Biopsychology

Question 1

What is the nervous system? What are the divisions of the nervous system?

Answer 1

The nervous systems is a network of nerve cells and fibres which transmits nerve impulses between parts of the body to regulate behaviour in response to the environment.
The Central Nervous System consists of the brain and the spinal cord. It is the origin of all complex commands and decisions.
The Peripheral Nervous System is responsible for connecting the CNS to the senses. It sends information to the CNS from the outside world and from the CNS to the muscles and glands. It can be divided into: the Somatic Nervous System, which controls voluntary skeletal muscle movement. And the Autonomic Nervous System, which operated involuntarily and controls smooth muscles and glands.

Question 2

What are the branches of the Autonomic Nervous System?

Answer 2

Parasympathetic Branch - relaxes the body. Known as the ‘rest and digest’ response.
Sympathetic Branch - arouses the body. Know as the ‘fight and flight’ response.

Question 3

What effect do the branches of the Autonomic Nervous System have on the body?

Answer 3

Heart: Sympathetic - heart rate increases. Parasympathetic- heart rate decreases

Lungs: Sympathetic - breathing rate increases to get more oxygen to the muscles. Parasympathetic - breathing rate decreases

Pupils: Sympathetic - pupils dilate to allow more light in to see better and further. Parasympathetic - pupils constrict.

Question 4

What are neurons? What are the three types of neurons?

Answer 4

The nervous system is made up of specialised nerve cells called neurons. Neurons communicate with one another by transmitting electrical impulses to one another.

1. Sensory neurons
2. Relay neurons
3. Motor neurons

Question 5

What are sensory neurons?

Answer 5

Sensory Neurons carry information from the sense organs towards the brain. They have long dendrites and short axons. They are part of the Peripheral Nervous System

Question 6

What are relay neurons?

Answer 6

Relay Neurons carry information to and from the brain. They connect the sensory neurons to motor and other relay neurons. Found in the Central Nervous System. They are involved in analysing information and deciding how to respond. They have short dendrites and short axons

Question 7

What are motor neurons?

Answer 7

Motor Neurons carry information from the Central Nervous System to muscles and glands. They have short dendrites and long axons. They are found in the Peripheral Nervous System

Question 8

Explain synaptic transmission?

Answer 8

When a neuron is activated by a stimulus this generates an electrical impulse, known as an action potential, that travels down the axon of the neuron. The gap between one neuron and another is called the synaptic cleft. For the electrical impulse to reach the next neuron it must travel across the synapse as a chemical signal using neurotransmitters

Question 9

Why can information only travel in one direction at a synapse?

Answer 9

Because receptors are only present on the post-synaptic membrane and not the pre-synaptic membrane. Neurotransmitters are only released from the pre-synaptic neuron. Vesicles containing the neurotransmitter are found in the pre-synaptic neuron, not the post-synaptic neuron.

Question 10

What are the stages of synaptic transmission?

Answer 10

1. An action potential arrives at the pre-synaptic neuron.
2. This causes vesicles in the pre-synaptic neuron to fuse with the pre-synaptic membrane and release neurotransmitters into the synaptic cleft.
3. Neurotransmitters diffuse across the synaptic cleft and attach to receptors on the post-synaptic membrane.
4. Neurotransmitters will either have an excitatory or inhibitory effect on the post-synaptic neuron.
5. A neuron has multiple connections so can receive both excitatory and inhibitory neurotransmitters at one time. The likelihood of the cell firing is determined by adding up the excitatory and inhibitory input, this is called summation.

Question 11

What is meant by excitatory or inhibitory neurotransmitter?

Answer 11

Excitatory - increases the likelihood of an action potential so increases neural activity e.g. adrenaline

Inhibitory- decreases the likelihood of an action potential so decreases neural activity e.g. GABA

Question 12

What is the endocrine system?

