Models for within-proposition representation tested by cued recall

A model is presented to account for the data from incremental cuing experiments that have been carried out to identify the representation of propositions in memory. In such experiments subjects first learn a list of sentences and are afterward cued for recall with words from the learned sentences. The model proposed distinguishes between a memory structure and stimulus and response processes. The all-or-none tendency in the data is captured by a Gestalt-like memory code. The model is compared with the stochastic theory of Anderson and Bower and the fragmentation hypothesis of Jones.     

The formation of reference systems in visual motion perception

Summary In visual perception complex movements are usually split up into components — e.g., in such a way that a moving reference system is applied, to which partial movements can be related. In the following experiment a perceptual vector analysis of this kind was investigated. It was shown that 1) a radial translatory movement (relative component) can be isolated perceptually from a rotatory movement (global component) and that 2) the precision of this decomposition of the complex movement is dependent on the strength at which the rotating reference system is anchored perceptually.The authors wish to thank M. Rauterberg for collecting the experimental data     

A three-component analysis of the modality effect in single-trial free recall

Johann-Wolfgang-Goethe Unversität, Frankfurt am Main, West-Germany In single-trial free recall a superiority of acoustical over visual presentation has been observed in the recency part of the serial position curve. The rehearsal-buffer model by Atkinson and Shiffrin (1968) was modified to distinguish between three different explanations that are discussed in the literature. The application of the model allowed some of the parameters to vary across modes of presentation while other parameters were held constant. A model assuming either a precategorical acoustical storage or additional processing for visually presented items gives a better account of the results than does a model derived from a two-store hypothesis.     

Launching the effect: Representations of causal movements are influenced by what they lead to

We investigated whether the representation of an observed causal movement is influenced by its observed effect. Subjects watched displays showing collisions between two objects. In this 'launching event' (Michotte, 1946/1963), one of the two objects (Object A) started to move and set a second, initially stationary, object (Object B) into motion, which gave a strong impression of apparent causality. The apparent effectiveness of A's movement was manipulated by varying the velocities of A and B. When the velocity of B was higher than that of A, the effectiveness of the collision was high; when it was smaller it was low. Then, subjects were asked to reproduce the velocity of the causal movement. Reproduced velocity followed the velocity of both Object A and Object B, which supports the hypothesis that the effect of a movement is integrated with its apparent cause. However, when apparent causality was reduced by changing the direction of motion of B or by covering the point of collision, the influence of the effect on the representation of the cause persisted, suggesting that retroactive interference may account for the findings. The interference effect could not be reduced to temporal recency or spatial integration and was not obtained in the reverse temporal order (proactive interference). Rather, the two successive movements were blended in memory.