bio-psych

Question 1

what are the different types of neurons?

Answer 1

Sensory neurons transmit electrical impulses from receptors to the CNS

Relay neurons transmit electrical impulses between the sensory neurons and motor neurons

Motor neurons transmit electrical impulses from the CNS to the effectors (E.g. glands)

Question 2

what is Synaptic transmission?

Answer 2

synaptic transmission is the process for transmitting messages from neuron to neuron.

The synapse is a specialized gap between neurons, through which the electrical impulse from the neuron is transmitted chemically.

Question 3

what are Neurotransmitters?

Answer 3

Neurotransmitters are the chemicals which are released from the synaptic knob (e.g. dopamine or serotonin.) They pass across the synapse to pass on the signal to the dendrites of the next neuron.

Dopamine

Serotonin

Acetylcholine

Question 4

Outline the organization of the autonomic nervous system (4marks)

Answer 4

The sympathetic part of the nervous system activates fight or flight.

An example of this is during a stressful situation when the bodies’ heart rate increases a provide the muscles with oxygen and increase running ability.

It is a part of the automatic nervous system where processes take place without having to make a conscious decision.

The body functions are caused by the parasympathetic nervous system such as digestion and urination.

The neurotransmitters causes the body to increase gland activity.

Question 5

what are neurotransmitters? and give two examples?

Answer 5

Neurotransmitters are the chemicals which are released from the synaptic knob (e.g. dopamine or serotonin.)

They pass across the synapse to pass on the signal to the dendrites of the next neuron.

Dopamine: Associated with thought and pleasurable feelings. Parkinson’s disease is one illness associated with deficits in dopamine, while schizophrenia is strongly linked to excessive amounts of this chemical messenger.

Serotonin: believed to play an important part of the biochemistry of depression, bipolar disorder and anxiety. However, the theory that low levels of serotonin lead to depression has been challenged by other research.

Question 6

describe the process of excitation and inhibition?

Answer 6

Stimulus causes an action potential (wave of charges) (AKA electrical impulse at GCSE)

This reaches a synapse

Causes the vesicles to move to edge of pre- synaptic knob

Vesicles fuse with membrane and release

neurotransmitters into the gap (synaptic cleft)

The neurotransmitter fits onto the complementary receptors (lock and key).

This causes ion channels to be inputted into the post synaptic membrane.

If ions flow in and trigger an action potential – this is known as excitation

If the ions flow in but the action potential is not triggered, this is known as inhibition

Question 7

explain the endocrine system?

Answer 7

The endocrine system provides a chemical system of communication via the blood stream.

It has a series of glands which release chemicals (hormones) throughout the body.

Hormones are chemical substances that help to regulate processes in the body.

Hormones are secreted by glands and travel to their target organs in the bloodstream.

Different hormones affect different target organs and each hormones affects behaviour in different ways.

Question 8

explain the fight or flight response?

Answer 8

This response is generated from the autonomic nervous system, specifically the sympathetic branch.

It is activated in times of danger and its function is to help use survive.

1. the hypothalamus in the brain recognizes a threat
2. It sends a message to the adrenal gland (adrenal medulla)
3. This triggers release of adrenaline to the endocrine system and noradrenaline to the brain
4. this prompts physical change

Question 9

explain some physical changes in the fight or flight response? and what happens after the response?

Answer 9

increased heart rate

breathing rate increases

Muscle Tension

pupil dilation

sweating

stop digestion

After escaping the danger (homeostasis) the parasympathetic system returns the body to its normal state

Heart rate decreases

Breathing decreases

Pupils constrict

Digestion is continued

Saliva production is continued

Question 10

describe the two main stress responses in the human body?

Answer 10

There are two main stress responses in the human body. The acute stress response (also known as the SAM or sympathy adreno medullary pathway) responds very quickly to immediate danger and readies the body for the classic fight or flight response.

The chronic stress response (also know as the HPA or hypothalamo pituitary adrenal pathway) responds to long-term constant stressors by keeping the body alert, however the chronic response can also have many harmful effects on the body such as reducing immune system functioning.

Question 11

annotate the diagram of the brain

Answer 11

see one-note

Question 12

describe hemispheric lateralization?

Answer 12

Hemispheric lateralization refers to one hemisphere carrying out a particular function.

The brain is contralateral so parts of the left hemisphere deal with the right side of the body and the right hemisphere does the same for the left side of the body.

That means that if someone had a stroke in their motor area in their right hemisphere, it will be the left hand side of the body which is affected.

What you see with your right visual field, is processed by your left hemisphere, and although you gather auditory information from both ears, the information from the left ear is dealt with by the right hemisphere.

Taste and smell are also contralateral, taste from the left side of your tongue and smells from your left nostril are processed in the right hemisphere.

Question 13

describe the left hemisphere?

Answer 13

Primarily for language processing (Broca’s and Wernicke’s area)– so if you have a stroke in left side of brain speech is affected.

Question 14

describe the right hemisphere?

Answer 14

For recognizing emotions 

Spatial information 

Question 15

describe the motor area?

Answer 15

At the back of the frontal lobe in both hemispheres is the motor area, which controls voluntary movement in the opposite side of the body.

