biological process

• The biological process argues that behaviour is a result of our genetic makeup and the neurons of our brains.

  
  

  As genetics are inherited, the biological process often looks at evolution to explain behaviour.
• The biological process argues that behaviour is a result of our genetic makeup and the neurons of our brains.

  As gentics are inherited, the biological process often looks that evolution to explain behaviour.
• WIthin the hypothalamus is the SCN. The SCN moitors our body clock.
• The SCN gets information from nerve cells in the eyes about whether it's light or dark which makes us feel alert/sleepy.

  The SCN therefore allows light to act as a zeitgeber (environmental trigger or 'time giver').
• The SCN also controls the release of the sleep hormone 'melatonin'
• Melatonin is the sleep hormone - high levels of melatonin stimulate sleep.
• Melatonin is released gradually (early evening) then peaks in the middle of the night.
• If the SCN is confused about light/dark then it may release melatonin at the wrong time, or not at all.
• Siffre (1975) - what was he trying to investigate?


  investigate the natural duration of his own sleep-wake cycle.
• Siffre (1975) - what did he do?


  He isolated himself from all daylight by hiding in a dark cave with only weak artifical light.
• Siffre(1975) - how long did he stay in the cave for?

  7 months
• Siffre (1975) - did he have any awareness of time? any contact with anyone?

  He had no clock or reference to time, but he did have verbal contact with the outside world.
• Siffre (1975) - what happened to his sleep-wake cycle?

  his sleep-wake cycle settled at around 25 hours, although sometimes ranging up to 48 hours.
• Siffre (1975) - conclusion?


  he concluded that absense of natural daylight allowed his biological clock to run at it's natural rate, and that normally daylight acts as a zeitgeber to re-synchronise the cycle.
• Siffre (1975) - The facts that this was 25 hours means...? (conclusion)

  ...means that light is not the only zeitgeber we rely on.
• Biological process argues that dreams are a result of random brain activity: therefore meaningless.
• Activation Synthesis Hypothesis - proposed by Hobson and McCarley (1977)

  -states that dreams result from neurons in a brain area called pons firing randomly. The neurocortex tries to make sense of these random signals, which results in dreams.
• Evaluation - strengths?

  +Hightly scientific - therefore has lots of evidence/

  +the explanation of sleep in terms of the SCN and release of melatonin is supported by studies of other animals.

  +melatonin supplements can be used to help you sleep.

  +although sleep varies across species, melatonin appears to play a clear role amoung all vertebrates.
• Evaluation - weaknesses?

  +drugs only treat the physical problem - not the psychological i.e. the cause and does not consider thoughts, feelings, experiences.

  +the biological process is limited in it's explanation of dreaming.

  +Although Activation Synthesis Hypothesis is compelling, it struggles to explain why dreams often make sense and are made up of experiences from the previous day. This theory does not explain why 70% of our dreams make sense and are often familiar (Domhoff, 2005).