Using clustering algorithms to examine the association between working memory training trajectories and therapeutic outcomes among psychiatric and healthy populations.

Working memory (WM) training has gained interest due to its potential to enhance cognitive functioning and reduce symptoms of mental disorders. Nevertheless, inconsistent results suggest that individual differences may have an impact on training efficacy. This study examined whether individual differences in training performance can predict therapeutic outcomes of WM training, measured as changes in anxiety and depression symptoms in sub-clinical and healthy populations. The study also investigated the association between cognitive abilities at baseline and different training improvement trajectories. Ninety-six participants (50 females, mean age = 27.67, SD = 8.84) were trained using the same WM training task (duration ranged between 7 to 15 sessions). An algorithm was then used to cluster them based on their learning trajectories. We found three main WM training trajectories, which in turn were related to changes in anxiety symptoms following the training. Additionally, executive function abilities at baseline predicted training trajectories. These findings highlight the potential for using clustering algorithms to reveal the benefits of cognitive training to alleviate maladaptive psychological symptoms.

Abnormalities in emotional and motor reactions among young prehypertensive individuals: employing continuous blood pressure analysis.

BACKGROUND: Essential hypertension is an important risk factor for cerebrovascular diseases and a major cause of premature death in industrialized societies. A predisposing factor for essential hypertension is prehypertension: blood pressure (BP) values at rest that are at the higher end of the normal range. Abnormally enhanced cardiovascular responses to motor and emotional tasks have been found as predictors of essential hypertension. Yet, knowledge regarding the BP reaction to aversive stimuli and motor reaction in prehypertension is limited. METHODS: We compared the reaction to aversive and neutral stimuli inducing an emotional response (experiment 1) and to the isometric handgrip exercise (IHE) inducing a motor response (experiment 2), between prehypertensive and normotensive controls. BP reactions were measured and analyzed in a continuous fashion, in contrast to previous studies that averaged BP responses across blocks. We applied a multilevel B-spline model, a continuous analysis that enabled a better understanding of the BP time course and the detection of subtle differences between groups. RESULTS: In both tasks, we found that prehypertensive individuals showed enhanced DBP reactions compared with normotensive controls; prehypertensive individuals exhibited lower BP responses to aversive pictures and higher BP responses to the IHE. These results are in line with previous studies with healthy or hypertensive participants and suggest abnormalities already in the prehypertensive stage. CONCLUSION: Considering the high frequency and health risks related to prehypertension, understanding the autonomic reactions to emotional and motor stimuli in this population is of clinical and theoretical importance and could serve as a behavioural marker to identify at-risk groups.

Blood pressure reaction to negative stimuli: Insights from continuous recording and analysis.

Individuals with a tendency toward abnormally enhanced cardiovascular responses to stress are at greater risk of developing essential hypertension later in life. Accurate profiling of continuous blood pressure (BP) reactions in healthy populations is crucial for understanding normal and abnormal emotional reaction patterns. To this end, we examined the continuous time course of BP reactions to aversive pictures among healthy participants. In two experiments, we showed participants negative and neutral pictures while simultaneously measuring their continuous BP and heart rate (HR) reactions. In this study, BP reactions were analyzed continuously, in contrast to previous studies, in which BP responses were averaged across blocks. To compare time points along a temporal continuum, we applied a multi-level B-spline model, which is innovative in the context of BP analysis. Additionally, HR was similarly analyzed in order to examine its correlation with BP. Both experiments revealed a similar pattern of BP reactivity and association with HR. In line with previous studies, a decline in BP and HR levels was found in response to negative pictures compared to neutral pictures. In addition, in both conditions, we found an unexpected elevation of BP toward the end of the stimuli exposure period. These findings may be explained by the recruitment of attention resources in the presence of negative stimuli, which is alleviated toward the end of the stimulation. This study highlights the importance of continuous measurement and analysis for characterizing the time course of BP reactivity to emotional stimuli.

Effects of Partial Sleep Deprivation on Information Processing Speed in Adolescence.

OBJECTIVES: Although chronic sleep loss is highly common among teens, few objective sleep studies have examined its effects on cognitive performance, and specifically on information processing speed (IPS), a measure of cognitive proficiency. METHODS: Forty-five adolescents underwent four consecutive nights of monitored sleep restriction (6-6.5 hr/night) and four nights of sleep extension (10-10.5 hr/night), in counterbalanced order, and separated by a washout period. Following each sleep period, cognitive performance was assessed, at a fixed morning time, using a computerized neuropsychological battery including an IPS task, a timed test providing both accuracy and reaction time outcome measures. RESULTS: Overall IPS performance was poorer in the restricted when compared to the extended condition. Increasing task load and pace were associated with increased accuracy for both sleep conditions. However, a significant pace by load interaction effect was only found in the extended condition, with post hoc tests showing that for medium and hard loads, IPS accuracies were better with increasing pace of task. Differences in IPS reaction times were not found between the sleep conditions. In addition, sleep-related changes in IPS indices were correlated with changes in executive function, motor skill, and attention performance. CONCLUSIONS: Adolescents' ability to process information may be especially vulnerable to sleep loss. Under ideal sleep conditions, however, they seem to be able to achieve optimal performance, particularly on more challenging problems. The functional implications of these findings may be particularly relevant to teens, who are often sleep deprived and are constantly required to process academic, social, and emotional input.