Table 2.

Computational measures of verbal fluency test behavior

Variable	Healthy controls	Early-stage psychosis	t	d
VFT score
Animals	26.15 (5.7)	16.95 (5.08)	5.39***	1.7
Letter F	14.7 (3.89)	11.4 (2.96)	3.02**	0.95
Letter S	17.2 (4.2)	12.1 (3.99)	3.94***	1.25
Percentage switches
Animals	28.59 (5.41)	29.22 (6.14)	−0.34	0.11
Letter F	55.84 (17.61)	52.96 (20.11)	0.48	0.15
Letter S	52.83 (17.43)	50.08 (15.86)	0.52	0.16
Switch count
Animals	7.4 (2.19)	4.75 (1.8)	4.18***	1.32
Letter F	7.7 (2.87)	5.7 (2.03)	2.55*	0.81
Letter S	8.3 (2.64)	6 (2.97)	2.59*	0.82
Mean cluster or chain size
Animals	3.27 (0.55)	3.05 (0.49)	1.32	0.42
Letter F+	1.8 (0.57)	1.96 (1.06)	−0.6	0.19
Letter S	1.93 (0.61)	1.82 (0.37)	0.66	0.21
Mean cluster-related similarity
Animals	0.52 (0.04)	0.48 (0.05)	2.95**	0.93
Letter F	0.48 (0.09)	0.45 (0.07)	0.94	0.3
Letter S	0.47 (0.06)	0.49 (0.08)	−0.6	0.19
Mean switch-related similarity
Animals	0.35 (0.05)	0.33 (0.05)	1.24	0.39
Letter F	0.21 (0.02)	0.21 (0.02)	0.83	0.27
Letter S+	0.18 (0.04)	0.19 (0.06)	−0.69	0.22

Values are presented as mean (standard deviation). VFT score = total number of correct responses in the verbal fluency test; d = Cohen’s d effect size. Similarity values are Word2Vec semantic similarity (animal VFT) and VFClust phonetic similarity (F and S VFT).

⁺Variables had non-normal distributions; group differences remained non-significant when using Mann Whitney U tests.

^*p < .05

^**p < .01

^***p < .001