Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
Add more filters










Publication year range
1.
Proc Biol Sci ; 291(2017): 20222584, 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38378153

ABSTRACT

All mobile organisms forage for resources, choosing how and when to search for new opportunities by comparing current returns with the average for the environment. In humans, nomadic lifestyles favouring exploration have been associated with genetic mutations implicated in attention deficit hyperactivity disorder (ADHD), inviting the hypothesis that this condition may impact foraging decisions in the general population. Here we tested this pre-registered hypothesis by examining how human participants collected resources in an online foraging task. On every trial, participants chose either to continue to collect rewards from a depleting patch of resources or to replenish the patch. Participants also completed a well-validated ADHD self-report screening assessment at the end of sessions. Participants departed resource patches sooner when travel times between patches were shorter than when they were longer, as predicted by optimal foraging theory. Participants whose scores on the ADHD scale crossed the threshold for a positive screen departed patches significantly sooner than participants who did not meet this criterion. Participants meeting this threshold for ADHD also achieved higher reward rates than individuals who did not. Our findings suggest that ADHD attributes may confer foraging advantages in some environments and invite the possibility that this condition may reflect an adaptation favouring exploration over exploitation.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Humans , Attention Deficit Disorder with Hyperactivity/diagnosis , Reward , Life Style , Self Report
2.
J Pers ; 91(3): 838-855, 2023 06.
Article in English | MEDLINE | ID: mdl-36156253

ABSTRACT

INTRODUCTION: People hold general beliefs about the world called primals (e.g., the world is Safe, Intentional), which are strongly linked to individual differences in personality, behavior, and mental health. How such beliefs form or change across the lifespan is largely unknown, although theory suggests that beliefs become more negative after disruptive events. The COVID-19 pandemic provided an opportunity to test whether dramatic world changes and personal adversity affect beliefs. METHOD: In a longitudinal, quasi-experimental, pre-registered design, 529 US participants (51% female, 76% White) provided ratings of primals before and several months after pandemic onset, and information about personal adversity (e.g., losing family, financial hardship). Data were compared to 398 participants without experience of the pandemic. RESULTS: The average person in our sample showed no change in 23 of the 26 primals, including Safe, in response to the early pandemic, and only saw the world as slightly less Alive, Interactive, and Acceptable. Higher adversity, however, was associated with slight declines in some beliefs. One limitation is that participants were exclusively American. CONCLUSION: Primals were remarkably stable during the initial shock wrought by a once-in-a-century pandemic, supporting a view of primals as stable lenses through which people interpret the world.


Subject(s)
COVID-19 , Humans , Female , Male , Pandemics , Individuality , Longevity , Mental Health
3.
Front Psychol ; 13: 989826, 2022.
Article in English | MEDLINE | ID: mdl-36582324

ABSTRACT

Introduction: Increasingly, business leaders and other professionals are called upon to be vulnerable and authentic in the workplace, which often includes disclosing emotions to others. While sharing emotions is known to enhance closeness, several questions remain underexplored. Specifically, disclosing personal facts about oneself and disclosing emotions have often been studied together, making it difficult to determine the effects of disclosing emotions per se. Moreover, not enough is known about factors that may influence effects of disclosing emotions, including recipients' attitudes toward emotion-sharing, the sharer's gender, and whether one considers the disclosure to be similar to one's own experiences. We examined the impact of disclosing positive and negative emotion on ratings of closeness, warmth, competence, and leadership ability. Methods: 119 participants (95 female) in the United States were shown headshots of individuals who were introduced in the first person in written format. For half of the pictures, an autobiographical fact about the individual's past was disclosed. For the other half, an autobiographical fact and an associated emotion were disclosed. Results: We found that sharing both positive and negative emotions increased feelings of closeness above and beyond the effects of autobiographical sharing alone. Sharing positive emotions also increased ratings of warmth, competence, and leadership ability. Male and female sharers benefited equally from disclosing emotions and effects were largely robust to recipients' attitudes toward emotional expression. Having something in common with the disclosed fact or emotion further increased all ratings. Conclusion: These findings indicate that disclosing emotions may improve interpersonal interactions, with potential management applications in business.

