MEMORY CAPACITY AND INTELLIGENCE - NOVEL TECHNIQUES FOR EVALUATING RIVAL MODELS OF A FUNDAMENTAL INFORMATION-PROCESSING MECHANISM

Data from a fundamental cognitive task in which participants discrimin ate the relative frequency of visual or auditory binary stimuli were e xamined, Accuracy on this task correlates well with psychometric intel ligence, The experimental paradigm is highly tractable, lending itself to rigorous analyses of precisely defined simulation models, Numerous models are evaluated, using multiple comparisons between response pat terns of individual (and pooled) participants and predictive measures based on simulations for each trial sequence, implications for theoret ical accounts of short-term memory, discrimination, and absolute judgm ent, as well as the measurement of individual differences in cognitive ability, are discussed. The results suggest a reinterpretation of mem ory capacity and support a new kind of model (with a, single estimable parameter) in which discrete. valued units of information are stochas tically displaced by further input.