Objective and subjective neurocognitive functioning in functional motor symptoms and functional seizures: preliminary findings

Figures & data

Table 1. Description of CANTAB connect tests.

Test	Cognitive Domain	Description	Outcome variables
Motor Screening	Sensorimotor speed	2-minute test. Participants detect and manually select colored crosses appearing in varied spatial locations onscreen, as quickly as possible.	Motor Mean Latency Total correct/incorrect
Reaction Time	Cognitive and motor response speed	3-minute test. Participants are asked to hold their finger on a central circle at the bottom of the screen until one of five circles at the top of the screen lights up. Participants must release the lower circle and manually select the target upper circle as quickly as possible.	Reaction Time Movement Time Total Error Score
Rapid Visual Information Processing	Attention (sustained)	7-minute test (approx.). Participants required to detect target digit sequences (e.g., 5-3-7) appearing within a stream of individually presented digits (100/minute). Participants must indicate the occurrence of the target sequence by manually selecting a button onscreen as quickly as possible.	Response Latency Ability score Total misses Probability of Hit False Alarm
Spatial Span	Working memory (visuospatial)	5-minute test. Participants are presented with sequences of squares changing color one-by-one in a variable spatial pattern. Participants are required to repeat each sequence manually, either in the same order, or backwards. Task difficulty increases as the task progresses (2–9 squares in a sequence).	Forward/reverse span length Forward/reverse errors
Intra-Extra Dimensional Set Shift	Attentional set-shifting, cognitive flexibility, visual discrimination	7-minute test. Adaptation of the Wisconsin Card Sorting Test. Pink shapes and white lines are presented, according to an implicit rule that the participant must identify. Participants are asked to select the box that they think adheres to the current rule and they are given feedback on each trial (“Correct” or “Incorrect”). Once the participant has correctly responded six times, the rule changes and the participant must identify a new rule. The rules either change within a dimension (i.e., intra-dimensional set shift), or the rule changes to focus on a different dimension (i.e., extra-dimensional set shift). Task difficulty increases throughout.	Total/adjusted errors Total trials completed Completed Stage Trials/Errors Stages completed Response latency
Stop Signal Task	Response inhibition	14-minute test. Arrows presented individually, pointing to the left or right. Participants must indicate the direction of the arrow as quickly as possible by pressing a left or right button. When an auditory stimulus is also present, participants must withhold the button press (response inhibition). The task is adaptive, with variable stop-signal delay dependent on the participant’s performance.	Errors (Go/Stop trials) Missed trials Stop signal reaction time
Emotional Bias Task	Social cognition	4-minute test. Each trial involves 150-millisecond presentation of a morphed emotional face, which vary in intensity from one emotion to another. Two versions of the task were included (happy-angry, happy disgust). Participants are given a forced-choice option to select which emotion they perceived.	Bias point: proportion of assessed trials where the subject selected “Happy,” (adjusted to 0–15) Reaction time by emotion
Emotion Recognition Test	Social cognition	6–10 minute test. Assesses recognition of six emotional facial expressions (anger, sadness, fear, disgust, surprise, happiness). Each trial involves a 200-millisecond presentation of an emotional face. Participants are asked to select one of six emotion labels to report which emotion they perceived, as quickly as possible.	Total hits/Unbiased hits Reaction times False alarms

Table 2. Sociodemographic and clinical characteristics.

	FND (n = 16)	HC (n = 17)	Comparison statistics
Self-reported FND symptoms: n (%)	Motor = 16 (100) Seizures = 7 (44) Sensory = 16 (100) Speech/swallowing = 9 (56) Dizziness = 14 (81) Cognitive = 14 (88) Other = 8 (50) Multiple = 16 (100%)
FND average symptom severity/impact (1–7): M (SD)	Severity = 4.17 (0.93) Impact = 4.19 (0.79)
Age (years): M (SD)	36.1 (10.8)	39.0 (11.0)	t(31) = 0.76, p = 0.45, g = 0.26
Sex: n (%)	F = 12 (75) M = 4 (25)	F = 13 (76) M = 4 (24)	p = 0.62 (Fisher’s exact)
Handedness: n (%)	R = 14 (88)	R = 15 (88)	p = 1.0 (Fisher’s exact)
Relationship status – married/cohabiting: n (%)	10 (63)	8 (47)	p = 0.49 (Fisher’s exact)
Ethnicity: n (%)	White: 13 (81) Black: 0 (0) Asian: 0 (0) Other: 3 (19)	White: 12 (71) Black: 3 (18) Asian: 2 (12) Other: 0 (0)	p = 0.69 (Fisher’s exact: White/nonwhite)
Education – post-compulsory: n (%)	15 (94)	17 (100)	p = 0.49 (Fisher’s exact)
Occupational status – employed/student: n (%)	6 (38)	16 (94)	p 0.001 (Fisher’s exact)
Current physical health diagnosis: n (%)	11 (69)	4 (24)	p = 0.01 (Fisher’s exact)
Current mental health diagnosis: n (%)	10 (63)	1 (6)	p < 0.001 (Fisher’s exact)
Current medication use: n (%)	15 (94)	5 (29)	p < 0.001 (Fisher’s exact)

