Abstract
This research is designed for the research and development with the following objectives 1) to study and develop the measurement of behavioral inhibitory control of substance abusers 2) to develop the Stop Signal Substance Task (SSST), and 3) to develop an integrative cognitive neuropsychological program emphasizing brain response to enhance inhibitory control (ICNIC program). The research study consisted of 2 phases, including: Phase 1) the development of research instruments to measure the behavioral aspects of inhibitory control, and Phase 2) the development of ICNIC program for substance abusers. In Phase 1, the participants consisted of 300 male substance abusers receiving community therapy at Chonburi Central Prison, aged 18-60 years, selected by simple random sampling without replacement. Research instruments included the Behavioral Inhibitory Control Inventory: Substance Use (BICI – SU) and the Stop Signal Substance Task (SSST) for drug addicts developed by the researchers. Analysis of basic data and confirmatory factor analysis were performed. During Phase 2, the recruited participants consisted of 30 substance abusers at the alternative rehabilitation communities in Eastern Thailand, selected with cluster random sampling from two rehabilitation centers. They were randomly assigned into the experimental group and the control group. Each group consisted of 15 substance abusers. There were 3 research instruments, including BICI – SU, SSST and ICNIC program, designed and developed by researchers. The data collection was performed during the pre-test, post-test, and follow up period of 3 weeks. The experimental group received an ICNIC program. The control group received regular treatment from the alternative rehabilitation communities. Data analysis was performed with the repeated-measures analysis of variance: one between-subject variable and one within-subject variable. Pairwise mean comparisons were conducted using the Bonferroni method. The results in this research study demonstrated that 1. BICI – SU consisted of 45 items 2 components and 4 subcomponents. According to the confirmatory factor analysis, the measurement model of BICI-SU was fitted well with the observed empirical data with Chi-squared value of 1976.68, degrees of freedom (df) of 898, and root mean square error of approximation (RMSEA) of 0.0063, statistically significant at the level of .01. The normative scores of BICI – SU, ranging from 1.00 to 3.50, meaning the lowest of inhibitory control (IC); additionally, the normative scores of BICI – SU, ranging from 5.38 to 6.00, indicating the highest IC. Furthermore, it was found that the substance abusers exhibited the low levels of IC. The types of substance use and duration of substance abuse had a significant effects on IC and discipline subcomponent at the statistical level of .05. 2. Two types of stop signal substance Task (SSST) were implemented, including the visual SSST and the audio SSST. Each SSST consisted of 200 Go trials and 50 Stop trials (ratio 80:20). The reliability test was performed using the test-retest method. The coefficient of stability was at a moderate level. In addition, the results showed that substance abusers who had been using drug less than 2 years exhibited significantly more IC than those who had been using drugs for more than 10 years, at the statistical level of .05. 3. The ICNIC program based on concepts of neuroscience, cognitive psychology, and acceptance and commitment therapy (ACT), which was designed and developed by the researchers. The ICNIC program consisted of 12 sessions, with 50-minute duration per session, conducted for 3 weeks. The ICNIC contained the neuropsycho-educational phase (3 sessions), the cognitive and behavioral skills acquisitions and brain stimulation phase (6 sessions), and the application as well as follow-up phase (3 sessions). 4. The results indicated the effectiveness of the ICNIC program, measuring with the BICI – SU. The experimental group had significantly higher IC after the implementation of ICNIC program and the follow-up period than before the implementation of the program; additionally, the IC was markedly higher than the control group at the statistical level of .05. The control group had a significantly higher mean IC score during the follow-up period than during before and after the implementation of ICNIC program, at the statistically significant at the .05 level. There were no differences during after the ICNIC program and before the program. The effectiveness of the ICNIC program after measuring with the visual SSST was implicated that the experimental group had a significantly higher mean reaction time score than the control group, at the statistical level of .05. The experimental group had mean score of Visual SSST no difference. Furthermore, the effectiveness of ICNIC program after measuring with the audio SSST was demonstrated that the experimental group had a significantly higher reaction time than the control group at the statistical level of .05, both after the program and at the follow-up period. The experimental group showed no differences in mean scores in all variables. In addition, the substance abusers in the experimental group had changes in the latency and amplitude of the P3 waves in the brain areas Pz, C4, Fz, F3, and C3. The N2 waves in the brain areas F4 and Fp2 were different than those in the control group after the experiment, with statistically significant at the .05 level. The experimental group had changes in latency and amplitude of the P3 waves in the F4 and Fp2 areas of the brain and the experimental group were significantly greater than before the ICNIC program, statistically significant at the .05 level. The experimental group had higher latency and amplitude of the N2 waves after the program in the F3 and F4 areas of the brain with the statistical significance at the .05 level. In conclusion, the ICNIC program may increase IC among substance abusers in alternative rehabilitation communities.
