Amy J. Haufler

Neuro-cognitive activity during a self-paced visuospatial task : comparative EEG profiles in marksmen and novice shooters

Log-transformed EEG power spectral estimates (6-7, 9,10-11,18-22, and 36-44 Hz), obtained from skilled marksmen and novice shooters at sites F3, F4, C3, C4,T3, T4, P3, P4, O1, and O2 during the aiming period (6 s) of a target shooting task for each of 40 trials up to the moment of trigger pull, were contrasted to determine regional differences in cortical activation. The EEG power obtained from both groups during the preparatory aiming period was also compared to that observed for a similar time period during the processing of standard verbal and spatial tasks. The marksmen exhibited less activation than the novice shooters at all sites during the aiming period with a pronounced difference in the left central-temporal-parietal area. Fewer group differences in cortical activation were observed during the comparative verbal and spatial tasks with which the groups held equal experience. Additionally, the novice shooters exhibited a cortical activation pattern during target shooting that was similar to that observed during the processing of the comparative verbal and spatial tasks. In contrast, marksmen generally exhibited less cortical activation during the aiming period when contrasted to that during the novel comparative tasks. These results are consistent with the notion of relative economy in the cortical processes of marksmen, relative to controls, during the specific challenge with which they are highly practiced.

Electroencephalographic studies of skilled psychomotor performance.

Measurements based on the EEG have featured prominently in shaping present-day concepts of the neurocognitive aspects of skilled performance. The techniques include measurements of spectral power, interelectrode coherence, event-related potential components such as the P300, slow potentials, and the method of cognitive inference. The advantages offered by EEG-based approaches lies in their spatiotemporal resolution (potentially 1 mm and less than 1 millisecond, respectively) and the potential to preserve ecological validity, i.e., to obtain measurements of cortical function under the same conditions that the task is normally performed. These studies indicate that activity is reduced in specific regions of the cerebral cortex of experts relative to that observed in novices. These changes occur over time as a result of practice. The authors argue that such cortical change results in less attentional demand and less cognitive interference with motor planning and execution. The findings attest to the plasticity of the central nervous system when one is engaged in goal-directed learning, and hold implications for understanding how the nervous system acquires voluntary skills, whether in the context of the training of an athlete or the rehabilitation of a patient who has lost motor skills due to a disease of the nervous system.

Beyond age and gender: Relationships between cortical and subcortical brain volume and cognitive-motor abilities in school-age children

There is growing evidence that cognitive and motor functions are interrelated and may rely on the development of the same cortical and subcortical neural structures. However, no study to date has examined the relationships between brain volume, cognitive ability, and motor ability in typically developing children. The NIH MRI Study of Normal Brain Development consists of a large, longitudinal database of structural MRI and performance measures from a battery of neuropsychological assessments from typically developing children. This dataset provides a unique opportunity to examine relationships between the brain and cognitive-motor abilities. A secondary analysis was conducted on data from 172 children between the ages of 6 to 13 years with up to 2 measurement occasions (initial testing and 2-year follow-up). Linear mixed effects modeling was employed to account for age and gender effects on the development of specific cortical and subcortical volumes as well as behavioral performance measures of interest. Above and beyond the effects of age and gender, significant relationships were found between general cognitive ability (IQ) and the volume of subcortical brain structures (cerebellum and caudate) as well as spatial working memory and the putamen. In addition, IQ was found to be related to global and frontal gray matter volume as well as parietal gray and white matter. At the behavioral level, general cognitive ability was also found to be related to visuomotor ability (pegboard) and executive function (spatial working memory). These results support the notion that cognition and motor skills may be fundamentally interrelated at both the levels of behavior and brain structure.

Development of a screen for predicting clinical outcomes in patients with work-related upper extremity disorders.