Answer 12

The endocrine system is a collection of glands that work alongside the nervous system to regulate the activity of cells and organs to control vital functions. It’s function is to secrete the hormones which are required to regulate many bodily functions and to provide a chemical system of communication

Question 13

Examples of glands in the endocrine system?

Answer 13

Adrenal glands - secrete adrenaline for the fight or flight response.

Pineal gland - secrete melatonin to regulate the sleep/wake cycle.

Question 14

What is the fight or flight response?

Answer 14

The fight or flight response provides us with the energy to fight a situation or get away from it. It is our body’s response to stress and is an example of the nervous system and the endocrine system working together.

Question 15

What are the stages of the fight or flight response?

Answer 15

1. Situation is perceived as a threat.
2. This causes the hypothalamus to activate the sympathetic branch of the Autonomic Nervous System.
3. This will release noradrenaline and will also cause the adrenal to release adrenaline.
4. Adrenaline will have several effects on the body.
5. This response will only last a short time as after a few minutes the parasympathetic branch is activated to return the body back to its normal state

Question 16

What effects does adrenaline have on the body?

Answer 16

Heart and breathing rate increases - to increase oxygen intake and transport for increased respiration

Pupils will dilate - to improve vision

Increased sweat production - to regulate body temperature

Question 17

Evaluation of the fight or flight response?

Answer 17

• ignores gender differences. The fight or flight response is a universal stress response meaning it should be the same for everyone. However, evidence has suggested women focus energy on protecting their offspring and forming defensive networks with other females. This is known as the ‘tend and befriend’ response. This means that the fight or flight response underestimated the differences between sexes and is an example of beta bias.
  + issue with this is that the evidence is based of animal research so can’t extrapolate to humans.
• reductionist idea. It reduces complex human cognitive processes and behaviour down to biological processes and then down to levels of hormones. This means the fight or flight response could be too simplistic as a theory.
  + scientific methods. Research into the physical responses to stress can be said to be scientific as the measures are usually objective. Therefore, opinion and judgment do not play a part. This increases the reliability of the results because of the controlled nature.

Question 18

Ways of studying the brain: what is functional magnetic resonance imaging?

Answer 18

fMRI indirectly measures activity of neurons by using magnetic field and radio waves to monitor blood flow in the brain. It works by measuring the change in the energy released by haemoglobin, which reflects activity of the brain through oxygen consumption. When an area is more active it consumes more oxygen, which means that more blood is being directed to the active area. This then provides and a moving picture of the brain to map activity in specific areas of the brain.

Question 19

Ways of studying the brain: evaluation of fMRI?

Answer 19

+ produces 3D images. This means they have high spatial resolution and provide information on localisation as they show which parts of the brain are activated in a particular mental process.

• expensive compared to other neuroimaging techniques which can lead to small sample sizes and issues with generalising the research.
• poor temporal resolution due to a 5 second time lag after neural activity. This means it is difficult to tell exactly what kind of brain activity is being represented on the screen.

Question 20

Ways of studying the brain: what is an electroencephalogram? And event related potentials?

Answer 20

EEG is a recording of general brain activity, usually linked to states such as sleep and arousal. They measure activity in the brain via electrodes that are fixed to an individuals scalp, using a skull cap. The recording represents the brainwave patterns that are generated from the action of millions of neurons, providing an overall account of brain activity.

ERPs are elicited by specific stimuli presented to the participant. There are types of brainwaves that are triggered by a particular event. Researchers have generated a way of isolating responses from EEG. It is a statistical averaging technique which filters out unnecessary information. Therefore, researchers can see responses that relate to the presentation of a specific stimulus.

Question 21

Ways of studying the brain: evaluation of electroencephalograms and event-related potentials?

Answer 21

+ They have high temporal resolution. They detect brain activity within a millisecond. This means researchers can be confident that the activity shown is occurring at that point in time.
+ They are cheaper so can be more widely used in research. This leads to larger sample sizes and more confident generalisations.
- They have poor spatial resolution and the information is too generalised as it is from many thousands of neurons. This means they are not useful in pin-pointing the exact area of neural activity.

