75 research outputs found

    Construct and Psychometric Properties of a New Version Quality of Life Scale Based on Choice Theory

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    BACKGROUND: Choice theory, as a psychopathological model, postulated five basics, genetically and universally, needs. Accordingly, the rate of everybody happiness and quality of life is depended on the number of his needs fulfilling. Although some scales have been constructed to assess basic needs, they have proposed unity of needs for all human. AIM: The present study was designed to construct a new scale, considering individualisation needs for each person; quality of life scale based on choice theory (QOLSCT). METHODS: Using cluster sampling, six hundred (49% female and 51% male) postgraduate students were selected. One hundred fifty participants also filled SF-36 and GHQ, and 80 participants refilled QOLSCT with four weeks’ interval again. RESULTS: Cronbach’s alpha, split-half and test re-test (one month) reliability scores were 0.78, 0.75, and 0.92 successively. The correlation between items and total scores range from 0.36 to 0.72, all with P values ≥ 0.0001. Confirmatory factor analysis showed satisfactory values of goodness-of-fit indices, RMSEA, CFI, NFI and GFI were, 0.05, 0.99, 0.99 and 0.99 respectively. Convergent and divergent validity also showed significant correlations. CONCLUSION: The result of the present study showed that the new version of quality of life scale based on choice theory could be confirmed. The good level of reliability, fairly goodness of fit indexes, and very good convergent validity support this idea

    Differential Contributions of Dopamine and Serotonin to Orbitofrontal Cortex Function in the Marmoset

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    We have shown previously that the inhibitory control functions of the orbitofrontal cortex (OFC) are disrupted by serotonin, but not dopamine depletions. However, both dopamine and serotonin terminals and receptors are present within the OFC and thus the aim of the present study was to determine the differential contributions of these neurotransmitters to orbitofrontal function. OFC and dopamine are involved in the process by which neutral stimuli take on reinforcing properties, by virtue of their prior association with reward, and guide behavior. Thus, we compared the performance of marmosets with dopaminergic or serotoninergic OFC depletions on a test of conditioned reinforcement. To further our understanding of serotonin in behavioral flexibility, the effect of these depletions was also compared on the extinction of a visual discrimination. Monkeys with serotonin depletions of the OFC displayed stimulus-bound responding on both tests of conditioned reinforcement and discrimination extinction suggesting that orbitofrontal serotonin plays a specific role in preventing competing, task irrelevant, salient stimuli from biasing responding. In contrast, monkeys with dopamine depletion were insensitive to conditioned reinforcers and displayed persistent responding in the absence of reward in extinction, a pattern of deficits that may reflect basic deficits in the associative processing of reward

    Quantitative analysis of performance on a progressive-ratio schedule: effects of reinforcer type, food deprivation and acute treatment with Δ⁹-tetrahydrocannabinol (THC)

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    Rats’ performance on a progressive-ratio schedule maintained by sucrose (0.6 M, 50 μl) and corn oil (100%, 25 μl) reinforcers was assessed using a model derived from Killeen’s (1994) theory of scheduled-controlled behaviour, ‘Mathematical Principles of Reinforcement’. When the rats were maintained at 80% of their free-feeding body weights, the parameter expressing incentive value, a, was greater for the corn oil than for the sucrose reinforcer; the response-time parameter, δ, did not differ between the reinforcer types, but a parameter derived from the linear waiting principle (Tₒ), indicated that the minimum post-reinforcement pause was longer for corn oil than for sucrose. When the rats were maintained under free-feeding conditions, a was reduced, indicating a reduction of incentive value, but δ was unaltered. Under the food-deprived condition, the CB1 cannabinoid receptor agonist Δ⁹-tetrahydrocannabinol (THC: 0.3, 1 and 3 mg kg-1) increased the value of sucrose; none of the other parameters was affected by THC. The results provide new information about the sensitivity of the model’s parameters to deprivation and reinforcer quality, and suggest that THC selectively enhances the incentive value of sucrose

    An investigation of the role of the orbital prefrontal cortex in impulsive choice behaviour

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    Comparison of Ccognitive Ffunctions of Ppatients with Ssubstance Ddependency and Nnormal Ppeople in WAIS Ssubscales

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    Abstract Background and aims: One of the most important sides affects effects of substance abuse and dependency is brain dysfunction, especially abnormality in cognitive activities. This study was established conducted to compare the functions of patients with substance dependency with normal populationpeople. Methods: In this study, 50 patients with substance dependency were selected, using easy sampling method and same amountnumber of people were selected as the control group, using neighborhood area sampling. The WAIS scale was used for assessingment the functions of both groups in cognitive activities. The data were analyzed, using SSPS SPSS statistical software, version 17. Results: In all of the WAIS subscales (only Digit span), functions of the patient group were significantly less than the normal group. The means and standard deviations of verbal, performance and total IQs in of the normal group were 39./38±7/56, 85./38±8./38, 83./18±9./51 respectively and 32./22±6./91, 76./54±6./91 and 75./66±7./6 in the patients group. Conclusion : The results showed that dependency to substance could affect the function of patients in cognitive performances. Key words: addiction, substance dependency, cognitive functions, WAI

    Effect of disconnecting the orbital prefrontal cortex from the nucleus accumbens core on inter-temporal choice behaviour: A quantitative analysis

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    Previous experiments showed that destruction of the orbital prefrontal cortex (OPFC) or the nucleus accumbens core (AcbC) in rats altered choice between two delayed food reinforcers. Application of a quantitative model of inter-temporal choice suggested that lesions of either structure increased the delay-dependent degradation of reinforcer value (delay discounting); destruction of the OPFC (but not the AcbC) also increased the relative value of the larger reinforcer. This experiment examined the effect of disconnecting the OPFC from the AcbC on inter-temporal choice. Rats received excitotoxin-induced contralateral lesions of the OPFC and AcbC (disconnection), severing of the anterior corpus callosum (callosotomy), a combined lesion (disconnection + callosotomy) or sham lesions. They were trained in a discrete-trials progressive delay schedule to press levers A and B for a sucrose solution. Responses on A delivered 50 μl of the solution after a delay dA; responses on B delivered 100 μl after a delay dB. dB increased across blocks of trials; dA was manipulated across phases of the experiment. Indifference delay, dB(50) (value of dB corresponding to 50% choice of B), was estimated for each rat in each phase, and linear indifference functions (dB(50)vs. dA) were derived. The disconnection + callosotomy group showed a lower intercept of the indifference function (implying a higher rate of delay discounting) than the sham-lesioned group; the disconnection group showed a similar but less robust effect, whereas the callosotomy group did not differ significantly from the sham-lesioned group. The results suggest that OPFC–AcbC connections are involved in delay discounting of food reinforcers, but provide no evidence for an involvement of OPFC–AcbC connections in regulating sensitivity to reinforcer size
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