Figure 1.
Example of distracters-present trial (T1D2) for the left hemifield.
Table 1.
Group means (and SD's) of Forward, Backward and Standardized Digit span scores (WAIS III), and WM-capacity K of the VSWM change detection task in adolescents and adults.
Figure 2.
Behavioral data from the VSWM change detection task.
Bar graphs of (A) Cowan's K, (B) average reaction times (in ms), and (C) percentage of correct responses for adolescents and adults in T1D0 (one target), T1D2 (one target, two distracters) and T3D0 (three targets) conditions. Error bars indicate 95% confidence intervals.
Figure 3.
Average ERP activity during the VSWM change detection task.
(A) HEOG activity ((HEOG left visual field trials*-1+HEOG right visual field trials)/2) and (B) CDA activity (computed by subtracting ipisilateral from contralateral activity), after smoothing with a 6 Hz low-pass filter, time-locked to the memory array and averaged across occipital and posterior parietal electrode sites for adolescents and adults, in conditions T1D0, T1D2 and T3D0. The analyzed window (300–550 ms) is indicated by a grey rectangle.
Table 2.
Mean CDA amplitudes (in µV, standard deviations between brackets) for adolescents and adults in the VSWM change detection task, averaged over lateral parietal and occipital electrode sites.
Figure 4.
CDA amplitudes for adults with high and low K-scores.
Mean amplitudes between 300 and 550 ms in T1D0, T1D2 and T3D0 conditions in adults with high (N = 5) and low (N = 12) working memory capacity (WMC), determined by a K-T3D0 score larger or smaller than 2.4. * p = .087, one-tailed, ** p<.001, one-tailed, n.s. = non-significant.
Figure 5.
Scatterplots of significant correlations between behavioral and CDA measures.
(A) Correlation between K-T3D0 and Unnecessary Storage (K-T1D0 minus K-T1D2) for adolescents (triangles) and adults (squares). (B&C) Correlation between distracter related parietal-occipital CDA effects (CDA-T1D2 minus CDA-T1D0) and Unnecessary Storage (K-T1D0-K-T1D2; panel B) or RT distracter effects (RT-T1D2 minus RT-T1D0; panel C). Negative CDA effects are observed when T1D2 CDA amplitude is larger than T1D0 CDA amplitude. Larger negative CDA (T1D2-T1D0) values reflect larger CDA increases when distracters are present. Larger positive distracter-related RT values reflect larger RT increases when distracters are present.