Neural signatures of shared subjective affective engagement and disengagement during movie viewing.

When watching a negative emotional movie, we differ from person to person in the ease with which we engage and the difficulty with which we disengage throughout a temporally evolving narrative. We investigated neural responses of emotional processing, by considering inter-individual synchronization in subjective emotional engagement and disengagement. The neural underpinnings of these shared responses are ideally studied in naturalistic scenarios like movie viewing, wherein individuals emotionally engage and disengage at their own time and pace throughout the course of a narrative. Despite the rich data that naturalistic designs can bring to the study, there is a challenge in determining time-resolved behavioral markers of subjective engagement and disengagement and their underlying neural responses. We used a within-subject cross-over design instructing 22 subjects to watch clips of either neutral or sad content while undergoing functional magnetic resonance imaging (fMRI). Participants watched the same movies a second time while continuously annotating the perceived emotional intensity, thus enabling the mapping of brain activity and emotional experience. Our analyses revealed that between-participant similarity in waxing (engagement) and waning (disengagement) of emotional intensity was directly related to the between-participant similarity in spatiotemporal patterns of brain activation during the movie(s). Similar patterns of engagement reflected common activation in the bilateral ventromedial prefrontal cortex, regions often involved in self-referenced evaluation and generation of negative emotions. Similar patterns of disengagement reflected common activation in central executive and default mode network regions often involved in top-down emotion regulation. Together this work helps to better understand cognitive and neural mechanisms underpinning engagement and disengagement from emotionally evocative narratives.

When the attention control condition works: A systematic review of attention control training for posttraumatic stress disorder.

Attentional bias and deficits in attentional control are associated with posttraumatic stress disorder (PTSD) symptoms. Attention control training (ACT) may address these factors. We reviewed randomized controlled trials (RCTs) of ACT for PTSD to address unanswered questions about ACT's effectiveness, tolerability, and implementation. Studies were included if they were an RCT that used an adult sample, recruited participants with a PTSD diagnosis, and had ACT as at least one treatment arm. The PTSD Trials Standardized Data Repository (PTSD-Repository) and additional databases were searched to identify PTSD RCTs published through May 2024. Seven studies met the inclusion criteria (N = 407). The effect size for ACT versus a comparison condition on PTSD symptoms was large, but the confidence interval (CI) overlapped with 0, g = 0.75, 95% CI [-0.63, 2.12]. The same pattern was observed for attention bias variability, g = 1.04, 95% CI [-0.90, 2.98]. There was a significant within-group effect of ACT on self-reported PTSD symptoms, g = -1.43, 95% CI [-2.83, -0.03]. Risk of bias varied, with high risk of bias being primarily due to bias in the measurement of the outcome. These effects should be interpreted cautiously given the significant heterogeneity and wide confidence intervals observed. It remains unclear for whom and under what conditions ACT may be most effective. Future studies should move beyond response time measures, employ an inactive comparator, and examine the mechanism of action to determine whether ACT could be a viable intervention for PTSD.

Not so fast! Response times in the computerized Benton Face Recognition Test may not reflect face recognition ability.

Response times (RTs) are commonly used to assess cognitive abilities, though it is unclear whether face processing RTs predict recognition ability beyond accuracy. In the current study, we examined accuracy and RT on a widely used face matching assessment modified to collect meaningful RT data, the computerized Benton Facial Recognition Test (BFRT-c), and measured whether RTs predicted face recognition ability and developmental prosopagnosia (DP) vs. control group membership. 62 controls and 36 DPs performed the BFRT-c as well as validated measures of face recognition ability: the Cambridge Face Memory Test (CFMT) and a Famous Faces Memory Test (FFMT). In controls, BFRT-c accuracy robustly predicted CFMT (r = .49, p < .001), FFMT (r = .43, p < .001), and a CFMT-FFMT composite (r = .54, p < .001), whereas BFRT-c RT was not significantly associated with these measures (all r's .21). We also found that BFRT-c accuracy significantly differed between DPs and controls, but RT failed to differentiate the groups.

