Development of set-shifting ability from late childhood through early adulthood

Dissociable default-mode subnetworks subserve childhood attention and cognitive flexibility: Evidence from deep learning and stereotactic electroencephalography

Cognitive flexibility encompasses the ability to efficiently shift focus and forms a critical component of goal-directed attention. The neural substrates of this process are incompletely understood in part due to difficulties in sampling the involved circuitry. We leverage stereotactic intracranial recordings to directly resolve local-field potentials from otherwise inaccessible structures to study moment-to-moment attentional activity in children with epilepsy performing a flexible attentional task. On an individual subject level, we employed deep learning to decode neural features predictive of task performance indexed by single-trial reaction time. These models were subsequently aggregated across participants to identify predictive brain regions based on AAL atlas and FIND functional network parcellations. Through this approach, we show that fluctuations in beta (12-30 Hz) and gamma (30-80 Hz) power reflective of increased top-down attentional control and local neuronal processing within relevant large-scale networks can accurately predict single-trial task performance. We next performed connectomic profiling of these highly predictive nodes to examine task-related engagement of distributed functional networks, revealing exclusive recruitment of the dorsal default mode network during shifts in attention. The identification of distinct substreams within the default mode system supports a key role for this network in cognitive flexibility and attention in children. Furthermore, convergence of our results onto consistent functional networks despite significant inter-subject variability in electrode implantations supports a broader role for deep learning applied to intracranial electrodes in the study of human attention.

Cognitive flexibility: neurobehavioral correlates of changing one's mind

Behavioral and cognitive flexibility allow adaptation to a changing environment. Most tasks used to investigate flexibility require switching reactively in response to deterministic task-response rules. In daily life, flexibility often involves a volitional decision to change behavior. This can be instigated by environmental signals, but these are frequently unreliable. We report results from a novel "change your mind" task, which assesses volitional switching under uncertainty without the need for rule-based learning. Participants completed a two-alternative choice task, and following spurious feedback, were presented with the same stimulus again. Subjects had the opportunity to repeat or change their response. Forty healthy participants completed the task while undergoing a functional magnetic resonance imaging scan. Participants predominantly repeated their choice but changed more when their first response was incorrect or when the feedback was negative. Greater activations for changing were found in the inferior frontal junction, anterior insula (AI), anterior cingulate, and dorsolateral prefrontal cortex. Changing responses were also accompanied by reduced connectivity from the AI and orbitofrontal cortices to the occipital cortex. Using multivariate pattern analysis of brain activity, we predicted with 77% reliability whether participants would change their mind. These findings extend our understanding of cognitive flexibility in daily life by assessing volitional decision-making.

Growth trajectories for executive and social cognitive abilities in an Indian population sample: Impact of demographic and psychosocial determinants

Cognitive abilities are markers of brain development and psychopathology. Abilities, across executive, and social domains need better characterization over development, including factors that influence developmental change. This study is based on the cVEDA [Consortium on Vulnerability to Externalizing Disorders and Addictions] study, an Indian population based developmental cohort. Verbal working memory, visuo-spatial working memory, response inhibition, set-shifting, and social cognition (faux pas recognition and emotion recognition) were cross-sectionally assessed in > 8000 individuals over the ages 6-23 years. There was adequate representation across sex, urban-rural background, psychosocial risk (psychopathology, childhood adversity and wealth index, i.e. socio-economic status). Quantile regression was used to model developmental change. Age-based trajectories were generated, along with examination of the impact of determinants (sex, childhood adversity, and wealth index). Development in both executive and social cognitive abilities continued into adulthood. Maturation and stabilization occurred in increasing order of complexity, from working memory to inhibitory control to cognitive flexibility. Age related change was more pronounced for low quantiles in response inhibition (β∼4 versus  -1 versus -0.25 for lower quantiles). Wealth index had the largest influence on developmental change across cognitive abilities. Sex differences were prominent in response inhibition, set-shifting and emotion recognition. Childhood adversity had a negative influence on cognitive development. These findings add to the limited literature on patterns and determinants of cognitive development. They have implications for understanding developmental vulnerabilities in young persons, and the need for providing conducive socio-economic environments.

