Table 2.

Details of the three “Social” versus “Non-social” comparisons (based on observer reports) performed as part of the GLM analysis

Analysis Number“Social” responder group“Non-social” responder groupRationale for the analysisStatistical comparisons for fMRIID of the analysis used in figures and text
1RANDOM MECHANICAL (Within animation, between participant)

  • Controls for low-level input

  • Most ambiguous animation

Two-sample t testRANDOM MECH
2COAXINGBILLIARD

  • Likely similar decision times during animation (as estimatedfrom online RT experiment)

Paired t testCOAXING-BILLIARD
(Between animation, within participant)
3All “Social”All “Non-social”

  • Maximizes power by comparing all “Social” responses with all“Non-social” responses within participants

One-sample t test after averaging runwise estimatesALL ANIMATIONS
Coded 1 (“Social”) and −1 (“Non-social”), in runwise GLMs