Biopsychology Flashcards
(56 cards)
What is localisation of functioning
What did people believe before this
Refers to the theory that different parts of the brain are responsible for different behaviours or processes.
-prior to this scientist believed that all parts of he brain was involved in the processing of thoughts and action I.e- the holistic theory of the brain
Where did the early research into localisation of the brain come from
How is local of functioning divided
Dr halows research on phineas Gage, he was proved to be correct through macmillians 2002 research.
The cerebral cortex (outer layer of the brain) (3 mm thick) and is subdivided into 4 lobes each associated with different functions.
What is the motor cortex - where is it located
Located in the back of the frontal lobe and controls voluntary movement. Sends messages to the muscles via the brain stem and spinal cord. It is important for complex movement. Both hemispheres have a motor cortex
What areas of the brain are involved in movement
Spinal cord and brain- coordinate movement
Premotor cortex - plans a movement prior to executing it
Prefrontal- stores sensory information prior to a movement and works out the probable outcome of the movement
What is the somatosensory
Located at the front of the parietal lobes, it is separated from the motor cortex by a valley Called the central sulcus.
Somatosensory refers to sensory information from the skin- perceives touch, pressure, pain and temperate.
The amount of neurones needed is dictated by the amount of somatosensory cortex needed for that area of the body.
Touch sensitive areas such as the the face need more somatosensory cortex.
Each hemisphere has a somatosensory with each side of the brain receiving information from the opposite side of the body
What is the visual centre of the brain
Where is this located
How is visual information sent and what does this mean could happen
What happens when light enters the eye
Primary visual cortex
- occipital lobe (back of the brain) - main visual centre
- from the right visual field to the left visual cortex vice versa, so damage to the left hemisphere can produce blindness in the right visual field of both eyes.
- activates the photoreceptors in the retina, nerve impulses are sent via the optic nerve . Most of the impulses are sent to the thalamus which acts as a rely station passing the Information to the visual cortex
What area of the brain is necessary for visual perception
What happens if this area is damaged
Where is the visual image transmitted
V1
- completely blind even In there dreams.
- transmitted along 2 pathways, one containing the components of the visual field and other being involved with the location within he visual field.
What research supports evidence into a damaged v1 (un conscious vision )
Bridgeman and staggs 1982
Occasionally individual with damage to the area V1 will show a blindside - this is a condition we’re someone appears qualitatively blind- they report no revision but they can locate objects in the visual field by pointing to them. Suggesting that some of the processing in the visual cortex is not conscious.
Overgaard- 31 year old known as GR. in tests asking to detect a letter shown on a screen she could not identify the letter but did report awareness of something despite seeing nothing (haemorrhage in the left occipital lobe)
How many primary auditory centre does the brain have
How does it receive information
What happens if it is damaged
What did Meyer et al find out about the primary cortex
2 - one in each hemisphere housed in the temporal lobes.
- receives info through both ears via 2 pathways that transmit info about sound and where it’s located, information from the right ear goes to the left hemisphere but some is transmitted to the left primary auditory centre too. Vice vesa.
- if damaged you do not go completely death- sound can be heard but some complex processing such as music can’t be heard.
- found that it’s not just conscious sound. If someone is watching a silent film their primary auditory cortex will active for instance if a door shuts the Bang will be imagined
What are the two language centres in the brain and where are they located
What happens to patients who have damage to brocas and wernicke’s area ( give examples )
Broca’s and wernicke’s area
Located in the left hemisphere
Broca’s- in the left frontal lobe.
Damage
Broca’s - called Broca’s aphasia (not all words are effected equally ) nouns and verbs are often u affected. But some classes of words such as prepositions and conjunctions cannot be spoken. Can’t read out lout “to be or not to be” but can say “two bee oar knot tow bee” also there speech is slow and lacks in fluency.
Tan- understood spoken language but unable to express his thoughts through writing. Broca stidied tan and other patients and found patients with the same damage in the right hemisphere wasn’t affected in the same way - identified a language centre in the frontal lobe in the left hemisphere.
Wernicke’s area - those with damage in the left temporal lobe close to the auditory cortex had specific language impairment. - the inability to comprehend language and anomia (struggle to find words they need ) but they do have fluent speech. Access words quickly but what they said was meaningless. People with wernicke’s area will often produce nonsense words.
What did fedorenko et al further discover in Broca’s area
What is wernicke’s area important in
Two regions, one involving language and the other responding to demanding cognitive tasks e.g.- maths problems.
- understanding language and accessing words.
How can the localisation be supported
-Peterson et al-
Brain scan to demonstrate that Broca’s area was active during a reading task and wernicke’s during a listening task. Suggesting different functions.
-Tulving- semantic and episodic memories reside in different parts of the prefrontal cortex
- neurosurgical evidence suggest that symptoms associated with mental disorders are localised. Dougherty et al 2002 - 44 OCD patients who had undergone cingulotomy after 32 weeks after the surgery 1/3 had met the criteria for success response to surgery and 14% had partial response.
What oils challenge the localisation
-Lashley- rats brains did not find a specific area associated with memory, it appeared to be stored all over the brain. He removed the cortex in rats that was learning a maze. No areas were seen as more important when trying to learn the maze. Suggesting that the learning is too complex to be localised.
