PMC

Startle reflex magnitude (A), habituation (B) and reflex latency (C) for W1 and W2. (* significant main effect of diagnosis for startle magnitude and peak reflex latency across trials, including pulse alone (P) and 30, 60 and 120 ms prepulse conditions).

A. PPI in all AP-free patients (n=120) vs. all HS (d=0.26), and B. the same comparison as “A”, with strict exclusion criteria applied for minimal startle magnitude (n=78 AP-free patients) (d=0.32). C. PPI in AP-free SZ patients in the first decade of their illness (n=24) vs. sex- and age-matched HS (case-matched 2:1; n=48, all “responders”) (d=0.57) (* significant main effect of diagnosis for 60 ms prepulse intervals, after significant interaction of diagnosis × interval).

%PPI for the full samples in W1 (n=1399) and W2 (n=621), including all subjects with measureable startle responses from both eye sides across the full test session. Independent analyses of W1 and W2 samples revealed relatively comparable patterns in W1 vs. W2, with significant interactions of diagnosis × prepulse interval, and statistically significant PPI deficits in SZ patients detected for 60 ms prepulse intervals (*). ANOVA of the combined W1+W2 samples confirmed these findings, with no main or interaction effect of “wave”.

Impact of different exclusion criteria on sample size and effect size for the key 60 ms PPI comparison for the combined W(1+2) subjects. A. Data from both PPI trial blocks (2 and 3) in (from left to right) the full COGS-2 sample (n=2020), criteria set at ≥ 10 units for block 2 and ≥ 5 units for block 3 (middle, n=1506) and criteria set at ≥ 10 units for both blocks 2 and 3 (right, n=1280). Increasingly strict startle magnitude exclusion criteria lead to sample attrition and modest reductions in effect size. B. Data from PPI block 2 only, from all subjects (left; n=2020) and subjects whose block 2 reflex magnitude was > 10 units (n=1557). C. Distribution of 60 ms PPI values for startle “non-responders” vs. “responders” (i.e. those excluded vs. included in “A”, right panel), showing a disproportionate number of startle “non-responders” among the extreme (negative) PPI values.