Biopsychology

Question 1

The Nervous System

Answer 1

> The nervous system consists of the Central Nervous System and the Peripheral Nervous System

• The Central Nervous System
  > Consists of the spinal cord (reflex actions) and the brain (mental processes) which receives and sends messages from receptors to environmental stimuli
• The Peripheral Nervous System
  > Transmits messages from the CNS to muscles and glands
  1. Autonomic Nervous System carries out unconscious, vital bodily functions such as regulating heart rate
  2. Somatic Nervous System controls voluntary muscle movement as it receives information from sensory receptors

Question 2

Neurons

Answer 2

> Neurones are specialised cells responsible for transmitting electrical impulses.

• Sensory neurones carry information from the PNS to the CNS. These neurones have long dendrites and short axons.
• Relay neurones connect the sensory neurones to the motor or other neurones. They have short dendrites and short axons.
• Motor neurones connect the CNS to effectors (glands or muscles). They have short dendrites and long axons
• Cell body (Soma) includes the nucleus which contains genetic information
• Dendrites carry nerve impulses towards the cell body
• Axons carry nerve impulses away from the cell body
• Myelin Sheath protects the axons. It is fatty and speeds up the electrical transmission
• Nodes of Ranvier speed up the transmission by forcing it to jump across the gaps of the axons.
• Terminal Buttons communicate with the next neurone across the synapse.
• Electrical transmission
  > is when a neurone is in a resting state, the inside of the cell is negative compared to the outside of the cell.
  > when the cell is activated by stimuli, the inside becomes positively charged for a split second, causing an action potential.
  > Action potential causes electrical impulses to travel down the axon towards the end of the neuron.

Question 3

Endocrine System

Answer 3

> Works to control vital functions in the body

• Hypothalamus - located in the brain. Maintains homoeostasis controls blood sugar levels and body temperature. Releases Adrenaline and Oxytocin
• Thyroid - located in the front of the neck. Regulates the metabolic rate. Releases the thyroid hormone
• Parathyroid - located behind the thyroid. Controls calcium levels in the blood. Releases the parathyroid hormone
• Pituitary gland - located at the base of the brain. Controls the release of hormones from all the other glands. Releases the growth hormone.
• Pancreas - located behind the stomach. Maintains healthy blood sugar levels. Releases insulin.
• Adrenal - located at the top of the kidneys. Controls blood sugar levels. Releases adrenaline.
• Testes. Causes the growth of the penis and facial hair. Releases testosterone.
• Ovaries. Promotes the development of breasts and have a healthy menstrual cycle. Releases oestrogen and progesterone.

Question 4

The Fight or Flight Response

Answer 4

> The F&F response is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival.

• The Autonomic Nervous System is responsible for vital functions such as heart rate and digestion. This is involved in the response.
• The Sympathetic Nervous System has control over the necessary bodily changes when we are faced with a situation where we may need to defend ourselves or escape.
• Slows digestion, increases heart rate, dilates pupil, inhibits saliva production and relaxes bladder
• The Parasympathetic Nervous System is activated when the body is comforted to return the body to normality.
• increases digestion, decreases heart rate, constricts dilation, increases saliva production and contracts bladder.
• Anxiety and fear is important for survival because they act as a mechanism to protect the body against danger.

Question 5

Motor Centres

Answer 5

• Motor Cortex: In charge of the movement. The brain sends messages to the muscles via the brain stem and spinal cord. Deals with complex movement.
• Somatosensory Centres: In charge of the sensation of the body. Located next to the Motor Cortex. It perceives touch.
• Visual Cortex: In charge of visual perception and information. Visual information is transmitted along two pathways. One containing the components of the visual field and the other being involved in the location within the visual field.
• Wernicke’s Area: In charge of our capability of understanding words and accessing words.
• Auditory Cortex: receives information from both ears that transmit information about what the sound is and it’s location.
• Broca’s Area: Responsible for speech production.

Question 6

Plasticity and Functional Recovery

Answer 6

• Plasticity is the brain’s ability to recover and adapt to the new environment. New neurones are made and old ones are replaced. However, if the body of the neurone is damaged it cannot be replaced, but the axons can.