Overcoming cognitive set bias requires more than seeing an alternative strategy

Determining when to switch from one strategy to another is at the heart of adaptive decision-making. Previous research shows that humans exhibit a ‘cognitive set’ bias, which occurs when a familiar strategy occludes—even much better—alternatives. Here we examined the mechanisms underlying cognitive set by investigating whether better solutions are visually overlooked, or fixated on but disregarded. We analyzed gaze data from 67 American undergraduates (91% female) while they completed the learned strategy-direct strategy (LS-DS) task, which measures their ability to switch from a learned strategy (LS) to a more efficient direct strategy (DS or shortcut). We found that, in the first trial block, participants fixated on the location of the shortcut more when it was available but most (89.6%) did not adopt it. Next, participants watched a video demonstrating either the DS (N = 34 Informed participants) or the familiar LS (N = 33 Controls). In post-video trials, Informed participants used the DS more than pre-video trials and compared to Controls. Notably, 29.4% of Informed participants continued to use the LS despite watching the DS video. We suggest that cognitive set in the LS-DS task does not stem from an inability to see the shortcut but rather a failure to try it.

Are poor set-shifting and central coherence associated with everyday function in anorexia nervosa? A systematic review

BACKGROUND

There is increasing interest in associations between cognitive impairments and clinical symptoms in Anorexia Nervosa (AN), however, the relationship with everyday function is unclear. The current review synthesizes existing data regarding associations between scores on tests of set-shifting and central coherence and functional outcome measures for individuals with AN.

METHOD

A systematic electronic database search yielded 13 studies which included participants with current or lifetime AN where scores on a neuropsychological test of set-shifting or central coherence were directly or indirectly compared to a functional outcome measure.

RESULTS

Associations between set-shifting and central coherence performance measures and functional outcomes were limited in number and noted only in adult or mixed-age cohorts. Associations were noted at subscale level, suggesting they are specific in nature. In younger cohorts, assessments of executive functioning in everyday life appear sensitive to cognitive-behavioral flexibility issues.

CONCLUSIONS

Associations between cognitive performance and functional outcome have not been as systematically assessed in AN as in other psychiatric disorders. Key factors to address in future research include: (a) the use of function measures which are sensitive to both the level of impairment, and specific rather than general impairments (b) the ecological validity of measures, (c) the task impurity problem, especially in regard to cognitive flexibility assessment, and (d) the need to measure both cognitive deficits and strengths, because tests of specific cognitive processes may underestimate the ability to function in daily life due to compensatory strategies.

Improvement of Working Memory is a Mechanism for Reductions in Delay Discounting Among Mid-Age Individuals in an Urban Medically Underserved Area

BACKGROUND

Delay discounting, or the tendency to devalue rewards as a function of their delayed receipt, is associated with myriad negative health behaviors. Individuals from medically underserved areas are disproportionately at risk for chronic health problems. The higher rates of delay discounting and consequent adverse outcomes evidenced among low-resource and unstable environments suggest this may be an important pathway to explain health disparities among this population.

PURPOSE

The current study examined the effectiveness of a computerized working memory training program to decrease rates of delay discounting among residents of a traditionally underserved region.

METHODS

Participants (N = 123) were recruited from a community center serving low income and homeless individuals. Subjects completed measures of delay discounting and working memory and then took part in either an active or control working memory training.

RESULTS

Analyses indicated that participants in the active condition demonstrated significant improvement in working memory and that this improvement mediated the relation between treatment condition and reductions in delay discounting.

CONCLUSIONS

Results suggest that a computerized intervention targeting working memory may be effective in decreasing rates of delay discounting in adults from medically underserved areas (ClinicalTrials.gov number NCT03501706).

Subjectively and Objectively Measured Sleep Predict Differing Aspects of Cognitive Functioning in Adults

OBJECTIVE

To examine associations between subjectively-reported sleep and objectively-measured sleep (i.e., actigraphy) with different domains of cognitive functioning, and determine whether age may moderate these associations.

METHOD

In this cross-sectional study, a total of 489 participants (mean age = 45.4 years; SD = 18.8) completed a self-reported sleep measure and one week of actigraphy. Participants also completed a battery of cognitive tests measuring episodic memory, social cognition, executive functioning, and complex cognition (i.e., reasoning, visuospatial, and language abilities).

RESULTS

Multiple regression analyses revealed that greater objective sleep quality and longer onset latencies were both associated with better performance on measures of conceptual flexibility. In contrast, subjective sleep quality was not associated with performance in any cognitive domain after accounting for objective sleep variables. Age moderated sleep-cognition relationships in differing ways based on cognitive domain and facet of sleep assessed. For example, whereas poorer subjective sleep quality was associated with poorer complex cognition in younger, but not older adults, poorer objective sleep quality was associated with poorer conceptual flexibility in older, but not younger adults.

