Individual differences in cognitive arithmetic

Unities in the processes involved in solving arithmetic problems of varying operations have been suggested by studies that have used both factor-analytic and information-processing methods. We designed the present study to investigate the convergence of mental processes assessed by paper-and-pencil measures defining the Numerical Facility factor and component processes for cognitive arithmetic identified by using chronometric techniques. A sample of 100 undergraduate students responded to 320 arithmetic problems in a true-false reaction-time (RT) verification paradigm and were administered a battery of ability measures spanning Numerical Facility, Perceptual Speed, and Spatial Relations factors. The 320 cognitive arithmetic problems comprised 80 problems of each of four types: simple addition, complex addition, simple multiplication, and complex multiplication. The information-processing results indicated that regression models that included a structural variable consistent with memory network retrieval of arithmetic facts were the best predictors of RT to each of the four types of arithmetic problems. The results also verified the effects of other elementary processes that are involved in the mental solving of arithmetic problems, including encoding of single digits and carrying to the next column for complex problems. The relation between process components and ability measures was examined by means of structural equation modeling. The final structural model revealed a strong direct relation between a factor subsuming efficiency of retrieval of arithmetic facts and of executing the carry operation and the traditional Numerical Facility factor. Furthermore, a moderate direct relation between a factor subsuming speed of encoding digits and decision and response times and the traditional Perceptual Speed factor was also found. No relation between structural variables representing cognitive arithmetic component processes and ability measures spanning the Spatial Relations factor was found. Results of the structural modeling support the conclusion that information retrieval from a network of arithmetic facts and execution of the carry operation are elementary component processes involved uniquely in the mental solving of arithmetic problems. Furthermore, individual differences in the speed of executing these two elementary component processes appear to underlie individual differences on ability measures that traditionally span the Numerical Facility factor.(ABSTRACT TRUNCATED AT 400 WORDS)     

Eye movement as a cue to figure motion in anorthoscopic perception

When a figure moves behind a narrow aperture in an opaque surface, if it is perceived as a figure, its shape will often appear distorted. Under such anorthoscopic conditions, the speed or direction of the object's motion is ambiguous. However, when the observer simultaneously tracks a moving target, a figure is always perceived, and its precise shape is a function of the speed or direction of tracking. The figure is seen as moving with the speed or in the direction of the target. Thus, it is argued that eye movement serves as a cue to the figure's motion, which, in turn, determines its perceived length or orientation.     

Time went by so slowly: Overestimation of event duration by males and females

In three experiments, 469 subjects watched a short videotape of a bank robbery and later estimated the duration of the tape. Subjects invariably overestimated the durations. Accuracy of time estimation was unrelated to amount of free recall (Experiment 1) or accuracy of memory (Experiment 2). Females overestimated to a greater degree than males (Experiments 2 and 3). A more stressful version of the event produced greater overestimates than a less stressful version (Experiment 3). The relationship between induced arousal and time estimation appears to be different for men and women.     

Acquisition of word-processing skills by younger, middle-age, and older adults

A total of 45 subjects in three age groups (younger, middle-age, older) were trained to word process on microcomputers using a commercial training program and an experimenter-designed test and evaluation protocol. Although all of the subjects mastered the essentials of word processing, the older group took significantly longer to complete the training and evaluation procedures and performed more poorly on a review examination that tested their knowledge of the word-processing commands and techniques. The results are discussed in relation to requirements for trainer assistance, motivational factors, and the need to design training protocols that meet the needs of older adults.     

Counseling in Malaysia: An Emerging Profession

The emergence of counseling in Malaysia illustrates the importance of a strong professional association and counseling training programs at the university level.     

Automatic detection of transient potentials in the EEG

A classifier based on the linear regression model was developed to automatically detect sharp transients in EEG, matching the definition of spikes and sharp waves accepted by IFSECN. Practical applications proved the accuracy of the method which succeeded in detecting 84% of sharp transients previously found by an experienced electronencephalographer. Computerized search for sharp transients in EEG records will be particularly useful in long term EEG records obtained from epileptic patients.     

Diagnostic value of myelography as an expanded clinical study method

The paper investigates 54 myelograms and their influence on diagnostic thinking efficacy, on patient management efficacy, and on ultimate outcome efficacy, using statistical methods. Conventional myelography contributes to diagnostic thinking efficacy having a LLR- value of approximately 0.9. With an accuracy value of 0.95 it can be regarded as a reliable method of diagnosis. It alters diagnostic thinking efficacy in no less than 83% (94%) of the cases and patients management efficacy in 89%. Thus, by definition, myelography may be said to affect the state of health of the myelographed patients in 94.4%.     

Psychopathology of progressive paralysis. Remarks on some personal cases

Four of our own cases that presented a clinical picture of dementia are discussed. A study of the relative literature has failed to reveal any "swing" in the pattern of the clinical condition: Just as it did ninety years age, paralytic dementia accounts today for well over 60% of all cases, those clinical pictures erroneously regarded as "typical" "classic", accounting for a mere 10%-15% of cases. The need for routine lues serology is pointed out.