The Biological ApproachBiological Changes in the Body

Sweat LevelsThere are approximately 2 million sweat glands in the body, and are used to cool the body down when we

get hot. The sweat glands in our skin are connected to the sympathetic nervous system, and when stimulated

produce sweat. The amount of sweat produced depends upon our state of emotions and physical

activity.

Anatomy of the skin

Galvanic Skin Response

This is a method of measuring the electrical resistance of the skin, the theory being that the more nervous the person is, the more sweat they produce and the less

resistance their skin has. The method has been under much criticism for it’s inaccuracy in measuring exactly what a person is

reacting to. The method doesn’t target why a person is now

sweating in relation to a simple true or false question. The person could be simply nervous, tired, easily

startled and generally have clammy hands and the response measured would indicate that they were

lying.

Uses: in polygraph machines, common place in hypnotherapy

fMRI Recent discovery that offers a non-invasive reports of neural activity

providing high resolution images using functional magnetic resonance imaging.

In laymen's terms fMRI is based on the increase of blood flow to areas of the brain, its main advantage being that it can image brain activity

related to a specific task or sensory process. It has excelled over various other scans including PET scans, as there is no need to inject radioactive isotopes, and imaging time is far quicker and resolution of

the image is superior.

It can be used to possibly explain certain reactions in individuals and also to explain behaviours by seeing which parts of the brain are active

when that behaviour is displayed.

It has very good reliability, extremely consistent and has no real ethical problems associated with it.

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