Keep in mind that these exercises are for persons who do not have a brain injury. The uninjured brain is much more capable of being retrained. The injured brain is a different story completely. The exercises may lead to improvement in these areas for an injured brain but to a different level of improvement.

For example,

A person can have a healthy but weak heart due to never exercising. They can do cardio exercises and improve the strength of their heart to equal a strong heart or even better.

A different person can have a healthy heart that is strong. Then, they suffer a heart injury. They can exercise to overcome the weakness from the injury and get improvement but it is difficult for them to recover to the same level of heart strength as before the injury. The scars in the heart muscle will be a limiting factor.

So, do these exercises carefully to avoid overwhelming your brain. Work for improvement but don't get discouraged if your improvement is not to the same level of function as prior to your injury.

The functions that do not recover to pre-injury levels can often be overcome with work-arounds.

If your loss in divided attention, selective attention and short and immediate term memory (combined as working memory) is due to an injury to the gating functions of the brain, your gains may be more difficult.