4.
Front Med (Lausanne) ; 9: 863257, 2022.
Article in English | MEDLINE | ID: mdl-35602507

ABSTRACT

Background: After learning new skills, healthcare professionals do not always apply them in practice, despite being motivated. This may be referred to as an intention-behavior gap. One example is the positioning of immobilized and disabled patients in hospitals, nursing homes, or neurorehabilitation clinics. Positioning is crucial to prevent complications such as pressure sores, pneumonia, and deep vein thrombosis. However, it is often not carried out optimally even when professionals have completed education programs. The LiN-method is a positioning procedure involving a special focus on aligning and stabilizing body parts, which has been shown to have advantages over conventional positioning. We assess which factors may facilitate or hinder the use of LiN in clinical practice after participants complete training. Methods: A longitudinal survey with 101 LiN-course participants was conducted in Germany. Each participant completed a questionnaire directly after the course and 12 weeks later, including a report of the frequency of use in practice. They also completed a questionnaire which surveyed 23 aspects that might facilitate or hinder use of the new skills, covering the workplace, socio-collegial factors, motivation, self-confidence, and mindset. Results: Most assessed aspects were associated with LiN-use, with the highest correlations found for confidence with the method, perceived ease of application, sufficient time, assessing one's skills as sufficient, remembering the relevant steps, and a work environment open to advanced therapeutic concepts. To reduce data complexity, the questionnaire was subjected to a factor analysis, revealing six factors. A regression analysis showed that four factors predicted use 12 weeks after course completion, in the following order of importance: (1) subjective aspects/confidence, (2) access to materials, (3) work context, and (4) competent support in the workplace. Conclusion: Numerous aspects are associated with the use of recently acquired clinical or nursing skills, such as LiN. Many of these can be improved by appropriately setting up the workplace. The aspects most associated with use, however, are confidence with the method and self-perceived competence of healthcare professionals. While causality still needs to be demonstrated, this suggests that education programs should support participants in developing confidence and foster a mindset of continuous learning.

5.
Soc Cogn Affect Neurosci ; 17(7): 683-693, 2022 07 02.
Article in English | MEDLINE | ID: mdl-34850226

ABSTRACT

Studies in decision neuroscience have identified robust neural representations for the value of choice options. However, overall values often depend on multiple attributes, and it is not well understood how the brain evaluates different attributes and integrates them to combined values. In particular, it is not clear whether attribute values are computed in distinct attribute-specific regions or within the general valuation network known to process overall values. Here, we used a functional magnetic resonance imaging choice task in which abstract stimuli had to be evaluated based on variations of the attributes color and motion. The behavioral data showed that participants responded faster when overall values were high and attribute value differences were low. On the neural level, we did not find that attribute values were systematically represented in areas V4 and V5, even though these regions are associated with attribute-specific processing of color and motion, respectively. Instead, attribute values were associated with activity in the posterior cingulate cortex, ventral striatum and posterior inferior temporal gyrus. Furthermore, overall values were represented in dorsolateral and ventromedial prefrontal cortex, and attribute value differences in dorsomedial prefrontal cortex, which suggests that these regions play a key role for the neural integration of attribute values.


Subject(s)
Brain Mapping , Decision Making , Brain/diagnostic imaging , Humans , Magnetic Resonance Imaging/methods , Neural Networks, Computer , Prefrontal Cortex
6.
J Behav Addict ; 10(3): 482-497, 2021 Jul 15.
Article in English | MEDLINE | ID: mdl-34264854

