Anouk Scheres | Radboud University Nijmegen (original) (raw)

Papers by Anouk Scheres

The ability to exert self-control over one's thoughts and actions is crucial for successful funct... more The ability to exert self-control over one's thoughts and actions is crucial for successful functioning in daily life. To date, self-control development has been primarily studied from the perspective of externally driven inhibition. In this review, we introduce a new perspective on the development of self-control by highlighting the importance of intentional inhibition. First, we will review the existing behavioral and neuroscientific literature on the development of self-control from the perspective of externally driven inhibition. Next, we will introduce a new framework for studying the development of self-control from the perspective of intentional inhibition. We will discuss several recent studies in this domain, showing that intentional inhibition within cold contexts has an early development, but continues to develop through adolescence in motivational contexts. We conclude that understanding the developmental trajectory of intentional inhibition in cold and motivationally relevant contexts and its underlying mechanisms is an important direction for future research, which has important implications for our understanding of developmental disorders associated with problems in self-control, such as Attention Deficit Hyperactivity Disorder. (M.A. Schel). Please cite this article as: Schel, M. A., et al. New perspectives on self-control development: Highlighting the role of intentional inhibition. Neuropsychologia (2014), http://dx.

Key words attention-deficit hyperactivity disorder, symptoms of impulsivity, hyperactivity and in... more Key words attention-deficit hyperactivity disorder, symptoms of impulsivity, hyperactivity and inattention, academic and general procrastination

The goal of this study was to examine age effects on the ability/willingness to wait for large re... more The goal of this study was to examine age effects on the ability/willingness to wait for large rewards in a real temporal reward discounting task from childhood to adulthood. Therefore, a real temporal discounting (TD) task was administered to children aged 6-12 (n = 39), adolescents aged 13-17 (n = 28), and young adults aged 18-19 (n = 55). Findings indicated that the cross-sectional development of TD followed a quadratic pattern across age groups, with adolescents choosing more often than children and adults to wait for the large delayed reward, resulting in reward-maximization. Various interpretations of this finding were offered, including a focus on reward maximization despite an immature ability to exert self-control, and flexible self-control which was high during this task as a result of strong motivation to maximize financial gains.

Age-related differences in temporal discounting (TD) and risk taking, and their association, were... more Age-related differences in temporal discounting (TD) and risk taking, and their association, were examined in adolescents and young adults (n = 337) aged 12-27 years. Since monetary rewards are typically used in TD and risk-taking tasks, the association between monetary reward valuation and age and decision making in these tasks was explored as well. TD declined linearly with age, with a particularly sharp decline from 15 to 16 years. In contrast, risk taking was not correlated with age and TD. Reward valuation was not associated with TD and risk taking, and age-related differences in TD remained significant after controlling for reward valuation. Together, these findings suggest that risk taking and TD are two separate constructs with distinct

A review of the existing functional magnetic resonance imaging (fMRI) studies on reward anticipat... more A review of the existing functional magnetic resonance imaging (fMRI) studies on reward anticipation in patients with attention-deficit/hyperactivity disorder (ADHD) is provided. Meta-analysis showed a significant medium effect size (Cohen's d = 0.48-0.58) in terms of ventral-striatal (VS)-hyporesponsiveness in ADHD.

Temporal reward discounting (TD) refers to the decrease in subjective value of a reward when the ... more Temporal reward discounting (TD) refers to the decrease in subjective value of a reward when the delay to that reward increases. In recent years, a growing number of studies on the neural correlates of temporal reward discounting have been conducted. This article focuses on functional magnetic resonance imaging (fMRI) studies on TD in humans. First, we describe the different types of tasks (also from behavioral studies) and the dependent variables. Subsequently, we discuss the evidence for three neurobiological models of TD: the dual-systems model, the single-system model and the self-control model. Further, studies in which nontraditional tasks (e.g., with nonmonetary rewards) were used to study TD are reviewed. Finally, we discuss the neural correlates of individual differences in discounting, and its development across the lifespan. We conclude that the evidence for each of the three neurobiological models of TD is mixed, in that all models receive (partial) support, and several studies provide support for multiple models. Because of large differences between studies in task design and analytical approach, it is difficult to draw a firm conclusion regarding which model provides the best explanation of the neural correlates of temporal discounting. We propose that some components of these models can complement each other, and future studies should test the predictions offered by different models against each other. Several future research directions are suggested, including studying the connectivity between brain regions in relation to discounting, and directly comparing the neural mechanisms involved in discounting of monetary and primary rewards.

