1. Research Methods in Physiological Psychology
Chapter One
Research Methods in
Physiological Psychology
Real brain – how do we get info out of it?

2. Diverse Research Methods Are Used in Biological Psychology
Histology
Autopsy/ Lesion
Imaging/ Recording
Stimulation
Pharmacological methods
Genetic methods
Methods of research
None of these methods are perfect, they all have problems and limitations, so what scientists do is try to collect information from several different kinds of methods, if results generally agree, then they start to think that are understanding the process, if they don’t there is clearly something else that they don’t understand yet
Let me go through some examples of a few of these techniques, then we’ll come back to this slide
Histology – studying brain tissues, often staining tissue to see things better (structure, connections)
Autopsy – studying brain structure after someone is dead (structure, function)
Imaging – studying working brain with new, mostly noninvasive techniques; blood or glucose use/patterns/ density of tissues (x-rays, CAT, MRI) (structure, function)
Recording – using electrodes to directly measure electrical activity of brain, often invasive (function)
Stimulation – pushing electricity into a cell/brain area, seeing how organism responds (function)
Lesion – damaging part of brain, seeing how organism responds – what can it do without area, or not do (function)
Pharmacological methods – give drugs and see what happens (chemistry, function)
Genetic methods – deleting genes in animals, or looking at people with naturally occurring deletions, or tracing differences in genes b/t people with different behaviors (genes)

3. Histology: The Study of Microscopic Structures and Tissues
Tissue to be viewed must be:
fixed by freezing or formalin.
sliced thinly by a microtome.
Stains are applied to highlight structures of interest
Histology: The Study of Microscopic Structures and Tissues
Tissue to be viewed must be:
fixed by freezing or formalin.
sliced thinly by a microtome.

4. Histology Examples Myelin Stain Golgi Stain Nissl Stain
Histology: The Study of Microscopic Structures and Tissues
Stains are applied to highlight structures of interest:
single cells (Golgi).
cell bodies (Nissl).
pathways (i.e., axons) (horseradish peroxidase).
antibodies (proteins found in a particular cell).
Golgi – you can see position of cell bodies, where axons, dendrites are
Nissl – position, size of cell bodies
Weigert (a Myelin stain) – some processes go up and down, some side to side
Nissl Stain

5. Using Histology: Horseradish Peroxidase
WHAT: cell bodies that are connected to axons WHY: to show where axons came from, to look at how brain areas are connected
HP actually stains axons too, although not all retrograde tracers do this
axon of
neuron
neuron
synapse
Normal flow of information
Thalamus
Retina
Retrograde Transport

6. Using Histology Explain which stain is which
Ask about differences you notice…
Layers II and IV small neurons, get info
Layers III and IV large neurons, project info out

7. Autopsy: Simon LeVay and INAH-3
INAH-3 is an area of the brain that is usually different in males and females, smaller in females
We don’t even know exactly what it does, but it is somehow involved in sexual behavior
Very controversial findings
Can you see any possible problems?
Who were the patients? Why did they die?
Has anyone else found similar results?

8. Lesions
The results of lesions can be used to determine the function of an area.
Lesions may be:
naturally occurring
artificially produced
heating the tips of surgically implanted electrodes
chemicals that kill cell bodies.
temporarily produced by cooling an area of the brain.
The results of lesions can be used to determine the function of an area.
Lesions may be:
naturally occurring
artificially produced
heating the tips of surgically implanted electrodes
chemicals that kill cell bodies.
temporarily produced by cooling an area of the brain.

