ATTENTION-CONTROL IN THE FREQUENTISTIC PROCESSING OF MULTIDIMENSIONAL EVENT STREAMS
MARQUES, TODD EMERSON
Doctor of Philosophy
A series of experiments was conducted to elucidate the role(s) of special or strategic effortful processes in the encoding and retrieval of frequentistic information. Previously, investigators have concluded that sensitivity to frequency was the result of an "automatic" mechanism. However, it is difficult to generalize these findings to what people do when processing real-world frequentistic data because most studies have involved highly artificial experimental stimuli. By contrast, the present series of studies employed multidimensional stimuli that had real world significance to the participants. The complexity and realism of the stimuli facilitated the relatively unobscured assessment of the cognitive processes involved in frequency encoding. The purpose of Experiment 1 was to classify individuals according to the ability to "timeshare" in a dual-task setting. Timesharing ability was operationalized in terms of subject responsiveness to a payoff scheme which was designed to induce tradeoffs in the distribution of attentive effort between two concurrent tasks. The thrust was on the classification of prospective subjects for further investigations of frequentistic encoding and retrieval operations. A sample of four subjects in possession of uniformly good to excellent timesharing skills was enlisted for participation in the subsequent experiments. In Experiment 2, a complex rating task was used to test the hypothesis that special effortful processing is required in the formation of frequency records. The task involved the consistent aggregation of the evaluative cues comprising hypothetical candidate profiles. The principal question was whether the encoding of frequency information would be an incidental by-product of the effortful processing associated with the rating task. The negative findings strongly suggest that special (or strategic) effortful processing is required in the formation of reasonably accurate frequency records. In Experiment 3, the tasks of frequency estimation and hypothetical candidate rating were examined concurrently in a dual-task paradigm. A pronounced performance tradeoff was found between the two tasks; that is, improved performance on the frequency task was gained at the expense of degraded rating task performance, and vice versa. This suggests that whatever the processes governing frequentistic encoding operations, they draw upon the same pool of limited cognitive resources as those governing the rating task. This, of course, provides further support for the view that frequency encoding is the result of special effortful processing strategies. Implications of these findings for real-world decision making are examined, and ideas for future research are discussed.