A randomized clinical trial of plasticity-based cognitive training in mild traumatic brain injury.

Clinical practice guidelines support cognitive rehabilitation for people with a history of mild traumatic brain injury (mTBI) and cognitive impairment, but no class I randomized clinical trials have evaluated the efficacy of self-administered computerized cognitive training. The goal of this study was to evaluate the efficacy of a self-administered computerized plasticity-based cognitive training programmes in primarily military/veteran participants with a history of mTBI and cognitive impairment. A multisite randomized double-blind clinical trial of a behavioural intervention with an active control was conducted from September 2013 to February 2017 including assessments at baseline, post-training, and after a 3-month follow-up period. Participants self-administered cognitive training (experimental and active control) programmes at home, remotely supervised by a healthcare coach, with an intended training schedule of 5 days per week, 1 h per day, for 13 weeks. Participants (149 contacted, 83 intent-to-treat) were confirmed to have a history of mTBI (mean of 7.2 years post-injury) through medical history/clinician interview and persistent cognitive impairment through neuropsychological testing and/or quantitative participant reported measure. The experimental intervention was a brain plasticity-based computerized cognitive training programme targeting speed/accuracy of information processing, and the active control was composed of computer games. The primary cognitive function measure was a composite of nine standardized neuropsychological assessments, and the primary directly observed functional measure a timed instrumental activities of daily living assessment. Secondary outcome measures included participant-reported assessments of cognitive and mental health. The treatment group showed an improvement in the composite cognitive measure significantly larger than that of the active control group at both the post-training [+6.9 points, confidence interval (CI) +1.0 to +12.7, P = 0.025, d = 0.555] and the follow-up visit (+7.4 points, CI +0.6 to +14.3, P = 0.039, d = 0.591). Both large and small cognitive function improvements were seen twice as frequently in the treatment group than in the active control group. No significant between-group effects were seen on other measures, including the directly-observed functional and symptom measures. Statistically equivalent improvements in both groups were seen in depressive and cognitive symptoms.

Associations between changes in somatic and psychiatric symptoms and disability alterations in recent-era U.S. veterans.

Cross-sectional work suggests that deployment-related posttraumatic sequelae are associated with increased disability in U.S. veterans deployed following the September 11, 2001 (9/11), terrorist attacks. However, few studies have examined the psychiatric and somatic variables associated with changes in functional disability over time. A total of 237 post-9/11 veterans completed comprehensive assessments of psychiatric and cognitive functioning, as well as a disability questionnaire, at baseline and 2-year follow-up. At baseline, higher levels of PTSD, depressive, and pain-related symptoms were associated with baseline global functional disability, semipartial r2 = .036-.044. Changes in symptoms of PTSD, depression, pain, and sleep, but not anxiety or alcohol use, were independently associated with changes in functional disability, semipartial r2 = .017-.068. Baseline symptoms of these conditions were unrelated to changes in disability, and cognitive performance was unrelated to disability at any assessment point. Together, this suggests that changes in psychiatric and somatic symptoms are tightly linked with changes in functional disability and should be frequently monitored, and even subclinical symptoms may be a target of intervention.

The impact of image degradation and temporal dynamics on sustained attention.

Many clinical populations that have sustained attention deficits also have visual deficits. Therefore, it is necessary to understand how the quality of visual input and different forms of image degradation can contribute to worse performance on sustained attention tasks, particularly those with dynamic and complex visual stimuli. This study investigated the impact of image degradation on an adapted version of the gradual-onset continuous performance task (gradCPT), where participants must discriminate between gradually fading city and mountain scenes. Thirty-six normal-vision participants completed the task, which featured two blocks of six resolution and contrast levels. Subjects either completed a version with gradually fading or static image presentations. The results show decreases in image resolution impair performance under both types of temporal dynamics, whereas performance is only impaired under gradual temporal dynamics for decreases in image contrast. Image similarity analyses showed that performance has a higher association with an observer's ability to gather an image's global spatial layout (i.e. gist) than local variations in pixel luminance, particularly under gradual image presentation. This work suggests that gradually fading attention paradigms are sensitive to deficits in primary visual function, potentially leading to these issues being misinterpreted as attentional failures.

