الفهرس 
Memory Functions and dysfunctionsOnly 14 pages are availabe for public view
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Abstract
Cognitive rehabilitation is defined as a systematic, functionally oriented service of therapeutic activities that is based on assessment and understanding of the patient’s brain-behavioral deficits.
Memory function is critical to daily life, and includes a variety of specific abilities that enable information to be stored and retrieved over variable periods, ranging from seconds to days to years memory. Five distinct types of memory are generally present. Semantic memory and episodic memory (collectively called declarative memory or explicit memory); procedural memory and priming or perceptual learning (collectively called non-declarative memory or implicit memory) all four of which are long term memory systems; and working memory or short term memory. Semantic memory is memory for facts, episodic memory is autobiographical memory , procedural memory is memory for the performance of skills, priming is memory facilitated by prior exposure to a stimulus and working memory is a form or short term memory for information manipulation.
Memory functions are related mainly to the medial temporal lobe and hippocampus, although wide spread connections and anatomical areas are involved.
Memory difficulties are one of the commonest cognitive problems arising from injury to the brain and, consequently, form a large part of cognitive rehabilitation. The memory affection by neurological insult depends on several factors such as the anatomical location of the injury and the specific nature of the disease process. About 36% of survivors of severe traumatic brain injury live with significant memory impairment Also, 70% of survivors of encephalitis will experience memory impairment. Survivors of stroke, cerebral tumor and other known conditions may also experience memory problems.
Executive functions are a wide range of cognitive processes and behavioral competencies which include functions such as planning, working memory, inhibition, mental flexibility, as well as the initiation and monitoring of action. These functions are mediated mainly by the prefrontal areas and their extensive connections to subcortical and limbic system as well as other anatomical areas.
Deficits in executive functions cause devastating social handicap after brain injury and therefore represent a major challenge for rehabilitation. These can include problems with abstract reasoning, making decisions, and showing good judgment; difficulties in maintaining attention; inappropriate social behavior as well as difficulties in devising and following plans.
Neuroplasticity is the ability of the nervous system to respond to intrinsic and extrinsic stimuli by reorganizing its structure, function and connections. The triggers and mechanisms for forms of synaptic plasticity will differ, but ultimately will depend on achieving a desired functional outcome such as consolidating a memory-trace, learning a new skill or compensating for brain damage.
Hopefully the understanding of neuroplasticity and its underlying mechanisms could enhance opportunities for the translation of neuroplasticity research into effective clinical therapies.
In order to have rehabilitation plan, thorough neuropsychological evaluation is conducted to help determining the loci of cognitive impairments within the neurocognitive architecture. Then, the details of the analysis are combined with the available treatment tools and the goals for treatment set by patients and therapists. Test scores help define points of strength and weakness of the patient in a systematic way, so that techniques can be applied in a fashion as appropriate as the state of knowledge allows. Progress in cognitive rehabilitation follows what is learned as therapy proceeds from the initial assessment, from the generation of hypotheses, and by monitoring the consequences of interventions.
As regard memory impairments, rehabilitation is done by several strategies by providing information and memory groups, environmental adaptation, external memory aids, facilitating new learning and through use of virtual reality and non-invasive brain stimulation.
The theoretical goal of these strategies is to improve or support damaged functions in order to facilitate new learning. Some remediation strategies were conceptualized in order to facilitate the encoding process: the errorless learning approach, and the visual imagery techniques. Other strategies have been developed in order to enhance the retrieval capacities: the spaced retrieval technique, the vanishing cues technique, and various external memory aids.
While for executive dysfunctions, most applications of rehabilitation are multimodal and offer a mixture of various treatment strategies. These strategies are summarized in four main approaches, including environmental modification, retraining or restoring impaired executive functions, use of external aids to initiate action sequences, changing action in response to changes in the environment. In addition, there is a role for virtual reality and non-invasive brain stimulation. Generalhy, for each patient, combining cognitive rehabilitation methods is the most effective treatment approach. .
Regardless of what approaches and materials are used in cognitive rehabilitation, the therapist must plan, from the beginning, ways to ensure that generalization of skills acquired during therapy will transfer to real world activities.
There are many variables in the response to rehabilitation tools. These factors include the age, the severity of impairment, the specificity of deficit and the premorbid state. Also, other variables are likely to be important, including insight and motivation, support from family members and work colleagues, and absence of major sensory, motor, or psychiatric disability .