Screening for lifetime concussion in athletes: importance of oculomotor measures.

HYPOTHESIS/OBJECTIVE: The purpose of the present study was to determine the utility of oculomotor-based evaluation protocols in screening for lifetime concussion incidence in elite hockey players. METHODS: Forty-two Division I collegiate male and female hockey players were evaluated using the guidelines of an overall oculomotor-based diagnostic clinical test protocol for the mTBI population. The sensitivity of the collected measures to lifetime concussion was then compared with the corresponding sensitivity of measures of neuropsychological functioning (ImPACT) often used with athletes for acute concussion diagnosis. RESULTS: This model showed that a hockey player with a Near Point of Fixation Disparity (NPFD) equal to or greater than 15 cm, Visagraph comprehension rate less than 85% and the total score on part A of an ADHD questionnaire equal to or greater than 11 was on average 10.72-times more likely to have previously suffered a concussion than an athlete with lower values on the NPFD and ADHD questionnaire and a higher comprehension rate on the Visagraph. None of the IMPACT baseline assessment measures were significantly predictive of the individual's concussion history. CONCLUSION: The study provides a relatively sensitive screening tool to assess the probability of previous concussion(s) in an athlete. This model may allow athletic personnel to address in a timely manner the risks associated with repeat concussions and to develop individualized concussion management protocols.

Delay and probability discounting of multiple commodities in smokers and never-smokers using multiple-choice tasks.

The purpose of the present study was to investigate temporal and probabilistic discounting in smokers and never-smokers, across a number of commodities, using a multiple-choice method. One hundred and eighty-two undergraduate university students, of whom 90 had never smoked, 73 were self-reported light smokers (<10 cigarettes/day), and 17 were heavy smokers (10+cigarettes/day), completed computerized batteries of delay and probability discounting questions pertaining to a total of eight commodities and administered in a multiple-choice format. In addition to cigarettes, monetary rewards, and health outcomes, the tasks included novel commodities such as ideal dating partner and retirement income. The results showed that heavy smokers probability discounted commodities at a significantly shallower rate than never-smokers, suggesting greater risk-taking. No effect of smoking status was observed for delay discounting questions. The only commodity that was probability discounted significantly less than others was 'finding an ideal dating partner'. The results suggest that probability discounting tasks using the multiple-choice format can discriminate between non-abstaining smokers and never-smokers and could be further explored in the context of behavioral and drug addictions.

Functional near-infrared spectroscopy is a sensitive marker of neurophysiological deficits on executive function tasks in young adults with a history of child abuse.

Previous research has shown the utility of imaging measures of neural activity in identifying deficits in cognitive functioning in individuals with a history of child abuse. The purpose of the present study was to measure differences that may exist between individuals who reported physical, emotional, or sexual abuse as children (n = 37) vs. those who did not (n = 47) using Functional Near Infrared Spectroscopy (fNIRS) during the completion of cognitive tasks of executive function. The results showed a significantly higher rate and number of errors of commission on the Conners CPT test in the child abuse group compared to the control group. The analyses also showed a statistically significant decrease in oxyhemoglobin (oxy-Hb) concentration in the left rostral prefrontal cortex in the child abuse group compared to the no-abuse group during the Wisconsin Card Sorting Test (WCST). A similar, albeit non-significant, trend toward decreased oxy-Hb concentration was observed in the child abuse group in the right dorsolateral prefrontal cortex (dlPFC) on the OSPAN and Connors CPT. The results suggest that the latter group may show subtle neurological deficits that persist into adulthood that may not manifest on traditional measures of cognitive function. These findings have implications for the development of remediation and treatment strategies in this population.

Differential executive functioning in young adulthood as a function of experienced child abuse.

INTRODUCTION: Previous research has shown cognitive dysfunction in adults with a history of child abuse. The purpose of the present study was to measure differences that exist in executive functioning skills between individuals who have been abused as children versus those without the history of childhood abuse. METHODS: The present study recruited 43 students from the University of North Dakota (33 women) between ages 18 and 23 years of age. The participants were administered several prescreening measures, including a measure of physical child abuse, emotional child abuse, and sexual child abuse. Based on responses to these measures, participants were grouped into a no-child-abuse group, a mild-child-abuse group, or a moderate-to-severe child abuse group. All participants were administered measures of executive functioning that included the Wisconsin Card Sorting Task, the Operation Span Task, and the Connors Continuous Performance Task with a simultaneous recording of electroencephalographic activity using a wireless 9 channel EEG system. RESULTS: There was a statistically significant main effect of child abuse group (no child abuse vs. moderate-to-high child abuse) for the EEG-derived probability of cognitive workload during the OSPAN. Beta bandwidths for individuals in the drug abuse group, which served as a covariate, were also found to be significantly attenuated during the Connors CPT. CONCLUSION: Individuals that have been abused as children must use significantly more mental effort to complete executive functioning tasks as compared to their non-abused counterparts. Increased neurological effort could be used to explain poor decision-making skills that are common within the population.

