Poststroke Fatigue and Daily Activity Patterns During Outpatient Rehabilitation:An Experience Sampling Method Study

OBJECTIVE: To advance our understanding of poststroke fatigue by investigating its momentary and time-lagged relationship with daily activities.DESIGN: Longitudinal observational study using the experience sampling method (ESM).SETTING: Outpatient rehabilitation care.PARTICIPANTS: Thirty individuals with stroke (N=30).INTERVENTIONS: Not applicable.MAIN OUTCOME MEASURES: ESM is a structured diary method that allows assessing real-time symptoms, behavior, and environment characteristics in the flow of daily life, thereby capturing moment-to-moment variations in fatigue and related factors. Using a mobile application, individuals with stroke were followed during 6 consecutive days, and were prompted at 10 random moments daily to fill in a digital questionnaire about their momentary fatigue and current activity: type of activity, perceived effort and enjoyment, and physical activity levels.RESULTS: Based on all completed digital questionnaires (N=1013), multilevel regression analyses showed that fatigue was significantly associated with type of activity and that fatigue was higher when participants had engaged in physical activity. Fatigue was also higher during activities perceived as more effortful and during less enjoyable activities. Time-lagged analyses showed that fatigue was also predicted by physical activity and perceived effort earlier during the day. Importantly, the relationship between these daily activity characteristics and fatigue differed substantially across individuals.CONCLUSIONS: This study illustrates the need for ESM to design personalized rehabilitation programs and to capture fatigue and other patient-reported outcomes in daily life.</p

Generalization in psychopathology: The role of memory

Generalization on the basis of prior experience is a central feature of human and non-human behavior. Generalization occurs when a stimulus elicits a change in behavior due to prior experience of a regularity in the environment that did not involve that stimulus. Although adaptive in general, anomalies in generalization can give rise to a wide array of problems. For instance, elevated levels of generalization have been shown in individuals suffering from an anxiety disorder. In the first part of this dissertation, generalization is approached from a memory perspective. After a general introduction describing how different cognitive processes such as attention and memory may influence generalization (Chapter 1), we report on a study investigating generalization in relation to working memory (Chapter 2). In a community sample, we found that the extent of generalization was a function of individual differences in the capacity to filter out irrelevant information from access to working memory. In Chapter 3, generalization is investigated in relation to autobiographical memory specificity, referring to memory for personally experienced events. In a sample of individuals suffering from an anxiety disorder, we found that individuals who had difficulty reporting specific memories of personally experienced events showed impaired discrimination learning in a predictive learning task. No differences in generalization were found. Further, we used an experimental approach to memory and manipulated the retention interval between the encoding of a learning experience and the test of generalization in a face recognition paradigm (Chapter 4), and a fear generalization paradigm (Chapter 5). We did not find convincing evidence for changes in generalization over time in either of these studies. In the second part of this dissertation, we report on longitudinal studies that focus on the identification of premorbid markers of (risk for) psychopathology. In Chapter 6, we investigated the exact nature of the relationship between discrimination learning, generalization and anxiety symptomatology. Although both impaired discrimination learning and elevated levels of generalization have previously been shown in individuals suffering from clinical or subclinical anxiety, it remains largely unclear whether these learning abnormalities represent antecedents or consequences of pathological anxiety (vulnerability factors or diagnostic markers, respectively). In a six month longitudinal study, we found that impaired discrimination learning and elevated generalization predicted higher levels of self-reported anxiety at follow-up. The final study of this dissertation (Chapter 7) deals neither with generalization, nor with memory, but nevertheless fits nicely within our efforts to identify individuals at risk for psychopathology. More precisely, we report on a questionnaire on attentional control that we helped to develop, and discuss its capacity to predict changes in diurnal cortisol values after exposure to a prolonged psychosocial stressor. Disturbances in diurnal cortisol secretion in response to psychosocial stressors have been implicated in – and proposed as a risk factor for – several psychological disorders, including major depressive disorder, and anxiety disorders. We found that individuals who reported low attentional control in the presence of emotion at Time 1 exhibited elevated cortisol responding at Time 2, following academic examination. Finally, we end this dissertation with a general discussion of our findings, and discuss several research topics in a series of freestanding commentaries (Chapter 8).status: publishe