CONCLUSIONS

Objectively-measured and self-reported sleep are associated with differing aspects of executive functioning, with the latter related to executive functioning broadly and the former associated with conceptual flexibility in particular. Age moderates sleep-cognition relationships differentially depending on the method by which sleep quality and quantity are measured.

Neuroscience and mental state issues in forensic assessment

Neuroscience has already changed how the law understands an individual's cognitive processes, how those processes shape behavior, and how bio-psychosocial history and neurodevelopmental approaches provide information, which is critical to understanding mental states underlying behavior, including criminal behavior. In this paper, we briefly review the state of forensic assessment of mental conditions in the relative culpability of criminal defendants, focused primarily on the weaknesses of current approaches. We then turn to focus on neuroscience approaches and how they have the potential to improve assessment, but with significant risks and limitations.

Sex Differences in Adolescent Anorexia and Bulimia Nervosa: Beyond the Signs and Symptoms

PURPOSE OF REVIEW

We review research related to sex differences in eating disorders (EDs) in adolescents. Prior work has explored clinical differences; thus, we examine literature in areas identified as playing an etiological or maintenance role in EDs including: genetics, hormones, neurocognitive inefficiencies, and reward circuitry.

RECENT FINDINGS

Sex steroids appear to a play role in the unmasking of genetic risk for development of EDs and puberty may be a heightened period of risk for females. While neurocognitive differences have been well studied in adults with ED, research with adolescents has been less conclusive. Recent work suggests that neural circuitry involved in reward and punishment may play role in development and maintenance of EDs in females. Males are underrepresented in these areas of research. Given known sex differences in healthy adolescents, it is likely there are sex differences in the putative biological etiology/maintenance of EDs. Males should be included in future research.

The developing significance of context and function: Neuroscience and law

Neuroscience has already changed the understanding of how intent forms and is acted upon, how an individual's cognitive processes shape behavior, and how bio-psychosocial history and neurodevelopmental approaches provide information that has been largely missing from the assessment of intent. In this paper, we first review the state of forensic assessment of mental condition and intent, focused primarily on the weaknesses of the current approach. In Section 2, we discuss neurobehavioral forensic assessment, which is a neuroscience-based approach. Section 3 focuses on the changing understanding of mental illness and how neuroscience is pushing law towards a functional capacity-and-ability model and away from a diagnostic cut-off model. Finally, in Sections 4 and 5, we turn to the role of social and environmental context in shaping behavior and propose a model of behavioral intent in line with the scientific evidence.

Differences in set-shifting and central coherence across anorexia nervosa subtypes in children and adolescents

OBJECTIVE

Regarding executive functioning in anorexia nervosa (AN), little is known about differences between the restricting (AN-R) and binge eating/purging (AN-BP) subtypes. Especially for adolescents, there is sparse data. Hence, the current aim is to investigate differences in set-shifting, central coherence, and self-reported executive functioning across adolescent AN subtypes.

METHODS

Ninety AN-R, 21 AN-BP, and 63 controls completed an extensive assessment battery including neuropsychological tests for executive functioning and the self-report questionnaire Behavior Rating Inventory of Executive Functioning.

RESULTS

Patients with AN-R and AN-BP did not differ on neuropsychological measures, and both performed similarly to controls. Behavior Rating Inventory of Executive Functioning scores fell within the normal range with AN subtypes showing mostly comparable ratings. AN-BP patients scored higher on 2 composite indices and the "shift" subscale compared with AN-R.

CONCLUSIONS

The results suggest similar cognitive functioning in adolescent AN subtypes as well as healthy controls. However, more research is needed to draw more general conclusions.

Age and sex differences in behavioral flexibility, sensitivity to reward value, and risky decision-making

Compared with adults, adolescent behavior is often characterized by reduced behavioral flexibility, increased sensitivity to reward, and increased likelihood to take risks. These traits, which have been hypothesized to confer heightened vulnerability to psychopathologies such as substance use disorders (SUDs), have been the focus of studies in laboratory animal models that seek to understand their neural underpinnings. However, rodent studies to date have typically used only males and have adopted standard methodological practices (e.g., weight loss inducing food restriction) that are likely to have a disparate impact on adolescents compared with adults. Here, we used adolescent and adult Sprague-Dawley rats of both sexes to study instrumental behavior tasks that assess behavioral flexibility (strategy shifting and reversal learning; Experiment 1), sensitivity to reward value (outcome devaluation; Experiment 2), and risky decision making (probability discounting; Experiment 3). In Experiment 1, we found that adolescents were faster to acquire reversal learning than adults but there were no differences in strategy shifting. In Experiments 2 and 3, adolescents and adults were equally sensitive to changes in reward value and exhibited similar reductions in preference for a large reward when reinforcement probability was decreased. However, adolescents responded more efficiently and earned reinforcers at a higher rate than their same-sex, adult counterparts. Together, these findings provide only limited support for the existence of an "adolescent-typical" phenotype in Sprague-Dawley rats and instead suggest that age differences in the expression of these behaviors may depend on conditions such as pubertal status and motivational state. (PsycINFO Database Record

