Developmental change in the nature of attention allocation in a dual task.

Younger children have more difficulty in sharing attention between two concurrent tasks than do older participants, but in addition to this developmental change, we documented changes in the nature of attention sharing. We studied children 6-8 and 10-14 years old and college students (in all, 104 women and 76 men; 3% Hispanic, 3% Black or African American, 3% Asian, 7% multiracial, and 84% White). On each dual-task trial, the participant received an array of colored squares to be retained for a subsequent probe recognition test and then an easy or more difficult signal requiring a quick response (a speeded task, clicking a key on the same side of the screen as the signal or the opposite side).

Alcohol effects on response inhibition: Variability across tasks and individuals.

Considerable research has investigated the acute effects of alcohol on response inhibition, but a number of issues remain unresolved. Given that most studies use only a single laboratory task to assess inhibition, it is often difficult to determine whether alcohol's effects are task specific or generalize across measures of the same construct. Moreover, relatively few studies have directly compared effects of alcohol under ascending and descending blood alcohol concentrations (BACs), and those that have often failed to disentangle BAC limb effects from the effects of repeated testing.

Tone series and the nature of working memory capacity development.

Recent advances in understanding visual working memory, the limited information held in mind for use in ongoing processing, are extended here to examine auditory working memory development. Research with arrays of visual objects has shown how to distinguish the capacity, in terms of the number of objects retained, from the precision of the object representations. We adapt the technique to sequences of nonmusical tones, in an investigation including children (6-13 years, N = 84) and adults (26-50 years, N = 31).

Acute alcohol effects on set-shifting and its moderation by baseline individual differences: a latent variable analysis.

Aims: To compare the acute effects of alcohol on set-shifting task performance (relative to sober baseline performance) during ascending and descending limb breath alcohol concentration (BrAC), as well as possible moderation of these effects by baseline individual differences.

Design: Shifting performance was tested during an initial baseline and a subsequent drinking session, during which participants were assigned randomly to one of three beverage conditions (alcohol, placebo or control) and one of two BrAC limb conditions [ascending and descending (A/D) or descending-only (D-only)].

Setting: A human experimental laboratory on the University of Missouri campus in Columbia, MO, USA.

Detection of the number of changes in a display in working memory.

Here we examine a new task to assess working memory for visual arrays in which the participant must judge how many items changed from a studied array to a test array. As a clue to processing, on some trials in the first 2 experiments, participants carried out a metamemory judgment in which they were to decide how many items were in working memory. Trial-to-trial fluctuations in these working memory storage judgments correlated with performance fluctuations within an individual, indicating a need to include trial-to-trial variation within capacity models (through either capacity fluctuation or some other attention parameter).