This study prospectively examined the extent to which a set of medical, physical, ergonomic, occupational psychosocial, and individual psychosocial variables would predict clinical outcome associated with a diverse set of work-related upper extremity disorders in recently diagnosed individuals. This investigation was designed to develop a tool for use in a clinical setting to assist in identifying patients at risk for poorer outcome. Outcome was measured at 1, 3, and 12 months after completing a baseline questionnaire. Outcome status was based on a median split of a standardized composite index (symptoms, function, workdays lost, and mental health). Logistic regression indicated that predictors of poorer outcome at 1 month were: upper extremity comorbidity (risk ratio [RR], 1.58), pain severity (RR, 1.45), ergonomic risk exposure (RR, 1.07), low job support (RR, 1.03), and pain coping style (RR, 1.54). At 3 months, poorer outcome was predicted by: symptom severity (RR, 10.46), job stress (RR, 1.20), and pain coping style (RR, 1.98). The number of prior treatments/providers (RR, 1.77), past recommendation for surgery (RR, 6.43), and pain coping style were found to predict poorer outcome at 12 months. Sensitivity and specificity, respectively, for the models were 77.4% and 71.8% at 1 month, 80.6% and 82.4% at 3 months, and 80.6% and 83.3% at 12 months. The results indicate that baseline measures of ergonomic and psychosocial stress, pain severity, and pain coping style predict clinical outcome at shorter intervals, whereas number of past treatments/providers, recommendation for surgery and pain coping style predict longer-term outcome. The resulting prognostic screen provides a simple tool that assesses the multidimensional nature of work-related upper extremity disorders and predicts clinical outcome. Furthermore, the findings suggest the importance of early intervention that addresses both physical and psychosocial stressors at work. Specific recommendations to reduce the impact of observed risk factors are discussed.

Electroencephalographic Coherence During Visuomotor Performance: A Comparison of Cortico-Cortical Communication in Experts and Novices

The authors assessed electroencephalographic coherence to determine the relation between cortico-cortical communication and visuomotor skill in 15 expert and 21 novice rifle shooters. They then calculated coherence and phase angles among the prefrontal (F3, F4) and ipsilateral cortical regions (central, temporal, parietal, occipital) during the aiming period for the theta (4-7 Hz), low-alpha (8-10 Hz), high-alpha (11-13 Hz), low-beta (14-22 Hz), high-beta (23-35 Hz), and gamma (36-44 Hz) bands. The authors subjected them separately to a series of analyses of variance (Group X Hemisphere X Region X Epoch). Experts generally exhibited lower coherence compared with novices, with the effect most prominent in the right hemisphere. The groups also exhibited differences in phase angle in a number of frequency bands. Coherence was positively related to aiming movement variability in experts. The results support refinement of cortical networks in experts and differences in strategic planning related to memory processes and executive influence over visual-spatial cues.

Workstyle: development of a measure of response to work in those with upper extremity pain.

Workstyle or the behavioral, cognitive, and physiological response that can occur in some individuals to increases in work demands has been proposed to help explain the link between ergonomic and psychosocial factors in the exacerbation of work-related upper extremity symptoms. Currently, there is no measure of this construct, hindering research on its potential link to work related upper extremity problems in the workplace. The present study describes the development and psychometric properties of a measure of workstyle. Questionnaire items reflecting dimensions of workstyle as per the original conceptualization were generated primarily through focus groups with office workers and separate groups held with occupational physicians, physical therapists, occupational health psychologists, and experts in ergonomics, behavioral science, and human factors. Items created through this process were then administered to 282 symptomatic and asymptomatic office workers. Measures of job stress, ergonomic risk, upper extremity symptoms, and functional limitations were also obtained. The workstyle questionnaire was divided into two broad dimensions: Characteristic responses to work and Response to increased work demands. The scale development process as indicated by factor analysis yielded subscales that are theoretically consistent with the workstyle construct. These subscales include: working through pain, social reactivity at work, limited workplace support, deadlines/pressure, self imposed work pace/workload, breaks, mood, pain/tension, autonomic response, and numbness tingling. The internal consistency of these subscales varied from 0.61 to 0.91, n = 282 while the test–retest (3 weeks) reliability for the various subscales ranged from r = 0.68 to 0.89, n = 143. A total workstyle score was computed that excluded the pain/tension and numbness/tingling subscales to avoid circular reasoning in terms of the measure’s relationship to outcomes of pain and functional limitations. The total score was stable over time and provided unique variance in relation to traditional measures of job stress. Total workstyle score was significantly associated with higher levels of pain, and greater functional limitations. Dimensions of the workstyle construct were identified. The workstyle measure possesses acceptable psychometric properties in office workers who work with computers. This measure can be used in future studies on the interaction of psychosocial and ergonomic factors in the exacerbation of upper extremity pain and functional limitation.