ABSTRACT

BACKGROUND AND AIMS: Maladaptive eating habits are a major cause of obesity and weight-related illness. The development of empirically-based approaches, such as mindfulness training (MT) that target accurate mechanisms of action to address these behaviors is therefore critical. Two studies were conducted to examine the impact of MT on maladaptive eating and determine the involvement of reinforcement learning mechanisms underlying these effects. METHODS: In Study1, maladaptive eating behaviors were assessed using self-report questionnaires at baseline and 8 weeks after an app-based MT intervention (n = 46). A novel mindful eating craving tool was embedded in our intervention to assess: eating behaviors (intake frequency/magnitude), and reward (contentment ratings) experienced after eating. Using a well-established reinforcement learning (Rescorla-Wagner) model, expected reward values (EV) were estimated as a function of contentment levels reported after eating. In Study2 (n = 1,119), craving tool assessments were examined in an independent sample using the app in a real-world naturalistic context. RESULTS: Study 1's results revealed a significant decrease in EV and eating behaviors across craving tool uses. In addition, changes in reward values predicted decreases in eating behaviors. Finally, Study 1's results revealed significant pre-post intervention reductions in self-reported eating behaviors. In Study2, we observed a significant decrease in EV, but not in eating behaviors, across craving tool uses. Study 2 also revealed a predictive relationship between EV and eating behaviors. DISCUSSION AND CONCLUSIONS: These results support the implementation of MT to prevent and treat maladaptive eating behaviors, which target reinforcement learning processes as mechanisms of action.


Subject(s)
Mindfulness , Ecological Momentary Assessment , Feeding Behavior , Humans , Obesity , Reward
7.
Perspect Psychol Sci ; 15(6): 1382-1399, 2020 11.
Article in English | MEDLINE | ID: mdl-32857672

ABSTRACT

To reach longer-term goals and live aligned with their values, people typically must regulate their behavior. Effortful self-control is one way to achieve this and is usually framed as a forceful struggle between lower-level impulses and higher-level cognitive control processes. For example, people may restrain themselves from eating cake in order to lose weight. An alternative avenue of self-regulation draws on autonomous motivation: Individuals eat healthfully because it is values-congruent or intrinsically satisfying. Recent advances in the understanding of reward valuation on a neural level (e.g., ventromedial prefrontal cortex/orbitofrontal cortex) and emerging treatments on a clinical level (e.g., mindfulness training) suggest a possible mechanistic convergence between brain and behavior that is consistent with a shift from forced to unforced behavior change. Here we propose how an overlooked aspect of reinforcement learning can be leveraged using a simple yet critical feature of experience that is not reliant on willpower: Bringing awareness to one's subjective experience and behavior can produce a change in valuation of learned but unhealthy behaviors, leading to self-regulatory shifts that result in sustainable behavior change without force.


Subject(s)
Awareness , Health Behavior , Reward , Self-Control , Humans , Learning , Mindfulness , Prefrontal Cortex/physiology , Reinforcement, Psychology
8.
J Altern Complement Med ; 26(10): 937-944, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32678712

ABSTRACT

Objectives: Mindfulness-based interventions (MBIs) have been shown to reduce engagement in disordered eating behaviors, although how these interventions engender change remains unclear. The objective of this exploratory qualitative study was to describe the experiences and perceived attitudinal and behavioral changes of women participating in a mindful eating program. Design: Focus group discussions were held with women participating in a community-based mindful eating program for binge and emotional eating. A semistructured interview guide was used to explore participants' conceptualizations of mindfulness-based attitudinal and behavior change, as related to food, eating, and body image. The focus group discussions were audio-recorded, transcribed, and analyzed using thematic analysis to identify salient concepts. Settings/Location: Focus group discussions were held at the Center for Mindfulness at the University of Massachusetts Medical School (UMMS) (United States). Participants: A sample of nine women who were enrolled in the mindful eating program at UMMS for problems with self-reported binge and/or emotional eating participated in this study. Results: Four themes were constructed that described a process of mindfulness-based behavior change, including (1) Learning Through Self-Awareness, (2) Self-Empowerment, (3) Mindful Choice-Making, and (4) Resilient Self-Care. An overarching description of the participants' perceived attitudinal and behavior changes was developed: "unforced freedom of choice, emerging from embodied awareness." Conclusions: These findings suggest that MBIs reduce may disordered eating behaviors through empowering women to make positive choices about food, eating, and coping, without focusing on weight control. Future research is needed to examine whether these findings replicate in larger and more diverse samples, and how they can be used to optimize and implement eating-specific MBIs in community-based settings.


