Physiological psychologyAre boys better at three point turns than

girls?

Physiological Approach

Can evolutionary theory explain human behaviour?Are our brains hardwired to behave in a certain way?Do our hormones affect our moods & behaviour?Are we genetically predisposed to become mentally ill?Can mental illness be due to a chemical imbalance in the brain?

What does this have to do with Psychology?

Psychologists are interested in how the different areas of the brain and their functions might affect

our behaviour.

Physiological Approach: Assumptions

• Much of human behaviour has a biological base

• Psychologists should study the brain, nervous system and other biological systems, e.g. hormones, chemicals acting on the brain

• Nature or Nurture?

Studying the brain

Brain imaging techniquesLooking inside the black box!

Computed Tomography Scan(CT Scan)

CT scans use a series of X-ray beams passed through the head, creating cross-sectional images of the

brain showing the structure, but not the

function.

Positron Emission Tomography(PET)

•A scanner detects radioactive material that is injected or inhaled to produce an

image of the brain. •Once in the bloodstream, it flows through the brain and oxygen and

glucose accumulate in brain areas that are metabolically active.

•As the glucose is used in the active parts of the brain, the radioactive

material breaks down and gives off a neutron and a positron.

•When a positron hits an electron, both are destroyed and two gamma rays are

released. •Gamma ray detectors record the brain

area where the gamma rays are emitted.

•This method provides a functional view of the brain.

Positron Emission Tomography(PET)

Advantages

Provides an image of brain activity.

Disadvantages

Expensive to use. Radioactive material used.

Magnetic Resonance Imaging(MRI)

MRI uses detection of radio frequency signals produced by displaced

radio waves in a magnetic field. It provides an

anatomical view of the brain.

Magnetic Resonance Imaging(MRI)

Advantages•No X-rays or radioactive

material is used. •Provides detailed view of the brain in different

dimensions. •Safe, painless, non-

invasive. •No special preparation (except removal of all metal) is required from

the patient.

DisadvantagesExpensive to use.

Cannot be used in patients with metallic devices, like

pacemakers. Cannot be used with

uncooperative (or claustrophobic) patients

because the patient must lie still.

Electroencephalogram (EEG)

The recording of electrical activity along the scalp

produced by the firing of neurons within the brain

over a short period of time, usually 20–40

minutes, as recorded from multiple electrodes placed

on the scalp.

EEG read out

Other Brain scans

Functional Magnetic Resonance Imaging(fMRI)

Functional MRI detects changes in blood flow to

particular areas of the brain. It provides both an

anatomical and a functional view of the brain.

Angiography

Angiography involves a series of X-rays after dye is

injected into the blood. This method provides an

image of the blood vessels of the brain.

Advantages• Physiological psychology helps us to

understand the influence of biology on our behaviour

• It helps us understand how differences in chemical processes, brain structures and forms may shape different people’s behaviour. These difference may be natural, the result of genetics (nature) or as a result of injury or disease

• Physiological research has many uses for man. It has resulted in the production of pain killing drugs and medication for treating the most severe mental illnesses

Limitations• Relies on opportunity samples or very small

samples, leading to low generalisability.• The reductionist approach is too simplistic –

not everything can be explained at a physiological level (e.g. dreaming)

• The physiological approach to psychology is an example of physiological determinism. This means that it usually only recognises that biology drives behaviour. It does not necessarily take account of free will, social or cognitive influences on behaviour. Surely humans have developed well beyond animals and our intelligence has freed us from biological determinism?

Exit TicketPracticing PEE:

Outline what is meant by the physiological approach in psychology.