Biomedical subjects

T Van Zandt

Publications and source records attributed to T Van Zandt.

6 recordsLinked to original sources

PubMed1995

Process dissociation, single-process theories, and recognition memory.

According to the assumptions of L. L. Jacoby's (1991) process dissociation method, performance in recognition memory is determined by the combination of an unconscious familiarity process and a conscious intentional recollection process. The process dissociation method is used to produce estimates of the contributions of the 2 components to recognition performance. This article investigates whether the method provides the correct estimates of components if performance actually depends on only a single process or on 2 processes different from those assumed by the method. The SAM model (G. Gillund & R. M. Shiffrin, 1984) was used to produce simulated data based on a single process. Variants of SAM with 2 processes and R. C. Atkinson and J. F. Juola's (1973) 2-process model were used to produce data based on 2 processes.

Cognition↗

PubMed1993

Stimulus-response compatability for moving stimuli: perception of affordances or directional coding?

Michaels reported a compatibility effect in which responses were fastest at the destination of a moving stimulus; she interpreted this "destination" compatibility effect in terms of catching actions "afforded" by the stimulus motion. The present study evaluated implications of the catching-affordance account and compared them with those of an account based on spatial coding of relative direction. The destination compatibility effect was obtained when the responses were keypresses rather that catching movements of a joystick and regardless of whether the stimulus expanded, contracted, or only changed location. This effect was a function of relative rather than absolute location of the responses. A similar compatibility effect was obtained when destinations were designated by static arrow stimuli. The results are inconsistent with the catching-affordance account and are best explained by the coding of relative direction.

Adult↗

PubMed1993

Self-terminating versus exhaustive processes in rapid visual and memory search: an evaluative review.

A major issue in elementary cognition and information processing has been whether rapid search of short-term memory or a visual display can terminate when a predesignated target is found or whether it must proceed until all items are examined. This study summarizes past and recent theoretical results on the ability of self-terminating and exhaustive models to predict differences in slopes between positive (target-present) and negative (target-absent) set-size functions, as well as position effects. The empirical literature is reviewed with regard to the presence of slope differences and position effects. Theoretical investigations demonstrate that self-terminating models can readily predict the results often associated with exhaustive processing, but a very broad class of exhaustive models is incapable of predicting position effects and slope differences typically associated with self-termination. Because position effects and slope differences are found throughout the rapid search literature, we conclude that the exhaustive processing hypothesis is not tenable under common experimental conditions.

Cognition↗

PubMed1992

Enhancement of the Simon effect by response precuing.

When stimuli are presented to the left or right of fixation, and stimulus location is irrelevant, responses are faster if the stimulus location coincides with the location of the assigned response. This phenomenon is called the Simon effect. The present study examined the influence on the Simon effect of attentional precues that signaled the likely stimulus location and intentional precues that signaled the likely response. Experiment 1 was a close procedural replication of an experiment by Verfaellie, Bowers, and Heilman (1988); consistent with their findings, the Simon effect was enhanced by the intentional precue and unaffected by the attentional precue. Experiments 2 and 3 demonstrated the importance of the intentional precue with simpler procedures that involved only intentional and attentional precues, respectively. Finally, the intentional precuing enhancement of the Simon effect was obtained when two stimuli were assigned to each response, regardless of whether the hands were uncrossed (experiment 4) or crossed (experiment 5). Overall, the results indicate that response precuing enhances the Simon effect and favor response-selection accounts over those that attribute the effect to stimulus identification.

Adult↗

PubMed1991

Same-different judgments of multiletter strings: insensitivity to positional bias and spacing.

Several recent studies of multiletter matching have included pairs of strings that have the same letters in different positions (rearranged pairs). The task can be defined such that these rearranged pairs are correctly classified as different (i.e., subjects respond "same" only if the strings have the same letters in the same positions--the order task) or as same (i.e., subjects respond "same" if the strings have the same letters regardless of their positions--the item task). The order task produces left-to-right serial-position effects, whereas the item task produces U-shaped serial-position effects. Because these differences suggest that subjects may be able to exert strategic control over the comparison process, two sets of experiments were designed to test whether or not subjects can change the relative weightings devoted to the respective serial positions. In Experiments 1 and 2, the probability that a mismatch occurred in the different positions was manipulated. In Experiments 3 and 4, the physical spacing between letters, as well as whether or not the spaces were filled with neutral noise characters, was varied. None of the manipulations had much influence on the serial-position effects. Thus, the distinct serial-position effects for the order and item tasks apparently are mandatory and not due to any voluntary comparison strategy.

Attention↗

PubMed1990

Effects of background symmetry on same-different pattern matching: a compromise-criteria account.

Two experiments are reported, which were designed to test predictions of an account of same-different matching that assumes that bilaterally symmetric backgrounds provide extraneous evidence toward same, whereas asymmetric backgrounds provide evidence toward different. When all backgrounds within a block of trials are of the same type, appropriate adjustments of response criteria can be made to accommodate the irrelevant evidence and thus maintain acceptable levels of accuracy. However, when backgrounds of different types are mixed randomly, compromise criteria are adopted. This compromise-criteria account predicts distinctive interaction patterns for reaction times when blocked versus mixed presentations of various background types are compared. The predicted interactions were obtained for asymmetric- and no-noise backgrounds in Experiment 1 and for symmetric-, asymmetric-, and no-noise backgrounds in Experiment 2. The findings support the general view that extraneous display attributes are weighted into the evidence for same and different, with criteria settings used that minimize errors under the noisiest conditions.

Adult↗