Research Methods Psychology 2617

Or, so how do we know this stuff We can look at the whole brain We can look at the whole brain We can look at parts thereof We can look at parts thereof We can look at neurons We can look at neurons We can look at synapses We can look at synapses

neurons Even before electron microscopes, we could look at neurons thanks to Golgi Even before electron microscopes, we could look at neurons thanks to Golgi He discovered that when stained with Silver chromate, neurons went black He discovered that when stained with Silver chromate, neurons went black Today we call this golgi stain Today we call this golgi stain Led to the classification of neurons, as we could finally see their physical properties Led to the classification of neurons, as we could finally see their physical properties

Stains are not always bad Golgi stain does not show number of neurons in a region that well though Golgi stain does not show number of neurons in a region that well though It stains just a few It stains just a few Nissl Used dyes! Nissl Used dyes! Methelyne blue Methelyne blue Myelin staining Myelin staining HRP and axonal transport allow us to see circuits! HRP and axonal transport allow us to see circuits!

Radiation, run for your lives! X Rays are cool, but, they don’t work well on brains X Rays are cool, but, they don’t work well on brains AEG, kinda dangerous AEG, kinda dangerous CAT scans are cool though CAT scans are cool though Gives us a good idea about form Gives us a good idea about form

Some of this stuff is a little, oh yucky Angiography Angiography Wada technique Wada technique Both involve injections into the blood supply of the brain while the patient is awake Both involve injections into the blood supply of the brain while the patient is awake Wada technique proved once and for all the idea of hemispheric specialization Wada technique proved once and for all the idea of hemispheric specialization

EEG Electroeds placed on the head Electroeds placed on the head

Brain waves Gamma activity is fast and big, peak activity Gamma activity is fast and big, peak activity Beta low amplitude but fast, being alert Beta low amplitude but fast, being alert Alpha quiet Alpha quiet Theta quiet, sleep Theta quiet, sleep Delta super slow, deep sleep Delta super slow, deep sleep

Diagnostic uses of EEG Epilepsy is associated with crazy EEGs Epilepsy is associated with crazy EEGs Basically uncontrollable firing Basically uncontrollable firing Spreads can lead to a seizure Spreads can lead to a seizure

Evoked potentials Stimulus given Stimulus given Basically computer subtracts out the background EEG Basically computer subtracts out the background EEG Used lots in research and in diagnostic areas Used lots in research and in diagnostic areas Some disorders show characteristic ERPs Some disorders show characteristic ERPs

Electrical Brain stimulation Basically put an electrode in the brain with the patient awake Basically put an electrode in the brain with the patient awake The classic Dr. Penfield approach The classic Dr. Penfield approach Not nearly as effective as Penfield made it out to be… Not nearly as effective as Penfield made it out to be…

Looking at metabolism Blood flow techniques Blood flow techniques Use radioactive isotopes Use radioactive isotopes Look for anomalies Look for anomalies SPECT sort of a poor mans…. SPECT sort of a poor mans….

PET scan Positron emission tomography Positron emission tomography

MRI Magnetic Resonance Imaging Magnetic Resonance Imaging

MRI Basically a combo of RF signals and a REALLY strong magnetic field Basically a combo of RF signals and a REALLY strong magnetic field Has no ill effects, unless you have a metal plate in your head Has no ill effects, unless you have a metal plate in your head Shows form and function Shows form and function

Behavioural techniques These are really the kind of thing that involve say, touching your nose These are really the kind of thing that involve say, touching your nose Or presenting a stimulus to one visual field and not the other Or presenting a stimulus to one visual field and not the other Really quite telling, but nowadays you then end up in an MRI often Really quite telling, but nowadays you then end up in an MRI often

Advances Basically the imaging techniques remain the same Basically the imaging techniques remain the same It is the computing power and software that is allowing for real time analysis that is having the biggest effect It is the computing power and software that is allowing for real time analysis that is having the biggest effect When MRI first came out the fastest desktop computer was MAYBE running a 75 MHz When MRI first came out the fastest desktop computer was MAYBE running a 75 MHz This little powerbook runs at 1.25 Ghz This little powerbook runs at 1.25 Ghz