Difficulty waiting plays a primary role in symptoms of ADHD, in particular impulsivity. Current t... more Difficulty waiting plays a primary role in symptoms of ADHD, in particular impulsivity. Current theories suggest that relatively strong preferences for small immediate rewards as observed in ADHD-Combined type are the result of delay-related negative feelings. However, the measurement of difficulty waiting is typically limited to objective choices between small immediate and large delayed rewards. This study aimed at extending the measurement of difficulty waiting in ADHD-Combined type with ratings about subjective feelings. Children and adolescents (ages 6-17) with ADHD-Combined type (n=25), ADHD-Inattentive type (n=20) and matched typically developing participants (n=37) performed temporal reward discounting tasks, and completed a Visual Analogue Scale of subjectively experienced ease/ difficulty waiting. Although those with ADHD-Combined type demonstrated relatively steep temporal reward discounting, as reported elsewhere , there were no group differences for subjectively experienced ease/difficulty waiting. Additionally, correlations between subjective and objective measures of difficulty waiting were significantly higher in the ADHD-Combined type group than in the control group. These findings suggest that (a) those with ADHD-Combined type do not choose impulsively because they have more negative feelings about waiting than controls; (b) choices in the ADHD-Combined type group are more in accordance with/driven by their feelings than choices made by participants in the control group. (A. Scheres).

Biological Psychiatry, 2010

Background: Theoretical models have hypothesized that one core problem in attention-deficit/hyper... more Background: Theoretical models have hypothesized that one core problem in attention-deficit/hyperactivity disorder (ADHD) is abnormal reward processing. Temporal reward discounting (decreases in subjective reward value due to prereward delay) is of interest because of its relation with a key symptom of ADHD-impulsivity. This study investigated 1) whether steep temporal reward discounting (TD) is associated with ADHD-combined type (ADHD-C)/symptoms of hyperactivity-impulsivity specifically; 2) the role of reward magnitude in TD in ADHD-C/participants with symptoms of hyperactivity-impulsivity; and 3) whether steep TD in ADHD-C/participants with symptoms of hyperactivity-impulsivity is affected by session length.

Neuropsychologia, 2006

This study investigated whether age and ADHD symptoms affected choice preferences in children and... more This study investigated whether age and ADHD symptoms affected choice preferences in children and adolescents when they chose between (1) small immediate rewards and larger delayed rewards and (2) small certain rewards and larger probabilistic uncertain rewards.

Cerebral Cortex, 2008

A. Di Martino and A. Scheres contributed equally to the manuscript.

The evolving fi eld of research on Attention-Defi cit/Hyperactivity Disorder (ADHD) has now moved... more The evolving fi eld of research on Attention-Defi cit/Hyperactivity Disorder (ADHD) has now moved beyond the search for a common core dysfunction towards a recognition of ADHD as a heterogeneous disorder of multiple neuropsychological defi cits and hypothesised causal substrates (e.g. ). The variety of topics and research areas covered by the chapters of this book attests to this important theoretical and empirical progression but also to the realisation of the complexity implied by such an undertaking.

Neuroreport, 2008

Split-brain patients present a unique opportunity to address controversies regarding subcortical ... more Split-brain patients present a unique opportunity to address controversies regarding subcortical contributions to interhemispheric coordination. We characterized residual functional connectivity in a complete commissurotomy patient by examining patterns of lowfrequency BOLD functional MRI signal. Using independent components analysis and region-of-interest-based functional connectivity analyses, we demonstrate bilateral resting state networks in a patient lacking all major cerebral commissures. Compared with a control group, the patient's interhemispheric correlation scores fell within the normal range for two out of three regions examined. Thus, we provide evidence for bilateral resting state networks in a patient with complete commissurotomy. Such continued interhemispheric interaction suggests that, at least in part, cortical networks in the brain can be coordinated by subcortical mechanisms. NeuroReport 19:703^709

Psychological Medicine, 2003

A. Di Martino and A. Scheres contributed equally to the manuscript.

British Journal of Developmental Psychology, 2005

In the target paper, lists concerns about measures of attention and control that are used through... more In the target paper, lists concerns about measures of attention and control that are used throughout the field of clinical developmental psychology. In particular, doubts are raised about the construct validity of the measures of attention that led to conclude that sustained attention is deficient in ADHD whereas selective attention is not. We support the criticism, but argue that Wilding's suggestion that executive dysfunction is the fundamental problem underlying ADHD symptoms does not bring us much closer to understanding ADHD. We illustrate this by evaluating the more specified claim that inhibitory deficiencies are the fundamental problem underlying ADHD.

