Research Methods in Physiological Psychology Chapter One Research Methods in Physiological Psychology Real brain – how do we get info out of it? http://fieldtrip.fcdonders.nl/_media/tutorial/layout/dalal_ecog.png?w=450

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)

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.

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 http://www.siumed.edu/%7Edking2/ssb/neuron.htm Nissl Stain

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

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

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?

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.

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) - 1973 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) - 1972 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) - 1977 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) - 1991 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

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.

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.

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

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

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

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