Table 1.
Behaviours recorded in instantaneous scan samples.
Fig 1.
Mean BPM of songs playing when chimpanzees entered and exited the pod with the music playing.
Error bars represent standard error. *P < .05
Table 2.
Tests were comparing mean proportion of scans spent engaging in Passive, Active, Socially Active, Self-grooming and Abnormal Behaviours between Music and Silence trials. Trends are italicised and significant differences are shown in bold and underlined.
Table 3.
Results comparing “classical difference” with “pop/rock difference”.
Positive mean values indicate more of the behaviour was observed in the music period (classical or pop/rock) compared to the matched silence period; whilst negative mean values indicate more of the behaviour was observed in the silence period compared to the matched music period (classical or pop/rock).
Table 4.
Results comparing the percentage time spent displaying abnormal behaviours between music and silence.
Paired T-tests were used to compare Music with Silence and “classical difference” with “pop/rock difference” were compared with Independent T-tests for Rene (N = 22), Lianne (N = 36) and Paul (N = 22).
Table 5.
Percentage time spent displaying abnormal behaviours during music and silence periods for all three individuals.
Fig 2.
Choices of the four possible button presses made by the four groups across all 64 trials.
Despite the higher number of classical presses, there was no significant difference between the different buttons.
Table 6.
Results of tests investigating preferences for each of the four groups.
Significant results are in bold and underlined.
Fig 3.
a and b. Graphs showing a) the choices of the four possible button presses made by group C2 and b)–the percentage of total presses by group C2 per individual.
Pacer, Cordova and Junie are not included in the graphs as they did not contribute any button presses.
Fig 4.
Scatterplot illustrating the mean button presses across all four groups in each of the 16 sessions.
Line of best fit is shown.
Fig 5.
a, b and c. Images of the three touchscreen buttons, as they appeared during training phases.
When pressed, each initiated the following actions: (a) turned on classical music for three seconds, (b) turned music off /silence on for three seconds and (c) turned on pop/rock music for three seconds.
Fig 6.
Illustration of the first trial in a classical button training session.
This shows the touchscreen images, associated auditory output, actions of the chimpanzees or experimenter, and timings. The downwards arrows indicates a change which is the result of the adjacent action, and is not reflected in an immediate change of visual stimulus. Training continued until the Classical music button had been successfully pressed 10 times, after which the touchscreen was turned off whilst the next training phase was loaded on the computer. If the touchscreen was not interacted with for 30 seconds during a training session, it reverted back to the green circle screen.
Fig 7.
Example first two trials during a session of individual testing.
Layout is as described in Fig 6. Testing continued until 40 buttons, not including the green start button, had been successfully pressed. If the touchscreen was not interacted with for 30 seconds, it reverted back to the green circle screen. If an individual did not complete the testing within a single approach of the touchscreen or experimental session then the remaining button presses were completed the next time the individual approached the touchscreen, whether it was later in the session or on another day.
Table 7.
Results of tests investigating preferences for Edith, Eva, Pearl, Kilimi, Louis and Frek.
Trends are italicised and significant results are shown in bold and underlined.
Fig 8.
a, b and c. The number of times a) Edith, b) Pearl and c) Kilimi pressed each type of button during individual testing.
Fig 9.
Relationship between how long the chimpanzees stayed in the research pods and the number of third party presses.
Scatterplot with line of best fit. Each data point represents a distinct stay in the research pods by one of the 17 individuals.
Table 8.
The number of times each individual pressed buttons during each of the nine experimental sessions.
The total number of button presses across all nine sessions is 45 and it can be seen that, with the exception of the first session, engagement with the touchscreen was low.