Question 22

Ways of studying the brain: what are post-mortem examinations?

Answer 22

Post mortem: brain is analysed after death to determine whether certain observed behaviours during the patients lifetime can be linked to abnormalities in the brain. Individuals who have had a rare disorder and experienced unusual deficits in mental processes/behaviour are most likely to have a post-mortem. Their brain will be compared to a ‘normal brain’ to identify differences.

Question 23

Ways of studying the brain: evaluation of post-mortems?

Answer 23

+ Post-mortem evidence was vital in early understanding of key processes in the brain. For example, Broca and Wernicke both relied on PM examinations for their research. This means it was an influential technique for studying the brain.

• As special permission needs to be granted to conduct post-mortems, there are small sample sizes. This means research can lack validity.
• Neuronal changes can occur during and after death. This means that it is difficult to establish if any brain differences identified were the cause of the behaviour when they were alive.

Question 24

Localisation of function: what is the 19th century theory? What is the modern theory?

Answer 24

In the 19th century scientists supported the holistic theory of brain structure and function. This theory proposed that all parts of the brain were involved in every thought and action. However, later research suggested there was evidence for localisation which proposed that different areas of the brain are for different behaviours, processes or activities.

Question 25

Localisation of function: where/what is the motor area? Where/what is the somatosensory area?

Answer 25

The motor area is found at the back of the frontal lobe, in both hemispheres. It controls voluntary movement in the opposite side of the body. Damage to this area may result in a loss of control in movements.

The somatosensory area is found at the front of the parietal lobe, in both hemispheres. It is separated from the motor area by the central sulcus. It is the area where the sensory information from the skin, such as heat or pressure, is represented.

Question 26

Localisation of function: Where/what is the visual area? Where/what is the auditory area?

Answer 26

The visual area is located in the occipital lobe at the back of the brain, in both hemispheres. Each eye sends information to the opposite side of the occipital lobe e.g. damage in the left hemisphere can cause blindness in the right visual field of both eyes.

The auditory area is located in the temporal lobes. This area analyses speech-based information. Damage can produce hearing loss.

Question 27

Localisation of function: where/what are the language centres?

Answer 27

The language centres are only found in the left hemisphere, they are localised and lateralised. In the 1880s Broca identified a small area in the left frontal lobe. Broca’s area is responsible for speech production. Damage to this area results in slow speech which lacks fluency, this is called Broca’s aphasia. Wernicke’s area is located in the left temporal lobe. It is responsible for language comprehension. Damage results in patients producing nonsense words as part of their speech, this is called Wernicke’s aphasia.

Question 28

Localisation of function: what are the conclusions about localisation?

Answer 28

Some functions are more localise than others e.g. somatosensory and motor functions are highly localised to particular areas of the cortex. Other function seem more widely distributed e.g. the language centres.

Question 29

Evaluation of localisation of function?

Answer 29

+ There is supporting evidence from a range of methodologies to suggest some functions are localised. Human clinical case studies, such as Phineas Gage, who demonstrated the role of the frontal lobe in mood regulation. Evidence from brain scans such as Petersen et al who showed how Wernicke’s area was active during a listening task and Broca’s area was active during a reading task. This means that scientists can be more confident in making conclusions about localisation of function.
- However, case studies are unique so generalisations that can be made are limited and brain scanning techniques also have their limitations. This means that having conclusive evidence about localisation can be difficult.
- Also, the brain is so complex that no one part acts independently, so strict localisation is impossible. Classical research evidence by Karl Lashley supports this. Lashley lesioned areas of the cortex in rats that were learning a maze. He found that no one area was proven to be more important than another and that the process of learning required every part of the cortex. Also, when the rats had lesions in a small specific part of the brain, other parts of the brain were compensating for the damaged part. This research suggests that some behaviours are too complex to be localised and require involvement of the whole brain.
- It is likely that simpler functions such as motor control will be localised more than complex behaviours such as personality and consciousness.
+ Research investigating localisation has practical applications. For example, knowledge about the language centres in the brain has led to applications in speech and language therapy. This shows that localisation provides useful insights.

