The forced swim test (FST) for rodents does not model despair or helplessness. It also is not a read-out for depression, anxiety, psychomotor retardation or autism, because these are... Show moreThe forced swim test (FST) for rodents does not model despair or helplessness. It also is not a read-out for depression, anxiety, psychomotor retardation or autism, because these are anthropomorphic interpretations of the rodent's acquired immobility. Rather, the transition from swimming to immobility allows to examine the mechanistic underpinning of coping with inescapable stressors. However, in a recent detailed analysis of the FST application over the past 40 years, we noted a dramatic surge in the use of this test to phenotype animals as 'depressed'. As a follow up to that report, we now present an analysis of the use of the FST over the past three years. This literature analysis shows that the popularity of the EST is still increasing and that the majority of researchers qualifies the rodent's floating response as depressive-like behavior. However, over the past few years we also note a trend to interpret immobility rather as the expression of a coping strategy. In view of this result, we have sent a poll to the relevant authors to learn how consistent they are in naming FST behavior. Remarkably, we find a dramatic inverse correlation between their first qualification of acquired immobility as depressive-like behavior towards their current interpretation as coping strategy. In this contribution we have embedded our literature analysis and poll results in an update on the management of coping with inescapable stressors by processing in prefrontal cortical circuitry and glucocorticoid feedback. Show less
The forced swim test (FST) for rodents does not model despair or helplessness. It also is not a read-out for depression, anxiety, psychomotor retardation or autism, because these are... Show moreThe forced swim test (FST) for rodents does not model despair or helplessness. It also is not a read-out for depression, anxiety, psychomotor retardation or autism, because these are anthropomorphic interpretations of the rodent’s acquired immobility. Rather, the transition from swimming to immobility allows to examine the mechanistic underpinning of coping with inescapable stressors. However, in a recent detailed analysis of the FST application over the past 40 years, we noted a dramatic surge in the use of this test to phenotype animals as ‘depressed’. As a follow up to that report, we now present an analysis of the use of the FST over the past three years. This literature analysis shows that the popularity of the FST is still increasing and that the majority of researchers qualifies the rodent’s floating response as depressive-like behavior. However, over the past few years we also note a trend to interpret immobility rather as the expression of a coping strategy. In view of this result, we have sent a poll to the relevant authors to learn how consistent they are in naming FST behavior. Remarkably, we find a dramatic inverse correlation between their first qualification of acquired immobility as depressive-like behavior towards their current interpretation as coping strategy. In this contribution we have embedded our literature analysis and poll results in an update on the management of coping with inescapable stressors by processing in prefrontal cortical circuitry and glucocorticoid feedback. Show less
AbstractBackgroundNeuroimaging studies have demonstrated gray matter (GM) volume abnormalities in substance users. While the majority of substance users are polysubstance users, very little is... Show moreAbstractBackgroundNeuroimaging studies have demonstrated gray matter (GM) volume abnormalities in substance users. While the majority of substance users are polysubstance users, very little is known about the relation between GM volume abnormalities and polysubstance use.MethodsIn this study we assessed the relation between GM volume, and the use of alcohol, tobacco, cocaine and cannabis as well as the total number of substances used, in a sample of 169 males: 15 non-substance users, 89 moderate drinkers, 27 moderate drinkers who also smoke tobacco, 13 moderate drinkers who also smoke tobacco and use cocaine, 10 heavy drinkers who smoke tobacco and use cocaine and 15 heavy drinkers who smoke tobacco, cannabis and use cocaine.ResultsRegression analyses showed that there was a negative relation between the number of substances used and volume of the dorsal medial prefrontal cortex (mPFC) and the ventral mPFC. Without controlling for the use of other substances, the volume of the dorsal mPFC was negatively associated with the use of alcohol, tobacco, and cocaine. After controlling for the use of other substances, a negative relation was found between tobacco and cocaine and volume of the thalami and ventrolateral PFC, respectively.ConclusionThese findings indicate that mPFC alterations may not be substance-specific, but rather related to the number of substances used, whereas, thalamic and ventrolateral PFC pathology is specifically associated with tobacco and cocaine use, respectively. These findings are important, as the differential alterations in GM volume may underlie different cognitive deficits associated with substance use disorders. Show less
This thesis focused on the development of creative thinking across adolescence and into adulthood. To this end, a range of creativity tasks, both with and without an fMRI scanner, and before and... Show moreThis thesis focused on the development of creative thinking across adolescence and into adulthood. To this end, a range of creativity tasks, both with and without an fMRI scanner, and before and after training paradigms has been used to ex_amine both age- and experience-related effects on creative thinking performance during functional brain develop_ment. Chapter 1 provides a theoretical background for the research described in chapters 2 to 6. In Chapter 2, developmental trajectories of creative cognition across adolescence and early adulthood were examined using a set of tasks gauging both insight and divergent thinking in the verbal and visual domain. In Chapter 3, behavioral and neural differences for creative problem solving in middle-adolescents and adults were examined. Chapter 4 examined the neural correlates of divergent thinking in adults and adolescents. Chapter 5 focused on the effectiveness of creative ideation training in adolescents and adults. In Chapter 6, the benefits of training creativity in adolescents were examined using fMRI techniques. Finally, Chapter 7 summarizes the main results of the empirical studies presented in this thesis. Here, implications of the results are discussed and suggestions for future research are presented. Show less
The studies described in this thesis aimed to investigate how affect and motivation impact cognitive control, in terms of both behavior and brain activation. Six out of the eight empirical studies... Show moreThe studies described in this thesis aimed to investigate how affect and motivation impact cognitive control, in terms of both behavior and brain activation. Six out of the eight empirical studies found support for indirect effects on cognitive control, as measured with sequential trial-to-trial adaptations in cognitive control tasks. Only two studies resulted in evidence for a direct modulation of cognitive control (Chapter 4 and 9). Indirect effects occurred on trial-to-trial adaptation in cognitive control tasks involving a random presentation of compatible and incompatible trials. We found that conflict adaptation, the transient improvement of behavioral control after incompatible in comparison to compatible trials, was subject to affective regulation. In particular, we found that after incompatible trials, positive emotional states reduced and negative emotional states increased adaptation. These effects occurred for both short-term (Chapters 2 and 3) and long-term affect manipulations (Chapters 5, 6, and 7). Motivation and task difficulty also interacted with conflict adaptation (Chapter 8). The neuroimaging studies described in Chapter 3 and 6 demonstrate the role of fronto-striatal interactions in this affective regulation of cognitive control. Taken together, this thesis demonstrates the role that positive and negative emotions play in the adaptation of behavior and mental effort. Show less
