fMRI results.

<p>(<b>A</b>) Cortical areas more strongly activated during MI (averaged across all five MI conditions) than during the resting baseline (p(FWE)<.05; T(16)>7.59). Activation peaks of this contrast served as seed regions for the connectivity analysis depicted in panel B. (<b>B</b>) Increased functional connectivity during bimanual MI as compared to unimanual MI. Two seed regions exhibited increased connectivity, the right supramarginal gyrus (red) and the right superior frontal gyrus (green).</p

Behavioral data.

<p>White bars and left axis denote raw force values averaged across both hands. Gray bars and right axis denote quality of imagination (QoI) rating (rating scale ranged from 1–7). Black bars and right axis denote estimated difficulty of overt performance of the actions (rating scale ranged from 1–5). Note that Difficulty values for the Bimanual condition were derived from an independent sample (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038506#s4" target="_blank">Methods</a>). For illustration purposes interval scale level was assumed for the Difficulty and QoI rating values and means and SEMs are displayed. Error bars denote SEM.</p

Pattern of connectivity changes between seed regions (leftmost column) and target regions (top row).

<p>Significant changes (p<.05, FWE) for the comparisons of Uni-L vs Baseline (L), Uni-R vs Baseline (R), and Biman vs Uniman (B).</p><p>Abbreviations. G  =  gyrus; SMA  =  supplementary motor area; supramarg  =  supramarginal; Prob  =  probability; BA  =  Brodmann's area; R/L  =  right/left hemispheric activation, respectively.</p

Anatomical locations and MNI coordinates of activation peaks for the comparison Imagery – Baseline.

<p>Probability (Prob) of the location according to the Anatomy toolbox. N/A if region is not assigned by Anatomy toolbox.</p><p>Abbreviations. G  =  gyrus; SMA  =  supplementary motor area; supramarg  =  supramarginal; Prob  =  probability; BA  =  Brodmann's area; R/L  =  right/left hemispheric activation, respectively.</p

Trial design.

<p>Trial design.</p

Summarized answers to the open comment question “Why do you think they are better?”.

<p><i>Notes</i>. Percentages rounded; Percentages relative to number of participants (208) and not to sum of statements (i.e., percentages add up to > 100%).</p><p>Summarized answers to the open comment question “Why do you think they are better?”.</p

Means of the answers to the question “Who do you think multitasks more?”.

<p><i>Legend</i>. Possible answers were “Men” (recoded as -1), “Same” (recoded as 0) and “Women” (recoded as 1). Thus, a positive value reflects that participants think women multitask more. Results of one-sample t-tests testing whether the mean rating differed significantly from a rating of 0 (“same”) are shown as asterisks:</p><p>* p < .05;</p><p>** p < .01;</p><p>*** p < .001.</p><p>Effects were not modulated by age, children, education, or relationship status.</p><p>Means of the answers to the question “Who do you think multitasks more?”.</p

Proportion (in percent, %) of participants choosing women in response to the question “Who do you think is better at multitasking?”.

<p><i>Legend</i>. Dichotomic scale with Men and Women as answer options (therefore, the proportion of participants who chose Men can be calculated by 100-%Women). This question was only presented to participants who believe in gender differences (Question 3).</p><p><i>Notes</i>. Please note that “Overall” is the percentage of participants choosing women across the whole sample of male and female participants. Since the numbers of males and females are usually not the same, “Overall” is not just the mean of the “Female” and “Male” columns, but a weighted average. Because the US sample is too small for this question (N = 11; 10f/1m), no tests were calculated.</p><p>Proportion (in percent, %) of participants choosing women in response to the question “Who do you think is better at multitasking?”.</p

Proportion “Yes”-responses (in percent, %) in response to the question “Do you think there are gender differences in multitasking?”.

<p><i>Notes</i>. “Overall Ratings” = mean of all respondents (i.e., an average of Female and Male ratings weighted by male and female sample sizes). “Lower bound CI” = Lower bound of the 95% confidence interval. It reflects the maximum value below the observed percentage which shows a significant difference (p < .05; determined using X² tests). For instance, 57% of All participants believe in gender differences, which is significantly more than 52%. <b>Y</b> = Younger participants (35 years or younger). <b>O</b> = Older participants (36 years or older).</p><p>Dichotomic scale with Yes and No as answer options.</p

Self-rated own multitasking (MT) abilities as assessed by the question “How good do you think you are at multitasking?”.

<p>Scale ranged from 0 (“extremely bad”) to 6 (“excellent”). In total (category ‘All’) 486 participants (274 females; 212 males) answered this question. Results of one-sample t-tests testing whether the mean rating differed significantly from a rating of 3 (“average”; centre of scale) are shown as asterisks above each bar (* p < .05; ** p < .01; *** p < .001). Results of independent samples t-tests testing for gender differences are shown above each pair of bars of a country (* p < .05). Error bars denote standard error of the mean (SEM).</p