标题：Predicting school achievement from self-paced continuous performance: Examining the contributions of response speed, accuracy, and response speed variability
摘要：Trial-to-trial fluctuations in self-paced performance have long been considered
an important aspect of an individual’s performance. Whereas average response
speed has been considered a cognitive factor indexing the speed of mental
processing, response speed variability has been considered an energetic factor
indexing an individual’s capability to sustain mental processes over prolonged
time periods. Here we investigated whether there is an incremental contribution
of response speed variability, compared to mental speed, in predicting school
achievement. A sample of 89 individuals was tested with the Serial Mental
Addition and Comparison Task (SMACT) twice within a retest-interval of three
days. In addition to the conventional performance measures speed (MRT) and
accuracy (error percentage, EP), we evaluated two intraindividual response speed
variability measures, standard deviation (SDRT) and coefficient of variation
(CVRT), with regard to their power to statistically predict secondary- and
high-school achievement. In general, school performance was best predicted by
MRT and not at all by EP. Response speed variability, especially CVRT, appeared
to be a good predictor of school performance, especially mathematics
performance. The combined intake of MRT and CVRT as predictors in a multiple
linear regression model, however, did not yield additional predictive value
compared to the single-predictor model that contained only MRT. A further
interesting finding was that the performance measures were differentially
predictive across genders. In sum, we suggest that response speed variability as
indexed by CVRT is a candidate dimension for the assessment of sustained
concentration performance. Before applying CVRT in practical assessment
settings, however, additional research is required to elucidate effects of
different task factors (e.g., task length, task complexity, content domain,
etc.) on the predictive power of this performance measure.
关键词：concentration, attention, school achievement, reaction time variability,
distractibility
