Table 1.
Demographic, psychopathological, and scanning characteristics of the two patient subgroups and healthy controls
| Variable | Hallucinating patients (N=32) | Nonhallucinating patients (N=24) | Healthy controls (N=23) | Statistical tests1 |
|---|---|---|---|---|
| Demographic | ||||
| Gender (M/F) | 18/14 | 13/11 | 13/10 | χ2 (2) = .03 (.98) |
| Race/ethnicity (Non-HisW/Af-Am/Other) | 27/5/0 | 21/2/1 | 16/6/1 | χ2 (6) = 7.5 (.27) |
| Age (yr)2 | 37.2 (8.8) | 41.1 (10.7) | 35.9 (9.7) | F(2,76)= 1.9 (.16) |
| Education (grades completed)2 | 13.8 (2.3) | 13.8 (2.0) | 14.1 (2.0) | F(2,76)= 0.2 (.80) |
| Clinical, behavioral and data acquisition characteristics | ||||
| Diagnosis (PS/SA-D/SA-B/UN)3 | 14/13/3/2 | 4/14/3/3 | * | χ2 (3) = 4.7 (.19) |
| No. of hospitalizations2 | 8.6 (9.0) | 8.6 (6.9) | * | t(54)= .01 (1.0) |
| PANSS Composite Positive Symptoms2 | 16.5 (4.9) | 16.6 (4.9) | * | t(54)= .07 (.94) |
| PANSS Delusion2 | 2.9 (1.6) | 3.3 (1.8) | * | t(54) = .77 (.44) |
| PANSS Disorganization2 | 1.5 (0.8) | 1.7 (1.2) | * | t(54) =.51 (.61) |
| PANSS Suspiciousness/persecution2 | 2.7 (1.3) | 3.3 (1.5) | * | t(54) =1.4 (.16) |
| PANSS Composite Negative Symptoms2 | 13.7 (5.0) | 16.1 (5.6) | * | t(54)= 1.7 (.09) |
| PANSS Composite General Psychopathology Symptoms2 | 33.0 (9.2) | 34.8 (8.6) | * | t(54)= .8 (.75) |
| Antipsychotic medication type (A/T/T+A/ND)4 | 20/3/7/2 | 17/4/2/1 | * | χ2(6)=2.4 (.49) |
| Chlorpromazine equivalent2 | 634 (457) | 474 (377) | * | t(54) = 1.4 (.17) |
| WAIS vocabulary scaled score2 | 10.8 (3.5) | 12.2 (2.9) | 12.0 (3.0) | F(2,76)= 1.5 (.23) |
| Edinburgh Handedness Inventory Score2,5 | 73.3 (21.5) | 63.5 (19.6) | 75.7 (19.5) | F(2,73) = 2.4 (.10) |
| Subjects depressing button during scanning (yes/no)6 | 11/21 | 9/15 | 11/12 | χ2(2)=1.1 (.59) |
| Number of scan runs (6/> 6)7 | 28/4 | 23/1 | 21/2 | χ2(2)=1.2 (.55) |
degrees of freedom and p-values in parentheses
data presented as mean (standard deviation)
PS=paranoid schizophrenia; SA-D=schizoaffective disorder, depressed; SA-B=schizoaffective disorder, bipolar; UN=undifferentiated schizophrenia
A=atypical; T=typical; T+A=typical plus atypical; ND=no drug
scale from Oldfield (71); data from three subjects not available (2 hallucinators and 1 nonhallucinating patient)
for subjects depressing button during runs, group comparison of rate of button depressions not significant different (F(2,28)=2.1, p=0.13)
One hallucinator had 7 runs, two hallucinators had 8 runs, and one hallucinator had 9 runs to collect additional hallucination event data for our parallel activation time-course analysis (ref 27); 1 nonhallucinating patient had 7 runs and 2 healthy control subjects had 7 runs in order to match frequency and duration of button presses in the hallucinator group.