The objective of this study was to understand older adults’ perceptions of the connections between an exergame intervention, “I Am Dolphin,” and their subjective well-being. Researchers conducted three focus groups with 14 older adults who participated in the exergame feasibility study. The semi-structured focus groups were transcribed, coded, and analysed using deductive and inductive techniques. Three themes were constructed related to playing the exergame and participants’ subjective well-being: 1) elevated mood (through scheduled activity, immersion, and socialization), 2) feelings of achievement (especially following frustration and competition), and 3) perceived cognitive or physical changes. These findings will help researchers better understand how exergames may relate to the well-being of older adults. Future investigators could use these findings to create and implement new exergame interventions.

Abstract Time spent out of the home and in the surrounding neighborhood has numerous physical health benefits, but the cognitive benefits are less clear. Evidence suggests that executive functions are important to navigating activity outside the home. This study examined whether time spent outside in participants’ immediate neighborhoods was more strongly associated with executive function than memory. Participants were adults with mild cognitive impairment and history of traumatic brain injury (TBI) enrolled in an immersive computer game intervention (N=11; 63.6% male; mean=59.0 years, range: 42-75). At baseline, participants completed the Life Space Questionnaire (LSQ) and cognitive tests of Stroop (executive function), Rey Auditory Verbal Learning Test (RAVLT) (memory), and Pattern Comparison Test (PCT) (processing speed). Cognitive tests were performed on an iPad to precisely measure reaction time. Pearson correlations were used to examine the association between the LSQ and cognitive measures. Although time spent in the neighborhood was not statistically associated with performance on cognitive measures, the magnitude of the correlations was noteworthy. After adjusting for age and education, days spent in the neighborhood were more strongly associated with better executive function (Stroop) (r=-0.58, p=0.10) and processing speed (PCT) (r=-0.27, p=0.49). Additionally, neighborhood exposure explained a larger proportion of the variance in Stroop and PCT rather than in RAVLT. In patients with past TBI, time spent outside of the home in the neighborhood may be associated with better executive functions through engagement with one’s environment. We will further describe objective measures of time spent outside the home using GPS.

Abstract Physical activity is an effective intervention to prevent or delay cognitive decline and dementia in older adults; however, many have difficulty achieving recommended moderate- to vigorous-intensity guidelines. This study examined the impact of low-intensity daily walking activity on executive cognitive and brain function in 66 older adults (mean age=67.26 ; SD=6.04). Daily walking activity was measured using a step activity monitor and brain function was assessed using functional magnetic resonance imaging during the Flanker task. Analyses included whole and region of interest (ROI) in the right middle frontal gyrus (RMFG), occipital cortex (OCC) and anterior cingulate (ACC). Partial correlations were performed between step activity, behavioral performance, and ROI activation, adjusting for age and education. Most of the step activity was in the low-intensity range. No associations were observed between step activity and task performance (p>.05). Task-related activation occurred in the RMFG, lateral OCC and paracingulate (p<.01). Increased activation in the RMFG was associated with greater amount r(62)=.390, p=.001, duration r(62)=.309, p=.013 and frequency r(62)=.327, p=.007 of step activity. Stratification by sex revealed a positive association between amount of step activity and RMFG activation in women r(44)= .360, p=.014, but not men. Whole brain correlation revealed that amount of step activity was positively associated with precuneus activation (p<.01), an area impacted early in Alzheimer’s disease. These results support the benefits of low intensity daily walking activity on prefrontal function in older adults and suggest the importance of designing attainable and sustainable physical activity interventions to promote brain health in older adults.