Key: M = mean; SD = standard deviation

Table 3. General intellectual functioning and performance validity scores.

	FND (n=16)	HC (n=17)	Comparison statistics
WASI-II FSIQ-2 scores: M (SD)	104.6 (10.7)	106.6 (9.2)	t(31)=0.58, p=0.57, g=0.20
Vocabulary T scores: M (SD)	54.1 (5.7)	55.0 (8.6)	t(31)=0.34, p=0.73, g=0.12
Matrix Reasoning T scores: M (SD)	51.4 (8.6)	52.8 (4.9)	t(24)=0.56, p=0.58, g=0.19
Medical Symptom Validity Test
Immediate Recall % Correct: Mdn (IQR)	100.0 (0.0)	100.0 (0.0)	W=136.0, p=1.00, r=0.00
Delayed Recall % Correct: Mdn (IQR)	100.0 (0.0)	100.0 (0.0)	W=120.0, p=0.18, r=0.24
Consistency %: Mdn (IQR)	100.0 (0.0)	100.0 (0.0)	W=120.0, p=0.18, r=0.24
Paired Associates % Correct: Mdn (IQR)	100.0 (0.0)	100.0 (0.0)	W=120.5, p=0.34, r=0.17
Free Recall % correct: M (SD)	83.1 (12.8)	82.6 (11.1)	t(31)=-.12, p=0.91, g=0.04
MSVT Pass: n (%)	16 (100)	17 (100)	-

Key: IQR = interquartile range; M = mean; Mdn = median; SD = standard deviation; WASI-II FSIQ-2 = Wechsler Abbreviated Scale of Intelligence–Full-Scale Intelligence Quotient 2 sub-test

Table 4. CANTAB Connect test statistics.

