instruction:
In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
question:
Context: Poor decision-making is a hallmark of addiction, whether to substances or activities. Performance on a widely used test of decision-making, the Iowa Gambling Task (IGT), can discriminate controls from persons with ventral medial frontal lesions, substance-dependence, and pathological gambling. Positron emission tomography (PET) studies indicate that substance-dependent individuals show altered prefrontal activity on the task. Here we adapted the IGT to an fMRI setting to test the hypothesis that defects in ventral medial and prefrontal processing are associated with impaired decisions that involve risk but may differ depending on whether substance dependence is comorbid with gambling problems.', '18 controls, 14 substance-dependent individuals (SD), and 16 SD with gambling problems (SDPG) underwent fMRI while performing a modified version of the IGT.', 'Group differences were observed in ventral medial frontal, right frontopolar, and superior frontal cortex during decision-making. Controls showed the greatest activity, followed by SDPG, followed by SD.\Question: Is prefrontal cortex activity reduced in gambling and nongambling substance users during decision-making?
answer:
Our results support a hypothesis that defects in ventral medial frontal processing lead to impaired decisions that involve risk. Reductions in right prefrontal activity during decision-making appear to be modulated by the presence of gambling problems and may reflect impaired working memory, stimulus reward valuation, or cue reactivity in substance-dependent individuals.


question:
Context: The measurement of affective symptoms in older persons who decline cognitively is uncertain. The authors investigated whether mood variability predicts dementia in patients with age-related macular degeneration (AMD).', 'Three-year observational study after a clinical trial.', 'Community follow-up of outpatients ascertained from retina clinics.', 'One hundred sixty patients with AMD.', "Geriatric Depression Scale (GDS) administered every 2 weeks for 6 months to subjects; Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) administered to subjects' knowledgeable informants.", 'Twenty-three subjects (14.4%) declined cognitively. Age, education, baseline GDS score > or =5, and variability in GDS scores (i.e., fluctuations between adjacent time points) were associated with cognitive decline. For GDS variability, each 1 unit increase in the residual standard deviation (SD) of the GDS increased the risk for cognitive decline by 93% (IDR = 1.92; 95% CI [1.27-2.91]). Thus, subjects with a residual SD of 1 were nearly twice as likely to become demented as subjects with no variability in GDS scores. The risk for subjects with SDs of 2 increased more than threefold (IDR = 3.68; 95% CI [1.61-8.47]). A multiple regression analysis showed that GDS variability was a significant risk factor for dementia after controlling for significant covariates.\Question: Does variability in depressive symptoms predict cognitive decline in age-related macular degeneration?
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These data suggest a useful approach to conceptualizing and measuring depressive symptoms in older persons. Variability in self-reported mood may be an early sign of dementia and may offer new insights into the neurobiological mechanisms linking depression and cognition


question:
Context: The number of positive axillary lymph nodes predicts prognosis and is often important in determining adjuvant chemotherapy in breast cancer patients. This study was undertaken to determine if differences in the extent of axillary node dissection would alter the number of reported positive nodes.', "The study population consisted of 302 patients with invasive breast cancer who underwent complete (level I/II/III) axillary lymph node dissection. Assuming that all patients had undergone a level I/II dissection, it was determined how frequently a patient's nodal category (0, 1-3, 4-9, >10 positive nodes) would have been altered if a level I or level I/II/III dissection were performed.", 'Assuming that all 302 patients had undergone a level I/II dissection, performing only level I dissection would have resulted in a change in nodal category in 15.9% of all patients and 36.1% of patients with positive nodes. The corresponding changes for a level I/II/III dissection would have been 4.3% and 9.5%, respectively.\Question: Does variation in axillary node dissection influence the degree of nodal involvement in breast cancer patients?
answer:

Variations in the level of axillary node dissection for breast cancer can result in significant changes in the number of positive axillary nodes. This can potentially bias adjuvant chemotherapy recommendations if treatment decisions are based on this prognostic factor.