Objectives: Although generalized anxiety disorder (GAD) is one of the most prevalent anxiety disorders in older adults, very little is known about the neurobiology of worry, the hallmark symptom of GAD in adults over the age of 60. This study investigated the neurobiology and neural circuitry of worry in older GAD patients and controls. Method: Twenty older GAD patients and 16 age-matched controls (mean age = 67.88) were compared on clinical measures and neural activity during worry using functional magnetic resonance imaging. Results: As expected, worry elicited activation in frontal regions, amygdala, and insula within the GAD group, with a similar but less prominent frontal pattern was observed in controls. Effective connectivity analyses revealed a positive directional circuit in the GAD group extending from ventromedial through dorsolateral prefrontal cortices, converging on the amygdala. A less complex circuit was observed in controls with only dorsolateral prefrontal regions converging on the amygdala; however, a separate circuit passing through the orbitofrontal cortex converged on the insula. Conclusion: Results elucidate a different neurobiology of pathological versus normal worry in later life. A limited resource model is implicated wherein worry in GAD competes for the same neural resources (e.g. prefrontal cortical areas) that are involved in the adaptive regulation of emotion through cognitive and behavioral strategies.

Adolescence is a transitional period in development that is marked by a distinct, typical behavioral profile of high rates of exploration, novelty-seeking, and emotional lability. While these behaviors generally assist the adolescent transition to independence, they can also confer vulnerability for excessive risk-taking and psychopathology, particularly in the context of specific environmental or genetic influences. As prevention research depends on the identification of targets of vulnerability, the following review will discuss the interplay among motivational systems including reward-related, avoidance-related, and regulatory processes in typical and atypical adolescent development. Each set of processes will be discussed in relation to their underlying neural correlates and distinct developmental trajectories. Evidence suggests that typical adolescent behavior and the risk for atypical development are mediated by heightened adolescent responsiveness of reward-related and avoidance-related systems under specific conditions, concurrent with poor modulation by immature regulatory processes. Finally, we will propose strategies to exploit heightened reward processing to reinforce inhibitory control, which is an essential component of regulatory processes in prevention interventions.

Cardiovascular (CV) risk factors, such as hypertension, diabetes, and hyperlipidemia are associated with cognitive impairment and risk of dementia in older adults. However, the mechanisms linking them are not clear. This study aims to investigate the association between aggregate CV risk, assessed by the Framingham general cardiovascular risk profile, and functional brain activation in a group of community-dwelling older adults. Sixty participants (mean age: 64.6 years) from the Brain Health Study, a nested study of the Baltimore Experience Corps Trial, underwent functional magnetic resonance imaging using the Flanker task. We found that participants with higher CV risk had greater task-related activation in the left inferior parietal region, and this increased activation was associated with poorer task performance. Our results provide insights into the neural systems underlying the relationship between CV risk and executive function. Increased activation of the inferior parietal region may offer a pathway through which CV risk increases risk for cognitive impairment.

A thorough understanding of the neurobiology of late life anxiety is likely to depend on the use of brain imaging techniques such as magnetic resonance imaging (MRI). Generalized anxiety disorder (GAD) is one of the most prevalent anxiety disorders in older adults, and is thus a focus for neurobiological studies using MRI. This study tested 1–3 weeks predictors of unsuccessful scan outcomes (i.e., scan trials in which the participant moved excessively or prematurely terminated the scan) in older adults with GAD (n = 39) and age- and sex-matched nonanxious controls (n = 21). It was hypothesized that successful completion of a prior MRI scan, clinical status (GAD versus control), and scores on the Anxiety Sensitivity Index (ASI; Peterson et al. 1986), a measure tapping psychological aspects of medical interventions, would predict scan outcome when current diagnoses of claustrophobia were controlled. In logistic regression analyses, unsuccessful scan outcome was predicted by prior MRI completion and ASI Mental Concerns subscale scores, but not clinical status. This model correctly classified 91% of successful and 71% of unsuccessful scans. An alternative model that included a single ASI item rather than Mental Concerns subscale scores showed similar performance, and a model including categorical anxiety sensitivity groups was also effective but slightly less accurate. Implications for improving the success rates of MRI with older adults are discussed.

