Equally divided by sex and distributed equally across fourth/fifth, eighth/ninth, and college grade levels, 144 subjects performed a mental rotation task under instructions emphasizing either accuracy or speed of response, or both. Instructions had large and consistent effects on speed of response but were not as uniformly effective in their…

The way cognitive, event-related brain potentials (ERPs) can aid in further understanding of memory span change in children is discussed. ERPs are time-dependent changes in electrical activity of the brain (as recorded by scalp electrodes) following the presentation of a physical stimulus through auditory, visual, or somatosensory modalities. The…

Tests two hypotheses concerning developmental change in the speed of cognitive processes: (1) age differences in processing time reflect changes that are specific to particular tasks, and (2) age differences in processing speed do not reflect task-specific change but are due instead to more general developmental change. (HOD)