Why can a brain injury change movement, memory and behaviour?
Short answer: because the brain doesn’t control one function at a time. Movement, memory, attention, emotion and behaviour rely on different regions of the brain constantly communicating with one another. When a traumatic brain injury (TBI) affects these regions or the pathways connecting them, the effects can appear in many different ways. For Brain Injury Awareness Week 2026, we’re looking at why.
Why can the same brain injury cause so many different symptoms?
The brain is often divided into different regions according to their main functions, but these areas don’t work independently.
Something as simple as getting ready to leave the house can require the brain to:
- remember what needs to be done
- plan the order of each task
- initiate the activity
- maintain attention
- coordinate movement and balance
- process what is happening around you
- manage time and distractions
- recognise and correct mistakes.
This is why a brain injury can affect much more than physical movement. Damage to a particular area, or disruption to the connections between areas, can influence how efficiently the brain performs everyday tasks.
What do the different areas of the brain control?
Different brain regions have particular roles, although most everyday activities rely on several regions working together:
- Frontal lobes: planning, initiation, problem-solving, attention, judgement, impulse control, emotional regulation and voluntary movement.
- Temporal lobes: memory, language, auditory processing, recognition and aspects of emotional processing.
- Parietal lobes: sensory processing, spatial awareness, body position, attention and visual guided movement.
- Occipital lobes: processing and interpreting visual information.
- Cerebellum: balance, coordination, movement accuracy, timing and motor learning.
This can help explain why two people with traumatic brain injury may present very differently depending on the location, severity and nature of their injury.
Why are changes in behaviour and motivation common after TBI?
The frontal regions of the brain play an important role in executive function, the skills we use to plan, organise, initiate, problem-solve, regulate behaviour and monitor our own actions.
Following a brain injury, someone may therefore know what they need to do but struggle to get started. They may require more prompting, become frustrated more easily, act impulsively or find it difficult to adapt when something goes wrong.
From the outside, this can sometimes appear to be poor motivation or unwillingness.
In reality, difficulties with initiation, attention, inhibition or executive function may be contributing to the behaviour.
The frontal and temporal areas of the brain are also commonly affected in traumatic brain injury. During rapid acceleration, deceleration or rotational forces, the brain can move within the skull, creating areas of impact, compression and stretching.
Why does brain injury rehabilitation look different for everyone?
Because the presentation is different.
Brain injury rehabilitation is not simply about following a standard list of exercises for TBI. Rehabilitation needs to consider where the person's difficulties actually occur and what those difficulties prevent them from doing.
For one person, the primary limitation may be weakness, balance or walking capacity.
For another, strength may be relatively good, but coordination makes movement difficult.
Someone may perform well in a quiet environment but struggle when noise and distractions are introduced.
Another person may physically understand and complete an exercise but require prompting to remember the sequence or initiate the next activity.
Brain injury rehabilitation can therefore include:
- strength and cardiovascular conditioning
- balance and coordination training
- gait and mobility rehabilitation
- task-specific movement practice
- dual-task activities combining movement and cognitive demands
- graded exposure to more complex environments
- fatigue and pacing strategies
- repetition, routines and external cues
- strategies to improve independence in meaningful everyday activities.