The association between symptoms of autism and neuropsychological performance in females with Anorexia Nervosa

The aim of this study was to investigate the relationship between symptoms of autism spectrum disorder (ASD) and performance on measures of set-shifting and central coherence in a sample of females with anorexia nervosa (AN). Ninety-nine females aged 12-47, recruited from inpatient and day patient eating disorder services, were assessed with the Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2), as well as the Wechsler Abbreviated Scale of Intelligence, 2nd edition (WASI-II); Wisconsin Card Sorting Test (WCST); Rey-Osterrieth Complex Figure Test (ROCFT) and self-report questionnaires assessing eating disorder pathology, depression, cognitive rigidity and attention to detail. Individuals scoring above clinical cut-off on the ADOS-2 (N = 35) reported significantly higher levels of cognitive rigidity than those with lower levels of ASD symptoms but there was no difference between groups on self-reported attention to detail. There group with high levels of ASD symptoms also made significantly more perseverative errors on the WCST but there was no association between ASD symptoms and performance on the ROCFT. The group who scored above cut-off on the ADOS-2 were significantly younger than the sub-clinical groups. The presence of symptoms associated with ASD appears to be related to increased cognitive rigidity in females with AN.

Transactional relations between caregiving stress, executive functioning, and problem behavior from early childhood to early adolescence

Developmental psychopathologists face the difficult task of identifying the environmental conditions that may contribute to early childhood behavior problems. Highly stressed caregivers can exacerbate behavior problems, while children with behavior problems may make parenting more difficult and increase caregiver stress. Unknown is: (a) how these transactions originate, (b) whether they persist over time to contribute to the development of problem behavior and (c) what role resilience factors, such as child executive functioning, may play in mitigating the development of problem behavior. In the present study, transactional relations between caregiving stress, executive functioning, and behavior problems were examined in a sample of 1,388 children with prenatal drug exposures at three developmental time points: early childhood (birth to age 5), middle childhood (ages 6 to 9), and early adolescence (ages 10 to 13). Transactional relations differed between caregiving stress and internalizing versus externalizing behavior. Targeting executive functioning in evidence-based interventions for children with prenatal substance exposure who present with internalizing problems and treating caregiving psychopathology, depression, and parenting stress in early childhood may be particularly important for children presenting with internalizing behavior.

Executive Functions Do Not Mediate Prospective Relations between Indices of Physical Activity and Academic Performance: The Active Smarter Kids (ASK) Study

Changes in cognitive function induced by physical activity have been proposed as a mechanism for the link between physical activity and academic performance. The aim of this study was to investigate if executive function mediated the prospective relations between indices of physical activity and academic performance in a sample of 10-year-old Norwegian children. The study included 1,129 children participating in the Active Smarter Kids (ASK) trial, followed over 7 months. Structural equation modeling (SEM) with a latent variable of executive function (measuring inhibition, working memory, and cognitive flexibility) was used in the analyses. Predictors were objectively measured physical activity, time spent sedentary, aerobic fitness, and motor skills. Outcomes were performance on national tests of numeracy, reading, and English (as a second language). Generally, indices of physical activity did not predict executive function and academic performance. A modest mediation effect of executive function was observed for the relation between motor skills and academic performance. Trial registration: Clinicaltrials.gov registry, trial registration number: NCT02132494.

Cognitive Flexibility in Juvenile Anorexia Nervosain Relation to Comorbid Symptoms of Depression, Obsessive Compulsive Symptoms and Duration of Illness

OBJECTIVE

Whereas the evidence in adolescents is inconsistent, anorexia nervosa (AN) in adults is characterized by weak cognitive flexibility. This study investigates cognitive flexibility in adolescents with AN and its potential associations with symptoms of depression, obsessive compulsive disorder (OCD), and duration of illness.

METHODS

69 patients and 63 age-matched healthy controls (HC) from 9 till 19 years of age were assessed using the Trail-Making Test (TMT) and self-report questionnaires.