AbstractThis chapter considers the relationship of disorders to brain function. It begins by defining executive functions and their importance to prosocial behavior and independent functioning. It then describes how these functions develop concomitantly with prefrontal brain growth through childhood and adolescence and decline in late life. Next it reviews specific mental disorders that arise during these developmental windows and the executive dysfunctions common to those disorders. The disorders considered include attention deficit hyperactivity disorder, schizophrenia, depression, generalized anxiety disorder, Huntington's disease, Parkinson's disease, and possibly Alzheimer's disease. The chapter concludes by highlighting the importance of imaging and biomarkers, methods that will continue to elucidate brain-behavior relationships and so aid early detection, prognosis, and treatment.

Recent advances in neuroimaging have permitted testing of hypotheses regarding the neural bases of individual differences, but this burgeoning literature has been characterized by inconsistent results. To test the hypothesis that differences in task demands could contribute to between-study variability in brain-behavior relationships, we had participants perform 2 tasks that varied in the extent of cognitive involvement. We examined connectivity between brain regions during a low-demand vigilance task and a higher-demand digit-symbol visual search task using Granger causality analysis (GCA). Our results showed 1) Significant differences in numbers of frontoparietal connections between low- and high-demand tasks 2) that GCA can detect activity changes that correspond with task-demand changes, and 3) faster participants showed more vigilance-related activity than slower participants, but less visual-search activity. These results suggest that relatively low-demand cognitive performance depends on spontaneous bi-directionally fluctuating network activity, whereas high-demand performance depends on a limited, unidirectional network. The nature of brain-behavior relationships may vary depending on the extent of cognitive demand. High-demand network activity may reflect the extent to which individuals require top-down executive guidance of behavior for successful task performance. Low-demand network activity may reflect task- and performance monitoring that minimizes executive requirements for guidance of behavior.

Despite the widespread prevalence of generalized anxiety disorder (GAD) in later life, almost nothing is known about the neural aspects of worry in adults over the age of 60. Given the ongoing rapid increase in the older adult population, the relatively poor response rates to current interventions for late life GAD, and the effects of age-related changes to the brain, additional research on worry neurobiology is needed. The study group comprised 15 older GAD patients and 15 matched controls who were compared on clinical measures and brain volumes. It was expected that prefrontal cortex (PFC) volumes [medial orbital cortex (mOFC), dorsolateral cortex (DLPFC)] would show positive relations to worry scores, and weaker relations to more general measures of anxiety and depression. Negative relations were expected between amygdala volumes and worry scores. As expected, mOFC volumes were positively related to worry scores; however, DLPFC and amygdala volumes were not. The mOFC is involved in emotional decision-making under uncertain conditions and has the ability to suppress the amygdala, both of which are hypothesized functions of worry. Results are partly consistent with GAD theory and suggest that worry may involve neural areas that are also involved in the successful control of anxiety.

We used event-related functional magnetic resonance imaging (fMRI) to measure prefrontal cortex (PFC) activity while younger and older adults performed an item-recognition task in which the memory-set size varied between 1 and 8 letters. Each trial was composed of a 4-sec encoding period in which subjects viewed random letter strings, a 12-sec retention period and a 2-sec retrieval period in which subjects decided whether a single probe letter was or was not part of the memory set. For both groups, reaction-time (RT) increased and accuracy decreased with increasing memory set-size. Analyses of individual subjects' performance and cortical activity indicated that speed and accuracy accounted for variance in different task periods in dorsal and ventral PFC. Age-related differences in accuracy-activation relations were observed in dorsal PFC during encoding and ventral PFC during maintenance. Age-related differences in RT-activation relations were observed in dorsal PFC during retrieval. These results and additional fMRI data we have collected during performance of a speeded processing task, directly support a model of cognitive slowing in which processing rate is related to neural efficiency.