Alertness Training Improves Spatial Bias and Functional Ability in Spatial Neglect.

OBJECTIVE: We conducted a multisite, randomized, double-blinded, controlled trial to examine the effectiveness of a digital health intervention targeting the intrinsic regulation of goal-directed alertness in patients with chronic hemispatial neglect. METHODS: Forty-nine participants with hemispatial neglect, who demonstrated significant spatially biased attention after acquired brain injury, were randomly assigned to the experimental attention remediation treatment or the active control group. The participants engaged with the remotely administered interventions for 12 weeks. The primary outcome was spatial bias on the Posner cueing task (response time difference: left minus right target trials). Secondary outcomes included functional abilities (measured via the Catherine Bergego scale and Barthel index), spatial cognition, executive function, quality of life, and sleep. Assessments were conducted before and immediately after participation in the experimental intervention or control condition, and again after a 3-month no-contact period. RESULTS: Compared with the active control group, the intervention group exhibited a significant improvement in the primary outcome, a reduction in spatially biased attention on the Posner cueing task (p = 0.010, Cohen's d = 0.96), in addition to significant improvements in functional abilities as measured on the Catherine Bergego and Barthel indices (p = 0.027, Cohen's d = 0.24). INTERPRETATION: Our results demonstrate that our attention training program was effective in improving the debilitating attention deficits common to hemispatial neglect. This benefit generalized to improvements in real-world functional abilities. This safe, highly scalable, and self-administered treatment for hemispatial neglect might serve as a useful addition to the existing standard of care. ANN NEUROL 2020;88:747-758.

Impaired executive function exacerbates neural markers of posttraumatic stress disorder.

BACKGROUND: A major obstacle in understanding and treating posttraumatic stress disorder (PTSD) is its clinical and neurobiological heterogeneity. To address this barrier, the field has become increasingly interested in identifying subtypes of PTSD based on dysfunction in neural networks alongside cognitive impairments that may underlie the development and maintenance of symptoms. The current study aimed to determine if subtypes of PTSD, based on normative-based cognitive dysfunction across multiple domains, have unique neural network signatures. METHODS: In a sample of 271 veterans (90% male) that completed both neuropsychological testing and resting-state fMRI, two complementary, whole-brain functional connectivity analyses explored the link between brain functioning, PTSD symptoms, and cognition. RESULTS: At the network level, PTSD symptom severity was associated with reduced negative coupling between the limbic network (LN) and frontal-parietal control network (FPCN), driven specifically by the dorsolateral prefrontal cortex and amygdala Hubs of Dysfunction. Further, this relationship was uniquely moderated by executive function (EF). Specifically, those with PTSD and impaired EF had the strongest marker of LN-FPCN dysregulation, while those with above-average EF did not exhibit PTSD-related dysregulation of these networks. CONCLUSION: These results suggest that poor executive functioning, alongside LN-FPCN dysregulation, may represent a neurocognitive subtype of PTSD.

Apolipoprotein E (APOE) ε4 moderates the relationship between c-reactive protein, cognitive functioning, and white matter integrity.

