Individual subject performance^*.

<p>Individual subject performance^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195182#t004fn001" target="_blank">*</a>}.</p

Handedness of pointing subjects.

<p>Handedness of pointing subjects.</p

The goal of ape pointing - Fig 2

<p>(<i>a</i>) On average, subjects spent more time pointing at the grapes per trial in the successful-look condition than in the failed-look condition (<i>p</i> = 0.016). (<i>b</i>) Subjects also spent more time pointing at the grapes in the first trial of the successful-look condition than in the first trial of the failed-look condition (<i>p</i> = 0.009). Results depicted are for points with eye contact. Box plots represent the interquartile range, minimum, and maximum values; depicted also are the means (crosses), medians (horizontal lines), and outliers (circles).</p

Main test design.

<p>Main test design.</p

The goal of ape pointing - Fig 3

<p>(<i>a</i>) We found no significant difference in the average time that subjects spent away from the experimental window per trial between the sessions of the successful-look condition (<i>p</i> = 0.176). (<i>b</i>) On average, subjects spent more time away from the experimental window per trial during the second session of the failed-look condition compared to the first session (<i>p</i> = 0.009). Box plots represent the interquartile range, minimum, and maximum values; depicted also are the means (crosses), medians (horizontal lines), and outliers (circles).</p

The general experimental setup for all conditions.

<p>The general experimental setup for all conditions.</p

We found no difference in the average time that subjects spent away from the experimental window per trial across the four sessions of the motivational condition.

<p>Box plots as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195182#pone.0195182.g003" target="_blank">Fig 3</a>.</p

The average percentage of points with eye contact directed at the grapes per trial was high in all three conditions with no significant difference across conditions.

<p>Box plots represent the interquartile range, minimum, and maximum values; depicted also are the means (crosses), medians (horizontal lines), and outliers (circles).</p

Main test participant information.

<p>Main test participant information.</p