Brain injury: Outcome

Brain Reserve and Cognitive Reserve explained

What is Reserve?

The idea of reserve following damage to the brain is rather a simple concept to understand. It can be considered as the idea that there is a reserve of function following brain damage. However, consideration of the concept demonstrates that is cannot simply be considered as unidimensional. Brain reserve is the idea of brain reserves as a rather passive process. This is in contrast to cognitive reserve which is the idea of reserve against concussion and brain damage as a result of active function.

Brain Reserve

Brain reserve capacity is a theoretical construct that may include synapse count. Persons are considered to have different amounts of brain reserve capacity as dependent on a number of factors (e.g., level of education, age, intelligence, learning disabilities, etc). As a result a brain injury may appear less in a person with a high brain reserve since their function remains above a functional impairment cutoff threshold. In contrast a person with a lower brain reserve who sustain the same degree of injury may subsequently fall below the functional impairment cutoff threshold. Thus more brain reserve can be considered as a protective factor and less brain reserve would impart vulnerability.

Cognitive Reserve

Brain reserve can be differentiated from cognitive reserve which is seen more as the brain actively attempting to cope with or compensate for pathology. Rather than considering that these individuals brains are grossly anatomically different than those with less reserve (e.g., they have more synapses), the cognitive reserve hypothesis posits that they process tasks in a more efficient manner. More specifically, cognitive reserve can be view as a more efficient utilization of brain networks and or the enhanced ability to recruit alternate brain networks as needed. In this model, persons are considered to have the same amount of brain reserve capacity and the cognitive reserve model does not assume that there is some fixed cut-off or threshold at which functional impairment will occur. The critical threshold differs from one person to the next based on how efficient or resilient the remaining neural substrate processing is. The outcome is based on what processing is lost and what processing remains. A proposed definition of cognitive reserve is: the ability to optimize or maximize performance through differential recruitment of brain networks, which perhaps reflect the use of alternate cognitive strategies.

Neuropsychological Assessment

Irrespective of the model, acquired brain injuries can have different impacts in a persons function. As such, neuropsychological testing as part of a neuropsychological assessment is indicated to determine the impact of a brain injury. Neurodynamics specializes in such neuropsychological assessment. Please contact us if you require assistance in this area.


Dr Nathaniel Popp
Clinical Neuropsychologist
BA., MA., DPsych., MAPS., CCN Member
TAC Provider number: 160 603 50
WorkCover Provider number: PS5676B

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