Biological Psychology

• CAT/CT - Many x-ray photographs are used to create a scan of the brain showing the basic structures, e.g. the volume of the hippocampus can be seen disadvantage = exposure to radiation

• MRI - powerful magnetic field makes use of the magnetic probabilities of the hydrogen in the brain, doesn't provide a functional measure of brain activity disadvantage = person must lie as motionless as possible 

• EEG - records the spontaneous electrical activity of neurons by placing electrodes on the scalp disadvantage = spatial resolution is relatively poor 

An electroencephalograph measures the average activity of the cells in a given region of the brain. 

• MEG - similar to EEG, records magnetic fields generated by the electrical activity of neurons 

• PET - records the emission of radioactivity from injected chemicals, the images show which parts of the brain are active, disadvantage = radioactive substances are used, expensive

• fMRI - magnetic field and RF pulses used to generate a signal, based on haemoglobin 

• Microelectrode Recordings - thin electrodes inserted into the brain, mainly restricted to animals for research, disadvantage = invasive 

Double Dissociation:

The link between the brain area and function is suggestive of localisation of function, but not proof. To prove, find 2 patients with mirror deficits, then those functions must be independent systems.

Lesion Methods:

Intentional damage of a selected area (only in lab animals). A stereotaxic instrument is used to locate the precise brain areas. 

Lesion = damage to a brain area

Ablation = removal of a specific brain area 

Brain Stimulation: 

TMS = Intense magnetic field is applied to the scalp which temporarily inactivates the neurons below the magnet, the safety is not yet fully confirmed. 

Muscle Tension:

• Measured using EMG
• Electrodes are taped to the surface of the skin over the muscle of interest

Skin Conductance:

• Measures the ability of the skin to conduct electricity 
• Applied to the study of emotional thought and experiences 

Cardiovascular Activity

• Heart rate (ECG)
• Blood Pressure (Sphygmomanometer)
• Blood Volume (Plethysmography)

Eye Movement:

• Measured by EOG
• Electrodes are taped above, below, and to the sides of the eyes 

Traditional Conditioning Paradigms, e.g. Pavlovian and Operant

Semi Natural Animal Learning Paradigms, e.g. Morris Water Maze 

Behavioural Responses to Biological Stimuli (e.g. hormones):

• Oxytocin is a hormone important in social bonding in many species 
• Oxytocin can be administered via intranasal spray
• Administering oxytocin can increase ratings of attractiveness and trustworthiness relative to the control group (Theodoridou et al 2009)
• Men and women have different levels of hormones (especially sex hormones), Law-Smith (2005) found faces with high estrogen were more feminine and attractive 
  

Encephalization Quotient (EQ) = The ratio of brain volume to the volume of body size 

Early studies have found no relationship between brain size and intelligence. Some new MRI studies have though (McDaniel, 2005). 

Because animals are linked by evolution, comparison across species is important (e.g. brain evolution).