Biological theories I Flashcards
Phineas Gage
railway construction iron rod went through his skull and out his head. He survived. No motor or speech problems, memory was intact
His personality changed, becoming selfish, erratic and unreliable
Lobotomies
Lobotomies have been used to cure aggressive impulses, probes with sharp ends are inserted so they have contact with the brain. Once in place, probes rotated in an egg beater motion. Physiological effects - intellectual impairment and seizures/paralysis, personality changes
Frontal lobotomy
two monkeys who were difficult to work with because they got frustrated easily and tended to lash out. Surgery was performed on these monkeys after the surgery both monkeys were cooperative and docile
The surgery did help some people with psychosis especially those with terrible anxiety but the cost side effects was huge
Prefrontal cortex
is an association area of the brain in which means that it integrates many other processes from other brain regions. Damage to the prefrontal cortex does not disrupt the basic function of sensory, memory of emotional systems, disrupts a persons ability to synthesise these systems and produce organised social behaviour
Crebelling
automatically coordinates all of limb and muscle movements
occipital lobe
processes information from eyes and turns it into meaningful pictures
parietal lobe
controls the sense of touch and how we use our hands to do things
cerebrum
the top of the brain, covered by the cerebral cortex, contains memories and language and correlates information received from your senses. It controls voluntary movement, emotions, and does the thinking
frontal lobe
controls ability to speak
temporal lobe
where signals from our ears are processed, responsible for hearing
pons
responsible for breathing, the regular beating of the heat and other involuntary activities of the body
brain stem
collects all the body-controlling messages from the brain and passes them on to the rest of the body
Brain stats
only 2.3% of body weight but uses 25% of blood supply
Thalamus
Relays incoming messages from the sense to the proper areas of the brain that need to process them
hypothalamus
helps to regulate sexual urges, body temperature, growth, thirst and hunger, maternal behaviour, aggression, pleasure and the biological clock which let’s one know when to wake up
corpus collasum
the connection between the two halves of the brain - right and left hemispheres
Cerebral cortex
Wrinkled and folded in order to cram more brain cells into the limited volume
Methods of monitoring the brain
EEG, ERP, MEG, CAT, PET, MRI, NIRS
EEG
electroencephalography (1929) measuring the electrical activity of the brain. Electrodes attached to the scalp and positioned in a specific way to record electrical activity of neurons. EEG is often used to diagnose seizure disorders, tumours, head injuries, degenerative diseases and brain death. Also used in research on brain activity
ERP
recording event related potentials (evoked potentials) sometimes brain waves recorded for a special stimulus and the experiment repeated several times. The graphs averaged, the resulting data are called Event related potentials
MEG
magentoencephalography a method similar to EEG but measures the magnetic fields created by the electrical activity of the brain, rather than the activity itself
CAT
Computerised Axial Tomography - CAT scan - one of the two most employed methods along with MRI for visualising the brain. X-ray images taken from a series of different angles, resolution is a lot better than conventional x-rays
PET
Positron Emission Tomography - measures the emission of positrons from the brain after a small amount of radioactive isotopes or tracers have been injected into the blood stream,. The result is a three-dimensional map with brain activity represented by colours
Scams produced colours related to areas of higher metabolic activity. Measures emissions of positrons from the brain after a small amount of radioactive isotopes, or tracers have been injected into the blood stream
MRI
passing a strong magnetic field 30,000 + of the earths. Through the head. Can detect radiation from certain molecules which are present in different concentrations in different tissues. The fluid contrast between structures in the brain can then be visualised. Goal is to create a cross-sectional imaging in which contrast between tissues of interest
Iron = magnetic, surgical clip inserted e.g. aneurysm Clip = not be able to have an MRI
FMRI
functional magnetic resonance imaging - localises brain activity rather than only structures. It produces images of activated brain regions by detecting the indirect effects of neural activity on local blood volume, flow and oxygen saturation
NIRS
near-infrared spectroscopy - spectroscopic method utilising the near infrared region of the electromagnetic spectrum, NIRS can be used for non-invasive assessment of the brain function through an intact skull by detecting changes in blood haemoglobin concentrations associated with neural activity
best results - brain scanning
two or more methods at once e.g. MEG and fMRI
Left hemisphere
analytical function and language
right hemisphere
visual and spatial skills
Commisurotomy
severing the corpus callosum. It is sometimes severed as a treatment of bad epilepsy. Hemispheres received sensory signals and output motor signals but cannot communicate with each other (split brains). Aspirants cannot name image presented to LVF because transfer to language centres in left side is prevented