9. Brain Imaging Example - Brain Activity
Positron Emission Tomography (PET)
Measures brain activity based on the utilization of radioactive glucose or oxygen.
Positron emission tomography (PET)
Inject radioactive atoms, brain areas being active supposedly use either oxygen or glucose and attract radioactive atoms
(when atoms breaking down, it emits a positron, hits electrons, emits gamma rays)- Brain activity averaged over time
Red/yellow – high activity
Blue/green – low activity
Pics: visual activity, listening, problem-solving
Pros: shows brain activity.
Cons: exposure to radioactive tracer; less spatial resolution than other methods; very expensive
Other types of brain imaging
Computerized Tomography (CT)
use x-ray technology to view brain structure
images made using x-rays depend on the absorption of the beam by the tissue it passes through.
Bone and hard tissue absorb x-rays well, air and water absorb very little and soft tissue is somewhere in between.
Thus, CT scans reveal the gross features of the brain but do not resolve its structure well.
Magnetic resonance imaging (MRI)
Hydrogen, part of water, has different concentrations in different locations of the brain.
Basically, magnet turned on, makes H+ atoms aligned to magnet, then radio frequencies pulsed (makes horrible noise), then turned off, and H+ atoms relax and returns to position where it is aligned to magnet, but while it does that it emits radio frequencies
Denser substances – white (bone); less dense – black (fluid)
Tumor in white
Pros: very high spatial resolution
Cons: effects of increasingly stronger magnets??; shows no function
CAT/MRI – shows anatomy
Magnetic fields, not usable on some subjects
Small, noisy location for subject
Does not show function
Functional MRI (fMRI)
uses a series of images taken in a short period of time to analyze brain activity.
Tracks changes in flow of oxygen and blood (still using hydrogen)
fMRI – blood gets less magnetic when it goes into capillaries, where it loses oxygen
Pros: good spatial resolution; shows function and structure
Cons: poor temporal resolution
Magnetoencophalograghy (MEG) – tiny electrical fields from neurons (xrays get stopped by hard tissue, but magnetic field pass right through)
EEG/ERP – overall general electrical activity of brain
Single-cell recording - Records activity from a single cell
Courtesy Dept. of Energy Office of Public Affairs

10. Stimulation
Delgado uses electrical stimulation to control his fighting bull.
The goal of stimulation is to discover the function of an area.
Stimulation can be applied:
during neurosurgery.
through surgically implanted electrodes.
Transmitter activated electrodes in bull that stopped its movement
Rats: transmitter activates electrodes in pleasure centers, tells rat which way to go
From Jose Delgado
“Ratbots” respond to stimulation by changing direction.

11. Pharmacological Methods
Drugs:
Administered to subject, behavior/brain activity monitored
Microdialysis:
Chemical samples are removed through micropipettes.
Identify chemicals present in a very small area.
Pharmacological methods
Drugs: Administered to subject (either systemically or to a particular brain area), behavior/brain activity monitored
Microdialysis: Chemical samples are removed through micropipettes, identify chemicals present in a very small area.

12. Genetic Methods Twin Studies Genetically Modified Animals
Monozygotic (identical) vs. dizygotic (fraternal) twins
Concordance rates
Genetically Modified Animals
Knockout genes
Genetic methods
Twin Studies
Monozygotic (identical) vs. dizygotic (fraternal) twins
Concordance rates – probability that one identical twin will develop same characteristic if one twin is already diagnosed
(if I have schizo, what are chances of my ID twin having it? If chances high, likely a genetic connection)
Adoption studies (is it the environment?)
Genetically Modified Animals
Knockout genes

13. Human Ethical Guidelines
No coercion
Informed consent
No harm
Confidentiality
Human ethical guidelines
No coercion
Informed consent
No harm
Confidentiality

14. Non-Human Animal Ethical Guidelines
Clear purpose and necessity
Excellent housing, food and health care
Minimal pain and suffering
Animal ethic guidelines
Clear purpose and necessity
Excellent housing, food and health care
Minimal pain and suffering

15. Research Ethics Oversight
Federal guidelines
Professional societies recommendations by (APA, Society for Neuroscience)
Institutional review boards
Human Subjects Committee
IACUC
Journals
Federal guidelines
Professional societies recommendations by (APA, Society for Neuroscience)
Institutional review boards
Human Subjects Committee
IACUC (Institutional Animal Care and Use Committee)
Journals