RESULTS

In hierarchical regression analyses, set-shifting ability did not differ between AN and HC, whereas AN patients reported significantly higher rates of depression symptoms and OCD symptoms. Age significantly predicted set-shifting in the total sample. Only among AN patients aged 14 years and older did set-shifting decline with increasing age.

DISCUSSION

The presence of AN with depression or OCD symptoms or the duration of illness do not influence cognitive flexibility in children and adolescents. Early interventions may be helpful to prevent a decline in cognitive flexibility in adolescent AN with increasing age.

The longitudinal development of social and executive functions in late adolescence and early adulthood

Our earlier work suggests that, executive functions and social cognition show protracted development into late adolescence and early adulthood (Taylor et al., 2013). However, it remains unknown whether these functions develop linearly or non-linearly corresponding to dynamic changes to white matter density at these age ranges. Executive functions are particularly in demand during the transition to independence and autonomy associated with this age range (Ahmed and Miller, 2011). Previous research examining executive function (Romine and Reynolds, 2005) and social cognition (Dumontheil et al., 2010a) in late adolescence has utilized a cross sectional design. The current study employed a longitudinal design with 58 participants aged 17, 18, and 19 years completing social cognition and executive function tasks, Wechsler Abbreviated Scale of Intelligence (Wechsler, 1999), Positive and Negative Affect Schedule (Watson et al., 1988), and Hospital Anxiety and Depression Scale (Zigmond and Snaith, 1983) at Time 1 with follow up testing 12–16 months later. Inhibition, rule detection, strategy generation and planning executive functions and emotion recognition with dynamic stimuli showed longitudinal development between time points. Self-report empathy and emotion recognition functions using visual static and auditory stimuli were stable by age 17 whereas concept formation declined between time points. The protracted development of some functions may reflect continued brain maturation into late adolescence and early adulthood including synaptic pruning (Sowell et al., 2001) and changes to functional connectivity (Stevens et al., 2007) and/or environmental change. Clinical implications, such as assessing the effectiveness of rehabilitation following Head Injury, are discussed.

Cognitive flexibility mediates the relation between intolerance of uncertainty and safety signal responding in those with panic disorder

There is a growing literature associating anxiety disorders with an inability to inhibit defensive responding during safety conditions of threatening tasks. However, investigations on the relation between panic disorder (PD) and defensive responding to safety have yielded mixed results. A recent study from our laboratory revealed that intolerance of uncertainty (IU) moderates this association, such that only individuals with PD and a high IU exhibit heightened startle potentiation during safety. The mechanism underlying this relationship is unknown. Given that safety conditions typically alternate with periods of threat, cognitive flexibility (i.e., the ability to adjust one's habitual responding to a situation, given the input of new information) may be involved in the ongoing reappraisal of danger and adjustment of defensive responding. Thus, the present study sought to investigate whether deficits in cognitive flexibility mediate the association between IU and defensive responding to safety among a sample of 71 adults diagnosed with PD. As hypothesised, cognitive flexibility mediated the relationship between IU and heightened startle potentiation during safety conditions. This finding suggests that within this subgroup, a failure to inhibit defensive responding during safety conditions may be due to deficits in cognitive flexibility.

Urinary brain-derived neurotrophic factor as a biomarker of executive functioning

BACKGROUND/AIMS

Neurotrophins such as brain-derived neurotrophic factor (BDNF) are vital for neuronal survival and adaptive plasticity. With high BDNF gene expression in the prefrontal cortex, BDNF is a potential regulatory factor for building and maintaining cognitive reserves. Recent studies suggest that individual differences in executive functioning, a broad cognitive domain reliant upon frontal lobe structure and function, are governed in part by variance in BDNF polymorphisms. However, as neurogenetic data are not necessarily indicative of in vivo neurochemistry, this study examines the relationship between executive functioning and the neurotransmitter by measuring peripheral BDNF levels.

METHODS

Fifty-two healthy young adults completed a battery of standardized executive function tests. BDNF levels, adjusted for creatinine, were quantified with enzyme-linked immunosorbent assay of urine samples taken at the time of testing.

RESULTS

BDNF concentration was positively associated with cognitive flexibility but had no relationship with working memory, abstract reasoning/planning, self-monitoring/response inhibition, or fluency.

CONCLUSIONS

These results individuate cognitive flexibility as the specific facet of executive functioning associated with in vivo BDNF levels. This study also validates urinary BDNF as a peripheral biomarker of cognition in healthy adults.

