Module 1: Introduction to Biological Psychology

What is Biological Psychology?

Often called Behavioural Neuroscience, it is a multidisciplinary field that combines the methods of psychology, biology, physiology, chemistry, and computer science to try and explain the biological processes underlying behaviour and experiences.

Approaches to studying biological psychology:

  1. Generalisation: conclusion made based on several similar observations

  2. Reduction: trying to understand a complex idea by breaking it down into smaller parts.

Bio Psych reduces behaviours to brain structure and function and makes generalisations about brain-behaviour relationships.

History of Bio Psych

  • Concepts of mind differed throughout history

    • Ancient Egypt: emphasis on heart not brain

    • Ancient China: holistic approach - body/mind/nature balance

    • Christian Bible: no mentions of brain, but mentions of heart

    • Ancient Greece: Aristotle - the brain cools the passions of the heart; Hippocrates - pleasure and sorrow rise from the brain; Galen - linked mind to brain because noticed that brain injuries were accompanied by behavioural changes

    • Descartes (1600s): behaviour of people and animals worked similarly to a machine; some behaviour separate from the mind (reflexes); mind-body interactions through Pineal Gland

    • Galvani (1700s): empirical testing of mind-body interactions through electrical stimulation on frog nerves

    • Muller (1800s): electrical Information from nerves; different parts of brain serve different functions - Doctrine of Specific Nerve Energies

    • Cajal (1900s): one of the first to look at brain structure on neuron level

    • Flourens and Broca: researched brain functional divide through looking at damage to different areas and its consequence

Epigenetics: study changes to gene expression induced by environmental factors

Natural Selection and Evolution

Functionalism: the physical features of a given species, which govern behaviour, are related to function, therefore, we have to consider function when studying how the brain shapes behaviour. (Ex: Binocular vs monocular vision)

  • The physical features and therefore behaviour of a given species are adaptive (Ex: Forelimb bones have adapted to serve different functions through natural selection across different species)

Natural Selection: some physical features increase chances of survival and reproduction, therefore such features are more likely to be inherited and become more common in a population, while the features hindering survival die out so to say.

How does natural selection work?

Organisms are made up of cells which contain chromosomes, which contain pairs of genes - alleles. Each allele is inherited from each parent, and together they act as instructions for producing proteins.

Mutation: changes in genetic information contained in the chromosomes of sperm or eggs, which can be passed to offspring - increases variation. Change physical characteristics (Ex. change in the brain might affect behaviour). Mutations can have negative effects, which decrease survival chances, or positive effects, which are referred to as selective advantage.

Mutations that do not have immediate effects on survival are still important as they contribute to Genetic Variability, which is useful particularly when there are changes in the environment (previously ineffective mutations become useful)

Evolution: gradual changes in a species brought via natural selection over time

Human Example of Evolution

  • Our ancestors had characteristics well suited for survival, such as communication, walking on two legs, colour vision, and tool use. These characteristics require complex brain circuitry, so a need for a relatively large brain appeared

  • The brain continues to grow after birth, therefore there are not only the task-specific cells given at birth, there is opportunity for the neural pathways to be shaped by the environment

    • The infant brain is tuned to all language sounds, but with experience their native language takes the spotlight

  • Although the size of the brain relative to the body matters when it comes to cognition, the number of cerebral cortex neurons available is a stronger predictor for complex cognition.

  • Neoteny: slow down of the rate of brain maturation among humans, compared to other species (like chimpanzees) - the brain has more time to develop

Ethics in Biological Psychology

Governing Principles in Animal Research:

  • Using animals only when its justified

  • Supporting the wellbeing of the animals involved

  • Avoiding or minimising harm, including pain and distress

  • applying high standards of scientific integrity

  • Applying Replacement, Reduction, and Refinement at all stages of animal care and use

    • Replacement of animals with other methods

    • Reduction in the number of animals used

    • Refinement of techniques used to minimise the adverse impact on animals

  • Knowing and accepting one’s responsibilities