The prefrontal cortex (PFC) is known to subserve working memory (WM) processes. Brain imaging studies of WM using delayed response tasks (DRTs) have shown memory-load-dependent activation increases in dorsal prefrontal cortex (PFC) regions. These activation increases are believed to reflect manipulation of to-be-remembered information in the service of memory-consolidation. This speculation has been based on observations of similar activation increases in tasks that overtly require manipulation by instructing participants to reorder to-be-remembered list items. In this study, we tested the assumption of functional equivalence between these two types of WM tasks. Participants performed a DRT under two conditions with memory loads ranging from 3 to 6 letters. In an "item-order" condition, participants were required to remember letters in the order in which they were presented. In a "reordering" condition, participants were required to remember the letters in alphabetical order. Load-related activation increases were observed during the encoding and maintenance periods of the order maintenance condition, whereas load-related activation decreases were observed in the same periods of the reordering condition. These results suggest that (1) the neural substrates associated with long-list retention and those associated with reordering are not equivalent, (2) cognitive processes associated with long-list retention may be more closely approximated by item-order maintenance than by reordering, and (3) multiple forms of WM manipulation are dissociable on the basis of fMRI data.

The present experiment was designed to determine whether individual variation in neurobiological mechanisms associated with substance abuse risk moderated effects of a brief preventive intervention on social competency skills. This study was conducted in collaboration with the ongoing preventive intervention study at Johns Hopkins University Prevention Intervention Research Center (JHU PIRC) within the Baltimore City Public Schools. A subsample (N = 120) of male 9th grade students was recruited from the larger JHU study population. Approximately half of the participants had a current or lifetime diagnosis of CD while the other half had no diagnosis of CD or other reported problem behaviors. Measures of executive cognitive function (ECF), emotional perception and intelligence were administered. In a later session, participants were randomly assigned to either an experimental or control group. The experimental group underwent a facilitated session using excerpted materials from a model preventive intervention, Positive Adolescent Choices Training (PACT), and controls received no intervention. Outcomes (i.e., social competency skills) were assessed using virtual reality vignettes involving behavioral choices as well as three social cognition questionnaires. Poor cognitive and emotional performance and a diagnosis of CD predicted less favorable change in social competency skills in response to the prevention curriculum. This study provides evidence for the moderating effects of neurocognitive and emotional regulatory functions on ability of urban male youth to respond to preventive intervention materials.

This study examined the psychometric properties of performance measures for three novel, interactive virtual reality vignette exercises developed to assess social competency skills of at-risk adolescents. Performance data were collected from 117 African-American male 15-17 year olds. Data for 18 performance measures were obtained, based on adolescents' interaction with a provocative virtual teenage character. Twelve of the 18 performance measures loaded on two factors corresponding to emotional control and interpersonal communication skills, providing support for their factorial validity. The internal reliability coefficients for the two multi-item measures were 0.88 and 0.91, respectively. Additional analyses with established measures of three psychosocial factors (beliefs supporting aggression, aggressive conflict-resolution style and hostility) and behavioral criteria (e.g., self-reported behavioral misconduct and drug use) provided limited support for the construct and criterion-related validity of the performance measures. Study findings suggest that the virtual reality vignette exercises may represent a promising approach for assessing adolescents' social competency skills.

In this study the authors compared the performance of abstinent drug abusers (n = 21) and nonuser control participants (n = 20) in neurocognitive and emotional functions by use of the Rogers Decision Making Task, Gambling Task, Emotional Stroop, impulsivity continuous performance task (CPT), and vigilance CPT. Skin conductance (SC) and heart rate (HR) monitoring was synchronized with task performance. Groups showed similar performance for vigilance, impulsivity, and emotional interference; however, drug abusers showed stronger SC responses. Drug abusers performed more poorly on the Gambling and Rogers Decision Making Tasks. When making risky decisions, drug abusers showed significantly less increase in SC activity than controls and exhibited lower HRs throughout performance on all tasks. In conclusion, complex tasks involving decision making, sensitivity to consequences, and emotional regulation discriminated between drug abusers and controls.