Elevated serum C-reactive protein (CRP) and possessing an APOE ε4 allele are two of the most prominent risk factors for cognitive and neurological dysfunction in older adults, but little is known about the unique or cumulative effects of these risk factors in young-to-middle-aged adults. To further characterize these potential relationships, measures of cognition and microstructural white matter integrity were examined using data from a sample of 329 post-9/11 war veterans that was collected as part of a comprehensive evaluation that included assessment of neuropsychological functioning, MRI scanning, psychiatric diagnoses, health screening, markers of inflammation, and APOE genotypes. Hierarchical linear regression analyses revealed the CRP and APOE ε4 interaction was associated with global cognition (ß = -0.633), executive functioning (ß = -0.566), and global fractional anisotropy (ß = -0.470), such that elevated CRP was associated with worse cognition and white matter integrity in APOE ε4 carriers. Diffusion tensor imaging (DTI) was used to determine if CRP × APOE ε4 presence was associated with regionally specific fractional anisotropy in white matter tracts. Tract-based spatial statistics revealed CRP × APOE ε4 presence was associated with fractional anisotropy in the corpus callosum, right superior longitudinal fasciculus, right posterior corona radiata, as well as the bilateral anterior and superior corona radiatas. This suggests that APOE ε4 carriers may be uniquely vulnerable to the potentially negative impact of elevated systematic inflammation to cognition and microstructural white matter integrity.

Apolipoprotein E (APOE) ε4 Status Moderates the Relationship Between Close-Range Blast Exposure and Cognitive Functioning.

OBJECTIVES: Recent studies suggest that close-range blast exposure (CBE), regardless of acute concussive symptoms, may have negative long-term effects on brain health and cognition; however, these effects are highly variable across individuals. One potential genetic risk factor that may impact recovery and explain the heterogeneity of blast injury's long-term cognitive outcomes is the inheritance of an apolipoprotein (APOE) ε4 allele, a well-known genetic risk factor for Alzheimer's disease. We hypothesized that APOE ε4 carrier status would moderate the impact of CBE on long-term cognitive outcomes. METHODS: To test this hypothesis, we examined 488 post-9/11 veterans who completed assessments of neuropsychological functioning, psychiatric diagnoses, history of blast exposure, military and non-military mild traumatic brain injuries (mTBIs), and available APOE genotypes. We separately examined the effects of CBE on attention, memory, and executive functioning in individuals with and without the APOE ε4 allele. RESULTS: As predicted, we observed a differential impact of CBE status on cognition as a function of APOE ε4 status, in which CBE ε4 carriers displayed significantly worse neuropsychological performance, specifically in the domain of memory. These results persisted after adjusting for clinical, demographic, and genetic factors and were not observed when examining other neurotrauma variables (i.e., lifetime or military mTBI, distant blast exposure), though these variables displayed similar trends. CONCLUSIONS: These results suggest APOE ε4 carriers are more vulnerable to the impact of CBE on cognition and highlight the importance of considering genetic risk when studying cognitive effects of neurotrauma.

Individual differences in sustained attention are associated with cortical thickness.

Several studies have examined how individual differences in sustained attention relate to functional brain measures (e.g., functional connectivity), but far fewer studies relate sustained attention ability, or cognition in general, to individual differences in cortical structure. Functional magnetic resonance imaging meta-analyses and patient work have highlighted that frontoparietal regions, lateralized to the right hemisphere, are critical for sustained attention, though recent work implicates a broader expanse of brain regions. The current study sought to determine if and where variation in cortical thickness is significantly associated with sustained attention performance. Sustained attention was measured using the gradual onset continuous performance task and the Test of Variables of Attention in 125 adult Veteran participants after acquiring two high-resolution structural MRI scans. Whole-brain vertex-wise analyses of the cortex demonstrated that better sustained attention was associated with increased thickness in visual, somatomotor, frontal, and parietal cortices, especially in the right hemisphere. Network-based analyses revealed relationships between sustained attention and cortical thickness in the dorsal attention, ventral attention, somatomotor, and visual networks. These results indicate cortical thickness in multiple regions and networks is associated with sustained attention, and add to the growing knowledge of how structural MRI can help explain individual differences in cognition.

Self-reported face recognition is highly valid, but alone is not highly discriminative of prosopagnosia-level performance on objective assessments.