Question 16

describe the Somatosensory centres?

Answer 16

At the front of both parietal lobes is the somatosensory area. This is where sensory information from the skin (heat, touch, pressure) is represented. The amount of neural connections denotes its sensitivity, ie receptors on our hands and face occupy over half of the somatosensory area.

Question 17

describe the visual centers?

Answer 17

There is one in each hemisphere, in the occipital lobe.

Each eye sends information from the right visual field, to the left visual cortex, and from the left visual field to the right visual cortex.

V1 is the primary visual centre and damage to this area leads to loss of vision.

However occasionally people show blindsight, where although they appear to be blind, they can locate objects in a visual field by pointing at them

What does this suggest?
It is still happening despite being unconscious

Question 18

describe the auditory centers?

Answer 18

One in each hemisphere, in the temporal lobes.

Damage may produce partial hearing loss, however does not generally lead to total deafness.

Question 19

describe and explain language centers?

Answer 19

Unlike the other areas, language is restricted to the left hemisphere in most people.

Broca’s area is responsible for speech production.

Damage in this area seems not to affect nouns and verbs, but people struggle with prepositions and conjunctions.

Expressive or motor aphasia is where speech may only include important content words and leave out insignificant words, like “the”.

Question 20

describe a key study into language areas?

Answer 20

Broca’s famous case study was conducted on a stroke victim named Tan because the only word he could say was “tan” (following this case, a condition such as Tan’s would become known as “Broca’s aphasia”).

An autopsy revealed a lesion in the left frontal lobe. The specific placement is now called Broca’s area, and has been found to be responsible for the co-ordination of the motor (muscle) movements required to produce coherent speech.

Conclusion: Broca concluded that parts of the left frontal lobe, including the area damaged in Tan, had the role of the “language center” in our brain.

Many subsequent studies have confirmed the role of Broca’s area in the production of speech.

Question 21

explain the wernickes area?

Answer 21

Wernicke’s area is where language processing occurs (understanding language and accessing words).

When someone has damage to this area they may struggle to find the word they need.

Receptive aphasia, is a type of aphasia in which an individual is unable to understand language in its written or spoken form.

Question 22

key study into wernickes area?

Answer 22

Peterson et al (1982) used brain scans to demonstrate how Wernicke’s area was active during a listening task and Broca’s area was active during a reading task

This study supports localization of function as it identifies the particular area, the Wernicke’s area is active during a listening tasks. The Wernicke’s is active as it is used during understanding language and the broaccas is sued for producing speech

This study supports lateralization as both of these areas are in the left hemisphere of the brain and are active during listening tasks

This has implications for neurorehabilitation as if we understand which sides of the brain are damaged we can support them through redeveloping these areas of the brain

Question 23

study into the brains function and learning?

Answer 23

Lashley (1950) removed areas of the cortex in rats that were learning a maze.

No area was proven to be any more important that another in terms of their learning – learning seemed to require every part of the cortex.

Learning is a higher cognitive function which does not appear to be localized but is distributed across the whole brain, maybe due to it being a more complex function

Question 24

study to do with murder and brain activity?

Answer 24

Raine (97) – found that 41 murderers (who had pleaded insanity) had less brain activity in the prefrontal lobe and abnormal activity in the amygdale than control groups matched for age and sex.

They also found an imbalance of activity between the two hemispheres in three other subcortical structures.

In the amygdala and the hippocampus, compared to the controls, the NGRIs had less activity in the left side and more activity in the right side.

Also, in the thalamus the NGRIs had more activity in the right side, though no difference in the left side

Question 25

evaluation of localization of function?

Answer 25

Plasticity -When the brain has become damaged through illness or accident, and a particular function has been lost, it seems to be able to reorganise itself in an attempt to recover lost function – ie surviving brain structures seem to ‘chip in’.

Question 26

study to support neuro plasticity?

Answer 26

Danelli (2013) EB had a large benign tumour removed from his left hemisphere at the age of 2.5- removing virtually his entire left hemisphere.

At the time, all of his linguistic abilities disappeared.

He was right handed and his language localisation was in his left hemisphere (as is the case with 95% of people).

He underwent an intensive rehabilitation programme and language started to improve by the age of 5.

He was later tested against normal controls at age 17 and they found that his right hemisphere had compensated for the loss of the left hemisphere.

However there were some minor grammatical errors and he was slower at naming objects in pictures.

This shows:

This contradicts localization of function and hemispheric lateralization as this suggests that although functions are lateralized there are still possibility for other parts of the brain to take over the functions.

Question 27

study to support neuro plasticity as evaluation of Lateralisation of function?

Answer 27

Erp (2000) – rats who were rewarded for aggressive behaviour showed reduced levels of serotonin in the prefrontal cortex over time and became more generally aggressive.

Question 28

methodological issue of research into localization of function

Answer 28

Much of the research into localization of function tends to be focused on case studies

Everyone’s brain is unique and it is therefore difficult to generalize to all brains

Issues with generalization because the wiring of their brain is already abnormal so there is clear individual differences

In general some people are left dominant, some people are right dominant – so generalizing from case studies int his area is problematic

Question 29

what is split brain research?