	FND (n = 16)	HC (n = 17)	Comparison statistics
Motor Screening Test Mean Motor Latency: M (SD)	862.2 (189.7)	751.8 (199.7)	t(31)=-1.63, p=0.11, g=0.55
Reaction Time Test
Mean Reaction Time (ms): M (SD)	382.2 (41.5)	361.1 (32.7)	t(31)=-1.62, p=0.12, g=0.55
Mean Movement Time (ms): Mdn (IQR)	252.2 (54.6)	217.9 (55.0)	W=92.0, p=0.12, r=0.27
Rapid Visual Information Processing
Mdn Response Latency (ms): Mdn (IQR)	403.5 (40.1)	440.0 (85.4) (n=16)*^1	W=179.5, p=0.05, r=0.3
RVIP Ability: M (SD)	0.89 (0.05)	0.91 (0.05) (n=16)*^1	t(30)=0.81, p=0.43, g=0.28
Total Misses: M (SD)	22.4 (10.3)	21.0 (12.2)	t(31)=-0.37, p=0.72, g=0.12
Probability of Hit: M (SD)	0.58 (0.19)	0.61 (0.23)	t(31)=0.37, p=0.72, g=0.12
Probability of False Alarm: Mdn (IQR)	0.006 (0.008)	0.004 (0.003) (n=16)*^1	W=96.0, p=0.23, r=0.21
Spatial Span
Forward Span Length: Mdn (IQR)	7.0 (1.0)	7.0 (3.0)	W=156.5, p=0.46, r=0.13
Forward Errors: M (SD)	15.9 (5.1)	17.2 (8.8)	t(26.0)=0.55, p=0.59, g=0.18
Reverse Span Length: Mdn (IQR)	6.0 (1.5) (n=15)*^1	6.0 (1.0)	W=107.0, p=0.44, r=0.13
Reverse Errors: M (SD)	14.4 (3.5) (n=15)*^1	12.2 (5.7)	t(27.0)=-1.34, p=0.19, g=0.45
Intra-Extra Dimensional Set Shift
Total Errors: Mdn (IQR)	14.0 (7.8) (n=12)*^4	12.0 (8.5) (n=10)*^7	W=55.0, p=0.77, r=0.05
Adjusted Errors: Mdn (IQR)	16.0 (28.5)	22.0 (47.0)	W=152.0, p=0.58, r=0.10
Total Trials Completed: M (SD)	80.7 (16.6) (n=12)*^4	75.4 (8.3) (n=10)*^7	t(20)=-0.26, p=0.80, g=0.11
Completed Stage Trials: M (SD)	70.0 (25.0)	71.2 (15.7)	t(31)=0.17, p=0.87, g=0.06
Completed Stage Errors: Mdn (IQR)	12.0 (7.75)	12.0 (11.0)	W=146.5, p=0.72, r=0.06
Stages Completed: Mdn (IQR)	9.0 (0.5)	9.0 (2.0)	W=112.5, p=0.33, r=0.17
Response Latency (ms): Mdn (IQR)	112341 (42752) (n=12)*^4	125164 (44040) (n=10)*^7	W=73.0, p=0.42, r=0.14
Stop Signal Task
Errors Go Trials: Mdn (IQR)	0.0 (1.0)	0.0 (2.0)	W=138.0, p=0.95, r=0.01
Errors Stop Trials: Mdn (IQR)	38.5 (8.5)	39.0 (6.0)	W=154.5, p=0.52, r=0.11
Number of Missed Trials: Mdn (IQR)	4.0 (5.3)	2.0 (5.0)	W = 105.5, p=.28, r=.19
Stop Signal Reaction Time (ms): M (SD)	241 (41.2)	249 (54.2)	t(31)=.44, p=.66, g=.16
Emotional Bias Task - Anger
Bias Point: M (SD)	8.56 (1.4)	8.82 (1.1)	t(31)=0.60, p=0.55, g=0.21
Mdn reaction time x Emotion: M (SD)			ANOVA Emotion: F(1, 30)=4.57, p=0.04, np2=0.13 Group: F(1, 30)=7.59, p=0.01, np2=0.20 Group x Emotion: F(1, 30)=0.24, p=0.63, np2=0.008 (FND n=15^#1, HC n=17)
Anger (ms)	772.4 (161.1)	958.4 (255.1)
Happiness (ms)	726.3 (122.7) (n=15)^#1	885.1 (198.6) (n=17)
Emotional Bias Task - Disgust
Bias Point: M (SD)	8.16 (.86) (n=15)*	7.94 (1.16)	t(30)=-0.59, p=0.56, g=0.20
Mdn reaction time x Emotion: M (SD)			ANOVA Emotion: F(1, 28)=1.4, p=0.24, np2=0.05 Group: F(1, 28)=3.1, p=0.09, np2=0.10 Group x Emotion: F(1, 28)=1.42, p=0.24, np2=0.05 (FND n=14*^1#1, HC n=16^#1)
Disgust (ms)	684.3 (95.1)	789.3 (170.0)
Happiness (ms)	723.4 (97.6) (n=14)*^1#1	789.4 (168.5) (n=16)^#1
Emotion Recognition Test
Total Hits: Mdn (IQR)	59.5 (8.25)	59.5 (7.0) (n=16)*^1	W=145.5, p=0.52, r=0.11
Total Hits x Emotion: M (SD)			ANOVA Emotion: F(5, 145)=24.3, p<.001, np2=0.46 Group: F(1, 29)=0.05, p=0.83, np2=0.002 Group x Emotion: F(5, 145)=2.31, p=0.047, np2=0.07 (FND n=15^#1, HC n=16*^1)
Anger	8.1 (2.2)	7.3 (2.4)
Disgust	9.8 (3.2)	10.8 (3.3)
Fear	7.2 (2.4)	7.4 (3.2)
Happiness	12.0 (2.2)	12.4 (1.6)
Sadness	11.4 (2.8)	9.6 (4.1)
Surprise	11.1 (1.8)	11.9 (1.7) (n=16)*^1
Unbiased Hit Rate x Emotion: M (SD)			ANOVA Emotion: F(5, 150)=22.5, p<0.001, np2=0.43 Group: F(1, 30)=0.02, p=0.88, np2=0.001 Group x Emotion: F(5, 150)=2.22, p=0.06, np2=0.07 (FND n=16; HC n=16*^1)
Anger	0.42 (0.17)	0.41 (0.17)
Disgust	0.42 (0.19)	0.50 (0.22)
Fear	0.32 (0.15)	0.31 (0.22)
Happiness	0.59 (0.13)	0.66 (0.11)
Sadness	0.54 (0.14)	0.45 (0.20)
Surprise	0.5 (0.09)	0.50 (0.12) (n=16)*^1
False Alarms x Emotion: M (SD)			ANOVA Emotion: F(3.3, 97.5^$)=4.87, p=0.003, np2=0.14 Group: F(1, 30)=0.006, p=0.94, np2=0.00 Group x Emotion: F(3.3, 97.5^$)=1.54, p=0.21, np2=0.05 (FND n=16; HC n=16*^1)
Anger	2.8 (2.5)	2.1 (3.0)
Disgust	7.4 (6.3)	6.3 (4.8)
Fear	4.5 (3.8)	6.3 (4.6)
Happiness	5.3 (5.2)	3.4 (2.8)
Sadness	5.1 (3.5)	4.4 (3.4)
Surprise	5.4 (2.6)	8.3 (5.5) (n=16)*^1
Mdn reaction time – Correct responses (ms): Mdn (IQR)	1039.0 (227.0)	1048.5 (188.0) (n=16)*^1	W=141.5, p=0.62, r=0.08
Mdn reaction time (correct) x Emotion (ms): M (SD)			ANOVA Emotion: F(2.3, 67.9^$)=7.88, p<0.001, np2=0.21 Group: F(1, 29)=0.13, p=0.72, np2=0.01 Group x Emotion: F(2.3, 67.9^$)=1.02, p=0.38, np2=0.03 (FND n=15*^1, HC n=16*^1)
Anger	1152.5 (521.0)	1201.6 (405.2)
Disgust	1301.2 (470.1)	1175.9 (223.9)
Fear	1362.7 (362.9)	1660.9 (1155.2)
Happiness	926.0 (289.3)	873.4 (172.1)
Sadness	1142.8 (237.8)	1082.6 (237.7)
Surprise	948.1 (272.1) (n=15) *^1	1050.5 (463.1) (n=16)*^1

