Fig 1.
Four automated cognitive testing units were built into the wall of the monkey enclosure.
Monkeys sat on a stool and reached through a hole to access the touchscreen, causing an RFID reader to identify the animal, via an antenna that surround the hole (the orange ring visible in the left two stations). Monkeys viewed the images presented on the touchscreen through a mesh window. Food rewards were delivered into the food cup positioned immediately above the window. Testing stations on the left had clear panels while testing stations on the right had opaque panels. Otherwise, the testing systems were identical.
Table 1.
General group demographics and touchscreen use measures across the three rank categories.
Fig 2.
Smoothed effect of month on the amount of touchscreen activity for all females.
Gray bands represent 95% confidence intervals for the fitted smooth effect. Areas where the gray bands do not overlap with the central y = 0 line reflect areas of significant seasonal effect. The x-axis is scaled in months, beginning in September and ending in August. The colored vertical bands represent the different seasons.
Fig 3.
Left. Amount of touchscreen activity by season for females of breeding age (> 3 years). Right. Amount of touchscreen activity by season for females of non-breeding age (< 3 years). Black lines represent means, grey areas represent 95% confidence intervals. When the grey line does not overlap with the central y = 0 line, the amount of touchscreen activity is significantly different from chance. The x axis is scaled in months, beginning in September and ending in August. The colored vertical bands represent the different seasons.
Fig 4.
Amount of touch screen activity relative to baseline over the course of a day.
Each time block is a period of three hours. Lines represent fitted means, shaded areas represent 95% confidence intervals. Areas where the shaded regions do not overlap are areas of significant difference between the two curves.
Fig 5.
Social network of overlap on touchscreen systems.
Edges (lines) represent two animals working together on the touchscreen system. Darker lines represent more monthly overlap than lighter lines. Males are represented as triangles and females are represented as circles. The color of the shapes reflects the animal’s rank grouping, where the light green is high ranking monkeys, dark green is medium ranking monkeys, and navy is the low-ranking monkeys. Left. Network for all individuals and all relationships. Low ranking monkeys tend to cluster together, while high and medium ranking monkeys are spread more widely. Right. Network when only the top 10% of relationships (in terms of strength) are plotted. Few low ranking monkeys appear on this graph, as they rarely show high levels of overlap with others.