Neuroscience and Biobehavioral Reviews, 2003

Five models of attention deficit/hyperactivity disorder (ADHD) are reviewed. It is proposed that ... more Five models of attention deficit/hyperactivity disorder (ADHD) are reviewed. It is proposed that the cognitive-energetic model provides a reasonably comprehensive account of ADHD by incorporating the features of both the inhibition and delay aversion models. It is suggested that ADHD can only be accounted for by an analysis at three levels: top-down control, specific cognitive processes and energetic factors. It is argued that a refined and conceptually comprehensive neuropsychological battery is needed to advance research in ADHD. A widely distributed neural network involving frontal, basal ganglia, limbic and cerebellar loci seem implicated in ADHD. q

International Journal of Disability Development and Education, 2006

Journal of Experimental Psychology-learning Memory and Cognition, 1999

Journal of Child Psychology and Psychiatry, 2001

This study was aimed at (a) replicating findings of slow and variable response execution and slow... more This study was aimed at (a) replicating findings of slow and variable response execution and slow response inhibition in Attention Deficit\Hyperactivity Disorder (AD\HD), (b) investigating whether these deficits are specifically related to AD\HD or may also be observed in Oppositional Defiant Disorder (ODD), and children comorbid for AD\HDjODD, and (c) examining the role of activation level in task performance of children with AD\HD. To meet these aims, the stop paradigm was administered at three levels of activation, using a slow, medium, and fast presentation rate of stimuli, to 4 groups of children : 24 AD\HD children, 21 children with ODD, 27 children with comorbid AD\HDjODD, and 41 normal controls. As hypothesized, children with AD\HD exhibited a slow response execution process with considerable variability in the speed of responding compared to normal controls. Slow response execution was also observed in the comorbid AD\HDjODD group but not in the pure ODD group. Larger variability in the speed of responding was common to all disruptive groups compared with controls. In contrast to our hypothesis, no group differences emerged for inhibitory functioning. Finally, the slow event rate condition caused a further deterioration in the speed of the response execution process in both the AD\HD group and ODD group.

Journal of Abnormal Child Psychology, 2005

This study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associate... more This study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3)~whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99~children ages 6–12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).

The ability to exert self-control over one's thoughts and actions is crucial for successful funct... more The ability to exert self-control over one's thoughts and actions is crucial for successful functioning in daily life. To date, self-control development has been primarily studied from the perspective of externally driven inhibition. In this review, we introduce a new perspective on the development of self-control by highlighting the importance of intentional inhibition. First, we will review the existing behavioral and neuroscientific literature on the development of self-control from the perspective of externally driven inhibition. Next, we will introduce a new framework for studying the development of self-control from the perspective of intentional inhibition. We will discuss several recent studies in this domain, showing that intentional inhibition within cold contexts has an early development, but continues to develop through adolescence in motivational contexts. We conclude that understanding the developmental trajectory of intentional inhibition in cold and motivationally relevant contexts and its underlying mechanisms is an important direction for future research, which has important implications for our understanding of developmental disorders associated with problems in self-control, such as Attention Deficit Hyperactivity Disorder. (M.A. Schel). Please cite this article as: Schel, M. A., et al. New perspectives on self-control development: Highlighting the role of intentional inhibition. Neuropsychologia (2014), http://dx.

Key words attention-deficit hyperactivity disorder, symptoms of impulsivity, hyperactivity and in... more Key words attention-deficit hyperactivity disorder, symptoms of impulsivity, hyperactivity and inattention, academic and general procrastination

The goal of this study was to examine age effects on the ability/willingness to wait for large re... more The goal of this study was to examine age effects on the ability/willingness to wait for large rewards in a real temporal reward discounting task from childhood to adulthood. Therefore, a real temporal discounting (TD) task was administered to children aged 6-12 (n = 39), adolescents aged 13-17 (n = 28), and young adults aged 18-19 (n = 55). Findings indicated that the cross-sectional development of TD followed a quadratic pattern across age groups, with adolescents choosing more often than children and adults to wait for the large delayed reward, resulting in reward-maximization. Various interpretations of this finding were offered, including a focus on reward maximization despite an immature ability to exert self-control, and flexible self-control which was high during this task as a result of strong motivation to maximize financial gains.

