The Allen Cognitive Levels is an ordinal scale that measures the type of sensorimotor information that arouses attention. An ordinal scale is also a hierarchical scale, which means that the scale measures both abilities and disabilities simultaneously.
The Allen Cognitive Levels scale has been divided into three different sections to serve different purposes:
- Levels: used to classify types of sensorimotor information and do public education.
- Modes: used to detect small changes in global ability to function and to match between what the person can still do with an action or activity.
- Profiles: used to make useful and practical discharge recommendations to long-term carers.
Levels
The levels within the Allen Cognitive Levels are:
- Sensory information
- Movement information
- Linear information
- Classification information
- Tangible information
- Abstract information
The first five levels contain sensorimotor information that is perceived by one or more of the five senses and connected to motor actions. Each Allen Cognitive Level has an additional type of information. When a type of information enters the scale, it is in the simplest form. Once a type enters the scale it continues to expand in complexity. The increasing complexity is determined by the type of information that enters at each consecutive level. A pyramid is built from the bottom up with the foundation of sensorimotor information. For example, the scale moves from obvious to subtle sensory cues and gross motor to fine motor actions.
The last level, ACL 6, is a normal adult where attention is aroused by abstract information, which is defined as information created in the mind and excludes knowledge gained by perceiving the effects of one's actions on one's self or on material objects.
Modes
There are 25 modes within the Allen Cognitive Levels. Each level has been divided into five modes.
Each mode begins with a definition of sensorimotor information that arouses attention.
Modes are represented as an even number after the decimal point, e.g. ACL 2.4. This is the third mode within level 2.
Profiles
In 1992 we added the decimal points to the ACL scale to make the scale longer and sensitive to smaller degrees of change (modes). At that time, point six was supposed to add a "little bit" of the next level. Since then, I have learnt that the little bit is a lot. By describing the profiles as qualities of information, the reason it was such a big change is clear. What happens is that information from the next level is added at point six. Even though the new information begins in the simplest form, it is still a big jump. The added information has a big impact on the person's ability to function. Opening up to a new type of information makes a big difference. The other big difference occurs at point zero, when the use of the new information is apparent in behaviour.
As a general guideline, point six (.6) and point zero (.0) are associated with big changes in all five of the levels. The new type of information, as it is added, always enters in the simplest form. Obvious behavioural uses of the information also make a big difference.
In ACL 1, the new type is movement information. Movement information is supplied by changing the location of parts of the body. Gravity effects the position of the body when any part is not fully supported. The smallest use of movement information is to move with the effects of gravity. The trunk is the first part of the body that is consciously controlled.
The type of information that is already being processed is always influenced by the new information that just entered.
In ACL 1, the information that is already being processed is sensory information.
Movement information is added to sensory information to create an internal sense of postural position.
By taking advantage of those big changes, I could describe 10 profiles. We can now make predictions that are explicit and accurate enough to be useful to long-term carers.