Schematic diagram of TT, TDT, and TTT conditions (not to scale).

<p>Schematic diagram of TT, TDT, and TTT conditions (not to scale).</p

Mean Age, IQ, and RAN scores (in seconds) as a function of reading group (poor vs. normal).

<p>Numbers in parentheses indicate standard error.</p

Scatter plot of Similarity Effect, calculated as the difference between T2 accuracy (given correct T1) in the low- and high-similarity conditions summed across lags, and mean RAN scores.

<p>Negative Similarity Effect scores indicate a larger AB when target-distractor similarity was high.</p

Scatter plots of AB Magnitude, calculated as the difference between 100% and T2 accuracy (given correct T1) summed across each lag, and mean RAN scores.

<p>The plot on the left (A), represents this relationship when target-distractor similarity was high. The plot on the right (B) represents this relationship when target-distractor similarity was low.</p

Second target accuracy (given correct T1) as a function of RAN performance, target-distractor similarity, and lag.

<p>“Fast” and “Slow” refer to groups comprising the top and bottom half of mean RAN scores. “High” and “Low” refer to level of target-distractor similarity (i.e., digit vs. random dot distractors). Error bars represent one standard error of the mean.</p

Schematic illustration of the sequence of events on a Lag 3 trial (not to scale).

<p>Participants were instructed to identity the two letters in the sequence when the last item disappeared.</p

ERP analysis of the C1 component evoked by T2.

<p>(A) Grand average difference waveforms collapsed across electrodes POz, PO4, PO8, Oz, and O2, shown separately for each lag condition. Note that negative is plotted upwards. (B) Medial views of the two cortical hemispheres depicting the estimated current density distribution calculated by sLORETA for the activity observed in the grand average difference waveforms (collapsed across lags) at the peak of the C1 component (87 ms). The regions sLORETA identified as most active are presented in yellow, and fall along the banks of the calcarine fissure in the left hemisphere, corresponding to area V1.</p

Schematic representation of the sequence of displays in the RSVP stream.

<p>The two target digits (T1 and T2) were embedded within a stream of distractor letters. Lag was manipulated by varying the number of distractor letters between the target digits. On half of the trials presented at each lag, an irrelevant probe stimulus was presented simultaneously with T2 in the upper-right quadrant of the display.</p

Mean percentage of correct T2 responses as a function of lag, plotted separately for each probe condition.

<p>Error bars represent the within-subjects standard error of the mean.</p

Allelic variation in dopamine D2 receptor gene is associated with attentional impulsiveness on the Barratt Impulsiveness Scale (BIS-11)

<p><b>Objectives:</b> Previous studies have postulated that noradrenergic and/or dopaminergic gene variations are likely to underlie individual differences in impulsiveness, however, few have shown this. The current study examined the relationship between catecholamine gene variants and self-reported impulsivity, as measured by the Barratt Impulsiveness Scale (Version 11; BIS-11)</p> <p><b>Methods:</b> Six hundred and seventy-seven non-clinical adults completed the Barratt Impulsiveness Scale (BIS-11). DNA was analysed for a set of 142 single-nucleotide polymorphisms (SNPs) across 20 autosomal catecholamine genes. Association was tested using an additive regression model with permutation testing used to control for the influence of multiple comparison.</p> <p><b>Results:</b> Analysis revealed an influence of rs4245146 of the dopamine D2 receptor (DRD2) gene on the BIS-11 attention first-order factor, such that self-reported attentional impulsiveness increased in an additive fashion with each copy of the T allele.</p> <p><b>Conclusions:</b> These findings provide preliminary evidence that allelic variation in DRD2 may influence impulsiveness by increasing the propensity for attentional lapses.</p