Phonological and motoric demands in handwriting: evidence for discrete transmission of information

In an experiment with handwriting tasks effects of phonological and motoric task factors upon reaction time and movement time were measured to test implications of a discrete information processing account of the task. The model is built up of serially organized stages, each of which monitors one specific type of operation, necessary to generate a message. The serial structure of the model is defined as the limitation that higher levels of the model provide their output to the next lower processor in the hierarchy, and receive their input from the next higher stage. The parallel character of the model is exemplified through the assumption that all processors are active at the same time and concurrently with the real time production of writing movements. The study adds evidence that a serial architecture of processors can be compatible with the parallel processing of a message as long as more abstract operations are prepared more in advance to real-time movements than operations lower in the hierarchy. In the experiment the prediction was tested that the time course of the manifestation of phonological and motoric task demands reflects the discrete and serial structure of the model.     

Arm-tracking performance with and without visual feedback in children and adults: developmental changes

Tracking performance was investigated in children (aged 6-7 and 10-11) and in adult subjects. Target signals, moving unpredictably along a straight line, were tracked with the preferred arm, alternately with and without visual feedback. Qualitative observations indicate that tracking is based on continuous adjustments of the ongoing response to the continuously changing target position. No step-and-hold strategy could be detected in any of the three age groups. Tracking performance was described with four simple parameters, derived from linear systems analysis: (a) the delay between target signal and tracking movement (DL); (b) performance at the low-frequency range (LF), (c) performance at the high-frequency range (HF); and (d) a measure of tracking quality or overall similarity in the shape of target signal and tracking movement (Q). There was a considerable improvement in tracking performance with age, even after the age of 10-11, which was mainly demonstrated by a decrease in DL and increases in HF and Q. Tracking performance decreased only to a small extent when visual feedback was withdrawn. Age-related differences in the contribution of visual feedback to tracking performance could not be demonstrated.     

Episodic memory in dementia of the alzheimer type and in normal ageing: Similar impairment in automatic processing

A perceptual identification task was used to provide an implicit measure for automatic memory processes. The facilitation of word identification on repeated presentation is taken as a measure of the automatic retrieval of an episode. In addition, recognition memory was tested. The recognition task is an explicit test of memory and relies mainly on controlled processing. In the first experiment 11 patients suffering from probable Alzheimer disease and 11 normal age- and sex-matched controls were tested. Both groups exhibited a rather small facilitation effect (ca 7%) but did not differ in the size of the effect. However, when tested explicitly, a difference in recognition memory existed between the two groups. In the second experiment the performance of 11 normal young subjects was compared to that of 11 normal elderly subjects. Whereas the elderly group showed a small facilitation effect similar to that observed in the first experiment, a considerable facilitation effect was found for the young group. Also, the elderly group had poorer recognition memory than the young group.     

New models in research and design: New concepts of unity in planning and policy-making

Van Lohuizen’s ideal of unity, must above all be seen as a challenge to attain the necessary integration of planning, research, and design to meet the requirements of a changing society. Though Van Lohuizen's ideas were influenced strongly by the rational and technical principles of the CIAM, he saw technology as a means to an end in an approach that is primarily based on humans and culture. In the ideas of Van Lohuizen, different dimensions can be traced. New developments in these dimensions are discussed in the article. There is no lack of innovative ideas and methods. Nearly all the ideas and methods discussed were developed in the forties, fifties, or sixties. On the basis of the incubation period required for introduction on a wider scale, it is now time for them to find greater favor with society. Following the years of a no-nonsense policy, it seems that in many fields there is a new need for a wider, more qualitative approach. Ron van Eck studied architecture and management research at the University of Technology of Delft. He is working at the RIW—Research Institute of the Department of Architecture at the University of Technology of Delft, and at the Network for Spatial Organisation in Amsterdam.     

Attitudinal and Social Factors in Adolescent Smoking: In Search of Peer Group Influence1

The smoking attitudes and behavior of two samples of British 15-year-olds (N = 278) were studied by questionnaire. “Smokers” (anyone who had smoked at all within the previous week) held less negative attitudes about smoking, were more likely to have a father who smoked, and anticipated less parental disapproval of their smoking. When asked to name their five best friends among their classmates, smokers were more likely to name other smokers than were nonsmokers. On the basis of these results, we argue that the notion of “peer group influence” should be reconceptualized in terms of intergroup processes and social identity concerns within the peer group.     

