On loss trials, smaller pupil dilation predicted response change in TD participants while larger dilation predicted it in FXS participants, with no robust effect in DS or WS¶

Claim · All claims
Evidence · 1 study (3 entries) · associational r? · q3
Currency · newest study 2026 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i? In TD participants, smaller pupil dilation was associated with a higher likelihood of response change on loss trials (b = -0.51). → Hallman 2026 q3 i? In FXS individuals the opposite pattern held: larger pupil dilation was associated with a higher likelihood of changing response (b = 1.24), with weak evidence (BF = 2.80). → Hallman 2026 (2) q3 i? No robust evidence for pupil dilation predicting response change was found for DS (BF = 0.45) or WS (BF = 0.36). → Hallman 2026 (3)

Evidence¶

Hallman 2026¶

Hallman, A. E. Z., Willfors, C., Frick, M. A., Nordgren, A. & Kleberg, J. L. (2026). Comparing feedback learning and arousal responses in Down, Fragile X, and Williams syndromes. npj Science of Learning. https://doi.org/10.1038/s41539-026-00438-2

q3 · i? · associational · r?

GLMM fitted on loss-feedback trials only with varying intercepts for participants, Results section, run separately for each syndrome group.

"Pupil dilation affected response behavior in TD participants, suggesting that smaller pupil dilation was associated with a higher likelihood of response change ( b = −0.51, 95% CI = [ −0.85, −0.18], BF = 9.64, pd =1 )."

Hallman 2026 (2)¶

Hallman, A. E. Z., Willfors, C., Frick, M. A., Nordgren, A. & Kleberg, J. L. (2026). Comparing feedback learning and arousal responses in Down, Fragile X, and Williams syndromes. npj Science of Learning. https://doi.org/10.1038/s41539-026-00438-2

q3 · i? · associational · r?

Same loss-trial GLMM, FXS group, Results section. The BF of 2.80 falls in the moderate evidence range per the article's guidelines, so the effect is only weakly supported.

"The opposite pattern was observed in FXS individuals, where a larger pupil dilation was associated with a higher likelihood of changing response on loss trials (b = 1.24, 95% CI = [0.02, 2.63], BF = 2.80,pd = 0.98)."

Hallman 2026 (3)¶

Hallman, A. E. Z., Willfors, C., Frick, M. A., Nordgren, A. & Kleberg, J. L. (2026). Comparing feedback learning and arousal responses in Down, Fragile X, and Williams syndromes. npj Science of Learning. https://doi.org/10.1038/s41539-026-00438-2

q3 · i? · associational · r?

Null result from the same loss-trial GLMMs for the DS and WS groups, Results section. Equivalence was not tested; the article reports absence of robust evidence rather than a measured null effect size.

"For WS and DS, there was no robust evidence for an effect regarding pupil dilation predicting response change on loss trials (DS: b = 0.43, 95% CI = [−0.52, 1.45], BF = 0.45, pd = 0.81; WS: b = −0.33, 95% CI = [ −1.16, 0.46], BF = 0.36, pd = 0.79)."

Discussion¶

Learner Variables¶

• Learning Disabilities and Developmental Differences — predictor: learners who differ on it differ in outcomes

Related Claims¶

• All groups, including individuals with Down, Fragile X, and Williams syndromes, adapted their choices based on deterministic feedback, staying with rewarded options and switching after losses — related
• Individuals with Williams syndrome show intact behavioral feedback learning but no loss-driven pupil dilation, a dissociation from typically developing controls — related
• After positive feedback, individuals with Down syndrome were more likely to switch responses and individuals with Williams syndrome less likely than typically developing controls, while evidence for Fragile X syndrome was inconclusive — related