> Children have better plasticity than older people meaning their brains find it easier to replace functions by brain damage

> Cell bodies can never be replaced but the axons, in some cases, can.

• Common Factors causing brain trauma
  > Falls, Vehicle related collisions, violence (20%), sports and explosive blasts
• Factors affecting recovery of the brain
  1. Perseverance. The more you try to recover, the more likely you are going to recover.

2. Gender. Women recover faster than men in terms of brain trauma as the functions are not as concentrated in one hemisphere in a woman’s brain.
3. Age. As you grow older, your brain deteriorates so the speed of the recovery and the extent to which the brain will recover decreases.
4. Physical exhaustion, stress and alcohol consumption. The recovery depends on how tired the person becomes after performing the task as well as being too stressed. Drinking alcohol can have an effect on the use of the regained function.

Question 7

Ways of studying the brain

Answer 7

1. Event Related Potential (ERP)
   This method helps capture neural activity related to sensory and cognitive processes.
   > Psychologists place electrodes on the scalp and amplify the signal. The changes of voltage are then plotted over a period of time. It is done multiple times and they average the results together.

• Costa et al (2003)
  Recorded the responses to nude photos of both genders in 19 - 29-year-olds.
  > Men generally said they were aroused by nude women and women generally said they had neutral feelings towards both genders.
  > The ERP found a higher response to opposite gender nude pictures than reported by both genders.
  Strength: ERP can provide a measure of processing of stimuli even when there are no behavioural changes.
  Weakness: it takes a large sample to accurately measure because of the small size of an ERP.

2. Electroencephalogram (EEG)
   This method helps detects abnormalities in the brain waves or to detect the electrical activity in the brain.
   > Psychologists places electrodes on the scalp that measures electrical impulses. They detect tiny electrical charges which appear as a graph.
3. Functional Magnetic Resonance Imaging (fMRI)
   This method uses magnetic fields and radio signals to monitor blood flow in the brain. Areas of the brain that are involved in activities will have a greater blood oxygenation and flow. This means we can link brain areas to specific abilities.

• Calni et al
  They first tested participant’s level of extroversion and neuroticism. They then showed them positive images (puppies and ice cream, for eg) and then pictures of negative images (cemeteries for eg) while laying in the fMRI scanner.
  > They found that extroverted people reacted more strongly to the positive images while the neurotic people reacted more strongly to the negative images.
  Strength: Provides a moving image of the brain activity. This means that pattern activity can be compared rather than the physiology of the brain.
  Weakness: The sample size of studies are often small due to limited availability and funding. The cost per participant is high, makes findings harder to generalise.

4. Post-Mortem Examinations
   This method determines the cause of death. It can be used to see where damage had occurred in the brain and how that might have explained the individual’s behaviour.

• Harrison (2000)
  Reviewed research in PME on Schizophrenia and it provided strong evidence that there are structural abnormalities in the brain of the sufferers. They had 25-40% larger lateral ventricles and had a 4% smaller volume in the cortex than healthy individuals.
  Weakness: Research conducted on the deceased means there is no brain activity being obtained. Cannot generalise findings to a living person.

Question 8

Split-Brain Research

Answer 8

The Corpus Callosum is what joins the right and left hemispheres.

The left hemisphere is in charge of language processing and processing of details.
The right hemisphere is in charge of performing tasks that use creativity.

• When people suffer from epilepsy (over-active electrical currents in the brain) they are considered for brain surgery.
  It usually occurs on one side of the brain, therefore removing that section will reduce epilepsy.
  In cases where it affects many places of the brain, the Corpus Callosum is removed so that it remains in the hemisphere, thus causing the hemispheres to work independently

