Durability of effects of instrumental enrichment in adults with intellectual disabilities

21 adults with intellectual disabilities were examined three years after participating in a cognitive intervention program in order to assess the durability of their cognitive achievements. The sample consisted of two age groups: 30-49 years (n=12) and 50-59 years (n=9). The primary intervention method was the Instrumental Enrichment Program. The effects of the intervention were examined by three types of thinking instruments: logical thinking (Reversal and Verbal Abstraction Tests), predictive thinking (Maze Tests), and insightful thinking (Postures and Children Tests). These tests were given five times: two times prior to the cognitive education program, spaced two months apart; two times after the cognitive education program, spaced two months apart; three years after the program. This repeated-measurement was used to compensate for the absence of a control group (an absence due to reality-based technical considerations). The original study yielded significant improvement from Time 2 to Time 3, and two months later (Time 4), showing a divergent effect for two types of thinking. The follow-up evaluation (Time 5) showed a drop in the cognitive functioning relative to Time 4, but not to Time 3, a finding that indicates a durability effect. The results support Feuerstein's structural cognitive modifiability theory, according to which long-term individual changes are possible regardless of the individual's age and cognitive functioning level