Studies testing the claim set forth by the continuum hypothesis have shown mixed results. For example, Ryan and Butters (1980) demonstrated that when required to perform demanding learning and memory tests, different subjects’ patterns of performance fell along a continuum: Alcoholics with Korsakoff’s syndrome performed more poorly than did alcoholics without Korsakoff’s syndrome who spontaneously had reported memory problems (but showed no clinical signs of amnesia). These people, in turn, performed less well than did alcoholics with no complaints of memory problems, who, in turn, performed less well than did nonalcoholics in a control group. In addition, the researchers provided evidence that alcoholics who had not complained of memory problems still exhibited memory deficits when the tasks were made more difficult, thereby increasing information-processing demands.