Subject(s)
Diet/psychology , Feeding Behavior/psychology , Food Preferences/psychology , Health Behavior , Mindfulness/methods , Self Efficacy , Adult , Female , Focus Groups , Humans , Meditation , Power, Psychological
9.
Front Behav Neurosci ; 12: 297, 2018.
Article in English | MEDLINE | ID: mdl-30564107

ABSTRACT

During self-control, we may resist short-term temptations in order to reach a favorable future (e.g., resisting cake to stay healthy). The neural basis of self-control is typically attributed to "cold," unemotional cognitive control mechanisms which inhibit affect-related regions via the prefrontal cortex (PFC). Here, we investigate the neural underpinnings of regulating cravings by mentally evoking the positive consequences of resisting a temptation (e.g., being healthy) as opposed to evoking the negative consequences of giving in to a temptation (e.g., becoming overweight). It is conceivable that when using these types of strategies, regions associated with emotional processing [e.g., striatum, ventromedial prefrontal cortex (vmPFC)] are involved in addition to control-related prefrontal and parietal regions. Thirty-one participants saw pictures of unhealthy snacks in the fMRI scanner and, depending on the trial, regulated their craving by thinking of the positive consequences of resisting, or the negative consequences of not resisting. In a control condition, they anticipated the pleasure of eating and thus, allowed the craving to occur (now-condition). In line with previous studies, we found activation of a cognitive control network during self-regulation. In the negative future thinking condition, the insula was more active than in the positive condition, while there were no activations that were stronger in the positive (> negative) future thinking condition. However, additionally, multivariate pattern analysis showed that during craving regulation, information about the valence of anticipated emotions was present in the vmPFC, the posterior cingulate cortex (PCC) and the insula. Moreover, a network including vmPFC and PCC showed higher connectivity during the positive (> negative) future thinking condition. Since these regions are often associated with affective processing, these findings suggest that "hot," affective processes may, at least in certain circumstances, play a role in self-control.

10.
Neuroimage ; 183: 553-564, 2018 12.
Article in English | MEDLINE | ID: mdl-30145207

ABSTRACT

In everyday life, we often deliberate about affective outcomes of decisions which can be described as ambivalent; i.e. positive and negative at the same time. For example, when looking forward to meet a dear friend at her/his favorite concert although one dislikes the music that is being performed. Thus, anticipation of bivalent emotions and their volitional regulation is an important ingredient of everyday choices. However, previous studies investigating neural substrates involved in anticipating emotional events mostly focused on anticipating either negative emotions (punishment) or positive emotions (reward) in isolation, thus inducing either of them separately. Furthermore, these studies rather focused on the effortful down-regulation of affect (i.e. reducing negative or positive affect), whereas such conflict situations may also require us to deploy attention on and thereby upregulate anticipated emotions in order to resolve a decision conflict (e.g., by focusing on positive consequences while orienting away from negative consequences of that same situation). To address this gap, we performed a series of three fMRI-experiments using simple visual and auditory stimuli in order to (i) determine the neural correlates involved when anticipating a bivalent affective outcome that is both positive and negative at the same time - related to a conflict situation and (ii) investigate their malleability during anticipation via voluntary emotion regulation using attentional focusing. In these studies, we (i) demonstrate that brain areas involved in anticipating positive (ventral striatum) and negative (anterior insula) emotional events are co-activated when anticipating the occurrence of both punishment and reward at the same time and (ii) provide evidence that attention on either the positive or the negative correlates with a shift in activations of these co-activated neural networks and associated anticipated emotions towards either the positive (increased activity in ventral striatum, ventromedial prefrontal cortex, posterior cingulate cortex) or the negative (increased activity in insula) aspect of the upcoming bivalent outcome. In summary, we provide self-report and neural evidence for the assumption that affective brain systems associated with the processing of bivalent anticipated emotions can be voluntarily controlled by cognitive emotion regulation strategies.