Question 30

Hemispheric lateralisation and split brain research: What is hemispheric lateralisation?

Answer 30

Hemispheric lateralisation is the theory that the two hemispheres of the brain are functionally different and certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other. For example, the ability to produce and comprehend language seems to be lateralised to the left hemisphere.

Question 31

Hemispheric lateralisation and split brain research: Sperry’s research, who were his participants?

Answer 31

Sperry’s research involved a unique group of 11 individuals who had undergone commissurotomy. This is where the corpus callosum had been cut to separate the two hemispheres. This was done to control epileptic seizures but allowed sperry to study people whose hemispheres were separated to see the extent to which each hemisphere was specialised and which brain functions are lateralised.

Question 32

Hemispheric lateralisation and split brain research: what was Sperry’s procedure and findings?

Answer 32

Sperry presented information to a patients left visual field (information would be processed by the right hemisphere) and to their right visual field (information would be processed by the left hemisphere). If visual material was presented to the right visual field, the participant was able to describe it in speech and draw it with their right hand, because information was being processed in the left hemisphere which is responsible for language and controls the right hand.
However, if the visual material was presented to the left visual field, the participant would say they saw nothing because the information was processed by the right hemisphere which is not responsible for language. And were able to draw the object using their left hand.
When patients were asked to match a face from a series of other faces, the picture projected to the left visual field was consistently selected. Whereas, the picture projected to the right visual field was consistently ignored.

Question 33

Hemispheric lateralisation and split brain research: what are the conclusions of Sperry’s split brain research?

Answer 33

Language is lateralised to the left hemisphere.

Drawing and face recognition is lateralised to the right hemisphere.

Question 34

Hemispheric lateralisation and split brain research: what is the evaluation of Sperry’s research?

Answer 34

+ Influential research. Sperry’s research and methodology led to a substantial body of research being published about lateralisation of functions in the brain. This research was highly influential in developing neuroscientists understanding about how the brain worked.
- However, Sperry’s research led to a growing body of pop-psychological research that oversimplifies and overemphasises the functional distinction. Current understanding suggest that the left and right hemispheres are in constant communication. Research into neural plasticity has demonstrated that functions typically associated with one hemisphere can be effectively performed by the other.
+ Strengths of the methodology. The procedures were standardised and well controlled e.g. Sperry’s method allowed him to ensure information was only being received by one hemisphere. This means that he could be confident in the conclusions he was making about hemispheric lateralisation.
- Issues with generalisation. Split brain patients are an unusual sample of people. There were only 11 participants that took part in Sperry’s research, all of whom had a history of epileptic fits. This means that researchers have urged caution when accepting the conclusions as the sample used is unlikely to be completely representative of the general population.

Question 35

Plasticity and functional recovery after trauma: what is plasticity?

Answer 35

Plasticity is also referred to as neuroplasticity and refers to the brains ability to change and adapt as a result of experience or new learning. During infancy the number of neural connections increases rapidly peaking at approximately 15,000 at the age of 2-3. This is about twice as many as an adult brain. Rarely used connections are deleted and frequently used connected are strengthened - know as synaptic pruning. Early theories about brain plasticity focused on there being a critical period in terms of brain structure and development. More recent research suggests that existing neural connections can change or new ones can be formed at any point in life.

Question 36

Plasticity and functional recovery after trauma: what is functional recovery after trauma?

Answer 36

Functional recovery after trauma is an example of plasticity. Following physical injury, or other forms of trauma such as a stroke, unaffected areas of the brain are often able to adapt and compensate for damaged areas. The brain is able to rewrite itself through the growth of new neurons and/or connects to compensate for damaged areas, called neuroregeneration. This involves:
• Axon sprouting - growth of new nerve endings to form new pathways.
• Denervation supersensitivity - axons performing similar functions to damaged ones will become more sensitive to compensate.
• Reformation of blood vessels.
The brain can also reorganise itself. This is where there is a transfer of functions to undamaged areas, known as functional compensation. This may involve recruitment of similar areas on the opposite hemisphere.

