DotPoint 2: Biological Levels of Analysis

Outline the principles of the Biological Level of Analysis

• That there are physical correlates of behaviour

It is assumed that behaviour can be observed through physical symptoms, and is at least partially caused by biological factors

See: Phineas Gage (1858-1860) by Harlowe

• That animal research can provide insight into human behaviour

It is assumed that in some species, biological/physical stimuli will prompt behaviour which will provide reflection on human behaviours.

See: Martinez and Kesner (1991)

• That human behaviour is, to some extent, genetically based

It is assumed that human behaviour can be traced to evolutionary or genetic prompts.

See: Bouchard et al. (1990)

Examine at least one study related to localisation of function in the brain

Localisation of function presupposes that each action that the brain carries out has a specialised centre of activity, distinct from others.

See: H.M. by Milner (1957) and Corkin et al. (1997)

The study of H.M. has contributed enormously to the knowledge of how memory processes are related to specific brain areas.

It shows that:

• Medial Temporal Lobes are important for the forming, organisation, consolidation and retrieval of memories.
• Cortical Areas are important for Long Term Memory, semantic and episodic memories, and the use of that information in daily life.
• Procedural memories are not processed by the hippocampus

Explain the effects of two neurotransmitters on human behaviour

When a nerve impulse reaches the end of the neuron, the neuron fires neurotransmitters, which are then released into the synaptic gap (the gap between neurons) and travel to the receiver neuron, when it binds to specific receptors at the other side
If a neurotransmitter is not absorbed it can be re-uptaken, diffused out, or destroyed.
If a neurotransmitter is blocked or replaced, then the messages change. This affects the physiological system, cognition, mood, or behaviour.

Neurotransmitter examples:

Acetylcholine: affects learning and short term memory

See: Martinez and Kesner (1991)

Serotonin: affects sleep, arousal levels, and emotion

See: Kasamatsu and Hirai (1999)

Explain the functions of two hormones on human behaviour

Adrenaline

Stimulates the "fight or flight" response. It quickens reaction times, dilates the blood vessels, increases blood pressure and emotional arousal.

See: Schacter and Singer

Melatonin

Affects arousal levels, seasonal adaptation, development during puberty, and regulates the circadian rhythm.

See: Rosenthal (1987)

Explain two effects of the environment on physiological processes

Neuroplasticity

is the theory that the brain can rearrange the connections between its neurons, changing itself structurally as well as functionally as a result of the environment. 

See: Maguire et al. (2000)

Twin Studies

investigate the effect that the environment has on psychological development of children. This is executed by contrasting siblings, dizygotic twins, and monozygotic twins

See: Bouchard et al. (1990)

Explain one interaction between cognition and physiology in terms of behaviour

Cognitive neuroscience is the scientific study of biological correlates of mental processes. This area of research investigates how various brain areas are involved in cognitive processes (e.g. how brain damage affects memory), but in recent years, researchers have also investigated how cognition and physiological processes may interact in people who engage in activities such as meditation.

See: Phineas Gage by Harlowe (1858-1860), H.M. by Scoville and Milner (1957) and Corkin et al. (1997)

Discuss the use of two brain imaging technologies in investigating the relationship between biological factors and behaviours

Brain-imaging techniques are used in neuroscience to investigate the relationship between behaviour and brain structures. 

One of the main issues with brain imaging technology is that it is mainly about mapping brain structures and activity. It may be possible to identify brain structures that are active during a task, but since most structures are linked with others, it is not possible at this point to say definitely where things are in the brain.

MRI (magnetic resonance imaging) Uses magnetic fields and radio waves to produce 3D images.

See: H.M. by Corkin et al. (1997), or Maguire et al. (2000)

PET (positron emission topography) Uses a radioactive glucose tracer injected into the brain to trace glucose absorption 

See: Tierny et al. (2001)

Discuss the extent to which genetics influence behaviour

Concordance rate is the probability that if one individual has the trait, then the other will also have it. This is assumed to establish if, or to what extent, a certain trait is inherited, when used in twin studies.

See: Bouchard et al. (1990)

There are some glaring issues with genetic research. It cannot at this point determine the true extent to which genetic inheritance influences behaviour because

• genes interact with environmental factors in complex ways, and it is difficult to measure the relative influence of environmental factors
• knowledge about genes is still fairly limited
• the methodology is flawed;
  • concordance rate does not establish a cause-effect relationship
  • the equal environment assumption may be flawed, and the idea that MZ twins would be treated the same as DZ twins may be a false assumption

Examine one evolutionary explanation for behaviour

Evolution is the changing in inherited traits of a species over time.

The theory of evolution is based on the assumption that living organisms face environmental challenges. Organims that adapt to their surroundings have a greater chance of passing on their genes to future generations. Organisms with specific genetic traits that enhance survival are thus said to be naturally selected.

In evolutionary psychology, it is assumed that if a behaviour exists today, it was helpful in past human survival and reproduction. These behaviours are labelled "adaptive", as they have assisted in extending survival or increasing possibility of strong offspring.

For example, we can study the behaviour of pregnant women in order to gain some insight into adaptive behaviours.

See: Curtis et al. (2004)

Discuss ethical considerations in research into genetic influences on behaviour

• genetic research is correlational by nature, so one should be careful about making definitive conclusions about the risk of developing disease - it may not be causal
• it is not certain that genetic research is ethically neutral (e.g. the eugenics movement, misuse of ethically charged data)
• knowledge about the role of specific genes in behaviour is still limited - no definite conclusions can be made, and this research doesn't account for the effect of the environment
• genetic research into complex behaviour (e.g. homosexuality) is controversial because of the social meaning and significance of that behaviour. The research may have flow-on effects.

See: DotPoint 5.3 - ethical concerns in diagnosis

• participants in a genetic study must be sure that their anonymity and confidentiality is protected. However in twin studies it can be difficult to ensure this
• participants have a right to know who owns the genetic information and how it will be used
• participants have the right to be fully informed about the nature of the research
• research into genetic influences on behaviour could pose risks to participants and the information could be misused.
• genetic research can reveal information that is unexpected or a source of distress to participants (e.g. genetic predisposition)