Subject(s)
Anticipation, Psychological/physiology , Attention/physiology , Brain Mapping/methods , Cerebral Cortex/physiology , Emotions/physiology , Nerve Net/physiology , Punishment , Reward , Ventral Striatum/physiology , Adult , Auditory Perception/physiology , Cerebral Cortex/diagnostic imaging , Female , Gyrus Cinguli/diagnostic imaging , Gyrus Cinguli/physiology , Humans , Magnetic Resonance Imaging , Male , Nerve Net/diagnostic imaging , Prefrontal Cortex/diagnostic imaging , Prefrontal Cortex/physiology , Ventral Striatum/diagnostic imaging , Visual Perception/physiology , Young Adult
11.
Neuroimage ; 172: 517-526, 2018 05 15.
Article in English | MEDLINE | ID: mdl-29409998

ABSTRACT

Delaying intentions bears the risk of interference from distracting activities during the delay interval. Motivation can increase intention retrieval success but little is known about the underlying brain mechanisms. Here, we investigated whether motivational incentives (monetary reward) modulate the processing of delayed intentions in the anterior prefrontal cortex (aPFC), known to be crucial for intention processing. Using a mixed blocked and event-related functional Magnetic Resonance Imaging design, we specifically tested whether reward affects intention processing in the aPFC in a transient or in a sustained manner and whether this is related to individual differences in retrieval success. We found a generalized effect of reward on both correct intention retrieval and ongoing task performance. Fronto-parietal regions including bilateral lateral aPFC showed sustained activity increases in rewarded compared to non-rewarded blocks as well as transient reward-related activity during the storage phase. Additionally, individual differences in reward-related performance benefits were related to the degree of transient signal increases in right lateral aPFC, specifically during intention encoding. This suggests that the ability to integrate motivational relevance into the encoding of future intentions is crucial for successful intention retrieval in addition to general increases in processing effort. Bilateral aPFC is central to these motivation-cognition interactions.


Subject(s)
Intention , Motivation/physiology , Prefrontal Cortex/physiology , Adult , Brain Mapping/methods , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging/methods , Male , Reward , Young Adult
12.
BMC Nurs ; 16: 60, 2017.
Article in English | MEDLINE | ID: mdl-29075147

ABSTRACT

BACKGROUND: Decubitus ulcers are associated with a burden for the patients and cause enormous costs. One of the reasons for the development of decubitus is prolonged exposure to pressure. The aim of this pilot study was to examine the pressure distribution of healthy individuals either positioned in Positioning in Neutral (LiN) or conventional positioning (CON). METHODS: Four healthy participants were positioned in a supine, 30° degree side lying and 90° side lying position both in LiN and CON. A thousand pressure sensors in a mattress enabled a visual presentation of low, medium and high pressure on a screen. This presentation was processed by Photoshop in order to count the pixels representing the total support pressure surface and the pressure intensity. RESULTS: LiN showed, on average, a smaller surface with measurable pressure compared to CON (46,293 versus 64,090 pixels). The areas of medium pressure were comparable. Mean areas of low and high pressure were both smaller in LiN as compared to CON (low: 8315 versus 22,790 pixels; high: 3744 versus 7277 pixels). CONCLUSION: The results of this pilot study indicate that LiN is suitable for pressure sore prophylaxis because LiN showed less support surface and less maximum pressure as compared to CON.