Marijuana is the most widely used illicit substance in the United States; however, previous imaging studies have not detected altered brain structure in marijuana users compared to non-users. Voxel-based morphometry was used to investigate possible differences in brain tissue composition in a group of 11 heavy marijuana users and a group of 8 non-users. All participants were male. Statistical comparisons were made at the voxel level on T1-weighted magnetic resonance images to determine differences in gray matter and white matter tissue density. Compared to non-users, marijuana users had lower gray matter density in a cluster of voxels in the right parahippocampal gyrus (P = 0.0001), and greater density bilaterally near the precentral gyrus and the right thalamus (P < 0.04). Marijuana users also had lower white matter density in the left parietal lobe (P = 0.03), and higher density around the parahippocampal and fusiform gyri on the left side compared to non-users (P < 0.002). Longer duration of marijuana use (in years) was significantly correlated with higher white matter tissue density in the left precentral gyrus (P = 0.045). Our preliminary results suggest evidence of possible structural differences in the brain of heavy marijuana users, and localize regions for further investigation of the effects of marijuana in the brain.

The anterior cingulate cortex (ACC) and lateral prefrontal (LPFC) cortex are brain regions important to executive cognitive functions (ECF). We determined ACC and LPFC function in 23-day abstinent cocaine abusers using positron emission tomography (PET H215O) during performance of a modified version of the Stroop Task. Cocaine abusers showed less activation than non-drug-using comparison subjects in the left ACC and the right LPFC and greater activation in the right ACC. Average amount of cocaine used per week was negatively correlated with activity in the rostral ACC and right LPFC. Disruption of ECF in substance abusers could interfere with attempts to stop drug use and undermine treatment. Since impairment in ECF may be a common feature of various neuropsychiatric disorders, these findings have applicability beyond the neurobiology of addiction.

OBJECTIVE:The characteristics of attention deficit hyperactivity disorder (ADHD) include abnormalities in reward responsivity that may interfere with decision making. The study examined reward responsivity in ADHD by comparing the neural correlates of decision making in adults with childhood-onset ADHD and in healthy adults.METHOD:The neural correlates of performance on a decision-making task and a control task were compared in 10 adults with ADHD and 12 age-matched healthy volunteers by using [(15)O]H(2)O positron emission tomography. The decision-making task tested the ability to weigh short-term rewards against long-term losses. The control task matched all components of the decision-making task except for the decision-making process and related contingency.RESULTS:The ventral and dorsolateral prefrontal cortex and the insula were activated during performance of the decision-making task in both the ADHD and healthy groups; however, activation in the ADHD group was less extended and did not involve other regions, such as anterior cingulate and hippocampus, that subserve emotion/memory processes. Direct comparison of data from the ADHD subjects and the healthy volunteers suggested that the healthy subjects engaged the hippocampal and insular regions more than did the ADHD subjects and that the ADHD subjects recruited the caudal part of the right anterior cingulate more than did the healthy subjects.CONCLUSIONS:The findings suggest that the neural circuits engaged during decision making differ in subjects with ADHD and healthy comparison subjects. This difference may explain observed deficits in motivated behaviors in ADHD. A better understanding of the nature of these deficits could ultimately be applied to refine treatment strategies for ADHD.

Background: Although about 7 million people in the US population use marijuana at least weekly, there is a paucity of scientific data on persistent neurocognitive effects of marijuana use. Objective: To determine if neurocognitive deficits persist in 28-day abstinent heavy marijuana users and if these deficits are dose-related to the number of marijuana joints smoked per week. Methods: A battery of neurocognitive tests was given to 28-day abstinent heavy marijuana abusers. Results: As joints smoked per week increased, performance decreased on tests measuring memory, executive functioning, psychomotor speed, and manual dexterity. When dividing the group into light, middle, and heavy user groups, the heavy group performed significantly below the light group on 5 of 35 measures and the size of the effect ranged from 3.00 to 4.20 SD units. Duration of use had little effect on neurocognitive performance. Conclusions: Very heavy use of marijuana is associated with persistent decrements in neurocognitive performance even after 28 days of abstinence. It is unclear if these decrements will resolve with continued abstinence or become progressively worse with continued heavy marijuana use.