Question 37

Plasticity and functional functional recovery after trauma: evaluation?

First two points

Answer 37

+ Evidence for plasticity. Maguire et al, scanned the brains of 16 male London taxi drivers. They were compared with scans of non-taxi drivers. They found that the posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects and that the hippocampul volume positively correlated with the amount of time spent as a taxi driver. Draganski et al, scanned the brains of German medical students 3 months before and after their final exams. Changes were observed in the hippocampus and parietal cortex suggesting leading-induced changes had occurred as a result of the exam.
- Individual differences and plasticity. Research has suggested that functional plasticity tends to reduce with age, this means that whilst the brain is still maturing recovery from trauma is more likely. However, research has still found neural changes in participants ages 40-60 suggesting plasticity still occurs across the lifespan. Research has also found that women tend to recover more effectively than men as their function is not as lateralised. This suggests that there are different factors involved in determining the plasticity of the brain.

Question 38

Plasticity and functional functional recovery after trauma: evaluation?

Last two points

Answer 38

• Negative/maladaptive plasticity. The brains ability to rewrite itself can also have negative consequences. For example, phantom limb syndrome due to a reorganisation of the somatosensory cortex. In addition research has found that prolonged drug abuse results in poor cognitive function and a greater risk of dementia.
  + Practical applications. Understanding the processes involved in plasticity has contributed to the field of neurorehabilitation. Often recovery slows after a period of time and people will require additional interventions for a full recovery. This shows that research in this area has important implications in the real world.

Question 39

Biological rhythms: what are they? What two things are they kept in sync by?

Answer 39

Biological rhythms are distinct patterns of changes in the body activity that relate to cyclical time periods. These rhythms are kept in sync by two things:

1. Endogenous pacemakers - our body’s internal body clocks.
2. Exogenous zeitgebers - external changes in the environment that reset/entrain our biological clocks.

Question 40

Biological rhythms: what are ultradian rhythms?

Answer 40

Ultradian rhythms have a duration of less than 24 hours so there is more than one cycle every 24 hours. Examples include the stages of sleep. It was previously thought that there were 4 stages of NREM sleep. In 2007 stages 3 and 4 were combined to form slow wave sleep. Each sleep cycle lasts approximately 90 minutes and continues throughout the night. Each stage can be identified by distinct patterns of electrical activity which are recorded using EEG.

Question 41

Biological rhythms: research support for ultradian rhythms?

Answer 41

Dement and Klietman monitored sleep patterns of 9 participants in a sleep lab. Activity was recorded in an EEG. They found that REM activity was highly correlated with the experience of dreaming. Replications of this study have reported similar findings. Consistency of the timings of sleep cycles between all participants suggesting the sleep wake cycle is controlled by endogenous pacemakers.

Question 42

Biological rhythms: what are infradian rhythms?

Answer 42

Infradian rhythms have a duration of more than 24 hours so there is less than one cycle every 24 hours. Examples include the female menstrual cycle. This is a monthly cycle that is controlled by changes in hormone levels which regulate ovulation. It typically lasts 28 days. During each cycle there is an increase in oestrogen and progesterone.

Question 43

Biological rhythms: research support for infradian rhythms?

Answer 43

Stern v McClintock demonstrated how exogenous factors such as pheromones of other women can influence a woman’s cycle. Samples of pheromones were taken from 9 women (pads under armpits for 8hrs). These pads were then treated and then given to other participants by rubbing the pad on upper lip i.e. on day one pads from day one of the menstrual cycle were applied and on day two they were given pads from day two and so on. They found 68% of the participants experienced changes that brought them close to their ‘odour donor’. This demonstrates how exogenous factors such as pheromones can influence a woman’s infradian menstrual cycle.