14.
Front Psychol ; 7: 382, 2016.
Article in English | MEDLINE | ID: mdl-27148101

ABSTRACT

Self-control can be defined as the ability to exert control over ones impulses. Currently, most research in the area relies on self-report. Focusing on attentional control processes involved in self-control, we modified a spatial selective attentional cueing task to test three domains of self-control experimentally in one task using aversive, tempting, and neutral picture-distractors. The aims of the study were (1) to investigate individual differences in the susceptibility to aversive, tempting, and neutral distraction within one paradigm and (2) to test the association of these three self-control domains to conventional measures of self-control including self-report. The final sample consisted of 116 participants. The task required participants to identify target letters "E" or "F" presented at a cued target location while the distractors were presented. Behavioral and eyetracking data were obtained during the performance of the task. High task performance was encouraged via monetary incentives. In addition to the attentional self-control task, self-reported self-control was assessed and participants performed a color Stroop task, an unsolvable anagram task and a delay of gratification task using chocolate sweets. We found that aversion, temptation, and neutral distraction were associated with significantly increased error rates, reaction times and gaze pattern deviations. Overall task performance on our task correlated with self-reported self-control ability. Measures of aversion, temptation, and distraction showed moderate split-half reliability, but did not correlate with each other across participants. Additionally, participants who made a self-controlled decision in the delay of gratification task were less distracted by temptations in our task than participants who made an impulsive choice. Our individual differences analyses suggest that (1) the ability to endure aversion, resist temptations and ignore neutral distractions are independent of each other and (2) these three domains are related to other measures of self-control.

15.
Soc Cogn Affect Neurosci ; 11(8): 1193-204, 2016 08.
Article in English | MEDLINE | ID: mdl-27013102

ABSTRACT

Both self-control and emotion regulation enable individuals to adapt to external circumstances and social contexts, and both are assumed to rely on the overlapping neural resources. Here, we tested whether high self-reported self-control is related to successful emotion regulation on the behavioral and neural level. One hundred eight participants completed three self-control questionnaires and regulated their negative emotions during functional magnetic resonance imaging using reappraisal (distancing). Trait self-control correlated positively with successful emotion regulation both subjectively and neurally, as indicated by online ratings of negative emotions and functional connectivity strength between the amygdala and prefrontal areas, respectively. This stronger overall connectivity of the left amygdala was related to more successful subjective emotion regulation. Comparing amygdala activity over time showed that high self-controllers successfully maintained down-regulation of the left amygdala over time, while low self-controllers failed to down-regulate towards the end of the experiment. This indicates that high self-controllers are better at maintaining a motivated state supporting emotion regulation over time. Our results support assumptions concerning a close relation of self-control and emotion regulation as two domains of behavioral control. They further indicate that individual differences in functional connectivity between task-related brain areas directly relate to differences in trait self-control.


Subject(s)
Amygdala/physiology , Brain Mapping/methods , Emotions/physiology , Individuality , Self-Control/psychology , Adult , Female , Humans , Magnetic Resonance Imaging/methods , Male , Self Report , Young Adult
16.
Front Behav Neurosci ; 9: 280, 2015.
Article in English | MEDLINE | ID: mdl-26578910

ABSTRACT

Humans value rewards less when these are delivered in the future as opposed to immediately, a phenomenon referred to as delay discounting. While delay discounting has been studied during the anticipation of rewards and in the context of intertemporal decision-making, little is known about its neural correlates in the outcome phase (during reward delivery) and their relation to personality. Personality traits that have been associated with increased delay discounting include impulsivity and, potentially, anxious-depressive traits. Here we performed functional magnetic resonance imaging (fMRI) in 72 healthy participants while they carried out a monetary incentive delay (MID) task with a delay manipulation. In sixty percent of the experimental trials, participants won rewards that differed in magnitude (0.05€, 0.50€ or 1€) and delay until delivery (immediately, 10 days, or 100 days). A factor analysis on questionnaires yielded two factors reflecting Impulsivity and Anxiety/Depression, which we used to examine potential relationships between personality and delay discounting. When winning a reward, medial prefrontal cortex (mPFC) activation was higher for immediate compared to delayed rewards. Moreover, amygdala activation correlated with reward magnitude for immediate but not for delayed rewards. Amygdala activation to winning immediate rewards was higher in more impulsive participants, while mPFC activation to winning immediate rewards was higher in more anxious-depressed participants. Our results uncover neural correlates of delay discounting during reward delivery, and suggest that impulsivity and subclinical anxious-depressive traits are related to stronger neural responses for winning immediate relative to delayed rewards.