Utility of the N-back task in survivors of childhood acute lymphoblastic leukemia

The N-back task is often used in functional brain imaging studies to activate working memory networks; however, limited information is available on its association to clinical outcomes in children or cancer survivors. A total of 137 survivors of acute lymphoblastic leukemia (ALL; mean current age = 14.3 years, SD = 4.8; time since diagnosis = 7.6 years, SD = 1.6) completed the N-back task and comprehensive neurocognitive testing, including standardized measures of attention, processing speed, and working memory. Results indicated that females demonstrated significantly slower reaction times (0-back p = .02; 1-back p = .03) than males. Survivors <15 years old at the time of testing demonstrated a significant decrease in accuracy as working memory load increased compared to survivors ≥15 years old (p < .001). Performance on the N-back task was associated with nonverbal working memory (rs = .56, p < .001) in survivors ≥15 years of age. For younger survivors, N-back performance was more strongly associated with attention skills. Results suggest the N-back assesses different cognitive constructs at younger compared to older childhood ages. These age differences should be considered in interpreting functional brain imaging results.

Endogenous-cue prospective memory involving incremental updating of working memory: an fMRI study

INTRODUCTION

Prospective memory paradigms are conventionally classified on the basis of event-, time-, or activity-based intention retrieval. In the vast majority of such paradigms, intention retrieval is provoked by some kind of external event. However, prospective memory retrieval cues that prompt intention retrieval in everyday life are commonly endogenous, i.e., linked to a specific imagined retrieval context. We describe herein a novel prospective memory paradigm wherein the endogenous cue is generated by incremental updating of working memory, and investigated the hemodynamic correlates of this task.

METHODS

Eighteen healthy adult volunteers underwent functional magnetic resonance imaging while they performed a prospective memory task where the delayed intention was triggered by an endogenous cue generated by incremental updating of working memory. Working memory and ongoing task control conditions were also administered.

RESULTS

The 'endogenous-cue prospective memory condition' with incremental working memory updating was associated with maximum activations in the right rostral prefrontal cortex, and additional activations in the brain regions that constitute the bilateral fronto-parietal network, central and dorsal salience networks as well as cerebellum. In the working memory control condition, maximal activations were noted in the left dorsal anterior insula.

CONCLUSIONS

Activation of the bilateral dorsal anterior insula, a component of the central salience network, was found to be unique to this 'endogenous-cue prospective memory task' in comparison to previously reported exogenous- and endogenous-cue prospective memory tasks without incremental working memory updating. Thus, the findings of the present study highlight the important role played by the dorsal anterior insula in incremental working memory updating that is integral to our endogenous-cue prospective memory task.

Less-structured time in children's daily lives predicts self-directed executive functioning

Executive functions (EFs) in childhood predict important life outcomes. Thus, there is great interest in attempts to improve EFs early in life. Many interventions are led by trained adults, including structured training activities in the lab, and less-structured activities implemented in schools. Such programs have yielded gains in children's externally-driven executive functioning, where they are instructed on what goal-directed actions to carry out and when. However, it is less clear how children's experiences relate to their development of self-directed executive functioning, where they must determine on their own what goal-directed actions to carry out and when. We hypothesized that time spent in less-structured activities would give children opportunities to practice self-directed executive functioning, and lead to benefits. To investigate this possibility, we collected information from parents about their 6–7 year-old children's daily, annual, and typical schedules. We categorized children's activities as “structured” or “less-structured” based on categorization schemes from prior studies on child leisure time use. We assessed children's self-directed executive functioning using a well-established verbal fluency task, in which children generate members of a category and can decide on their own when to switch from one subcategory to another. The more time that children spent in less-structured activities, the better their self-directed executive functioning. The opposite was true of structured activities, which predicted poorer self-directed executive functioning. These relationships were robust (holding across increasingly strict classifications of structured and less-structured time) and specific (time use did not predict externally-driven executive functioning). We discuss implications, caveats, and ways in which potential interpretations can be distinguished in future work, to advance an understanding of this fundamental aspect of growing up.

