Brain Function in Old Age

Experimental gerontopsychology attempts to test causal hypotheses about old age-related behavioral changes by the manipulation of age-differences. An experimental treatment is introduced with the purpose of equating different age-groups with respect to a potentially relevant function. If the treatment results in an assimilation of the behavior of the different age-groups (age­ by-treatment interaction), differences in this function are con­ sidered as causal for the normally observed behavioral