17.
Conscious Cogn ; 35: 158-70, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26036837

ABSTRACT

The distinct feeling of wanting to act and thereby causing our own actions is crucial to our self-perception as free human agents. Disturbances of the link between intention and action occur in several disorders. Little is known, however, about the neural correlates of wanting or intending to act. To investigate these for simple voluntary movements, we used a paradigm involving hypnotic paralysis and functional magnetic resonance imaging. Eight healthy women were instructed to sequentially perform left and right hand movements during a normal condition, as well as during simulated weakness, simulated paralysis and hypnotic paralysis of the right hand. Right frontopolar cortex was selectively hypoactivated for attempted right hand movement during simulated paralysis while it was active in all other conditions. Since simulated paralysis was the only condition lacking an intention to move, the activation in frontopolar cortex might be related to the intention or volition to move.


Subject(s)
Frontal Lobe/physiology , Hypnosis , Intention , Movement/physiology , Paralysis , Adult , Brain/physiology , Brain Mapping , Female , Functional Neuroimaging , Hand , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Pilot Projects , Psychomotor Performance , Reaction Time , Volition , Young Adult
18.
Neuroimage ; 111: 549-61, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25731995

ABSTRACT

Attentional control in demanding cognitive tasks can be improved by manipulating the motivational state. Motivation to obtain gains and motivation to avoid losses both usually result in faster reaction times and stronger activation in relevant brain areas such as the prefrontal cortex, but little is known about differences in the underlying neurocognitive mechanisms of these types of motivation in an attentional control context. In the present functional magnetic resonance imaging (fMRI) study, we tested whether potential gain and loss as motivating incentives lead to overlapping or distinct neural effects in the attentional network, and whether one of these conditions is more effective than the other. A Flanker task with word stimuli as targets and distracters was performed by 115 healthy participants. Using a mixed blocked and event-related design allowed us to investigate transient and sustained motivation-related effects. Participants could either gain money (potential gain) or avoid losing money (potential loss) in different task blocks. Participants showed a congruency effect with increased reaction times for incongruent compared to congruent trials. Potential gain led to generally faster responses compared to the neutral condition and to stronger improvements than potential loss. Potential loss also led to shorter response times compared to the neutral condition, but participants improved mainly during incongruent and not during congruent trials. The event-related fMRI data revealed a main effect of congruency with increased activity in the left inferior frontal gyrus (IFG) and inferior frontal junction area (IFJ), the pre-supplementary motor area (pre-SMA), bilateral insula, intraparietal sulcus (IPS) and visual word form area (VWFA). While potential gain led to increased activity in a cluster of the IFJ and the VWFA only during incongruent trials, potential loss was linked to activity increases in these regions during incongruent and congruent trials. The block analysis revealed greater activity in gain and loss blocks compared to the neutral condition in most of these regions but no differences in the direct comparison of gain and loss blocks. These findings show that potential monetary gain and loss rely on different mechanisms: Gain was more effective in reducing the reaction time compared to potential loss. Brain data indicate that in the gain context attentional control is executed specifically in incongruent trials, whereas the loss context induces an unspecific increase of attentional control. These findings extend previous studies by providing evidence for diverging neural mechanisms for the effects of different types of motivation on attentional control, specifying the underlying activity patterns in task- and stimulus-related regions.


