Impacto de las alteraciones neuropsicológicas sobre aspectos clínicos en tabaquismo / Impact of neuropsychological disorders on clinical aspects of smoking

Los estudios que examinan las asociaciones entre las medidas cognitivas y los aspectos clínicos del tabaquismo son limitados y, en general,se limitan a predecir perfiles de riesgo o recaídas. Sin embargo, esesencial comprender la influencia de varias medidas de la funciónejecutiva en la adicción a la nicotina a fin indagar factores asociadosal mantenimiento del tabaquismo. En el presente estudio se examinóla capacidad de la memoria de trabajo y el descuento por retraso parapredecir los años de tabaquismo. La muestra consistió en 180 fumadores que fueron evaluados en la línea de base con medidas de impulsividad cognitiva (Tarea de Descuento de Retraso) y memoria de trabajo[Prueba de Búsqueda y Atención Visual (VSAT) y Secuenciación deNúmeros de Letras (WAIS III)] mientras que la medida de resultadofue los años de adicción. De acuerdo con las predicciones, la memoriade trabajo evaluada con la Prueba de Búsqueda y Atención Visual fueun factor estadísticamente significativo para predecir los años de adicción a la nicotina. Estos hallazgos sugieren que la memoria de trabajoes clínicamente relevante en la dependencia de la nicotina y planteaun patrón de funcionamiento ejecutivo asociado al tabaquismo. (AU)

Studies examining associations between cognitive measures and clinical aspects of smoking are scarce and generally limited to predictingrisk profiles or relapses. However, it is essential to understand the influence of several measures of executive function in nicotine addiction in order to investigate factors associated with smoking maintenance. This study examined the ability of working memory and delaydiscount to predict years of smoking. The sample consisted of 180smokers who were assessed at baseline with measures of cognitiveimpulsivity (Delay Discounting Task) and working memory [VisualSearch and Attention Test (VSAT) and Letter-Number Sequencing(WAIS III)] while the outcome measure was years of smoking. Consistent with predictions, working memory evaluated with Visual Searchand Attention Test was a statistically significant factor in predictingyears of nicotine addiction. These findings suggest that working memory is clinically relevant in nicotine dependence and proposes a pattern of executive functioning associated with smoking. (AU)

Neural correlates of delay discount alterations in addiction and psychiatric disorders: A systematic review of magnetic resonance imaging studies.

Delay discounting (DD) represents decreased subjective value for delayed reward relative to the same reward at present. The concept of DD has been applied for pathophysiology of addiction and psychiatric disorders. However, the detailed neuroimaging correlates of DD underlying pathophysiology still remain unclear. Thus, we conducted a systematic review to investigate neural correlates of DD on magnetic resonance imaging studies among addiction and psychiatric disorders. Specific search terms were set on PubMed to identify relevant articles. Initial search identified 551 records and 31 studies met the inclusion criteria. The present review revealed that greater DD was correlated with increased activity in areas related to reward evaluation and prediction as well as decreased activity in areas related to cognitive control. Healthy controls showed smaller changes in activities of these areas associated with DD when compared to patient groups. As the neural basis related to DD, three neural networks have been proposed that are associated with the actions of short-term interests and long-term benefits. Among the three potential neural networks on DD, the first one included the ventromedial prefrontal cortex and ventral striatum and implicated in evaluating reward values, the second network included the anterior cingulate cortex and linked to cognitive control, and the third network included the middle temporal gyrus and was involved in predictions and affection. This review generated consistent findings on the neural basis of DD among patients with addiction and psychiatric disorders, which may represent the pathophysiology related to DD and impulsivity of mental illness.

The study of intertemporal decision-making of mild cognitive impairment patients / 中华行为医学与脑科学杂志

Objective To explore whether the ability of intertemporal choice is impaired in patients with mild cognitive impairment. Methods Twenty-seven patients with mild cognitive impairment and thirty-five healthy controls were recruited in this study. All subjects completed the " delay-discounting" task and the delayed discount rate (K value) was used to evaluate the patients' decision-making ability. Results (1) The delay discount rate(median=0. 0256,P25=0. 016,P75=0. 100) in mild cognitive impairment patients was higher than that of healthy cotrols(median =0. 006,P25=0. 0025,P75=0. 016). There was significant difference in K-value between the two groups ( Z=-2. 988,P<0. 01). ( 2) Spearman correlation analysis showed that the significant negatively correlation between K-value and digital span forward test (r=-0. 389, P=0. 045) in mild cognitive impairment group. Conclusion The ability of intertemporal choices is impaired in patients with mild cognitive impairment and negatively correlated with attention function.

The study of intertemporal decision-making of schizophrenia and their unaffected siblings / 中国神经精神疾病杂志

Objective To explore whether the ability of intertemporal choice is impaired in schizophrenic patients and in their unaffected siblings.Methods Twenty-five schizophrenia patients,twenty-five unaffected siblings of patients and thirty healthy controls were recruited in the study."Delay-discounting" task and a battery of cognitive neuropsychological assessment were used to examine the intertemporal decision-making.Results (1) the value of k was ((0.005±0.009 in schizophrenia,0.011±0.014 in unaffected siblings and 0.024±0.029 in healthy controls,respectively.There was significant difference in k value among these three groups (F=9.487,P＜0.001).There were significant differences in k value between patients group and healthy controls,and between unaffected siblings and healthy controls (P＜0.05).There was no significant difference between schizophrenia and their unaffected siblings (P＜0.05).(2) Pearson correlation analysis not showed any relationship between neuropsychological test and the value of k.Conclusion The ability of intertemporal choices is impaired in schizophrenia and their unaffected siblings to a great degree.

The study of intertemporal decision-making of schizophrenia and their unaffected siblings / 中国神经精神疾病杂志

Objective To explore whether the ability of intertemporal choice is impaired in schizophrenic patients and in their unaffected siblings.Methods Twenty-five schizophrenia patients,twenty-five unaffected siblings of patients and thirty healthy controls were recruited in the study."Delay-discounting" task and a battery of cognitive neuropsychological assessment were used to examine the intertemporal decision-making.Results (1) the value of k was ((0.005±0.009 in schizophrenia,0.011±0.014 in unaffected siblings and 0.024±0.029 in healthy controls,respectively.There was significant difference in k value among these three groups (F=9.487,P＜0.001).There were significant differences in k value between patients group and healthy controls,and between unaffected siblings and healthy controls (P＜0.05).There was no significant difference between schizophrenia and their unaffected siblings (P＜0.05).(2) Pearson correlation analysis not showed any relationship between neuropsychological test and the value of k.Conclusion The ability of intertemporal choices is impaired in schizophrenia and their unaffected siblings to a great degree.

Immediate return preference emerged from a synaptic learning rule for return maximization.

Animals including human often prefer immediate returns to larger delayed returns. It holds true in the human communications. Standard interpretation of the immediate return preference is that an animal might subjectively discount the value of a delayed reward, and that might choose the larger valued one. The interpretation has been successfully applied to explain behavior of many species including human. However, the description is not necessarily sufficient to apply for interactions of individuals. This study adopts a different approach to seek a possibility that immediate return preference may be reproduced by learning rule to maximize objective outcomes. We show that a synaptic learning rule to achieve the temporal difference (TD) learning for outcome maximization fails the maximization and exhibits immediate return preference if the context is not properly represented as a internal state.