Sensitivity of fNIRS to cognitive state and load

Functional near-infrared spectroscopy (fNIRS) is an emerging low-cost noninvasive neuroimaging technique that measures cortical bloodflow. While fNIRS has gained interest as a potential alternative to fMRI for use with clinical and pediatric populations, it remains unclear whether fNIRS has the necessary sensitivity to serve as a replacement for fMRI. The present study set out to examine whether fNIRS has the sensitivity to detect linear changes in activation and functional connectivity in response to cognitive load, and functional connectivity changes when transitioning from a task-free resting state to a task. Sixteen young adult subjects were scanned with a continuous-wave fNIRS system during a 10-min resting-state scan followed by a letter n-back task with three load conditions. Five optical probes were placed over frontal and parietal cortices, covering bilateral dorsolateral PFC (dlPFC), bilateral ventrolateral PFC (vlPFC), frontopolar cortex (FP), and bilateral parietal cortex. Activation was found to scale linearly with working memory load in bilateral prefrontal cortex. Functional connectivity increased with increasing n-back loads for fronto-parietal, interhemispheric dlPFC, and local connections. Functional connectivity differed between the resting state scan and the n-back scan, with fronto-parietal connectivity greater during the n-back, and interhemispheric vlPFC connectivity greater during rest. These results demonstrate that fNIRS is sensitive to both cognitive load and state, suggesting that fNIRS is well-suited to explore the full complement of neuroimaging research questions and will serve as a viable alternative to fMRI.

The development of mental scenario building and episodic foresight

Episodic foresight is the future-directed counterpart of episodic memory. It is a sophisticated, potentially uniquely human capacity, with tremendous adaptive consequences. Here we review what is currently known about its development through early childhood. We tackle this from two distinct perspectives. First, we present the first systematic evaluation of the development of purported components of mental scenario building as highlighted by a theater metaphor: the stage, the playwright, the set, the actors, the director, the executive producer, and the broadcaster. We find that, although there are diverse developmental trajectories, by 4 years of age children have acquired the basic cognitive components required to mentally construct specific future events. Second, we examine recent attempts to test children's episodic foresight more directly and find that results are in line with those examining the development of required components. This is not to say that children younger than four have no inkling of upcoming events or that older children have nothing left to learn about constructing the future. Episodic foresight, and its neurocognitive foundations, continues to develop throughout childhood.

Women are more sensitive than men to prior trial events on the Stop-signal task

Sexual dimorphism in the brain and cognition is a topic of widespread interest. Many studies of sex differences have focused on visuospatial and verbal abilities, but few studies have investigated sex differences in executive functions. We examined two key components of executive function - response inhibition and response monitoring - in healthy men (n = 285) and women (n = 346) performing the Stop-signal task. In this task, participants are required to make a key press to a stimulus, unless a tone is presented at some delay following the initial stimulus presentation; on these infrequent trials, participants are instructed to inhibit their planned response. Response inhibition was assessed with an estimate of the latency needed to inhibit a response (stop-signal reaction time), and response monitoring was measured by calculating the degree to which participants adjusted their reaction times based on the immediately preceding trial (e.g., speeding following correct trials and slowing following errors). There were no sex differences in overall accuracy or response inhibition, but women showed greater sensitivity to trial history. Women sped up more than men following correct 'Go' trials, and slowed down more than men following errors. These small but statistically significant effects (Cohen's d = 0.25-0.3) suggest more flexible adjustments in speed-accuracy trade-offs in women and greater cognitive flexibility associated with the responsive control of action.

fMRI task parameters influence hemodynamic activity in regions implicated in mental set switching

Mental set switching is a complex executive function that is required when the focus of attention must be altered in order to adapt to a frequently-changing environment. While there is generally acceptance that switching is subserved by a fronto-parietal network, there is a considerable lack of consistency across studies as to other brain regions involved in executing mental set switches. This functional magnetic resonance imaging study sought to determine whether paradigmatic design aspects such as stimulus complexity, motor response complexity, and stimulus ordering could account for the differences in reporting of brain regions associated with mental set switching across previous studies. Several brain regions, including the striatum and anterior cingulate, previously associated with mental set switching were found to be related more to resolving intra-stimulus interference conferred by increased stimulus complexity and increased motor response complexity than to executing the mental set switch. In considering stimulus ordering, defined as the number of non-switch trials preceding a switch trial, brain activity was not observed in the fronto-parietal regions typically associated with switching but rather in regions in the anterior prefrontal cortex, sensorimotor cortex, and secondary visual cortices. Our results indicate that these important paradigm design aspects that are theoretically unrelated to set switching per se should be balanced and controlled for in future experiments, so as not to obscure clear identification of brain regions truly engaged in mental set switching.