Answer 29

The procedure involves severing the corpus callosum, the main bond between the brain’s left and right hemispheres.

After a split-brain surgery the two hemispheres do not exchange information as efficiently as before.

This can reduce the number of fits experience by those epileptics that do not respond to drugs.

However despite improving epilepsy, there are side effects on behaviour and perception.

Question 30

what conclusions can we draw from Sperry’s research?

Answer 30

That the corpus callosum is involved in conveying information between hemispheres

That each hemisphere is independently responsible for processing motor and sensory activity for the opposite side of the body and visual field

That language (especially speech) is lateralised (usually to the left hemisphere)

That personality and intelligence are not affected by the corpus callosum

Corpus Callosum should only be cut when absolutely necessary as it results in some problems in functioning

Firstly, the left hemisphere is dominant in terms of speech and language. Secondly, the right hemisphere is dominant in terms of visual-motor tasks.

Question 31

explain Sperry’s experiment?

Answer 31

Aim: The aim of their research was to examine the extent to which the two hemispheres are specialised for certain functions.

Method: An image/word is projected to the patient’s left visual field (which is processed by the right hemisphere) or the right visual field (which is processed by the left hemisphere). When information is presented to one hemisphere in a split-brain patient, the information is not transferred to the other hemisphere (as the corpus callosum is cut).

Sperry and Gazzaniga conducted many different experiments, including describe what you see tasks, tactile tests, and drawing tasks.

Question 32

strengths of Sperry’s research?

Answer 32

highly specialised standardised producedures

Participants stared at a fixation point whilst one eye was blindfolded. The image was projected for one-tenth of a second, meaning the split brain patient would not have time to move their eye across the image, and so spread the information across both sides of the visual field/both sides of the brain. Sperry could therefore ensure that only one hemisphere was retrieving the information.

Question 33

limitations of Sperry’s research?

Answer 33

not internally valid as may be measuring the effects of epilepsy rather than having corpus collosum severed

some patients had experienced drug therapy for much longer than others – instead of measuring the effects of having a corpus collosum severed it is measuring the differences between drug therapy time

Research relates to small sample sizes. - every brain is different, there is only 11 people with split brains

informed consent – as they had had major brain surgery they may not have the capacity to give informed consent

HOWEVER

However the cost/benefit analysis suggests that it is worth it

Question 34

Briefly evaluate research using split brain patients to investigate hemispheric lateralisation of function (4 marks)

Answer 34

The data were artificially produced as in real life a severed corpus callosum can be compensated for by the unrestricted use of two eyes and therefore the findings are not reflective of the impact of hemispheric laterization in real life.

some patients had experienced drug therapy for much longer than others – instead of measuring the effects of having a corpus collosum severed it is measuring the differences between drug therapy time. Therefore the research may lack internal validity as it may not be investigating the impact of hemispheric lateralization but instead investigating the effects of the length of time of drug therapy

Question 35

define brain plasticity?

Answer 35

Brain plasticity refers to the ability of the brain to change throughout life, as a result of experience and new learning.

Question 36

ket study into neuroplasticity (everyday)

Answer 36

Maguire (2000) studied the brains of London taxi drivers and found significantly more volume of grey matter in the posterior hippocampus than in matched controls. The longer they had been in the job, the more pronounced the structural difference.

This supports neuroplasticity because it demonstrates that there area of the brain linked with being a taxi driver changes structure through the longer the job is done for. This suggests that the brain has plasticity and can adapt through our own experiences as more neural connections are biolt through being used more.

Question 37

explain functional recovery of the brain after trauma?

Answer 37

Functional recovery is a form of plasticity. Following damage from physical injury, or through trauma such as the experience of a stroke, the brain has the ability to redistribute or transfer functions usually performed by a damaged area to other, undamaged areas. Neuroscientists suggest that this process can occur quickly after trauma (spontaneous recovery) and then slow down after several weeks/months. At this point, the individual might need rehabilitation therapy to further their recovery.

The brain is able to rewire and reorganise by forming new synaptic connections close to the area of damage.

Secondary neural pathways that would not be typically used to carry out functions are activated to enable functioning to continue.

This is supported by a number of other structural changes:
Axonal sprouting – growth of new nerve endings, which connect to undamaged nerve cells to form new neuronal pathways

Reformation of blood vessels

Recruitment of homologous (similar) areas on the opposite side of the brain to perform specific tasks.

If the undamaged is hemisphere is stimulated, recovery can be improved.

Denervation supersensitivity – axons that do a similar job become aroused at a higher level to compensate for function. However it can lead to over-sensitivity to messages such as pain.

Question 38

study into age and effect on functional recovery and study to evaluate it?

Answer 38

Functional plasticity seems to reduce with age. The brain has a greater ability to reorganise in childhood, as it is constantly adapting to new experiences and learning. Whereas in old age, there is a deterioration of the brain, which affects the extent and speed of recovery (Corkin et al., 1989)

However, Bezzola et al. (2012) showed that after giving 40-60 year olds 40 hours of golf training, this produced changes in their neural representations of movement.