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No / Dementia is one of the biggest fears in the process of ageing and the most common cause is Alzheimer’s Disease(AD). Topographic disorientation is an early manifestation of AD and threatens activities of their daily lives. Finding solutions are essential in the early diagnosis of dementia if medical treatment and healthcare services to be deployed in time. Recent studies have shown that people with mild cognitive impairment (MCI) may convert to Alzheimer’s disease (AD) over time although not all MCI cases progress to dementia. The diagnosis of MCI is important to allow prompt treatment and disease management before the neurons degenerate to a stage beyond repair. Hence, the ability to obtain a method of identifying MCI is of great importance. This work presents a virtual environment which can be utilized as a quick, easy and friendly tool for early diagnosis of dementia. This tool was developed with an aim to investigate cognitive functioning in a group of healthy elderly and those with MCI. It focuses on the task of following a route, since Topographical Disorientation (TD) is common in AD. The results shows that this novel simulation was able to predict with about 90% overall accuracy using weighting function proposed to discriminate between MCI and healthy elderly.

Background: Multiple Sclerosis (MS) is a chronic, degenerative, neurological condition affecting approximately 85,000 people in the UK. The impact of MS on physical abilities is well‐known and there is increasing recognition of the impact of MS on mood and cognitive function. Recently MS has been linked to impaired emotion recognition and impaired Theory of Mind (ToM –the ability to attribute mental states, e.g. beliefs to oneself and others). Methods: This study measured executive function, ToM, empathy and quality of life in an MS sample (n=42). A correlational analysis was then conducted to determine whether executive function was associated with the other variables. Results: Two executive function measures (Mental Flexibility and Response to Feedback) were significantly associated with two ToM tasks (Revised Eyes and Stories). Mental Flexibility and the Revised Eyes ToM task were significantly associated with measures of empathy, but this effect was not present in the other executive function or ToM tasks. Neither executive functioning nor ToM measures were significantly associated with reported quality of life. Conclusion: Overall, the MS sample demonstrated specific ToM impairment, no significant empathy impairment and widespread executive impairment relative to normative data. Low rates of depression (10%) and higher levels of anxiety (29%) were found. MS participants rated the psychological impact of MS as equivalent to the physical impact, highlighting the importance of addressing psychological aspects of MS.

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The purpose of this study was to investigate whether cannabis use can affect cognitive functions. The method that was chosen to answer the purpose of the study was a general literature review. Article search occurred in the databases PsycINFO and PubMed. Nine articles were selected based on the study’s inclusion criteria. These studies was then analysed to see that they matched the criterias that were selected in the study regarding study quality. The results show that cannabis use can affect cognitive functions. Though it is not certainly established that the use of cannabis always leads to a negative impact on cognitive functions, two of the nine included studies showed that this was not the case. It was possible to see that cannabis use can lead to a change in activity in regions of the brain that are associated with cognitive function. Seven out of nine studies showed that cannabis use leads to a negative impact on cognitive functions, particularly in the form of memory impairment.