Executive functions, depressive symptoms, and college adjustment in women

Many students have difficulty adjusting to college, and the contribution of academic and relational factors have been considered in previous research. In particular, depression commonly emerges among college women at this time and could be related to poor adjustment to college. This study examined the relationship between executive functions, depressive symptoms, and college adjustment in college women. Seventy-seven female participants from a midsize urban university completed the Wechsler Abbreviated Scale of Intelligence, College Adjustment Scale, Beck Depression Inventory-Second Edition, Behavior Rating Inventory of Executive Function-Adult Version, and four subtests from the Delis-Kaplan Executive Function System: the Trail-Making Test, Design Fluency Test, Verbal Fluency Test, and Color-Word Interference Test. After controlling for IQ score, hierarchical regression analyses showed that subjective and objective measures of executive functioning and depressive symptoms were significantly related to college adjustment problems in academic, relational, and psychological areas. The current study provides evidence for a relationship between cognitive abilities, psychiatric symptoms, and college adjustment.

The contribution of children's temperamental fear and effortful control to restraint and seclusion during inpatient treatment in a psychiatric hospital

The current study examined temperament characteristics as risk factors for restraint and seclusion (R/S) events in psychiatrically hospitalized youth, extending work that has sought to identify R/S risk factors and research examining temperament-behavior problem associations that has largely relied upon community samples. It was anticipated that children with poor effortful control (EC) and greater frustration would have more instances of R/S during psychiatric hospitalization. The contribution of children's fearfulness to R/S was also examined. A measure of temperament was completed by youths' clinicians and youths (n = 52) completed objective measures of EC. The frequency of R/S events for each participant was obtained from hospital records. After controlling for R/S risk factors, lower EC and higher fearfulness predicted increased R/S occurrences during the first 2 weeks of hospitalization and over the course of children's entire hospitalization. These findings indicate that temperament should potentially be considered in individualized treatment plans targeting the prevention and/or reduction of R/S. Additional implications of the findings are also discussed.

Cognitive set-shifting in anorexia nervosa

OBJECTIVE

Adult anorexia nervosa (AN) is associated with inefficient cognitive flexibility and set-shifting. Whether such inefficiencies also characterize adolescent AN is an important area of research.

METHOD

Adolescents with AN and matched controls were administered a computerized task that required initial learning of an explicit rule using corrective feedback and learning of a new rule after a set number of trials. Adult patients with AN and controls were also examined.

RESULTS

Adolescents with AN did not differ from matched controls with respect to set-shifting cost (decrease in performance after rule change), whereas adults with AN had significantly greater set-shifting cost compared with controls.

DISCUSSION

This study suggests that set-shifting inefficiencies may not be a vulnerability factor for AN development in adolescents with AN, but might become an important aspect of the disorder at later age, and could point towards developmental neurobiologic brain changes that could affect AN at different ages.

A three-year longitudinal functional magnetic resonance imaging study of performance monitoring and test-retest reliability from childhood to early adulthood

Previous cross-sectional functional magnetic resonance imaging studies have shown that performance monitoring functions continue to develop well into adolescence, associated with increased activation in brain regions important for cognitive control (prefrontal cortex, anterior cingulate cortex, and parietal cortex). To date, however, the development of performance monitoring has not yet been studied longitudinally, which leaves open the question whether changes can be detected within individuals over time. In the present study, human boys and girls, between ages 8 and 27 years, performed a child-friendly rule-switch task in the scanner on two occasions ∼3.5 years apart. Change versus stability was examined using two methods: (1) repeated-measures analyses and (2) test-retest reliabilities of blood oxygenation level-dependent responses. Results showed that with increasing age, participants performed better on the task. The changes in neural activation associated with the processing of performance feedback were, however, more reliably correlated with changes in performance than with age. Test-retest reliability was at least fair to good for adults and adolescents, but poor to fair for the youngest age group. Substantially more variability was observed in the pattern and magnitude of children compared with adults, which may be interpreted as proxy for developmental change. Together, the results show that (1) change within individuals is variable, and more so for children than for adolescents and adults, and (2) performance is a better predictor for change in neural activation over time. These findings set the stage for studying developmental change in the perspective of multiple predictors, rather than solely by divisions based on age groups.

The developmental course of executive functioning in schizophrenia

Executive dysfunction is a core feature of schizophrenia, but our understanding of the developmental course of this neuropsychological domain in the disease remains largely unexplored. A review of the research evidence points to a number of persistent debates about the course of executive functioning and its relation to illness course. A better understanding of the neurocognitive trajectories of executive functioning in schizophrenia could help identify the risk and modifying factors that influence the onset, severity and course of disease, and the chance to re-direct or re-shape that course and improve outcomes. To accomplish this requires assessment of the diverse and integrated nature of those abilities, and the changes over time in those abilities requires multiple instruments and techniques in order to improve the research methods and understanding of an important area of impairment in schizophrenia.