Key: ANOVA=Analysis of Variance; IQR = interquartile range; M = mean; Mdn = median; ms = milliseconds; SD = standard deviation;

*sample size diverges from total n due to missing data

#sample size diverges from total n due to outlier exclusion

^$Greenhouse-Geiser correction for non-sphericity

Table 5. Subjective performance ratings.

	FND (Total n = 16) Mdn (IQR)	HC (Total n = 17) Mdn (IQR)	Comparison statistics
WASI-II	4.5(1.0)	4.5 (0.5)	W=171.0, p=0.19, r=0.23
Motor Screening Test	5.5 (1.25)	6.0 (1.0)	W=143.5, p=0.79, r=0.05
Reaction Time	5.0 (1.0) (n=15)	4.0 (1.0)	W=112.5, p=0.55, r=0.11
Rapid Visual Information Processing	3.5 (1.0)	3.0 (1.0)	W=133.0, p=0.92, r=0.02
Spatial Span
Forward	4.0 (2.0)	4.0 (1.0)	W=128.0, p=0.78, r=0.05
Reverse	4.0 (2.0) (n=15)*	4.0 (1.0)	W=130.5, p=0.92, r=0.02
Intra-Extra-Dimensional Set Shift	5.0 (2.0)	4.0 (1.0)	W=97.0, p=0.15, r=0.25
Stop Signal Task	4.0 (0.5) (n=15)*	4.0 (1.0)	W=132.0, p=0.86, r=0.03
Emotion Bias Task
Anger	4.5 (1.0)	5.0 (1.0)	W=155.0, p=0.48, r=0.12
Disgust	5.0 (1.0) (n=15)*	5.0 (1.0)	W=141.5, p=0.59, r=0.13
Emotion Recognition Test	4.0 (1.3)	4.0 (1.0) (n=16)*	W=140.0, p=0.65, r=0.08
CANTAB Average	4.3 (0.78)	4.3 (0.68)	W=140.5, p=0.89, r=0.03
Medical Symptom Validity Test	5.0 (1.0)	5.0 (1.0)	W=141.5, p=0.85, r=0.03

Key: CANATB = Cambridge Neuropsychological Test Automated Battery; FND = functional neurological disorder; HC = healthy controls; IQR = interquartile range; Mdn = median; W = Wilcoxon’s W; WASI-II = Wechsler Abbreviated Scale of Intelligence – Second edition

*sample size diverges from total n due to missing data