The studies described in this thesis were undertaken to examine the factors affecting adolescents cognitive function across the school morning. Specifically, the effects of breakfast consumption, breakfast glycaemic index (GI) and a mid-morning bout of exercise were examined, whilst the final experimental chapter examined their combined effects. The battery of cognitive function tests used in the present study was administered via a laptop computer and took approximately 15 min to complete. Across all experimental chapters, the visual search test (assessing visual perception), the Stroop test (assessing attention) and the Sternberg paradigm (assessing working memory) were used. Furthermore, in chapter V the Flanker task (also assessing attention) was added to the testing battery. The first experimental study (chapter IV) examined the effects of consuming a self-selected breakfast on cognitive function, compared to breakfast omission. Ninety-six adolescents (12 to 15 years old) completed two experimental trials (breakfast consumption and breakfast omission), scheduled seven days apart, in a randomised crossover design. Following breakfast consumption, accuracy on the more complex level of the visual search test was higher than following breakfast omission (p = 0.021). Similarly, accuracy on the Stroop test was better maintained across the morning following breakfast consumption when compared with breakfast omission (p = 0.022). Furthermore, responses on the Sternberg paradigm were quicker later in the morning following breakfast consumption, on the more complex levels (p = 0.012). Breakfast consumption also produced higher self-report energy and fullness, lower self-report tiredness and hunger, and higher blood glucose concentrations, compared with breakfast omission (all p < 0.001). Overall, the findings suggested that breakfast consumption enhanced adolescents cognitive function, when compared with breakfast omission. The second experimental study (chapter V) examined the effects of consuming a high GI breakfast, a low GI breakfast and breakfast omission on cognitive function. Forty-one adolescents (12 to 14 years old) completed three experimental trials, each scheduled seven days apart, in a randomised crossover design. There was a greater improvement in response times across the morning following a low GI breakfast, compared to breakfast omission on the complex level of the Stroop test (p = 0.009) and both levels of the Flanker task (p = 0.041), and compared to following a high GI breakfast on the complex level of the visual search test (p = 0.025) and all levels of the Sternberg paradigm (p = 0.013). Furthermore, accuracy was enhanced following a low GI breakfast, compared to breakfast omission on the more complex levels of the visual search test (p = 0.032), Sternberg paradigm (p = 0.051) and Flanker task (p = 0.001), and compared to following a high GI breakfast on both levels of the Stroop test (p = 0.033) and the more complex levels of the Sternberg paradigm (p = 0.002) and Flanker task (p = 0.014). Furthermore, participants exhibited a lower glycaemic response following the low GI breakfast (p < 0.001), though there was no difference in the insulinaemic response (p = 0.063), compared to following the high GI breakfast. Overall, the findings suggest that a low GI breakfast is the most beneficial for adolescents cognitive function, compared with a high GI breakfast and breakfast omission. The third experimental study (chapter VI) examined the effects of a mid-morning bout of exercise, following a self-selected breakfast, on cognitive function. Forty-five adolescents (12 to 13 years old) completed two experimental trials (exercise and resting), scheduled seven days apart, in a randomised crossover design. There was a greater improvement in response times across the morning following the mid-morning bout of exercise on all levels of the Sternberg paradigm (p = 0.010). There was also a greater improvement in response times across the morning on the visual search test following the exercise (p = 0.009), but this improved speed was combined with a greater decrease in accuracy following the exercise (p = 0.044). This suggests that following exercise, the adolescents exhibited a speed-accuracy trade-off, whereby they responded quicker, but this was to the detriment of accuracy. Overall, the findings suggest that whilst the mid-morning bout of exercise improved some components of cognitive function (e.g. response times on the Sternberg paradigm), it did not affect other components (e.g. Stroop test performance). The final experimental study (chapter VII) examined the combined effects of breakfast GI and a mid-morning bout of exercise on adolescents cognitive function. Forty-two adolescents (11 to 13 years old) were allocated to matched high GI (n = 22) and low GI (n = 20) breakfast groups. Within the matched groups, participants completed two experimental trials (exercise and resting) in a randomised, crossover design. The findings indicate that, for the complex level of the Stroop test, following the high GI breakfast there was a greater improvement in response times across the morning on the resting trial, whereas following the low GI breakfast response times improved across the morning on both the exercise and resting trials, though the magnitude of the improvement was greatest on the exercise trial (p = 0.012). On the Sternberg paradigm, response times improved across the morning following the low GI breakfast regardless of exercise, whereas following the high GI breakfast response times improved across the morning on the exercise trial, though remained similar across the morning on the resting trial (p = 0.019). Overall, the findings suggest that the effects of the mid-morning bout of exercise were dependent upon the breakfast GI and the component of cognitive function being examined and that, for the Stroop test, the beneficial effects of the low GI breakfast and mid-morning bout of exercise were additive. Overall, the results from this thesis suggest that breakfast consumption is more beneficial than breakfast omission and more specifically, that a low GI breakfast is more beneficial than both a high GI breakfast and breakfast omission, for adolescents cognitive function across the school morning. However, the effects of exercise appear to be more variable, with the effect of exercise depending upon the component of cognitive function examined and the GI of the breakfast consumed. Overall, the findings presented in this thesis suggest that the nutritional effects on adolescents cognitive function (i.e. the effects of breakfast consumption and GI) were stronger and more consistent than the exercise induced effects.

Background: Despite substantial research and development investment in Alzheimer's disease (AD), effective therapeutics remain elusive. Significant emerging evidence has linked cholesterol, beta-amyloid and AD, and several studies have shown a reduced risk for AD and dementia in populations treated with statins. However, while some clinical trials evaluating statins in general AD populations have been conducted, these resulted in no significant therapeutic benefit. By focusing on subgroups of the AD population, it may be possible to detect endotypes responsive to statin therapy. Methods: Here we investigate the possible protective and therapeutic effect of statins in AD through the analysis of datasets of integrated clinical trials, and prospective observational studies. Results: Re-analysis of AD patient-level data from failed clinical trials suggested by trend that use of simvastatin may slow the progression of cognitive decline, and to a greater extent in ApoE4 homozygotes. Evaluation of continual long-term use of various statins, in participants from multiple studies at baseline, revealed better cognitive performance in statin users. These findings were supported in an additional, observational cohort where the incidence of AD was significantly lower in statin users, and ApoE4/ApoE4-genotyped AD patients treated with statins showed better cognitive function over the course of 10-year follow-up. Conclusions: These results indicate that the use of statins may benefit all AD patients with potentially greater therapeutic efficacy in those homozygous for ApoE4.

