Physiological/Biological Psychology

E. Kent Rogers

What is it?• Physiological psychology

investigates human behavior, emotion, thought, perception, learning, memory and all other elements of psychology in terms of biological structures (different regions of the brain and organs of the endocrine system) and physiological processes.

• It is materialistic, assuming that the human being is a biological machine, thus deterministic, not allowing room for free-will.

• Mind and consciousness arise from biological processes.

• All experiences and behaviors are all caused by the nervous system, the endocrine system, genetic programming and biology in general.

• Evolution plays an important role in the thinking of physiological psychologists (though there is also evolutionary psychology)

• No discrete distinction between animal and humans, only a matter of degrees along a continuum.

Go Back, we messed everything up.

Tools Employed

MRI: Magnetic Resonance Imaging

• Also known as N(nuclear)MRI and magnetic resonance tomography MRT

Very basically, it uses pulses of massively powerful magnets to excite hydrogen atoms which then emit a radio signal which is interpreted into images..

Offers very clear, high resolution images of the inside of the body, and is especially useful for seeing the structures of the brain.

fMRI (funcional MRI)• Using the similar technology as MRI, fMRI works by

detecting blood flow volume in the brain. • Higher rate of blood flow to any given area of the brain

indicates that area to be in use and so needing more blood.

• Thus experimenters tell people to think or do things and find out which parts of the brain are involved in different tasks.

• It can also be used to discover what different psychoactive drugs do in the brain.

• It can also help determine what is malfunctioning in different psychological and psychiatric disorders

• It can illustrate developmental changes in brain functioning

X-ray Computed TomographyX-ray CT

• Often shortened to CT scan, though other forms of computed tomography exist such as PET scans

• A computer analyses x-rays into three dimensions.

• Used to be called CAT scan.

Tomography means any technique of imaging cross sections (slices) of the body

Positron Emission Tomography• Radioactive substance (called a tracer) is

placed into the body and it emits gamma rays which are detected by a sensor.

• The tracer is usually an analog to glucose and so when metabolism increases in an area of the body due to activity, this shows up in the scan and offers an image of what parts are used for different functions. So it works similarly and offers similar information to fMRI

Single Photon Emission Tomography (SPECT)

• Again uses a radioactive substance to map out the functioning of brain areas during different tasks, but the higher concentrations are according to blood flow (like fMRI) and not metabolism (like X-ray CT scan)

Electroencephalogram (EEG)Measures electrical signals (brain waves) corresponding to brain activity

Other tools of investigation• Abnormal/normal comparisons• Damage/normal comparisons• Electro-stimulation• Introduction of drugs directly into brain tissue• Introduction of drugs orally/injection• Blood tests• Brain samples• Unconscious behavior observations• Animal research• And more

Values to the Approach• Helpful in identifying specific organic disruptions in

mental illness and disturbances• Helps remove stigma from mental illnesses.• Offers important information about possible cures

for mental/neurological issues.• Offers very concrete, quantitative data• Does not usually require deception or involve

elaborate behavior/roles/scripts in experimentation

Values cont.• Useful for investigation of individual

differences• High reliability• Generally high validity• Generally high generalizability

Drawbacks• Does not accommodate idea of holism—that the

human being is something more than the biological machine; that human consciousness is more than a survival tool resulting from evolution.

• Can be invasive.• Experimental use of animals raises ethical

questions.• Experimental use of animals may not generalize to

humans• fMRI's don't actualy show brain activity, but blood

flow and PET's show tracer levels

Drawbacks continued• May undervalue talk therapies in favor of

drug, surgical and genetic therapies.• May lead to dangerous assumption of liberty

in tinkering with human “machine”• Can lead to alarming “advances” such as the

–the “humanzee” my term –creation of so called “super-humans.” –Downloading for those who can afford it

Debates Involved• Spirit or just machine?• Inherent value or meaningless mechanics?• Determinism or freewill?• Situational or individual?• Biological or social?• Nature or nurture?