Peak activations of brain regions for all sound locations, as revealed by sLORETA analysis.

<p>Activations at the time of the N1 and P2 components of the responses to the sound onset were contrasted with a 40-ms prestimulus period of silence. Colour coding shows <i>t</i>-values, with statistically significant activations (<i>p</i><0.05) at <i>t</i>≥4.1 for N1 and <i>t</i>≥3.6 for P2. Data from all subjects were projected onto a single anatomical image (T2 MNI-template “Colin 27” of sLORETA). Horizontal and coronal slices were positioned at MNI <i>Z</i> and <i>X</i> coordinates as given in the figure (A, anterior; L, left; P, posterior; R, right). Data are as given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025146#pone-0025146-t002" target="_blank">Table 2</a>.</p

ROI-analysis of primary auditory cortex (BA 41) at the time of the N1 and P2.

<p>Data were collapsed for four adjacent loudspeaker positions, resulting in four data sets, each covering a range of 40 degrees (LE, left eccentric; LC, left central; RC, right central; RE, right eccentric; black arcs in the schematic view of the set-up). In the coronal and horizontal slices (MNI-template as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025146#pone-0025146-g002" target="_blank">Fig. 2</a>), voxels of the ROI are marked in white. The plots show <i>t</i>-values as a function of sound location (error bars, standard errors across subjects), resulting from contrasts of activations with a 40-ms prestimulus period of silence for the whole ROI.</p

Auditory-evoked potentials.

<p>(<b>A</b>) Grand-average AEPs with N1 and P2 components at a left (C3), vertex (Cz), and right (C4) electrode position, plotted as a function of time relative to sound onset for left-eccentric (LE), left-central (LC), right-central (RC), and right-eccentric (RE) ranges of sound locations. Black horizontal bars indicate stimulus duration. (<b>B</b>) Topographies for the four ranges of sound locations (LE, LC, RE, RC) at the time of N1 and P2. (<b>C</b>) Difference topographies of N1 and P2, comparing right and left sound positions, and central and eccentric sound positions. Filled circles indicate electrodes with significant differences in amplitude values (significant <i>t</i>-values according to permutation tests, all <i>p</i><0.05).</p

Significant variation of activation as a function of location for six examplary areas, as revealed by different contrasts either at the time of the N1 (black bars) or at the time of the P2 (gray bars).

<p>For the voxel with maximum activation in each of the areas (coordinates taken from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025146#pone-0025146-t003" target="_blank">Table 3</a>), the plots show the mean <i>t</i>-values as a function of sound location (error bars, standard errors across subjects), resulting from contrasts of activations with a 40-ms prestimulus period of silence (as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025146#pone-0025146-g003" target="_blank">Figs. 3</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025146#pone-0025146-g004" target="_blank">4</a>). Note that these <i>t</i>-values are based on statistical comparisons of the estimated current densities at a specific sound location versus baseline, whereas the images are based on comparisons between estimated current densities for different sound locations. Coordinates given in brackets indicate <i>X</i>, <i>Y</i>, <i>Z</i> MNI coordinates of the maximum activation, as are shown in horizontal slices. Areas are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025146#pone-0025146-t003" target="_blank">Table 3</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025146#pone-0025146-g005" target="_blank">Fig. 5</a>.</p

Processing of left, right, central, and eccentric sound locations (all <i>p</i><0.05).

<p>Processing of left, right, central, and eccentric sound locations (all <i>p</i><0.05).</p

Locations of peak <i>t</i>-values for N1 and P2 responses to all sound positions vs. silence as revealed by sLORETA (all <i>p</i><0.01).

<p>Locations of peak <i>t</i>-values for N1 and P2 responses to all sound positions vs. silence as revealed by sLORETA (all <i>p</i><0.01).</p

Experimental design.

<p>(A) Experimental environment with driving simulator configuration and (B) task set-up with one initial practice block followed by three experimental blocks. Each experimental block consisted of nine segments with three different crosswind levels.</p

Oscillatory brain activity in different frequency bands.

<p>Spectral power (means and standard errors of means) of fronto-central and posterior Alpha (A), (overall) Beta (B) and Theta (C) band as function of crosswind level (no, weak, strong), shown for younger participants and older participants with high (Old-High) and low (Old-Low) driving lane variability. Significant group differences are indicated by asterisks; *<i>p</i> < .05; **<i>p</i> < .01.</p

Proactive vs. reactive car driving: EEG evidence for different driving strategies of older drivers

<div><p>Aging is associated with a large heterogeneity in the extent of age-related changes in sensory, motor, and cognitive functions. All these functions can influence the performance in complex tasks like car driving. The present study aims to identify potential differences in underlying cognitive processes that may explain inter-individual variability in driving performance. Younger and older participants performed a one-hour monotonous driving task in a driving simulator under varying crosswind conditions, while behavioral and electrophysiological data were recorded. Overall, younger and older drivers showed comparable driving performance (lane keeping). However, there was a large difference in driving lane variability within the older group. Dividing the older group in two subgroups with low vs. high driving lane variability revealed differences between the two groups in electrophysiological correlates of mental workload, consumption of mental resources, and activation and sustaining of attention: Older drivers with high driving lane variability showed higher frontal Alpha and Theta activity than older drivers with low driving lane variability and—with increasing crosswind—a more pronounced decrease in Beta activity. These results suggest differences in driving strategies of older and younger drivers, with the older drivers using either a rather proactive and alert driving strategy (indicated by low driving lane variability and lower Alpha and Beta activity), or a rather reactive strategy (indicated by high driving lane variability and higher Alpha activity).</p></div

Locations of significant activation evoked by deviant stimuli relative to standard stimuli for the P3a deflection.

<p>Activations resulted from contrast of physically active and inactive participants, as revealed by sLORETA. Coordinates are in standard stereotaxic space <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074539#pone.0074539-Talairach1" target="_blank">[61]</a> and refer to maximally activated foci, as indicated by the highest t-score within an area of activation. Number of voxels refers to significant voxel (<i>t</i>-value >4.48; <i>p</i><0.05). BAs, Brodmann Areas.</p