Modification of muscle activation patterns during fast goal-directed arm movements

The motor programming of fast goal-directed arm movements was studied in a tracking task. A target jumped once or twice randomly to the left or right direction with an interstimulus interval (ISI) in a range between 50 and 125 msec. Double step stimuli were either two steps in the same direction (C-trial) or in opposite direction (R-trial). Tracking results show that at the beginning average EMG-activity is the same for responses to single step trials, R-trials and C-trials. Differences set in after some time equal to or somewhat shorter than ISI. It was concluded that muscle activation patterns of fast goal-directed movements are not preprogrammed but that they can be modified during the movement. The time interval between second target step and the moment when EMG activity of the double step response deviates from the EMG activity of a single step (RT2) could be smaller than the time interval between first target displacement and EMG onset. (RT1). If modification of the muscle activation pattern required a longer or larger activation of the active muscle, RT2 tended to be smaller than RT1, whereas RT2 was about equal to RT1 if the new muscle activation required a termination of the ongoing muscle activation pattern and the activation of another muscle.     

Replicability and invariance of dimensions of parental rearing behaviour: Further Dutch experiences with the EMBU

In a recent article, Ross, Clayer and Campbell (1983) argued and showed by means of factor analysis that the number of child-rearing dimensions found previously with the EMBU appears to be dependent on the type of rotation used in factoring. Based on the assumption and empirical evidence that the dimensions found earlier are significantly correlated, Ross et al. (1983) argued that Oblique rotation would appear to give rise to a larger number of distinguishable dimensions than previous analyses (e.g. Arrindell, Emmelkamp, Brilman and Monsma, 1983). We contend that their conclusion was based on an inappropriate analysis of the data with a neglect of relevant psychometric principles. Employing objective techniques of factorial invariance the factors obtained in our previous study were shown here to be congruent across rotational procedures (Oblique vs Varimax). Supporting the stability and factorial and construct validity of the EMBU Rejection, Emotional Warmth, Overprotection and Favouring Subject dimensions, they were shown in further analyses to be: (a) replicable across split samples of phobics (Ns: 421 vs 420); and (b) invariant across distinct populations (phobics, N = 841 vs normals, N = 277).     

Actors' and Observers' attributions,self-serving bias and positivity bias

An experiment was conducted to investigate the influence of evaluative factors upon preference for situational and dispositional attributions. Subjects listened to a tape recording of a group discussion on smoking, two actors presenting arguments in favour of smoking and two actors arguing against smoking. Subjects were then asked to explain in attributional terms the actors' behaviour and their own smoking behaviour, their evaluation of smoking being separately assessed. Results provided no support for a general self-other attributional difference; subjects did not explain their own behaviour in more situational terms while explaining the behaviour of others in more dispositional terms. Findings indicated that individuals generally attributed positively evaluated behaviour to dispositional factors and negatively evaluated behaviour to situational factors, regardless of attributor role (actor or observer). The results are interpreted as offering support for a positivity bias in attributional preference.     

Some evidence for a limited capacity parallel selfterminating process in simple visual search tasks.

An experiment was carried out in order to investigate the questions of exhaustive vs selfterminating and serial vs parallel processing in a simple visual search task. In the experiment, 1, 2 or 3 letters were placed on an imaginary circle round the fixation point. Two different letters were used, one of which was defined as the ‘signal’. Ss had to respond ‘yes’ when one or more signals were in the display, ‘no’ otherwise. The number of signals in the display was varied from ‘no signals’ to ‘all signals’.A decrease in latencies with increasing number of signals for a fixed number of elements presented was observed indicating a selfterminating search. A decrease in latencies with increasing number of elements when only signals were presented was taken as evidence for a parallel selfterminating process. A further analysis of the error data showed that a limited capacity system had to be assumed. It was shown that it was possible to construct the overall pattern of latencies over conditions from the error data obtained.