Mentally Handicaped

Definition

Intellectual disability is one of the largest categories in the special education population. It is also referred as mental retardation or mental handicap. mental handicap is defined by the American Psychiatric Association in the Diagnostic and Statistic Manual of Mental Disorders (DSM-IV) as a disorder with (1) significantly sub-average intellectual functioning (an IQ score of approximately 70 or below) (2) concurrent deficits or impairments in present adaptive functioning in at least two of the following skill areas : communication, self-care, home living, social / interpersonal skills, use of community resources, self-direction, functional academic skills, work leisure, health and safety. (3) onset before the age of 18. There are four levels, reflecting different degrees of severity : mild (IQ = 55-70), moderate (IQ = 40-55), severe (IQ = 25-40) and profound (IQ below 25). Approximately 90% of children with mental retardation are functioning at the mild levels and can benefit from mainstream schooling.

Characteristics

Children with intellectual disability have an impaired ability to process information. They have problems in central processing, which is the use of memory, reasoning and evaluation. Weak ability in organizing or classifying information is one of their difficulties. School age children usually quickly learn to cluster or group things or events into meaningful categories, e.g. banana, apple and grapes belong to the set of “fruits” whereas red, yellow and green belongs to the set of colors. However, children with mental retardation are less able to group and tell similarities among concepts (Krik, Gallagher & Anastasiow, 1999).

Memory, another central processing function, is also difficult for children with intellectual disability. The greater the severity of intellectual deficit, the greater the deficit in memory. Memory problems can stem from poor initial perception or poor judgment about applying of what has been stored to a given situation, or insufficient rehearsal of information. Therefore, they many have problem remembering events or the proper sequence of events. Teachers can assist students to develop memory strategies such as making a picture notebook that sequences a checklist of things to do before leaving home for school (Poon-BcBrayer and Lian, 2002)

Impaired executive function is also one of the characteristics and the major factor in poor performance (Borkowski and Day, 1987). Executive function is the decision-making ability to receive, process and express. Although these children are capable of perceiving the stimulus, they have difficulties paying attention to the relevant stimulus, and may lack metathinking strategies to organize information. Sometimes inappropriate responses are produced due to the lack of judgment. All these difficulties are due to their poor ability to make good judgment and decision.

Besides, they may be incapable of transferring learning from previous experiences to new situations (generalization), especially in moderate or profound level of intellectual disability. They are less able to acquire knowledge through incidental learning from ordinary daily experiences. Direct instruction is always required.

As there is a close link between language and cognition, impairment in cognitive function inevitably leads to delayed language development. In fact, delayed language development could also result in cognitive impairment especially in thinking, planning and reasoning. Language develops in the same fashion, but in a slower rate in children with intellectual disability compared with their non-disabled peers. For example, a child at age 5 would possess similar linguistic skills of a 10-year old child whose mental age was 5.

Adaptive deficit is also prominent. Lack of adaptive functioning is in fact one of the diagnostic criteria. Their failure to adjust to academic world and the community can result in emotional and social difficulties. Self-injurious acts, such as self-biting, head banging, and face slapping are evidenced in severely mentally handicapped children.

Due to their insufficient language skills to make themselves understood by peers, social and emotional problems sometimes developed. For instance, they may not be liked by their peers or do not feel connected with them, therefore, a sense of loneliness may be built. Their constant lag behind than their same-aged peers could also cultivate a low self esteem which further create negative thoughts and feelings. As their cognitive abilities are less developed, when faced with cognitively challenging tasks, they could easily give up or become bored.

Educational Implications

The learning characteristics of the students with cognitive disabilities bring

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