Localisation of Brain Function

Overview

The localisation of brain function refers to the concept that specific parts of the brain are associated with particular physical and psychological functions.
This concept is key in understanding a range of behaviours and cognitive processes in the biological approach to psychology.

Phineas Gage’s accident: A key event that promoted the idea of localisation was the case of Phineas Gage, who had a railroad spike accidentally driven through his skull, damaging his frontal lobes. His personality considerably changed after the accident, indicating that this part of the brain may control personality and social behaviour.
Various techniques like MRI scans and fMRI scans are used to study the localisation of brain function in living samples.

The frontal lobes are responsible for problem-solving, decision making, and conscious thought.
The parietal lobes manage sensory information from various parts of the body.
The occipital lobes are involved in visual processing.
The temporal lobes are associated with auditory processing and memory.

The brain is divided into two hemispheres: the left and right hemisphere. Each hemisphere is associated with different functions—a phenomenon known as hemispheric lateralization.
For example, in most right-handed individuals, language functions (like speech and comprehension) are lateralized in the left hemisphere.

Understanding localisation of brain function has been key in developing treatments for neurological disorders, such as Parkinson’s disease and various types of aphasia.
Knowledge of brain localisation has been applied in forensic psychology, helping to explain criminal behaviour. Damage or functional abnormalities in certain brain areas have been linked to violent or antisocial behaviour.

The concept of localisation has been contested by proponents of the holistic theory of brain function, which argues that brain functions aren’t localised to specific regions but rather, the whole brain is involved.
The effects of brain plasticity are a limitation. Brain plasticity refers to the ability of the brain to adapt or alter as a result of experience. This challenges strict views of localisation as the brain can sometimes ‘re-wire’ itself following damage.

Paul Broca and Carl Wernicke: Both have made significant contributions to understanding the localisation of brain function, particularly regarding speech and language.
Roger Sperry: He conducted “split-brain” research, leading to our understanding of lateralization of brain function.