How much “effort” should be devoted to memory?

We focus on the issue of whether cognitive effort is causally related to memory. We begin with a discussion of the concept of cognitive effort as derived from capacity models of attention. We then suggest that the theoretical analysis of memory may involve concepts from different levels of psychological analysis, and we draw a distinction between concepts that represent boundary conditions and sufficient cause. When applied to memory phenomena, attentional concepts serve only as a boundary--or limiting--function in memory theory. In contrast, concepts that represent memorial processes serve as a sufficient cause function. In some instances, cognitive effort appears to have been used as a sufficient cause concept, resulting in some confusion. A review of the literature reveals a haphazard correlation between indexes of cognitive effort and of memory performance. Alternatively, the application of cognitive effort or capacity to the memory performance of certain populations (clinical, children, and elderly) illustrates a potentially more appropriate use of the concept.     

Haptic integration of planar size with hardness, texture, and planar contour

Three studies investigate the role of size information in haptic classification of custom-made planar objects when size covaries with hardness, texture, or planar contour. The haptic exploratory procedure (Lederman & Klatzky, 1987) associated with size extraction is also sufficient for encoding shape, which should promote their integration. Experiment 1 showed substantial facilitation of classification by redundant size and shape cues, indicating the coprocessing of size and shape. Experiments 2 and 3 used a withdrawal paradigm: Classification trials began with two redundant properties, and one was then held constant (withdrawn). Experiment 2 showed that when size and shape were redundant, withdrawal of either impaired responses, whereas when size was redundant with texture or hardness, only size withdrawal had an effect. Experiment 3 demonstrated that this size weighting was not restricted to a single procedure for exploration. Size appears to be highly weighted in haptic classification and potentially integrated with other properties having compatible methods of extraction.     

Detection of parts in patterns and images

Memory & Cognition - Subjects performed in an embedded-figures detection task which required them to judge whether one pattern was a part of another. In the perception condition, the part was...     

Encoding strategy and sensory and semantic interference

Studies were designed to compare the effects of encoding strategies on two types of interference, sensory and semantic. Paired-associate lists were learned under instructional sets encouraging interactive imagery or repetitious rehearsal. Sensory interference was created by mispairing rhymes and semantic interference was produced by mispairing associatively related words. In control lists word pairs were unrelated. The results indicated that encoding strategy did not influence amounts of sensory and semantic interference. Mispairing rhymes produced the same amount of confusion as mispairing associates whether pairs were encoded through interaction imagery or through repetitious rehearsal. These effects were found with both short and long encoding intervals. The findings are inconsistent with the idea that encoding operations or strategies applied to word pairs completely determine the type of code activated for those pairs. Both sensory and semantic codes appear to be activated under each kind of encoding strategy.     

Associative processes and strategies in disjunctive reaction time

Scaling analysis based on variable criterion theory has been applied to the c-reaction form of disjunctive RT. In addition to previously identified sensory growth functions, two associative processes have been identified and functions of time describing their growth have been obtained. Associative strength to the positive stimulus begins at about 200 msec, or after, and grows with initial positive and later negative acceleration. Associative inhibition to the negative stimulus begins earlier, shortly after the sensory detection functions, and grows rapidly with negative acceleration. Subjects may adopt strategies which emphasize the use of either of these associative processes. With the pure inhibitory strategy, they respond to the positive stimulus entirely on the basis of sensory detection, but associatively inhibit response to the negative stimulus. With either strategy, the speed-accuracy tradeoff was determined by the level of criterion adjustment.     

MODPAC: A modular package of programs for fitting model parameters to data and plotting fitted curves

A modular package of computer programs is described. The package is designed for parameter fitting in psychology, and includes a program for plotting the fitted curves.     

The actions of others as determinants of behavior in social trap situations

Three studies were conducted to determine the effects of observing the behaviors of others upon an individual's actions in a simulated social trap situation. In Experiment 1, it was found that merely having the opportunity to make comparative appraisals of the actions of others led to greater competition for a finite common resource than when subjects were physically isolated from one another. In Experiment 2, false feedback was given to subjects to determine if the actions of others alone were responsible for the deleterious effects of having the opportunity for comparative appraisal; it was found that subjects quickly conformed to the behavior pattern of the interacting others, regardless of whether the false feedback indicated that the other subjects were consuming more or less than no-treatment control subjects. Experiment 3 was conducted to determine the motivation of subjects reacting to the actions of others; differential predictions based upon a competition/relative outcome explanation and upon an information search explanation were made. The data were consistent with the information search explanation.     

Emerging from imaginary time

Recent models in quantum cosmology make use of the concept of imaginary time. These models all conjecture a join between regions of imaginary time and regions of real time. We examine the model of James Hartle and Stephen Hawking to argue that the various no-boundary attempts to interpret the transition from imaginary to real time in a logically consistent and physically significant way all fail. We believe this conclusion also applies to quantum tunneling models, such as that proposed by Alexander Vilenkin. We conclude, therefore, that the notion of emerging from imaginary time is incoherent. A consequence of this conclusion seems to be that the whole class of cosmological models appealing to imaginary time is thereby refuted.We would like to thank Quentin Smith for helpful comments on an carlier version of this eassy. Read Guy gratefully acknowledges support from the M.J. Murdock Charitable Trust.