Twenty-four psychiatric staff, 24 clinically depressed inpatients, and 24 nondepresssed schizophrenic patients at a state psychiatric facility completed five tasks under either reward or punishment conditions. Each task consisted of 30 trials of pressing or not pressing a button to make a light appear. Monetary reinforcement was contingent on light onset for the final ten trials of each task. Cash incentives for judgment of control accuracy were added for Tasks 3, 4, and 5. Cognitive functioning was evaluated on each task by measuring expectancy, judgment of control, evaluation of performance, and attribution. Mood and self- esteem were measured before and after the procedure. No significant differences were observed across mood groups for expectancy of control or judgment of control accuracy. Subject groups also did not differ in the attributions they made or in how successful they judged their performances to be. They set realistic, attainable criteria for success which were consistent with relevant conditional probabilities. Subjects in reward gave themselves more credit for task performance than subjects in punishment gave themselves blame for comparable performances. Punishment subjects demonstrated more stable, external attributions than those in reward. Across tasks, subjects overestimated when actual control was low and underestimated when actual control was high. Contrary to the "depressive realism" effect described by Alloy and Abramson (1979), clinical depressives did not display more accurate judgments of control than did nondepressives. All subjects appeared to base their control estimates on reinforcement frequency rather than actual control. Subjects showed a type of illusion of control for high frequency, low control tasks. Presumably, success in turning the light on led them to assume that their actions controlled light onset. Comparison to previous subclinical studies suggests a possible curvilinear relationship between judgment of control accuracy and level of psychopathology, with mild depressives displaying relatively greater accuracy than either nondepressives or clinical depressives.

Thesis advisor: Barbara E. Wolfe / Postoperative cognitive dysfunction (POCD) is characterized by a decline in cognitive performance following anesthesia and surgery and is a major cause of morbidity and mortality in the postoperative period. Moreover, studies suggest that patients who develop POCD may be at higher risk for cognitive decline later in life. POCD is of critical importance in relation to independent living, need for care, personal and economic cost, and quality of life. The majority of studies to date examine risk factors, prevalence, and complications associated with POCD. There is a lack of effective intervention strategies being developed to promote improved cognitive processing in this patient population. The primary aim of this study was to examine the feasibility and acceptability of a cognitive training intervention (CTI) for postoperative cardiac surgical patient. Feasibility was examined by conducting an attrition analysis to compare percent of attrition between intervention and control groups. A chi-square was conducted to answer the research question examining the difference between groups on attrition from study. Acceptability was examined by the administration of a "feasibility and acceptability" questionnaire, which was a 15-item questionnaire specific to the intervention. Fifteen one-sample t tests were used to determine acceptability of the intervention in the treatment population. The secondary purpose of the study was to investigate the preliminary effect of the CTI on cognitive outcomes following cardiac surgery. A randomized controlled, single-blind, repeated measures design was used to test the hypothesis that following cardiac surgery, patients who receive a 6-week CTI when compared with those who receive usual care will demonstrate a significantly greater improvement in cognitive status when comparing discharge scores to scores at 6 weeks and 3 months postoperatively. Collection of data from 53 patients who underwent cardiac surgery was conducted from May 2008 to January 2010 at Catholic Medical Center in Manchester, NH. Factorial Analyses of Variance were conducted to answer the research question assessing the effectiveness of a cognitive training intervention (CTI) on cognitive outcomes following cardiac surgery. However given assumptions of ANOVA were violated and non parametric statistics including two Kruskall Wallis H tests for independent samples at each assessment period as well as two Wilcoxon's signed ranks tests for related samples for each group were conducted. The results of the chi-square were not significant, x2(1) = 0.95, p = .329, suggesting no relationship exists between withdrawn participants and group. After Bonferroni adjustment the results of the fifteen one-sample t tests on the feasibility questionnaire (Q1-Q15) for the intervention group reveal questions 2-8, 10, 14 and 15 have a larger mean compared to the neutral median value of 3.0, suggesting that participants tended toward a high level of acceptability over neutrality. Wilcoxon signed rank test on TICS scores by control group and time period (posttest vs. six week follow up and posttest vs. three month follow up) revealed a significant main effect by time period, p< .01 at both time periods. Wilcoxon signed rank test on TICS scores by experimental group and time period (posttest vs. six week follow up and posttest vs. three month follow up) revealed a significant main effect by time period, p< .01 at both time periods. Kruskall Wallis test at six week follow up and three month follow up by group (control vs. experimental) was not significant, x2 (1) = 0.01, p = .934, and x2 (1) = 0.02, p = .891 respectively suggesting no statistical difference at six week follow up by group. The Wilcoxon signed rank on TICS by group and time period (six week follow up vs. 3 month follow up) was not significant (p=.274) and the Kruskall Wallis test at three month follow up by group (control vs. experimental) was not significant, x2 (1) = 0.02, p = .891, suggesting no statistical difference at three month follow up by group. The results of this study suggest that a CTI is feasible to conduct and acceptable to patients following cardiac surgery. Results of the preliminary effect of the CTI suggest that cognitive performance improves over a six-week period following cardiac surgery independent of the CTI and there are no significant changes from the six-week to the three-month period. Preliminary findings yield further inquiry into cognitive enhancing interventions in the cardiac surgical patient. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Connell School of Nursing. / Discipline: Nursing.