Severe developmental deficits in face recognition ability (developmental prosopagnosia, or DP) have been vigorously studied over the past decade, yet many questions remain unanswered about their origins, nature, and social consequences. A rate-limiting factor in answering such questions is the challenge of recruiting rare DP participants. Although self-reported experiences have long played a role in efforts to identify DPs, much remains unknown about how such self-reports can or should contribute to screening or diagnosis. Here, in a large, population-based web sample, we investigated the effectiveness of self-report, used on its own, as a screen to identify individuals who will ultimately fail, at a conventional cutoff, the two types of objective tests that are most commonly used to confirm DP diagnoses: the Cambridge Face Memory Test (CFMT) and the famous faces memory test (FFMT). We used a highly reliable questionnaire (alpha = .91), the Cambridge Face Memory Questionnaire (CFMQ), and revealed strong validity via high correlations of .44 with the CFMT and .52 with the FFMT. However, cutoff analyses revealed that no CFMQ score yielded a clinical-grade combination of sensitivity and positive predictive value in enough individuals to support using it alone as a DP diagnostic or screening tool. This result was replicated in an analysis of data from the widely used PI20 questionnaire, a 20-question self-assessment of facial recognition similar in form to the CFMQ. We therefore recommend that screens for DP should, wherever possible, include objective as well as subjective assessment tools.

Attentional Fluctuations Influence the Neural Fidelity and Connectivity of Stimulus Representations.

Attention is thought to facilitate both the representation of task-relevant features and the communication of these representations across large-scale brain networks. However, attention is not "all or none," but rather it fluctuates between stable/accurate (in-the-zone) and variable/error-prone (out-of-the-zone) states. Here we ask how different attentional states relate to the neural processing and transmission of task-relevant information. Specifically, during in-the-zone periods: (1) Do neural representations of task stimuli have greater fidelity? (2) Is there increased communication of this stimulus information across large-scale brain networks? Finally, (3) can the influence of performance-contingent reward be differentiated from zone-based fluctuations? To address these questions, we used fMRI and representational similarity analysis during a visual sustained attention task (the gradCPT). Participants ( n = 16) viewed a series of city or mountain scenes, responding to cities (90% of trials) and withholding to mountains (10%). Representational similarity matrices, reflecting the similarity structure of the city exemplars ( n = 10), were computed from visual, attentional, and default mode networks. Representational fidelity (RF) and representational connectivity (RC) were quantified as the interparticipant reliability of representational similarity matrices within (RF) and across (RC) brain networks. We found that being in the zone was characterized by increased RF in visual networks and increasing RC between visual and attentional networks. Conversely, reward only increased the RC between the attentional and default mode networks. These results diverge with analogous analyses using functional connectivity, suggesting that RC and functional connectivity in tandem better characterize how different mental states modulate the flow of information throughout the brain.

Tracking behavioral and neural fluctuations during sustained attention: A robust replication and extension.

Novel paradigms have allowed for more precise measurements of sustained attention ability and fluctuations in sustained attention over time, as well as the neural basis of fluctuations and lapses in performance. However, in recent years, concerns have arisen over the replicability of neuroimaging studies and psychology more broadly, particularly given the typically small sample sizes. One recently developed paradigm, the gradual-onset continuous performance task (gradCPT) has been validated behaviorally in large samples of participants. Yet neuroimaging studies investigating the neural basis of performance on this task have only been collected in small samples. The present study completed both a robust replication of the original neuroimaging findings and extended previous results from the gradCPT task using a large sample of 140 Veteran participants. Results replicate findings that fluctuations in attentional stability are tracked over time by BOLD activity in task positive (e.g., dorsal and ventral attention networks) and task negative (e.g., default network) regions. Extending prior results, we relate this coupling between attentional stability and on-going brain activity to overall sustained attention ability and demonstrate that this coupling strength, along with across-network coupling, could be used to predict individual differences in performance. Additionally, the results extend previous findings by demonstrating that temporal dynamics across the default and dorsal attention networks are associated with lapse-likelihood on subsequent trials. This study demonstrates the reliability of the gradCPT, and underscores the utility of this paradigm in understanding attentional fluctuations, as well as individual variation and deficits in sustained attention.

