Abnormal prefrontal brain activation during a verbal fluency task in bipolar disorder patients with psychotic symptoms using multichannel NIRS

Figures & data

Figure 1 VFT task design.

Note: Four-block (vegetables, domestic applications, four-legged animals, and fruits) semantic category versions of VFT included a 30-second pre-task baseline, a 30-second VFT, and a 30-second post-task baseline.
Abbreviation: VFT, verbal fluency task.

Table 1 Characteristics of subjects

Demographics	BDn	BDp	HC	Significance (BDn, BDp, HC)	Significance (BDn vs HC)	Significance (BDp vs HC)	Significance (BDn vs BDp)
Age (years)	30.93±8.98	28.38±6.83	32.91±10.18	0.173	0.410	0.065	0.257
Gender (female/male)	17/14	14/15	11/12	0.837
Education level (years)	13.51±3.18	13.82±3.06	13.47±3.55	0.908	0.966	0.710	0.711
YMRS	1.48±1.61	1.17±1.44	1.39±1.37	0.334	0.822	0.600	0.421
HAMD	24.71±3.39	25.24±3.59	7.04±4.24	<0.001	<0.001	<0.001	0.581
BPRS	26.83±4.65	82.72±24.22	26.60±5.03	<0.001	0.955	<0.001	<0.001
Vegetables
Corrected word	7.77±2.26	8.03±2.27	10.04±2.72	0.002	0.001	0.004	0.676
Accuracy	90.34±10.05	92.26±10.62	91.80±6.75	0.728	0.587	0.863	0.445
Family applications
Corrected word	7.64±1.52	7.27±1.38	9.43±1.78	<0.001	<0.001	<0.001	0.360
Accuracy	86.94±11.41	88.71±13.34	88.02±8.02	0.832	0.730	0.830	0.549
Four-foot animals
Corrected word	7.09±1.66	7.13±1.24	7.71±1.69	<0.001	<0.001	<0.001	0.910
Accuracy	88.73±11.43	90.01±11.48	93.48±7.56	0.255	0.105	0.242	0.683
Fruits
Corrected word	7.00±1.18	7.62±2.62	9.08±1.31	<0.001	<0.001	0.006	0.197
Accuracy	85.01±11.99	87.31±12.46	88.65±8.96	0.495	0.251	0.674	0.439

Note: Data are expressed as mean±SD.

Abbreviations: BDn, BD patients without psychotic symptoms; BDp, BD patients with psychotic symptoms; BPRS, Brief Psychiatric Rating Scale; HAMD, Hamilton Rating Scale for Depression; HC, healthy controls; YMRS, Young Mania Rating Scale.

Figure 2 A map showing statistically significant lower oxy-Hb changes in BDn patients compared with the controls during the VFT.

Notes: Channels in color show significantly lower oxy-Hb changes during the VFT in BDn compared with healthy controls (FDR-corrected P<0.2). Channels in gray show FDR-corrected P-values >0.2.
Abbreviations: BDn, bipolar disorder patients absence of psychotic symptoms; FDR, false discovery rate; oxy-Hb, oxygenated hemoglobin; VFT, verbal fluency test.

Figure 3 A map showing statistically significant lower oxy-Hb changes in BDp patients compared with the controls during the VFT.

Notes: Channels in color show significantly lower oxy-Hb changes during the VFT in BDp compared with HC (FDR-corrected P<0.2). Channels in gray show FDR-corrected P-values >0.2.
Abbreviations: BDp, bipolar disorder patients presence of psychotic symptoms; FDR, false discovery rate; HC, healthy controls; oxy-Hb, oxygenated hemoglobin; VFT, verbal fluency test.

Figure 4 Histogram of the average oxy-Hb concentrations changes in the four channels.

Note: Both BDp and BDn groups showed significantly reduced activation in the four channels than HC (FDR-corrected P<0.2).
Abbreviations: BDp, bipolar disorder patients presence of psychotic symptoms; BDn, bipolar disorder patients absence of psychotic symptoms; FDR, false discovery rate; HC, healthy controls; oxy-Hb, oxygenated hemoglobin.

Figure 5 A map showing statistically significant lower oxy-Hb changes in BDp patients compared with BDn during the VFT.

Notes: Channels in color show significantly lower oxy-Hb changes during the VFT in BDp compared with BDn (FDR-corrected P<0.2). Channels in gray show FDR-corrected P-values >0.2.
Abbreviations: BDp, bipolar disorder patients presence of psychotic symptoms; BDn, bipolar disorder patients absence of psychotic symptoms; FDR, false discovery rate; oxy-Hb, oxygenated hemoglobin; VFT, verbal fluency test.

Figure 6 Scatter plot of the oxy-Hb changes in channel 14 changing with BPRS scores.

Note: oxy-Hb changes of channel 14 were negatively correlated with BPRS scores.
Abbreviations: BPRS, Brief Psychiatric Rating Scale; oxy-Hb, oxygenated hemoglobin.