythm

Show question

Question

Which of the following is the hormone responsible for regulating the sleep-wake cycle? 

Show answer

Answer

Melatonin

Show question

Question

How does the suprachiasmatic nucleus affect sleep?

Show answer

Answer

The suprachiasmatic nucleus, residing in the hypothalamus, is able to detect light. It regulates the secretion of melatonin through the pineal gland. When light levels are low, more melatonin is secreted and produced in response, and when light levels are high, less melatonin is secreted and produced. 

Show question

Question

How does sunlight affect plants? 

Show answer

Answer

When plants are exposed to increased sunlight their leaves open this is so that they can absorb more nutrients to grow healthily. When there is decreased sunlight plants do not do this. This is to prevent losing too much water at night.

Show question

Question

During what period is the core body temperature high?

Show answer

Answer

Wakefulness 

Show question

Question

Why does the body's temperature start to rise before waking up? 

Show answer

Answer

 Before waking up, the body's core temperature starts to rise. This is the body's preparation for the increased activity that happens during wakefulness. 

Show question

Question

How does hunger affect the sleep-wake cycle? 

Show answer

Answer

When hungry the stomach sends a signal to the brain. This signal is essentially telling the body that it needs to wake up so that the body can be fueled. 

Show question

Question

What may happen to the sleep-wake cycle when travelling to another time zone? 

Show answer

Answer

When travelling to a new time zone, the sleep-wake cycle is disrupted and is no longer synchronised to the external environment.

Show question

60%

of the users don't pass the Sleep and Zeitgebers quiz! Will you pass the quiz?

Start Quiz

Discover the right content for your subjects

No need to cheat if you have everything you need to succeed! Packed into one app!

Study Plan

Be perfectly prepared on time with an individual plan.

Quizzes

Test your knowledge with gamified quizzes.

Flashcards

Create and find flashcards in record time.

Notes

Create beautiful notes faster than ever before.

Study Sets

Have all your study materials in one place.

Documents

Upload unlimited documents and save them online.

Study Analytics

Identify your study strength and weaknesses.

Weekly Goals

Set individual study goals and earn points reaching them.

Smart Reminders

Stop procrastinating with our study reminders.

Rewards

Earn points, unlock badges and level up while studying.

Magic Marker

Create flashcards in notes completely automatically.

Smart Formatting

Create the most beautiful study materials using our templates.

Just Signed up?

Yes
No, I'll do it now

Sign up to highlight and take notes. It’s 100% free.