Modulating Reward Induces Differential Neurocognitive Approaches to Sustained Attention.

Reward and motivation have powerful effects on cognition and brain activity, yet it remains unclear how they affect sustained cognitive performance. We have recently shown that a variety of motivators improve accuracy and reduce variability during sustained attention. In the current study, we investigate how neural activity in task-positive networks supports these sustained attention improvements. Participants performed the gradual-onset continuous performance task with alternating motivated (rewarded) and unmotivated (unrewarded) blocks. During motivated blocks, we observed increased sustained neural recruitment of task-positive regions, which interacted with fluctuations in task performance. Specifically, during motivated blocks, participants recruited these regions in preparation for upcoming targets, and this activation predicted accuracy. In contrast, during unmotivated blocks, no such advanced preparation was observed. Furthermore, during motivated blocks, participants had similar activation levels during both optimal (in-the-zone) and suboptimal (out-of-the-zone) epochs of performance. In contrast, during unmotivated blocks, task-positive regions were only engaged to a similar degree as motivated blocks during suboptimal (out-of-the-zone) periods. These data support a framework in which motivated individuals act as "cognitive investors," engaging task-positive resources proactively and consistently during sustaining attention. When unmotivated, however, the same individuals act as "cognitive misers," engaging maximal task-positive resources only during periods of struggle.

Trauma Sequelae are Uniquely Associated with Components of Self-Reported Sleep Dysfunction in OEF/OIF/OND Veterans.

While the associations between psychological distress (e.g., posttraumatic stress disorder [PTSD], depression) and sleep dysfunction have been demonstrated in trauma-exposed populations, studies have not fully explored the associations between sleep dysfunction and the wide range of common physical and physiological changes that can occur after trauma exposure (e.g., pain, cardiometabolic risk factors). We aimed to clarify the unique associations of psychological and physical trauma sequelae with different aspects of self-reported sleep dysfunction. A comprehensive psychological and physical examination was administered to 283 combat-deployed trauma-exposed Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) veterans. The Pittsburgh Sleep Quality Index (PSQI) and PSQI Addendum for PSTD (PSQI-A) were administered along with measures of PTSD, depression, anxiety, pain, traumatic brain injury, alcohol use, nicotine dependence, and cardiometabolic symptoms. We first performed a confirmatory factor analysis of the PSQI and then conducted regressions with the separate PSQI factors as well as the PSQI-A to identify unique associations between trauma-related measures and the separate aspects of sleep. We found that the PSQI global score was composed of three factors: Sleep Efficiency (sleep efficiency/sleep duration), Perceived Sleep Quality (sleep quality/sleep latency/sleep medication) and Daily Disturbances (sleep disturbances/daytime dysfunction). Linear regressions demonstrated that PTSD symptoms were uniquely associated with the PSQI global score and all three factors, as well as the PSQI-A. For the other psychological distress variables, anxiety was independently associated with PSQI global as well as Sleep Efficiency, Perceived Sleep Quality, and PSQI-A, whereas depression was uniquely associated with Daily Disturbances and PSQI-A. Notably, cardiometabolic symptoms explained independent variance in PSQI global and Sleep Efficiency. These findings help lay the groundwork for further investigations of the mechanisms of sleep dysfunction in trauma-exposed individuals and may help in the development of more effective, individualized treatments.

Network-targeted cerebellar transcranial magnetic stimulation improves attentional control.