Fear generalization predicts post-traumatic stress symptoms:A two-year follow-up study in Dutch fire fighters

IntroductionExcessive fear generalization has been associated with pathological anxiety, including posttraumatic stress disorder (PTSD). However, studies investigating the longitudinal relationship between generalization and the development of anxiety symptomatology are scarce. This study aims to test the predictive value of fear generalization for PTSD symptoms in a high-risk profession sample and to explore the relationship between generalization and neuroticism, which are both linked to PTSD.MethodLongitudinal data from a multi-wave study in 529 Dutch fire-fighters were used. Fear generalization, PTSD symptoms and neuroticism were assessed at baseline. PTSD symptoms were reevaluated at six, 12, 18, and 24 months. Generalization was assessed in a differential conditioning paradigm by measuring expectancies of an aversive outcome when presented with stimuli similar to previously conditioned stimuli.ResultsHigher expectancy ratings towards stimuli most similar to safety signals predicted PTSD symptoms at follow-up after controlling for baseline PTSD symptoms, whereas higher expectancy ratings towards stimuli most similar to danger signals was associated with neuroticism. Neuroticism weakened the predictive power of fear generalization when considered simultaneously.DiscussionThese findings suggest that heightened fear generalization is associated with the development of anxiety and trauma-related symptoms. Targeting problematic fear generalization may be a promising intervention approach

Tired of pain or painfully tired? A reciprocal relationship between chronic pain and fatigue

status: publishe

Generalization of conditioned responding: effects of (autobiographical) memory specificity

status: publishe

Learning to feel tired: A learning trajectory towards chronic fatigue

Chronic fatigue complaints are frequently reported in the general population and fatigue ranks among the most commonly reported symptoms in chronic disease. In contrast to its high prevalence and impact on quality of life, relatively little is understood about the etiology of chronic fatigue. We present a cognitive-behavioral framework, the ‘ALT+F’ model, that conceptualizes fatigue from an associative learning perspective, and we will evaluate the current evidence for this position. Central to this framework is the notion that interoceptive and exteroceptive stimuli can become associated with the fatigue experience. Consequently, these stimuli may acquire the capacity to elicit fatigue as well as anticipatory fear-related avoidance behavior. We will argue that associative learning processes may contribute to the development of chronic fatigue, fear of fatigue, avoidance of fatigue and activity, and eventually, functional disability. The extent to which associative learning processes give rise to chronic fatigue and fear-related avoidance behavior may depend on a number of risk factors, including perceptual-cognitive biases, sensitization, fatigue catastrophizing, and excessive generalization. The presented framework offers a new window on treatment and intervention options for chronic fatigue.status: publishe

The influence of nocebo information on fatigue and urge to stop:An experimental investigation

Background and objectives: Fatigue is an adaptive state after prolonged effort and often goes hand in hand with changes in behavior and motivation, such as the urge to stop exerting further effort. However, fatigue may become chronic in nature, as seen in multiple psychiatric disorders and chronic diseases, thereby losing its adaptive function. The etiology of fatigue symptoms remains poorly understood. We aimed to investigate whether nocebo information about the fatigue inducing nature of a cognitive task may contribute to the experience of fatigue and the motivational urge to stop. Methods: Participants (N = 46) repeatedly rated currently experienced fatigue while engaging in cognitive effort (working memory task). Crucially, half of participants received nocebo instructions prior to this task, whereas the other half only received neutral information. Results: Over the entire sample, results showed an increase in fatigue and urge to stop as the task progressed. Crucially, participants in the nocebo condition reported a higher urge to stop throughout the task relative to participants in the neutral condition. No significant effects were found for fatigue. Interestingly however, after controlling for baseline differences between conditions in negative affect, there was a significant Condition*Task block interaction effect on fatigue. Limitations: Limitations include the relatively short experimental protocol and the underrepresentation of male relative to female participants. Conclusions: These findings suggest that heightened awareness among clinicians and therapists about potential nocebo effects in their communication is warranted