Biopsychology of Motivation and Internal Regulation

Question 1

What did Richtor (1922) hypothesise?

Answer 1

Richtor hypothesised Endogenous circadian rhythms = internally controlled cycles that last about a day

Question 2

How much of our lives do we spend sleeping

Answer 2

We spend one third of our lives in a suspended state doing almost nothing

Question 3

How do we know that this rhythm is internally generated?

Answer 3

If you stay up all night, you feel sleepier as it gets later, but then perk up a bit in the morning. Humans kept in an environment with a 28hr cycle cannot synchronise, they slip back into a 24hr cycle.

Question 4

What generates rythm

Answer 4

Richter (1967) theorised that we all have a biological clock

Question 5

Define biological clock

Answer 5

a mechanism in our brain that generates our sleep and wake cycle

Question 6

Where is the biological clock

Answer 6

Suprachiasmatic nucleus or SCN

Question 7

How do we know it generates a rhythm automatically?

Answer 7

Remove the SCN and keep it as a tissue culture it continues to produce a 24hr rhythm of action potentials…(Earnest et al, 1979)

Question 8

What happens when the SCN is damaged?

Answer 8

Damage to SCN causes damage to circadian rhythms

Answer 9

Zeitbeger

Question 10

Define Zeitbeger

Answer 10

Stimulus which changes the biological clock

Question 11

Define Jet Lag

Answer 11

Is the disrupting of sleeping rythms through changing time zones

Question 12

Why is light so important?

Answer 12

It helps ‘reset our rythms’

Question 13

What study backs the idea that light can help reset our sleeping cycle

Answer 13

Miles (1977) Blind man needed sedatives to settle circadian rythm to 24 hr cycle

Question 14

Name the 4 stages of sleep that exhibit different levels of brain activity than relaxed wakefulness

Answer 14

Stage 1 and 2

Stage 3 and 4

Question 15

What is involved in stages 1 and 2

Answer 15

Irregular activity

Neuronal activity high

Sensory input reduced

Question 16

What is involved in stages 3 and 4

Answer 16

Slow wave sleep (SWS) = neuronal activity is highly Synchronised

Chronic masturbation

Sensory input reduced

Question 17

What is REM?

Answer 17

Rapid Eye Movement sleep

• Also called paradoxical sleep
  
  • Neither light nor deep sleep
  • Light because lots of brain activity
  • Deep because muscles are relaxed

Question 18

Name 4 Sleeping Disorders

Answer 18

• Insomnia
• Sleep Apnea
• Narcolepsy
• Periodic Limb Movement Disorder

Question 19

Define Insomnia

Answer 19

– Stress, anxiety, depression

– Shifting circadian rhythms

– Dependence on sleeping pills

Question 20

Define Sleep Apnea

Answer 20

– Inability to breathe while sleeping

– Obesity? Old-age?

Question 21

Narcolepsy

Answer 21

– Attacks of sleepiness during the day

– REM during the day?

Question 22

Define Periodic Limb Movement Disorder

Answer 22

– Involuntary movement of the legs/arms

– Maybe something to do with the pons?

Question 23

Is sleep a form of Hibernation?

Answer 23

– Conserving energy when you can’t get much done

– when food is scarce, light is too high, too low etc.

– Hibernating hamsters live longer than other hamsters (Lyman et al. 1981)

Question 24

How do animals vary in how much sleep they need?

Answer 24

– Safety from predators

– How much time they need to find food

– Whether they need to surface for air! (dolphin sleeps on one side of the brain at a time..)

Question 25

What suggests that there must be mor to sleep than just conservation of energy?

Answer 25

– Sleep deprivation causes dizziness, hallucinations etc.

– Eventually the immune system fails in animals severely deprived

– Sleep enhances memory

Question 26

Why do we need sleep?

Answer 26

1. To strengthen memories, and weed out the pointless connections
2. Moistening the eyeballs…

Question 27

Name 2 hypotheses that may explain why we dream?

Answer 27

The Activiation-Synthesis Hypothesis

The Clinico-Anatomical Hypothesis

Question 28

Describe the Activation-Synthesis Hypothesis

Answer 28

• Effort to make sense of distorted info
• PGO waves from pons activate parts of the cortex, which synthesises a story
• But not always in REM…

Question 29

Describe the Clinico-Anatomical Hypothesis

Answer 29

• Dreaming is thinking…
• Senses are suppressed, so brain left to its own devices
• Motor cortex suppressed, so no action
• Pre-frontal cortex suppressed, so no working memory to link a believable story together!

Question 30

How do we react to temperature change?

Answer 30

Responds to changes in its own temp, and also temp receptors in the skin

Question 31

What do we do when we are thirsty?

Answer 31

If water is scarce, the pituitary gland secretes vasopressin

Blood vessels constrict

Raises blood pressure and compensates for the low fluid volum

Question 32

What is Vasopressin

Answer 32

Vasopressin in also an antidiuretic hormone (ADH) – makes urine more concentrated by causing the kidneys to reabsorb fluid from urine

Question 33

How do we know what to eat

Answer 33

combination of learned and unlearned strategies

• learned from peers, culture
• but, innate tastes are essential
• likeness of sweet food, disgust for bitter/sour

Question 34

How do we know when to eat?

Answer 34

• centres around the hypothalamus (forebrain area associated with regulating behaviours)
• hypothalamus has neurons sensitive to hunger and feeling full
• these feeding mechanisms seem to have changed very little during mammalian evolution (more relevant to study animals?

Question 35

How can our understanding of when and what we should eat help us with understanding eating disorders?

Answer 35

1. Obesity
   - Big problem in industrialised countries, excessive eating due to huge availability of food
2. Anorexia Nervosa and Bulimia Nervosa
   - Poorly understood, biological issues associated with it, but cultural and individual issues are more likely to be the cause

Question 36

Describe Obesity

Answer 36

• Huge cultural influence
• Social aspect of eating
• Still rooted in our biology, propensity to like fatty foods!

Question 37

What is Anorexia Nervosa

Answer 37

• unwillingness to eat
• 0.3% young women
• perception of fatness, even when thin
• body can deteriorate, muscle wasting, can even cause death

Question 38

Define Bulimia Nervosa

Answer 38

• extreme dieting mixed with binge eating
• vomit after mealtimes (not all)
• imbalance of hormones associated with feeding

Question 39

How does our sex (and gender) affect our behaviour?

Answer 39

Evolutionary theory

• we are the product of successful strategies, so we should have inherited successful strategies
• men and women were subject to different selection pressures in evolutionary history, therefore exhibit different traits

Question 40

Name 2 ways in which men and women may differ in reproductive behaviours

Answer 40

1. Sexual strategies – reproductive behaviour - Mate choice, attitudes to sexual behaviour
2. Cognition - Cognitive skills rooted in different reproductive and survival strategies

Question 41

How do Men and Women differ in terms of Sexual Strategies

Answer 41

Men – Numerous, mobile sperm; potential to father many offspring

Women – Few, immobile eggs; maximum 20 (?) in lifetime - the ‘choosy’ sex

Question 42

Name the role of hormones in sexual strategies for men

Answer 42

• androgens (testosterone) produced in the testes and the adrenal gland (in the brain)
• sensitises regions of the brain underlying sexual motivation
• removal of the testes (i.e. cancer) results in decreased sex drive, BUT still some production in the brain

Question 43

Name the role of hormones in sexual strategies for women

Answer 43

• oestrogens produced by the ovaries
• AND androgens produced by the adrenal gland
• as in men, androgens associated with sex drive
• postmenopausal women can still have high sex drive due to androgen production (even when oestrogens have dropped)