Developing non-invasive brain stimulation interventions to improve attentional control is extremely relevant to a variety of neurological and psychiatric populations, yet few studies have identified reliable biomarkers that can be readily modified to improve attentional control. One potential biomarker of attention is functional connectivity in the core cortical network supporting attention - the dorsal attention network (DAN). We used a network-targeted cerebellar transcranial magnetic stimulation (TMS) procedure, intended to enhance cortical functional connectivity in the DAN. Specifically, in healthy young adults we administered intermittent theta burst TMS (iTBS) to the midline cerebellar node of the DAN and, as a control, the right cerebellar node of the default mode network (DMN). These cerebellar targets were localized using individual resting-state fMRI scans. Participants completed assessments of both sustained (gradual onset continuous performance task, gradCPT) and transient attentional control (attentional blink) immediately before and after stimulation, in two sessions (cerebellar DAN and DMN). Following cerebellar DAN stimulation, participants had significantly fewer attentional lapses (lower commission error rates) on the gradCPT. In contrast, stimulation to the cerebellar DMN did not affect gradCPT performance. Further, in the DAN condition, individuals with worse baseline gradCPT performance showed the greatest enhancement in gradCPT performance. These results suggest that temporarily increasing functional connectivity in the DAN via network-targeted cerebellar stimulation can enhance sustained attention, particularly in those with poor baseline performance. With regard to transient attention, TMS stimulation improved attentional blink performance across both stimulation sites, suggesting increasing functional connectivity in both networks can enhance this aspect of attention. These findings have important implications for intervention applications of TMS and theoretical models of functional connectivity.

Sustained attention training reduces spatial bias in Parkinson's disease: a pilot case series.

Individuals with Parkinson's disease (PD) commonly demonstrate lateralized spatial biases, which affect daily functioning. Those with PD with initial motor symptoms on the left body side (LPD) have reduced leftward attention, whereas PD with initial motor symptoms on the right side (RPD) may display reduced rightward attention. We investigated whether a sustained attention training program could help reduce these spatial biases. Four non-demented individuals with PD (2 LPD, 2 RPD) performed a visual search task before and after 1 month of computer training. Before training, all participants showed a significant spatial bias and after training, all participants' spatial bias was eliminated.

Sustained Attention Across the Life Span in a Sample of 10,000: Dissociating Ability and Strategy.

Normal and abnormal differences in sustained visual attention have long been of interest to scientists, educators, and clinicians. Still lacking, however, is a clear understanding of how sustained visual attention varies across the broad sweep of the human life span. In the present study, we filled this gap in two ways. First, using an unprecedentedly large 10,430-person sample, we modeled age-related differences with substantially greater precision than have prior efforts. Second, using the recently developed gradual-onset continuous performance test (gradCPT), we parsed sustained-attention performance over the life span into its ability and strategy components. We found that after the age of 15 years, the strategy and ability trajectories saliently diverge. Strategy becomes monotonically more conservative with age, whereas ability peaks in the early 40s and is followed by a gradual decline in older adults. These observed life-span trajectories for sustained attention are distinct from results of other life-span studies focusing on fluid and crystallized intelligence.

Posttraumatic Psychological Symptoms are Associated with Reduced Inhibitory Control, not General Executive Dysfunction.

Although there is mounting evidence that greater PTSD symptoms are associated with reduced executive functioning, it is not fully understood whether this association is more global or specific to certain executive function subdomains, such as inhibitory control. We investigated the generality of the association between PTSD symptoms and executive function by administering a broad battery of sensitive executive functioning tasks to a cohort of returning Operation Enduring Freedom/Operation Iraqi Freedom Veterans with varying PTSD symptoms. Only tasks related to inhibitory control explained significant variance in PTSD symptoms as well as symptoms of depression, while measures of working memory, measures of switching, and measures simultaneously assessing multiple executive function subdomains did not. Notably, the two inhibitory control measures that showed the highest correlation with PTSD and depressive symptoms, measures of response inhibition and distractor suppression, explained independent variance. These findings suggest that greater posttraumatic psychological symptoms are not associated with a general decline in executive functioning but rather are more specifically related to stopping automatic responses and resisting internal and external distractions.