1. K.S
   was a 20-year-old sophomore who never developed a corpus callosum. She underwent brain surgery to treat the hydrocephalus. After the operation, the experimenter gave her an ‘intelligence test’ and found that her IQ and grades reflected ‘slightly above average’.
   The experimenters came to the conclusion that the results were due to the fact that she developed the skill to deal with separate hemispheres.
2. A.A
   due to brain injury at birth, he had limited use in his right arm and had seizures which started when at 4 months old. From 5 they got worse where he would have a lack of sensation in his right arm. At 14 he decided to have the operation which led to decreased sensitivity and co-ordination in his arm. Also had slow speech and was not able to verbal tasks.
3. L.B
   started having seizures at 3. When at 13 he had an operation, afterwards his personality and mannerisms remained intact. However, he had to wear glasses as his sight was dominant in the left eye. He also suffered from alien hand syndrome.
4. R.V
   at 13 he was in a car accident that left him with a closed head injury. Seizures did not begin until he was 17. At 43 he had the surgery and was able to carry on conversations normally. However, he became disorientated and lost control in his left arm.
5. C.C
   had limited use in his right arm due to a brain surgery at birth. At age 10 his family realised that when he had seizures he would go silent which was paired with turning his head to the right, falling and becoming unconscious. He had the operation at 13 with an EEG showing that there was damage in his left hemisphere of the brain.

Question 9

Synaptic Transmission

Answer 9

• there two types of transmissions; electrical (within the neurone) and chemical (between neurones)
• Axons is where the electrical transmission passes through
• The synaptic vesicles are used to send signals to the next neurone that a message is being passed
• When the neurotransmitter passes through the synapse by diffusion it changes into a chemical transmission
• When the neurotransmitter hits the post-synaptic receptor sites they become electrical again
• The neurotransmitter is vital in deciding whether action potential occurs.
• Excitation Transmitters cause sodium ions to flow into the axons causing a positive action potential (increased likelihood) These stimulate the brain. For example, adrenaline, dopamine
• Inhibition Transmitters cause potassium ions to flow out of the axon causing a negative action potential (decreased likelihood) which calms the brain. For example, serotonin and gaba

Question 10

Biological Rhythms

Answer 10

• Circadian: lasts about 24 hours. E.g. The Sleep-Wake cycle.
• Ultradian: occurs more than once a day. E.g. Temperature levels, heartbeat, appetite
• Infradian: lasts more than a day but less than a year. E.g. the menstrual cycle.
• Entrainment: when the internal working clock is adjusted to match the environment
• Endogenous Pacemakers: is the internal body clock. They are mechanisms that manage the cycles.
• Suprachiasmatic Nucleus (SCN) is a tiny cluster of nerve cells that lie in the Hypothalamus.
• The Pineal Gland controls the production of melatonin.
• Exogenous Zeitgebers: external factors from the environment that affect behaviour, specifically sleep. E.g. light, weather, temperature.

Question 11

Circadian Rhythm

Answer 11

Folkard et al (1977) investigated how the circadian variation in body temperature is linked to cognitive abilities.

> Studied the learning ability of 12 and 13-year-olds.
Stories were read to them at either 9am or 3pm (independent groups)

> After one week, the afternoon group showed better recall and comprehension. The body temperature was increased which shows that long-term recall is best when body temperature is higher.

Evaluation

1. Extraneous variables. The time of when the participants went to sleep and woke up.
2. Independent groups. Individual differences could be the cause of the results.
3. Lacks population validity. Very limited sample