Subject(s)
Attention/physiology , Executive Function/physiology , Frontal Lobe/physiology , Magnetic Resonance Imaging/methods , Motivation/physiology , Nerve Net/physiology , Psychomotor Performance/physiology , Adult , Female , Humans , Male , Young Adult
19.
Addict Biol ; 20(5): 990-9, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25639749

ABSTRACT

Alcohol-dependent patients have been shown to faster approach than avoid alcohol stimuli on the Approach Avoidance Task (AAT). This so-called alcohol approach bias has been associated with increased brain activation in the medial prefrontal cortex and nucleus accumbens. Cognitive bias modification (CBM) has been used to retrain the approach bias with the clinically relevant effect of decreasing relapse rates one year later. The effects of CBM on neural signatures of approach/avoidance tendencies remain hitherto unknown. In a double-blind placebo-controlled design, 26 alcohol-dependent in-patients were assigned to a CBM or a placebo training group. Both groups performed the AAT for three weeks: in CBM training, patients pushed away 90 percent of alcohol cues; this rate was 50 percent in placebo training. Before and after training, patients performed the AAT offline, and in a 3 T magnetic resonance imaging scanner. The relevant neuroimaging contrast for the alcohol approach bias was the difference between approaching versus avoiding alcohol cues relative to soft drink cues: [(alcohol pull > alcohol push) > (soft drink pull > soft drink push)]. Before training, both groups showed significant alcohol approach bias-related activation in the medial prefrontal cortex. After training, patients in the CBM group showed stronger reductions in medial prefrontal cortex activation compared with the placebo group. Moreover, these reductions correlated with reductions in approach bias scores in the CBM group only. This suggests that CBM affects neural mechanisms involved in the automatic alcohol approach bias, which may be important for the clinical effectiveness of CBM.


Subject(s)
Alcoholism/physiopathology , Alcoholism/therapy , Brain/physiopathology , Cognitive Behavioral Therapy/methods , Magnetic Resonance Imaging , Adult , Alcoholism/psychology , Cognition/physiology , Cues , Double-Blind Method , Germany , Humans , Male , Middle Aged , Nucleus Accumbens/physiopathology , Prefrontal Cortex/physiopathology
20.
Dtsch Arztebl Int ; 112(3): 35-42, 2015 Jan 16.
Article in English | MEDLINE | ID: mdl-25657075

ABSTRACT

BACKGROUND: Severe immobility due to lesions of the brain necessitates therapeutic positioning over the long term. There is little scientific evidence concerning the efficacy of different positioning methods. This clinical trial compares the effects of conventional positioning (CON) with those of positioning in neutral (LiN). METHODS: A prospective, multicenter, investigator-blinded, randomized, controlled trial was performed on a total of 218 non-ambulatory patients (underlying disease: stroke, 141 patients; hypoxic brain damage, 28; traumatic brain injury, 20; other, 29). The subjects were randomly assigned to either LiN (105 patients) or CON (113 patients) and stratified within each of these two positioning concepts to five different positions. They remained in the assigned positions for two hours. The primary endpoint was change in the passive range of motion (PROM) of the hip joints. Secondary endpoints were change in the PROM of the shoulder joints and patient comfort. RESULTS: Patients in the LiN group had a significantly better PROM of the hips after positioning than those in the CON group (difference, 12.84°; p<0.001; 95% confidence interval [CI], 5.72°-19.96°). The same was true for PROM of shoulder flexion (11.85°; p<0.001; 95% CI, 4.50°-19.19°) and external rotation (7.08°; p<0.001; 95% CI: 2.70°-11.47°). 81% of patients in the LiN group reported their comfort level as good, compared to only 38% in the CON group (p<0.001). CONCLUSION: Positioning severely immobilized patients in LiN for two hours improved passive hip and shoulder mobility and patient comfort compared to conventional positioning. Further studies are needed to determine whether prolonged LiN positioning might improve rehabilitation and quality of life, prevent pressure sores, or ease nursing care.


Subject(s)
Brain Injuries/complications , Brain Injuries/nursing , Paralysis/etiology , Paralysis/nursing , Patient Positioning/methods , Pressure Ulcer/prevention & control , Aged , Austria , Female , Germany , Humans , Male , Pressure Ulcer/etiology , Single-Blind Method , Treatment Outcome
SELECTION OF CITATIONS
SEARCH DETAIL
...