brain learning and motivation: cognitive neuroscience Flashcards
**cortex
wheremost o the higher function takes place
size of brains
male brains are usually around 200g heavier than female brains
humans don’t have the heaviest brains i the world
the longitudinal issuer
divides the brain into its right and left hemispheres
though the two sides are still connected
**Corpus Callosum
the connection tissue between the right and left hemispheres of brain
Pia Mater layer and the Arachnoid layer
the brain is protected by many layers of tissue these are two of them between which there is cerebral fluid
stroe
occurs when blood supply to the brain is cut off/ not getting to the right place
Ventricles in brain
primarily contain cerebral fluid, produced by the brain
the Broca area and Wernicke areas
respectively responsible for language production and language comprehension
lesions in these areas can lead to aphasia as they are on left hemisphere
The Penfield & Rasmusen experiment, in 1950
involved stimulating parts of a patient brain to determine which areas were responsible for what function
the size of corresponding brain areas
depends on the importance of the body part they represent e.g. the hand has a large area because it is very sensitive
can carry out a number of different functions
and is packed with receptors
techniques used in cognitive neuroscience: single cell recording
a technique used in research to observe changes in voltage or current in a neuron.
n this technique an animal, usually anesthetized, has a microelectrode inserted into its skull and into a neuron in the area of the brain that is of interest
the electrode measures the change in charge as the neuron reaches its action potential ( the voltage at which the neuron is active)
… in response to cerain stimuli
single cell recording : found
different cells react to different stimuli e.g. a light moving in a line would stimulate different cells to one situated in a different orientation
visual cortex and central vision (fovea
in monkeys it was found during a single cell recording that 40% of cells in the visual cortex were stimulated by the central vision because this is the most detailed point of vision
primary visual cortex
receives all visual input from the retina
techniques used in cognitive neuroscience: lesion studies
lesions on the brain caused by stroke i.e. loss of blood supply to certain areas, brain damage and trauma
some patients could have one lesion , some could have several and some could have one large lesion… therefore its impotent that tests are carried out to understand which lesions cause which conditions i.e.. which part of the brain being damaged is responsible
lesion studies: Aphasia
caused by lesion of the left hemisphere of the brain
effects of aphasia
sufferers may have difficulty speaking, reading, writing, recognizing the names of objects, or understanding what other people have said
hemispatial neglect
caused by a lesion on the right hemisphere of the brain
hemispatial neglect effects
causes sufferers to ignore the left side e.g. eat dinner only off the right side of the plate
tests for hemispatial neglect
patients would be given a sheet with something on it and be asked to copy it withou moving the sheet,
if a sufferer they would only copy the right hand side
another test is to give them a sheet with big stars and little stars and ask ten to cross out all small stars… sufferers would not cross out small stars on left
techniques used in cognitive neuroscience: transcranial magnetic stimulation (TMS)
uses n electrically charged coil which is placed against the scap.
this creates a magnetic fied that interferes with brainwaves in the desired area that the coil is positioned at
use to create artificial lesions this helps in determining which lesions cause what behaviour in specific areas in the brain
TMS advantages
can be done on healthy undamaged brains and subjects
wider range of subjects
rules out interference of other lesions
TMS disadvantages
patients participating often move around when having the hlmrt put on discharging the magnetic field
depending on which part of the brain you want to test you need to know exactly where to place the coil this can be difficult in small areas
coil position must be guided and monitored
since the magnetic field is weak it cannot reach deeper areas in the brain
brain imaging techniques
can be broken into 2 categories:
Structural techniques
functional techniques