Question 12

Endogenous Pacemakers / Circadian Rhythms

Answer 12

1. Siffre (1975) spent over six months living in a cave in Texas, deep underground with no light or anything else to tell him what time of day it was. He was wired up so that some of his body functions could be recorded. He had a telephone link to the outside world and was monitored by video camera. Siffre had a fairly erratic sleep-wake pattern at first but it settled down to a pattern that averaged just over 25 hours. This shows that we do have internal mechanisms that regulate our sleep-wake cycle but it shifts to a length of approximately 25-30 hours if we do not have external zeitgebers to reset it.
   > Confounding variables. Having interaction with the outside world could give an indication of the time of day.
   > Sample. it has only experimented on one person, therefore, you cannot generalise findings to a large population.
2. Aschoff and Webber (1962) studied participants living in a bunker that only had electric light and no windows. Lights could be turned on and off as they wished. Eventually, their bodies settled into a sleep-wake cycle of 25-27 hours. This suggests that endogenous pacemakers are the factors that influence the sleep-wake pattern because they have control over exogenous zeitgebers.
   > Lack of ecological validity because it was not set in a realistic environment, no windows and no electricity.
3. Ralph et al (1990) removed the SCN from genetically abnormally hamsters with a circadian cycle of 20 hours. They then placed this SCN into normally functioning rats. After the operation, the rat’s circadian cycle reduced from 24 hours to 20 hours. This shows that the SCN gland in the endogenous pacemakers has an influence on sleep patterns. Still had the external conditions.
   > Extrapolation issues. Humans have different biological brain structures to animals, therefore, we cannot generalise these findings to humans.
4. Steel et al (2008) investigated the effects of constant daylight on circadian rhythms. Six participants were living in isolation in the Arctic for six weeks. There was constant daylight during this ti,e. Participants were asked to keep sleep logs. The findings showed that three participants developed a free running sleep-wake cycle lasting longer than 24 hours. However, the other three showed no change to their sleep-wake cycle. This suggests that internal bodily factors influence sleep patterns.
   > Protection from harm. They were isolated in the Arctic. They could have developed psychological or emotional distress.

GRENADES
> Deterministic. These researchers assume certain patterns of behaviour will occur if certain factors are in place.
> Scientific. They conduct these studies in an objective way with a standardised procedure so replication is possible.
> Nature and Nurture. Endogenous is nature and exogenous is nurture.
> Ethnocentric. These studies are conducted in Western culture but then are generalised to all countries.

Question 13

Infradian Rhythms

Answer 13

1. Reinberg (1967) reported on a woman who spent 3 months in a cave without natural lighting. Her menstrual cycle shortened to 25.7 days. This demonstrates that menstrual cycles are affected by external factors such as lighting.
   > Lacks ecological validity. Not a realistic event that would occur.
   > Lacks population validity. One female is not a reliable sample for findings to be generalised.
2. McClintock (1971) found that women who work in male-dominated environments have shorter menstrual cycles. Suggesting that their infradian rhythms are affected by evolution, as shorter menstrual cycles would mean more advantage of pregnancy occurring. Therefore our bodies are adapting in order to reproduce.
   > Lack of scientific evidence. This is the only study on the idea therefore it is falsifiable.
3. McClintock and Stem (1998) found that when women were exposed to other women’s sweat in the later half of their menstrual cycle, their cycle was shortened due to the pheromones from the other women. However, if this was done at the beginning of their cycle their cycle increased. This suggests that the menstrual cycles can be affected by their interaction with other women.
   > Face validity. They clearly investigated their aim and got their results.

GRENADES
> Gender bias. Focuses on the cycles that are aimed at females.
> Deterministic
> Nurture is a more dominating factor in menstrual cycles.

Question 14

Ultradian Rhythm: Sleep stages

Answer 14

1. The brain is in a relaxed state, heart rate slows and muscles relax. The person can be easily woken. This stage can last between 5-15 minutes.
2. The brain has short bursts of activity, the body continues to relax. The person can still be easily woken. This stage can last between 5-15 minutes.
3. The brain has short delta waves and has some short bursts of activity. The body relaxes and it becomes harder to wake the person up. This stage can last between 5-15 minutes.
4. The brain’s delta waves increase and the level of activity is slower than all other stages. The body’s metabolic rate is low, growth hormones are released and it is difficult to wake the person up. This stage lasts 40 minutes
5. Rapid Eye Movement. The most brain activity occurs here. There is complete relaxation, irregular breathing and heart rate. This is when dreams occur. This stage lasts 15 minutes initially but it increases throughout the night.

• Dement and Kleitmen (1957) conducted a study on 9 sleeping participants for 62 nights in a laboratory. By monitoring the EEG record during sleep, they were able to wake participants during each of the different stages of sleep. They asked participants to report their experiences and emotions. They found that people awakened during REM sleep reported dreams 80-90% of the time. The dreams were recalled in great detail and included elaborate visual images
  > Protection from harm. Interruption in sleep could lead to many physical and psychological issues. Therefore, researchers did not take caution. Making the study unethical.

GRENADES
> Scientific. Studies conducted on the theory were conducted in a lab environment and in an objective manner.
> Deterministic. Scientists have predicted behaviours and emotions.