Age-related differences in temporal discounting (TD) and risk taking, and their association, were... more Age-related differences in temporal discounting (TD) and risk taking, and their association, were examined in adolescents and young adults (n = 337) aged 12-27 years. Since monetary rewards are typically used in TD and risk-taking tasks, the association between monetary reward valuation and age and decision making in these tasks was explored as well. TD declined linearly with age, with a particularly sharp decline from 15 to 16 years. In contrast, risk taking was not correlated with age and TD. Reward valuation was not associated with TD and risk taking, and age-related differences in TD remained significant after controlling for reward valuation. Together, these findings suggest that risk taking and TD are two separate constructs with distinct

A review of the existing functional magnetic resonance imaging (fMRI) studies on reward anticipat... more A review of the existing functional magnetic resonance imaging (fMRI) studies on reward anticipation in patients with attention-deficit/hyperactivity disorder (ADHD) is provided. Meta-analysis showed a significant medium effect size (Cohen's d = 0.48-0.58) in terms of ventral-striatal (VS)-hyporesponsiveness in ADHD.

Temporal reward discounting (TD) refers to the decrease in subjective value of a reward when the ... more Temporal reward discounting (TD) refers to the decrease in subjective value of a reward when the delay to that reward increases. In recent years, a growing number of studies on the neural correlates of temporal reward discounting have been conducted. This article focuses on functional magnetic resonance imaging (fMRI) studies on TD in humans. First, we describe the different types of tasks (also from behavioral studies) and the dependent variables. Subsequently, we discuss the evidence for three neurobiological models of TD: the dual-systems model, the single-system model and the self-control model. Further, studies in which nontraditional tasks (e.g., with nonmonetary rewards) were used to study TD are reviewed. Finally, we discuss the neural correlates of individual differences in discounting, and its development across the lifespan. We conclude that the evidence for each of the three neurobiological models of TD is mixed, in that all models receive (partial) support, and several studies provide support for multiple models. Because of large differences between studies in task design and analytical approach, it is difficult to draw a firm conclusion regarding which model provides the best explanation of the neural correlates of temporal discounting. We propose that some components of these models can complement each other, and future studies should test the predictions offered by different models against each other. Several future research directions are suggested, including studying the connectivity between brain regions in relation to discounting, and directly comparing the neural mechanisms involved in discounting of monetary and primary rewards.

Difficulty waiting plays a primary role in symptoms of ADHD, in particular impulsivity. Current t... more Difficulty waiting plays a primary role in symptoms of ADHD, in particular impulsivity. Current theories suggest that relatively strong preferences for small immediate rewards as observed in ADHD-Combined type are the result of delay-related negative feelings. However, the measurement of difficulty waiting is typically limited to objective choices between small immediate and large delayed rewards. This study aimed at extending the measurement of difficulty waiting in ADHD-Combined type with ratings about subjective feelings. Children and adolescents (ages 6-17) with ADHD-Combined type (n=25), ADHD-Inattentive type (n=20) and matched typically developing participants (n=37) performed temporal reward discounting tasks, and completed a Visual Analogue Scale of subjectively experienced ease/ difficulty waiting. Although those with ADHD-Combined type demonstrated relatively steep temporal reward discounting, as reported elsewhere , there were no group differences for subjectively experienced ease/difficulty waiting. Additionally, correlations between subjective and objective measures of difficulty waiting were significantly higher in the ADHD-Combined type group than in the control group. These findings suggest that (a) those with ADHD-Combined type do not choose impulsively because they have more negative feelings about waiting than controls; (b) choices in the ADHD-Combined type group are more in accordance with/driven by their feelings than choices made by participants in the control group. (A. Scheres).

Biological Psychiatry, 2010

Background: Theoretical models have hypothesized that one core problem in attention-deficit/hyper... more Background: Theoretical models have hypothesized that one core problem in attention-deficit/hyperactivity disorder (ADHD) is abnormal reward processing. Temporal reward discounting (decreases in subjective reward value due to prereward delay) is of interest because of its relation with a key symptom of ADHD-impulsivity. This study investigated 1) whether steep temporal reward discounting (TD) is associated with ADHD-combined type (ADHD-C)/symptoms of hyperactivity-impulsivity specifically; 2) the role of reward magnitude in TD in ADHD-C/participants with symptoms of hyperactivity-impulsivity; and 3) whether steep TD in ADHD-C/participants with symptoms of hyperactivity-impulsivity is affected by session length.

Neuropsychologia, 2006

This study investigated whether age and ADHD symptoms affected choice preferences in children and... more This study investigated whether age and ADHD symptoms affected choice preferences in children and adolescents when they chose between (1) small immediate rewards and larger delayed rewards and (2) small certain rewards and larger probabilistic uncertain rewards.

