AO1

• assumptions

  There is a direct correlation between brain activity and cognition

  Biochemical imbalances can affect behaviour

  Brain physiology can affect behaviour

  Behaviour can be inherited (as it is determined by genetic information)
• Genes are the genetic information carried by DNA in chromosomes, found within a cell’s nucleus; they are passed on through generations of a species if individuals survive and successfully reproduce. In line with Darwin’s theory of evolution, it might also follow that genes form a basis of behaviour, as both behaviour and genes appear to be heritable. An example might be aggressive behaviour, in light of obvious survival benefits such as warding off predators and competing for resources.
• The genotype describes the genetic configuration of an individual, whereas phenotype describes the combined effects of genetic makeup and surrounding environment on behaviour. The nature-nurture debate highlights a key argument in psychology, over the relative influence of biology and environment on the characteristics of an individual; an extreme biological approach assumes that these are determined solely by nature.
• Effects of brain physiology and neurochemistry - Interactions between regions of the brain help to control different functions, which biological psychologists assume to be significant in determining our actions. For instance, the occipital lobe is involved heavily in processing sight, along with the frontal lobe, which is thought to be involved in control and attention.
• Electrical impulses enable an important means of internal communication that directs our behaviour, travelling around the brain and to/from the body via the nervous system. Impulses are transmitted between neurons (nerves) at synapses, junctions where neurotransmitters are released that inhibit or excite other neurons to achieve different responses.
• Neurochemical imbalances in the brain are often associated with abnormal behaviour – for instance, evidence suggests that imbalances of dopamine (a neurochemical linked with the brain’s natural ‘pleasure’ system) are associated with mood disorders such as depression.
• The endocrine system is a slower-acting communication system that regulates the circulation of hormones, released by glands into the bloodstream. For example, cortisol and adrenaline are key hormones that facilitate the fight or flight response, a key evolutionary survival mechanism whereby the body primes itself for imminent danger (e.g. increasing heart rate, initiating sweating to cool down, dilation of pupils, sharpened sense of hearing).
• Animal studies – used to investigate biological mechanisms that govern human behaviour, often where ethical guidelines would not allow human participation. Many species (e.g. rats) are thought to have a similar biological makeup to humans, such that studies’ conclusions can be generalised to humans.
• Case studies – can investigate normal behaviour by observing behavioural abnormality alongside corresponding changes in biology. A very early example is the apparent personality alteration observed in Phineas Gage (mid 1800s) after a railroad construction accident drastically changed his physiology by forcing an iron rod through his brain’s frontal lobe.
• Drug therapy – behaviour can be manipulated by altering an individual’s biochemistry, a research method that can ultimately lead to developing drug applications to improve health and wellbeing. Initial phases of research are usually conducted on non-humans.
• Scans – physiology and activity across the brain can be gauged using various techniques (e.g. MRI, PET, CAT), helping researchers to identify the functions of specific regions (known as localisation of cortical function).
• Twin/family studies are useful for investigating the heritability of behaviour. For instance, research can investigate the likelihood that both of two twins develop a characteristic, known as a concordance rate. However, these studies can be time-consuming, due to long delays often required before follow-up data is collected. It is also difficult finding a large samples of participants for twin studies.