Fig. 7: Human and object numerosity estimation tasks for both PD patient groups (PD-PH and PD-nH) (study 2).

a Performance is shown in PD patients for each tested numerosity in the human numerosity estimation task for PD-PH (dark blue) and PD-nH (light blue) separately. Each dot indicates the individual human numerosity estimation task mean estimate for the tested numerosity (PD-PH (dark blue) and PD-nH (light blue)). The dots with the bar on the left and right sides indicate the mixed-effects linear regression between PD-PH (dark blue) and PD-nH (light blue) at each presented numerosity. b Human numerosity estimation task in PD patients (PD-PH vs PD-nH). The occurrence of presence hallucinations significantly modulates online human numerosity estimation task (t(122) = −3.16; p = 0.002; effect size = −0.41 (95% confidence interval = [−0.67; −0.15])). Each dot indicates the individual human numerosity estimation task mean estimate (PD-PH (dark blue) and PD-nH (light blue)). The dots with the bar on the left and right sides indicate the mixed-effects linear regression between PD-PH (dark blue) and PD-nH (light blue). c Object numerosity estimation task in PD patients (PD-PH vs PD-nH). No statistical difference in online object numerosity estimation task was observed between PD groups (PD-PH vs PD-nH) (t(122) = −0.59; p = 0.42; effect size = −0.10 (95% confidence interval = [−0.36; 0.15]))). Each dot indicates the individual object numerosity estimation task mean estimate (PD-PH (dark red) and PD-nH (light red)). The dots with the bar on the left and right sides indicate the mixed-effects linear regression between PD-PH (dark red) and PD-nH (light red). Error bar represents 95% confidence interval. **P ≤ 0.01. n = 118 patients with PD (63 PD-PH & 55 PD-nH). Source data are provided as a Source Data file. PD Parkinson’s Disease; PD-PH Parkinson’s Disease patients with Presence Hallucination, PD-nH Parkinson’s Disease patients with no Hallucination.