Can this be generalised though?
- the fact that’s there rehabilitation following brain injury suggests that there in no localisation. If there were task specific areas then there would be no brain plasticity. The law of equipotentability suggests that in fact areas of the cortex can take over the responsibility for specific functions following damage to the area normally responsible.
- Danelli et al -EB had his left hemisphere removed during surgery at 2.5 years old loosing his linguistic abilities- after a rehabilitation programme he began to improve around the age of 5 and by 8 he had regained most of his ability. This would seem like there’s no localisation/ lateralisation of functioning. However EB never fully recovered as at the age of 17 he had minor grammatical problems and was slow at naming objects and pictures - this suggests there is some localisation with certain areas of the brain.
How are the two hemisphere in the brain bridged
Define lateralisation and contralateral
By the corpus callosum - a bundle of fibres is effectively a communication pathway so the two hemispheres can exchange information.
- lateralisation: two hens are functioning different with certain mental process mainly controlled by one hem rather than the other
- contralateral: when the right hem deals with the left hand side of the body and vice Versa.
What is the division of functions between the two hemispheres known as
What did toda and Morois find ?
What suggest that the right hemisphere is associated with spatial awareness
Hemisphere lateralisation
- through brain images he found greater activity in the left hemisphere for a visual task and greater activity In the right hemisphere for a spatial task ( working memory model)
- Clarke et al: woman with damage to right hem- she would often get lost if she was not given verbal directions even in familiar places - right hen deals with spatial info.
Along side spatial awareness what else is the right hem associated with
What may suggest that the left hem focus on the detail and the right process overall patterns ?
Recognising emotions.work has soon that if a image is presented that has been split with a happy and a sad face, the emotion of the left side of the picture is more likely to be the most recognised emotions, ( heller and levy)
- if somebody asks you to identify the small detail there will be greater level of activity in the left hem however if someone asks you to look at a image holistically this prompts more activity in the right hem.
What was the aim, procedure and results of sperrys split brain research
Aim: the effects of hemisphere disconnection and show that each hemisphere has different functions
Method : 11 split brain patients( all undergone disconnection of the cerebral hemispheres ) all suffered a history of epilepsy which couldn’t be controlled through media. Quasi experiment - IV- a person with hemisphere disconnection or not. DV- how participants performed on tasks. Lab conditions and lab equipment - highly standardised.
Results : when presented with a image to the left visual field they could not respond to the same of the stimulus ( information can’t pass to the left where language Is processed)
- participants couldn’t give a description of an image presented to the left visual field but could draw it with there left hand.
How can sperrys research be evaluated
Support
-quasi + case study - combine qualitative and quantitive data - statistically reliable info.
- Localisation of functioning
Challenge
- 11 ps - small sample however there is not many split brain patients ( ore depth)
- ingenious tasks - highly standardised procedures
- the extent to which the split brains were indicative of normal functioning prior to surgery is an issue, especially as the surgery was to treat a problem with the brain
What does diamond say in addition to sperrys’s research
The person feels like 2 people in once body. The left hemisphere takes control of situations and suppresses interference from the right hemisphere by Using smaller pathways that connect the hemisphere
What is synaptic pruning
What can be formed as a result of learning and new experiences
Rarely used connections are deleted and frequently used connections are strengthened
- neural connections can change or new neural connections can be formed.
What is the research into plasticity
Kempermann et at - found evidence of an increased number of neurones in the brain of rats housed in complex environments compared to rats housed in lab cages. Rats housed in complex environments showed an increase in neurones in the hippocampus associated with the formation of new memories and the ability to navigate from one direction to the next.
Maguire et al - studied the brain of London taxi drivers and found that they had more volume of grey matters in the hippocampus than in a matched control group. This was the area associated with the development of spatial and navigational skills in humans and other animals. As part of London cabbies training they must take a test called ‘the knowledge’ which assess their recall of London streets and other possible routes. It appears that the result of this learning experience is to alter the structure of the taxi drivers brain.
What are the 3 main anatomic ways the body can replace axon function in the brain after trauma
Axonal sprouting - growth of new nerve endings with connect with other undamaged nerve cells to form new neuronal pathways.
- reformation of blood cells
- recruitment of homologous areas on the opposite side of the brain eg- damage to the left hem would result in a similar area in the right hem taking over functionality.
What research has been done into functional recovery
Schneider et al - retrospective study. Asked on date from the us traumatic brain injury systems database. Of 769 patients studied 214 had achieved disability free recovery after one year. 39.2% of patients with 16 or more years of education had achieved DFR as 30% of those with 12-15 years of education.
What does FMRI stand for and what are they?
Functional magnetic resonance imaging.
Operate in the same way as standard MRI’s but can also show changes in Brian activity as it occurs while a person performs a task.
Measures changes in blood flow in areas which indicate increased neural activity.
Measures the energy realised in haemoglobin - when haemoglobin is oxygenated it reacts differently to when it’s deoxygenated. So when an area of the brain is more active it produces more oxygen, the different amount of energy realised. Y the haemoglobin is detected by the scanner and the change measured.
Dynamic moving picture - showing activity one second after it occurs, it is also accurate to within 1-2mm in the brain. This has important indications in understanding of localisation of function.