Localisation of Cognitive Functions in relation to the parts of the brain

Ever wondered what would happen if you damaged a certain part of their brain such as the frontal lobe, a region directly responsible for our behaviour and emotional control? Would this head injury suddenly make it hard for you to speak, remember faces, or move one side of your body? Well the impact that it has on you isn’t random, they depend on which specific part of the brain was affected. This theory, known as localization of cognitive functions, explains how different regions in the brain are responsible for specific mental processes. In this article, we’ll take a deeper dive into the different lobes of the brain and their functions. 

What is Localisation Theory? 

First Introduced in the mid-1700s by the work of German physiologist Franz Joseph Gall, localisation theory holds that different regions of the brain serve their own specific function such as memory and vision. The theory gained significant traction in the early 1800s when Gall started to base his work off of it and since then has paved the way for significant improvements and developments in the understanding of brain function with many recent neuroimaging studies supporting the theory. 

Localisation of functions in different parts of the brain 

(SaveMyExams, Claire Neeson, 2025)

1. Motor Cortex 

The motor cortex is located in the frontal lobe which is highlighted yellow in the diagram above and plays a crucial role in the voluntary control of movement by sending different signals to muscles all around our body. Damage to the motor cortex can result in motor impairments, such as weakness, paralysis, or loss of coordination in specific body parts, including the loss in the ability to precisely move individual fingers. 

2. Broca’s Area 

Also located in the frontal lobe, Broca’s area plays a critical role in the production of speech and language, particularly the extensive motor planning that is required to articulate words and construct grammatically correct sentences. It was discovered and named after by Paul Broca in 1861 as he realised that his patients who had the ability to understand but not speak or write in a language would have damaged tissue in the place which we now know as Broca’s area. Damage to this area causes Broca’s aphasia, where patients struggle significantly with language production, often unable to express themselves through writing or speaking. 

3. Somatosensory Cortex 

Located in the parietal lobe highlighted pink, the somatosensory cortex is the primary area for processing sensory information from touch, producing sensations like temperature, pressure and pain.  If this area is damaged, patients may experience numbness, loss of tactile sensation, or develop a condition known as astereognosis where there are difficulties in recognizing objects by touch as information is not being correctly processed. 

4. Visual cortex 

The visual cortex is primarily located in the occipital lobe highlighted green, at the back of the brain. It is responsible for processing visual information received from the eyes via our optic nerves. Damage to this area can result in visual impairments due to an increased difficulty in processing visual information. 

5. Wernickie’s area 

Wernicke’s area is located in the temporal lobe, and is vital for language comprehension. This area allows individuals to understand both spoken and written language by recognising different sounds as language while associating them all with meaning and is used to formulate coherent sentences. It was discovered and named after German neurologist Carl Wernickie in 1874 who had patients who could speak but the words that they spoke could not be formed into a sentence with meaning. Damage to this area results in Wernicke’s aphasia or otherwise known as receptive aphasia, and is characterized by fluent but meaningless speech and significant difficulty understanding language. Unlike Broca’s aphasia, where patients still had comprehension, Wernicke's aphasia severely impairs the ability to grasp the meaning of words and sentences. 

6. Auditory Cortex  

The primary auditory cortex is located in the temporal lobe and is the area responsible for processing sound information. It lies close to and provides information to Wernickie’s area to assign words meaning. Damage to the auditory cortex can lead to various auditory processing disorders, where patients  may have difficulty interpreting or recognising sounds, even if their hearing is otherwise normal.

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