Working with low back pain: problem-solving orientation and function

&NA; A number of ergonomic, workplace and individual psychosocial factors and health behaviors have been associated with the onset, exacerbation and/or maintenance of low back pain (LBP). The functional impact of these factors may be influenced by how a worker approaches problems in general. The present study was conducted to determine whether problem‐solving orientation was associated with physical and mental health outcomes in fully employed workers (soldiers) reporting a history of LBP in the past year. The sample consisted of 475 soldiers (446 male, 29 female; mean age 24.5 years) who worked in jobs identified as high risk for LBP‐related disability and reported LBP symptoms in the past 12 months. The Social Problem‐Solving Inventory and the Standard Form‐12 (SF‐12) were completed by all subjects. Hierarchical multiple regression analyses were used to predict the SF‐12 physical health summary scale from interactions of LBP symptoms with each of five problem‐solving subscales. Low scores on positive problem‐solving orientation (F(1,457)=4.49), and high scores on impulsivity/carelessness (F(1,457)=9.11) were associated with a steeper gradient in functional loss related to LBP. Among those with a longer history of low‐grade LBP, an avoidant approach to problem‐solving was also associated with a steeper gradient of functional loss (three‐way interaction; F(1,458)=4.58). These results suggest that the prolonged impact of LBP on daily function may be reduced by assisting affected workers to conceptualize LBP as a problem that can be overcome and using strategies that promote taking an active role in reducing risks for LBP. Secondary prevention efforts may be improved by addressing these factors.

The influence of social evaluation on cerebral cortical activity and motor performance: A study of “Real-Life” competition☆

Motor performance in a social evaluative environment was examined in participants (N = 19) who completed a pistol shooting task under both performance-alone (PA) and competitive (C) conditions. Electroencephalographic (EEG), autonomic, and psychoendocrine activity were recorded in addition to kinematic measures of the aiming behavior. State anxiety, heart rate, and cortisol were modestly elevated during C and accompanied by relative desynchrony of high-alpha power, increased cortico-cortical communication between motor and non-motor regions, and degradation of the fluency of aiming trajectory, but maintenance of performance outcome (i.e., score). The findings reveal that performance in a complex social-evaluative environment characterized by competition results in elevated cortical activity beyond that essentially required for motor performance that translated as less efficient motor behavior.

How do job stress and ergonomic factors impact clinic visits in acute low back pain? A prospective study.

Objective: We sought to identify whether ergonomic factors, job stress, health behavior, and emotional distress are prospectively related to return visits for acute back pain. Methods: A total of 368 U.S. Army soldiers completed a baseline survey of health and work factors at their first visit for back pain. Multivariable regression and structural equation modeling were used to describe the relationships among ergonomic exposure, job stress, smoking, and emotional distress and their ability to predict repeat clinic visits. Results: The path analysis indicated that higher levels of ergonomic exposures were directly related to increased job stress (β = 0.29). Higher levels of job stress were directly related to higher levels of general distress (β = −35). General distress (β = −0.70) and smoking (β = 0.67) were directly linked to clinic visits. Conclusions: Efforts to directly impact emotional distress or indirectly reduce distress by intervening at the levels of ergonomic risks and psychosocial workplace stress should prove useful in the management of acute low back pain.

Brain Processes and Neurofeedback for Performance Enhancement of Precision Motor Behavior

Based on a number of empirical investigations of cerebral cortical dynamics during precision aiming tasks (i.e. marksmanship) employing electroencephalography (EEG) refinement of cortical activity and attenuation of nonessential cortico-cortical communication with the motor planning regions of the brain results in superior performance. Employment of EEG neurofeedback during the aiming period of target shooting designed to reduce cortical activation resulted in improved performance in skilled marksmen. Such an effect implies that refinement of cortical activity is causally related to performance. Recently, we examined cerebral cortical dynamics during the stress of competitive target shooting and observed increased activation and cortico-cortical communication between non-motor and motor regions relative to a practice-alone condition. As predicted, this finding was associated with degradation of shooting performance. These findings imply that neurofeedback targeted to brain regions related to emotional responding may preserve the cortical dynamics associated with superior performance resulting in improved accuracy of precision aiming performance.