The age of onset of a cognitive disability seems to effect the person with either getting stuck with an obsolete identity or having a better identity.

People who have a history of functioning normally will probably continue to believe that they still can. Lots of evidence to the contrary rarely affects their sense of self. A few changes in their methods of doing activities may be negotiated.

An obsolete identity is a memory of how the person functioned before the onset of a cognitive disability. Learning and memory since the onset of a cognitive disability are reduced, making an update of the identity impossible. They may be aware of the mistakes they make, may not remember the frequency of their mistakes and rarely understand the implications of potential disasters. Insufficient cognitive abilities to pay attention to abstract information causes a lack of awareness of the need to adjust their evaluation of what they can and cannot do or say now.

The reduction in information that arouses their attention creates a different perspective. Their sense of identity and their memories of the past are narrowed down to the information that arouses their attention. Those memories are probably stored in the same region of the cortex. Their sense of other people and what they are doing is connected to the information that arouses their attention too. Their senses of space, direction and time have been woven into the methods for selecting and presenting actions and activities.

The reductions in the physiological operations of the brain have an effect on the person's abilities to:

• pay attention to information,
• access procedural and long-term memories,
• retain information in working memory,
• learn and remember new information,
• talk,
• coordinate their gross, fine motor and bilateral movements,
• understand what they read,
• write or text a message, and
• comprehend what money is.

All these reductions reduce their capacity to manage their own affairs.

Neurophysiology has provided three processes that form a unit of functional abilities. The processes that unite ability to function are:

A person's cognitive ability can be defined as their global ability to function, which is: everything the person says and does, 24 hours a day, 7 days a week.

The Allen Cognitive Disability Model (ACDM) is a conceptual framework for producing actions and activities that people with cognitive disabilities can feel good about doing now.

The focus of the ACDM is on the sensorimotor information that does arouse attention because those cognitive abilities can be connected to actions and activities that a person with a cognitive disability can do.