Fig 1.
Distribution of doubt scores in internet participants (N = 152).
Fig 2.
Cumulative probability distributions of doubt scores in OCD and non-OCD participants.
OCD (red color; N = 67); non-OCD participants (blue color; N = 27). Participants with OCD exhibited significantly higher doubt scores (rank sum test, p<0.0001).
Fig 3.
Behavioral task performance in OCD cases and controls.
A) A posterior distribution of group mean drift rate was calculated using HDDM, and indicates the rate of evidence accumulation over 7 different coherences. The most likely group means are plotted; error bars indicate the posterior standard deviation. With higher coherence, higher drift rates were observed for both OCD (red, n = 26) and control (blue, n = 44) subjects. However, at higher levels of coherence, OCD subjects exhibited significantly slower drift rates and reaction times than OCD subjects (q<0.05 for 30%, and 45% coherence; q<0.01 for 70% coherence). B) No significant differences in the posterior distribution of HDDM threshold were observed between OCD and control subjects.
Fig 4.
Behavioral task performance in participants with high (>60) and low (≤60) doubt scores.
A) A posterior distribution of group mean drift rate was calculated using HDDM, and indicates the rate of evidence accumulation over 8 different coherences. The most likely group means are plotted; error bars indicate the posterior standard deviation. With higher coherence, higher drift rates were observed for both high doubt (orange color, N = 10) and low (black color, N = 36) subjects. However, at higher levels of coherence, high doubt subjects exhibited even faster drift rates and reaction times than low doubt subjects (q<0.01 for 70% coherence). B) No significant differences in the posterior distribution of HDDM threshold were observed between high and low doubt subjects.
Fig 5.
Relationship between doubt score and drift rate independent of OCD diagnosis.
HDDM was used to calculate the most likely drift rate for each subject with both a doubt score and an OCD diagnosis. Comparisons of all subjects revealed a correlation between doubt score and drift rate at 70% coherence in the no cost condition (v = 3.63 − 0.034DQ; R2 = 0.11; p = 0.024. When subjects with OCD were excluded, control subjects (blue) also exhibited a correlation between doubt score and drift rate at 70% coherence in the no cost condition (v = 4.04 − 0.044DQ; R2 = 0.13; p = 0.038). In OCD subjects alone (red), there was not a significant correlation between doubt score and drift rate OCD subjects: v = 2.66 − 0.016DQ; R2 = 0.04; p = 0.53.