The role of executive processes in prospective memory tasks

Prospective remembering refers to remembering and acting on behavioural intentions. Three experiments tested the hypothesis that prospective remembering requires the availability of executive processes. It was expected that this is more important when intentions are stated in categorical terms. Type of instruction (specific versus categorical), typicality of the cue in relation to the category specified, and executive load were manipulated. Results showed a general benefit of specific instructions. Furthermore, with categorical instructions, performance was better with typical cues. Although the data suggested that executive processes are responsible for the processing of cues, the load manipulation had no significant effect on the prospective memory measure. Thus, no evidence was found for the hypothesis that prospective remembering requires the availability of executive processes. It is argued that it is a matter of strategic choice whether executive processes are deployed: One does not need to monitor for cues but can choose to rely on bottom‐up processes. Monitoring may be sufficient, but not necessary for successful prospective remembering.     

Development of an instrument for measuring different types of cognitive load

According to cognitive load theory, instructions can impose three types of cognitive load on the learner: intrinsic load, extraneous load, and germane load. Proper measurement of the different types of cognitive load can help us understand why the effectiveness and efficiency of learning environments may differ as a function of instructional formats and learner characteristics. In this article, we present a ten-item instrument for the measurement of the three types of cognitive load. Principal component analysis on data from a lecture in statistics for PhD students (n = 56) in psychology and health sciences revealed a three-component solution, consistent with the types of load that the different items were intended to measure. This solution was confirmed by a confirmatory factor analysis of data from three lectures in statistics for different cohorts of bachelor students in the social and health sciences (ns = 171, 136, and 148), and received further support from a randomized experiment with university freshmen in the health sciences (n = 58).     

PDP and Gestalt: An integration?

Summary The possibility of a synthesis between parallel distributed processing approaches (PDP) and Gestalt psychology is discussed. The empiricist outlook of PDP is an obstacle to such a synthesis. Gestalt's belief in organization of the psychological field as the basic principle is not shared by the PDP approach. It is claimed that, nevertheless, Gestalt psychology can use PDP techniques for modeling organization processes, provided that some constraints are obeyed. From a PDP point of view, importing Gestalt constraints could be a useful strategy for obtaining testable predictions.     

The derivation of some tests for the rasch model from the multinomial distribution

The present paper is concerned with testing the fit of the Rasch model. It is shown that this can be achieved by constructing functions of the data, on which model tests can be based that have power against specific model violations. It is shown that the asymptotic distribution of these tests can be derived by using the theoretical framework of testing model fit in general multinomial and product-multinomial models. The model tests are presented in two versions: one that can be used in the context of marginal maximum likelihood estimation and one that can be applied in the context of conditional maximum likelihood estimation.I am indebted to Norman Verhelst and Niels Veldhuijzen for their helpful comments. Requests for reprints should be sent to Cees A. W. Glas, Cito, PO Box 1034, 6801 MG Arnhem, THE NETHERLANDS.     

“Ratios” and “differences” in perceived sweetness intensity

For a number of perceptual continua, it has been shown in previous studies that subjects use only one quantitative comparison between two sensory impressions of a pair of stimuli, irrespective of whether they are instructed to judge “ratios” or “differences”. This comparison can be described by algebraic subtraction. The present study was designed to investigate whether this one-operation theory for psychophysical judgment also applied to the sensory continuum of sweetness. Subjects were presented with pairs of fructose solutions, and judged “ratios” of, or “differences" in, perceived sweetness intensities. The pairs were constructed on the basis of a factorial judgment design. The results showed that the reported “differences” could be adequately described by a difference response model, and that the reported “ratios” could be adequately described by a ratio response model. However, the reported “ratios” and reported “differences” were monotonically related, and the marginal means of the log-transformed response matrix of “ratios” were a linear function of the marginal means of the response matrix of “differences”. These results are incompatible with the notion that subjects judged differences when instructed to judge “differences”, but ratios when instructed to judge “ratios”. The consistency of the ratio response model with “ratio” judgments is probably caused by a comparative operation based on “differences” in combination with an exponential response output function. It may be concluded that subjects judge only “differences”, and not “ratios”, between perceived sweetness intensities.     

Anomalous orientation effects in the Bourdon illusion

All current explanations of the Bourdon illusion imply that the illusion persists under mirror imaging over the vertical or horizontal axes. We tested this hypothesis in three experiments. For orientations of the standard Bourdon figure of about 135°, the illusion shows a dip, which is unexplainable in terms of current theories.     

Mass-Media Information Campaigns and Knowledge-Gap Effects1

The knowledge-gap hypothesis of Tichenor, Donohue, and Olien (1970) states that people from the higher socioeconomic segments of society acquire information at a faster rate than people from the lower socioeconomic segments. The consequence is a growing knowledge gap between the high and low segments. The present study investigates some potential causes for this knowledge-gap phenomenon by means of data sets from evaluation studies of 3 mass-media information campaigns. The observed differences in knowledge between low and highly educated respondents could partly be explained by differences in the attention paid to the campaigns but not by differences in information processing.     

Differentiation of holistic processing in the time course of letter recognition

Pairs of letters, pseudo-letters, and basic geometrical shapes were presented in a sequential same-different task, in which the time between the first and second items was varied. The second item was either presented in isolation or surrounded by an irrelevant geometrical shape that could be congruent or incongruent to the target. Congruence effects were obtained for shapes and pseudo-letters, but not for letters if the interval between the first and second items was short. Absence of congruence effects was interpreted, in accordance with earlier findings, as categorical influence on early visual integration processes; letters are processed less holistically than non-letter shapes. The present result indicates that categorical influence of letters depends on the time course of stimulus processing. As a highly automatized process, it is effective for stimuli appearing at a relatively fast rate, whereas, a slower rate of stimulus presentation eliminates task-irrelevant categorical influences.