Table 3.
Dichotic Listening Task Performance for Bipolar Patients, First-Degree Relatives of Bipolar Patients, and Nonpsychiatric Control Groups.
| Task | Patients | Relatives | Controls | Test Value | p Value1 |
|---|---|---|---|---|---|
|
|
|
|
|||
| n=18 Mean (SD) |
n=25 Mean (SD) |
n=36 Mean (SD) |
|||
| Accuracy: Number of Correct Targets2 | |||||
| High Tones | 39.35 (1.17) | 39.76 (.44) | 39.25 (1.66) | F(2,75)=1.2 | n.s. |
| Low Tones | 36.65 (3.90) | 38.56 (1.80) | 36.78 (5.05) | F(2,75)=1.7 | .18 |
| Total | 76.00 (4.64) | 78.32 (2.06) | 76.03 (5.83) | F(2,75)=2.1 | .13 |
| Target Detection: d′ | |||||
| High Tones | 4.41 (.54)b | 4.84 (.18) | 4.63 (.53) | F(2,75)=4.0 | .02 |
| Low Tones | 4.12 (.82)b | 4.64 (.40) | 4.41 (.70) | F(2,75)=2.9 | .06 |
| Total | 4.27 (.61)b | 4.74 (.23) | 4.52 (.53) | F(2,75)=4.4 | .01 |
| Response Threshold:β | |||||
| High Tones | .99 (.04) | .98 (.004) | .98 (.03) | F(2,75)=0.6 | n.s. |
| Low Tones | .93 (.07) | .96 (.04) | .94 (.08) | F(2,75)=1.5 | n.s. |
| Total | .96 (.04) | .97 (.02) | .96 (.05) | F(2,75)=1.3 | n.s. |
| Reaction Time for Targets: (msec) | |||||
| High Tones | 343 (85) | 350 (72) | 362 (69) | F(2,75)=0.4 | n.s. |
| Low Tones | 442 (98) | 418 (79 | 440 (85) | F(2,75)=0.5 | n.s. |
| Total | 392 (89) | 384 (71) | 401 (73) | F(2,75)=0.3 | n.s. |
Note. SD=Standard Deviation. A correction factor was used in computing d′ in cases of a perfect hit rate (1.0) or false-alarm rate (0.0) to allow for unbiased estimation of d′. A two-way ANOVA of d′ with group (patients, relatives, and controls) and trial type (high tones: 2400 Hz and 1600 Hz collapsed across attended side; low tones 1200 Hz and 800 Hz collapsed across attended side) revealed main effects for trial type, F(2,75) =10.64, p < .005 but no group-by-trial type interaction. A similar two-way ANOVA of β yielded a main effect of trial type, F(2,75) =28.03, p < .0001 but no group-by-trial type interaction. Participants responded faster to the high tone pairs of tones as compared to low tone pairs, F(1,75)=206.32, p <.0005.
Denotes significance level of Oneway ANOVA for specified set of trials.
Total number of targets presented at each tone was 40.
Bipolar Patients < Relatives of Bipolar Patients.