Question 44

Biological rhythms: what are circadian rhythms?

Answer 44

Circadian rhythms have approximately a 24 hour duration. This comes from the Latin terms of circa, meaning about, and diem, meaning duty. To be considered a circadian rhythm it must be endogenously controlled. Examples include the sleep/wake cycle and body temperature.
The sleep wake cycle is one of the most well-known circadian rhythms. It’s control relies on the interaction between endogenous pacemakers and exogenous zietgebers.

Question 45

Biological rhythms: the effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle. Endogenous pacemakers?

Answer 45

Endogenous pacemakers. Suprachiasmatic nucleus - a bundle of fibres found in the hypothalamus. It is connected to the visual cortex and receives information about light. The pineal gland receives information from the SCN and it secreted melatonin which induces sleep. The SCN also has an influence on the adrenal gland which secretes cortisol which induces wakefulness.

Question 46

Biological rhythms: the effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle. Exogenous zeitgebers?

Answer 46

1. Light - key zietgebers in humans that can reset the SCN. Light provides information for the SCN which then suppresses the release of melatonin from the pineal gland.
2. Social cues - research suggests that adapting to local times for eating and sleeping rather than responding to ones own feelings of hunger or tiredness is an effective way of resetting circadian rhythms that have been desynchronised due to travel over long distances.

Question 47

Biological rhythms: the effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle. Research support?

Answer 47

DeCoursey et al. destroyed the the SCN in the brains of 30 chipmunks who were then return to their natural habitat for 80 days. The sleep/wake disappeared. Without SCN connections the chipmunks cannot receive and project information about light to the pineal gland. Suggests endogenous pacemakers are not the only system involved in the sleep/wake cycle, and that light as an exogenous zeitgeber is essential for maintaining the sleep/wake cycle too.
Kleitman and Richardson. spent 32 days living in a cave where no detectable sunlight reaches due to its depth. Richardson developed an endogenous sleep/wake cycle of 26-28 hours and Kleitmans was just over 24 hours. Without light both maintained an endogenous biological rhythm but these were inconsistent with the 24 hour cycle seen when people are exposed to light. Suggests that sunlight entrails each persons individual body clock to 24 hours a day, acting as an exogenous zeitgeber.

Question 48

Evaluation for biological rhythms?

Strengths?

Answer 48

+ All research evidence.
+ Implications and applications of research. Knowledge of circadian rhythms has been useful in explaining the negative effects of desynchronisation. For example, research into shift work has shown that shift workers are more likely to develop heart disease, have lowered vigilance and have more anxiety. This means that research into the sleep/wake cycle may have economic implications in terms of how to best manage worker productivity and therefore has implications for the economy.

Question 49

Evaluation for biological rhythms?

Limitations?

Answer 49

• Generalisation and small samples. Research generally involves small numbers of participants which means that it may not be representative of the wider population and limits the extent to which meaningful generalisations can be made. In addition there are issues with animal research being generalised.
• Ethical issues in DeCoursey et al. Chipmunks were exposed to considerable harm and risk and is debatable whether the research is justified.
• Some research has poor control of extraneous variables. Kleitman and Richardson still had access to food and social interactions, which also act as exogenous zeitgebers. This means that it cannot be concluded that the sleep/wake cycle was just being completely endogenously controlled.
• Individual differences. It has been assumed that biological rhythms are the same for everyone when research has suggested this is not the case. For example, Dutty et al. revealed that there are ‘larks’ who are most productive in the mornings and ‘owls’ who find their productivity is the highest in the evening/during the night. There are also age differences in the sleep/wake cycles. According to neuroscientists adolescents circadian rhythms appear to run 2 hours later than adults. This led to a school in North Tyneside beginning lessons at 10am over a two year period. There were found to be very positive academic and health outcomes. This suggests there are important implications of knowing about this differences.