IV. Results
4.1 Behavior Performance
4.1 Behavior Performance
The response time of the tasks (the deviation and the math) was collected to study behavior of the subjects in the experiments. The outliers were first removed from the 11 subjects’ behavior data. By using one way ANOVA, the significance of the behavior data were tested for every subject. The testing results were showed in Fig.
4-1. The response time to deviation was given in Fig. 4-1(A). The blue bars were in the figures represented the case of math-400ms-deviation (case-1), the light blue bars were represented the case of math-deviation (case-2), the yellow bars were represented the case of deviation-400ms-math (case-3), and the red bars were represented the case of single-deviation (case-5).
The response time to deviation in case-5 (single deviation) was significantly larger than that in the case-1 (math present 400 ms before deviation) for most of the subjects (8 out of 11). The response time to deviation in case-5 (single deviation) was
significantly larger than that in the case-2 (two tasks present at the same time) for four subjects. And, the response time to deviation in case-5 (single deviation) was significantly larger than that in the case-3 (deviation present 400 ms before math) for only one subject. These results were shown in Fig. 4-1(A). This meant it take longer time for the subjects to reply to the driving task in single deviation case. Because when the deviation task appeared in the case-1 subjects were in order to continuously resolve the mathematical equations, they had to firstly and rapidly response to the deviation task to avoid hitting the wall.
The Responses to Deviation
Time (ms)
S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11
A The Responses to Deviation
Time (ms)
S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11
The Responses to Deviation
Time (ms)
S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11 S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11
A
The Responses to Math
Time (ms)
S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11
B The Responses to Math
Time (ms)
S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11
The Responses to Math
Time (ms)
S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11 S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11
B
Fig. 4-1: Bar charts of the averaged response time to the deviation (A) or the math (B) onsets between four cases. The blue bars: case-1 (the math occurred at 400ms before the deviation onset); the light blue bars: case-2 (the math and deviation occurred at the same time); the yellow bars: case-3 (the math occurred at the 400 ms after the deviation onset); and the red bars: case-4 (only presented the math question in this case) or case-5 (only deviation occurred in this case).
In Fig.4-1 (B), the response time to math in case-4 (single math) was significantly shorter than that in the case-1 (math present 400 ms before deviation) for most of the subjects (7 out of 11). The response time to math in case-4 (single math) was significantly shorter than that in the case-2 (two tasks present at the same time) for six subjects. And, the response time to math in case-4 (single math) was significantly shorter than that in the case-3 (deviation present 400 ms before math) for four subjects. This meant it take shorter time for the subjects to reply to the math task in single math case.
In order to investigate the overall of behavior index, we used the technology of nonparametric tests. The nonparametric analysis was used because several extremely large scores significantly skewed. First, the data was randomly selected the trials which there was the same trials in all cases. Then, the response time of the two tasks in the five cases were normalized to the single-deviation and single-math tasks. We used the Statistical Package for Social Science (SPSS) for Friedman test, and the result was shown in Fig. 4-2.
The normalized response time to deviation was given in Fig. 4-2(A). The response time to deviation for dual tasks (case-1 to case-3) were significantly shorter than that for the single task (case-5). There were no statistical significant differences between the case-2 and the case-3. The largest response time to the deviation onset was the case-5. The normalized response time to math was given in Fig. 4-2(B). The response time to math presented for dual tasks (case-1 to case-3) were significantly longer than that for the single task (case-4). There were no statistical significant differences between case-1 and case-2. The shortest response time to the math onset was the case-4.
The Responses to Deviation
A
The Responses to Deviation* *
The Responses to Math
*
D&M
The Responses to Math
*
D&M
Fig. 4-2: Bar charts of normalized response time to the deviation (A) and math (B) presented between 5 cases across 11 subjects. The filled black bar: case-1; dark gray bar: case-2; light gray bar: case-3; the opened bar: single case. The bottom insets showed the onset sequences between two tasks. Note: the response time to deviation for dual tasks (case-1 to case-3) were significantly shorter than that for the single task (case-5). The largest response time to the deviation onset was the case-5. The response time to math presented for dual tasks (case-1 to case-3) were significantly longer than that for the single task (case-4). The shortest response time to the math onset was the case-4.
Further, we wanted to know the difference which cases was made. Then, Post Hoc test was to use Student-Newman-Keuls test, and the result was shown in Table-3.
The explanations were showed below.
(1) Normalized response time to deviation:
The result of test statistic was χ02.05,3 =16.04 from Friedman test, and p=0.000 <
0.05. Therefore, the result rejected the null hypothesis. In the analysis, we found the four cases (case-1, case-2, case-3, and case-5) significantly different with each other.
Using Student-Newman-Keuls test, we found three significant groups (case-1, case-2 and case-3, case-5).
(2) Normalized response time to math:
The test statistic was χ02.05,3 =148.859 from Friedman test, and p= 0.000 < 0.05.
The four cases (case-1, case-2, case-3, and case-5) were significantly different with each other. And, we used Student-Newman-Keuls test to also find three significant groups (case-1 and case-2, case-3, case-4).
Table-3 the normalized response time to deviation and math
Response time to deviation Response time to math
Case Mean (SD) Difference
(dual-single) Mean (SD ) Difference (dual-single) Case 1 1.216864 0.151223 -0.07
p<0.01 1.891619 0.509387 0.23 p<0.01 Case 2 1.265610 0.157821 -0.02
p<0.01 1.860181 0.472608 0.2 p<0.01 Case 3 1.269600 0.169142 -0.01
p<0.01 1.811820 0.478367 0.15 p<0.01 single(baseline) 1.287392 0.211970 1.659849 0.413884