Examples of the stimuli used in the three experiments during the habituation and test phases.

<p>With dashed lines, the AOI relating to the hat and the top and bottom part of the faces. The subjects of the photograph have given written informed consent, as outlined in the PLOS consent form, to publication of their photograph.</p

The percentages of looking time in the three experiments during the habituation and the test phase.

<p>Dashed lines indicate chance levels. The asterisks indicate the percentages of looking time that significantly differed from chance levels. </p

Numerical and non-numerical magnitudes presented as cues in Experiment 1 and in Experiment 2, respectively.

<p>Numerical and non-numerical magnitudes presented as cues in Experiment 1 and in Experiment 2, respectively.</p

Mean times to target fixation exhibited by participants on congruent and incongruent trials for the Dots and Arabic digits conditions of Experiment 1 and for the Brightness and Size conditions of Experiment 2.

<p>Error bars represent standard error of the means.</p

Schematic representation of a congruent trial in the Arabic digits condition of Experiment 1.

<p>Schematic representation of a congruent trial in the Arabic digits condition of Experiment 1.</p

Stimuli used in Experiment 1.

<p>(a) Example of dynamic stimuli showing still from the three motion types in upright orientation. Dynamic impression was created by showing the frame 1 and the frame 2 alternately at 1 Hz. Frame 1 was shown at the onset of the stimuli, and was also used for static stimuli. (b) Schematic representation of central and peripheral stimulus position. The dotted area around the middle face represents the central AOI, while those around the left and right faces represent the peripheral AOI. (c) Schematic representation of stimulus sequence showing a trial where the peripheral stimulus appears on the right. As soon as infants fixate on the fixation point, experimenter started the trial. The central face remained on the screen for 2seconds before presentation of peripheral face which ramined on the screen together with the central face for another 5 seconds for 4-month-olds or 10 seconds for newborns.</p

Results from Experiment 1.

<p>(a) Mean saccadic latency for each stimulus combination in 4month-olds (Experiment 1a). (b) Mean gaze saccadic rate per milliseconds in 4-month-olds (Experiment 1a). Note that greater values represent faster saccades. (c) Mean saccadic latency for each stimulus combination in newborn infants (Experiment 1b). Error bars in each graph represent +/-1 <i>SE</i>.</p

Stimulus combination in Experiment 2.

<p>Stimulus combination in Experiment 2.</p

Mean (SD) number of the valid trials for each stimulus combination as a percentage of the total number of trials for each infant in Experiment 1a, 1b, 2a, and 2b.

<p>Mean (SD) number of the valid trials for each stimulus combination as a percentage of the total number of trials for each infant in Experiment 1a, 1b, 2a, and 2b.</p

Results from Experiment 2.

<p>(a) Mean saccadic latency for each stimulus combination in 4month-olds (Experiment 2a). (b) Mean saccadic rate per second in 4-month-olds (Experiment 2a). Note that greater values represent faster saccades. (c) Mean saccadic latency for each stimulus combination in newborns infants (Experiment 2). Error bars in each graph represent +/-1 <i>SE</i>.</p