Cerebral Cortex, 2008

A. Di Martino and A. Scheres contributed equally to the manuscript.

The evolving fi eld of research on Attention-Defi cit/Hyperactivity Disorder (ADHD) has now moved... more The evolving fi eld of research on Attention-Defi cit/Hyperactivity Disorder (ADHD) has now moved beyond the search for a common core dysfunction towards a recognition of ADHD as a heterogeneous disorder of multiple neuropsychological defi cits and hypothesised causal substrates (e.g. ). The variety of topics and research areas covered by the chapters of this book attests to this important theoretical and empirical progression but also to the realisation of the complexity implied by such an undertaking.

Neuroreport, 2008

Split-brain patients present a unique opportunity to address controversies regarding subcortical ... more Split-brain patients present a unique opportunity to address controversies regarding subcortical contributions to interhemispheric coordination. We characterized residual functional connectivity in a complete commissurotomy patient by examining patterns of lowfrequency BOLD functional MRI signal. Using independent components analysis and region-of-interest-based functional connectivity analyses, we demonstrate bilateral resting state networks in a patient lacking all major cerebral commissures. Compared with a control group, the patient's interhemispheric correlation scores fell within the normal range for two out of three regions examined. Thus, we provide evidence for bilateral resting state networks in a patient with complete commissurotomy. Such continued interhemispheric interaction suggests that, at least in part, cortical networks in the brain can be coordinated by subcortical mechanisms. NeuroReport 19:703^709

Psychological Medicine, 2003

A. Di Martino and A. Scheres contributed equally to the manuscript.

British Journal of Developmental Psychology, 2005

In the target paper, lists concerns about measures of attention and control that are used through... more In the target paper, lists concerns about measures of attention and control that are used throughout the field of clinical developmental psychology. In particular, doubts are raised about the construct validity of the measures of attention that led to conclude that sustained attention is deficient in ADHD whereas selective attention is not. We support the criticism, but argue that Wilding's suggestion that executive dysfunction is the fundamental problem underlying ADHD symptoms does not bring us much closer to understanding ADHD. We illustrate this by evaluating the more specified claim that inhibitory deficiencies are the fundamental problem underlying ADHD.

Neuroscience and Biobehavioral Reviews, 2003

Five models of attention deficit/hyperactivity disorder (ADHD) are reviewed. It is proposed that ... more Five models of attention deficit/hyperactivity disorder (ADHD) are reviewed. It is proposed that the cognitive-energetic model provides a reasonably comprehensive account of ADHD by incorporating the features of both the inhibition and delay aversion models. It is suggested that ADHD can only be accounted for by an analysis at three levels: top-down control, specific cognitive processes and energetic factors. It is argued that a refined and conceptually comprehensive neuropsychological battery is needed to advance research in ADHD. A widely distributed neural network involving frontal, basal ganglia, limbic and cerebellar loci seem implicated in ADHD. q

International Journal of Disability Development and Education, 2006

Journal of Experimental Psychology-learning Memory and Cognition, 1999

Journal of Child Psychology and Psychiatry, 2001

This study was aimed at (a) replicating findings of slow and variable response execution and slow... more This study was aimed at (a) replicating findings of slow and variable response execution and slow response inhibition in Attention Deficit\Hyperactivity Disorder (AD\HD), (b) investigating whether these deficits are specifically related to AD\HD or may also be observed in Oppositional Defiant Disorder (ODD), and children comorbid for AD\HDjODD, and (c) examining the role of activation level in task performance of children with AD\HD. To meet these aims, the stop paradigm was administered at three levels of activation, using a slow, medium, and fast presentation rate of stimuli, to 4 groups of children : 24 AD\HD children, 21 children with ODD, 27 children with comorbid AD\HDjODD, and 41 normal controls. As hypothesized, children with AD\HD exhibited a slow response execution process with considerable variability in the speed of responding compared to normal controls. Slow response execution was also observed in the comorbid AD\HDjODD group but not in the pure ODD group. Larger variability in the speed of responding was common to all disruptive groups compared with controls. In contrast to our hypothesis, no group differences emerged for inhibitory functioning. Finally, the slow event rate condition caused a further deterioration in the speed of the response execution process in both the AD\HD group and ODD group.

Journal of Abnormal Child Psychology, 2005

This study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associate... more This study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3)~whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99~children ages 6–12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).