The use of single-electrode wireless EEG in biobehavioral investigations.

The purpose of this chapter is to introduce novice and intermediate EEG researchers to a convenient and user-friendly EEG system from NeuroSky, Inc. In our recent study we were interested in changes in the frontal cortical EEG activity of healthy adults as a function of accommodative stress during performance of a sustained attention task. We used a commercially available low-cost wireless EEG device from NeuroSky (MindSet), which has a single active Fp1 dry electrode capable of recording research-grade EEG coupled with powerful noise-filtering and data software support. The convenience and ease-of-use of MindSet is further enhanced with validated eSense meters of Attention and Meditation. In this chapter we also provide additional data analytic support for EEG power spectrum using SPSS syntax commonly used in many biobehavioral sciences.

Relationships between health behaviors and weight status in American Indian and white rural children.

PURPOSE: Preventing obesity in childhood is an increasingly important public health goal. Prevention efforts can be improved by better understanding relationships between health behaviors and overweight and obesity. This study examined such relationships in young American Indian and white children living in the rural United States. METHODS: Self-report measures of diet, screen time (passive and active), and physical activity were combined with cardiovascular fitness in cross-sectional analyses to predict weight categories based on body mass index percentiles in 306 American Indian and white children (aged 8-9 years) from a rural area in the upper Midwestern United States. FINDINGS: Multinomial logistic regression models were statistically significant for girls (χ2 [20] = 42.73, P < .01), boys (χ2 [20] = 50.44, P < .001), American Indian (χ2 [20] = 36.67, P < .05), and white children (χ2 [20] = 55.99, P < .001). Obesity was associated with poorer cardiovascular fitness in girls (OR = 0.82), boys (OR = 0.83), American Indian (OR = 0.79), and white children (OR = 0.85), and with passive screen time in girls (OR = 1.69), boys (OR = 2.1), and white children (OR = 1.81). Overweight was associated with passive screen time (OR = 2.24) and inversely with active screen time (OR = 0.54), but only in boys. CONCLUSIONS: Logistic regression models were more successful at predicting obesity than overweight in all groups of participants. Poorer cardiovascular fitness showed the strongest and most consistent association with obesity, but passive screen time was also a significant and important contributor to the prediction of obesity in most prediction models. Prediction models were similar in girls, boys, American Indian, and white children.

Lower but not higher doses of transdermal nicotine facilitate cognitive performance in smokers on gender non-preferred tasks.

One of the most widely used treatments for smoking cessation is nicotine replacement therapy (NRT). There is some evidence that smokers experience abstinence-induced deficits in cognitive function, which are attenuated by NRTs. Additionally it's been suggested that the degree of reversal of cognitive deficits may depend on the NRT dose and the smoker's gender. In the present placebo-controlled study we investigated effects of three doses of transdermal nicotine (7 mg, 14 mg and 21 mg) on cognitive performance of 48 male and 48 female smokers after overnight abstinence and 6h of patch application. Cognitive tasks used in the study included the Conners' CPT, emotional Stroop, mental arithmetic, and verbal recall of affective prose passages. The results showed greater probability of attentional problems in the male sample compared to females as identified by the Conners' CPT. Within gender women showed improved performance in the 7 mg and 14 mg conditions on several measures of the Conners' CPT, and faster hit reaction time on the emotional Stroop test compared to women in the placebo and 21 mg of nicotine groups. Conversely, males showed a moderate overall advantage on the mental arithmetic task and were differentially sensitive to nicotine treatment on the prose recall task, on which the greatest improvement in recall of affective material was observed for the 14 mg group compared to the 21 mg group. The results are explained on the basis of an inverted U-shaped relationship between nicotinic stimulation and cognitive performance as well as greater sensitivity to nicotine dose manipulation on gender non-preferred cognitive tasks.

Accommodative response and cortical activity during sustained attention.

Greater accommodative lag and vergence deficits have been linked to attentional deficits similar to those observed in Attention Deficit Hyperactivity Disorder (ADHD). The purpose of the present study was to assess the effect of accommodative-vergence stress on a measure of sustained attention (Conners CPT) used in the diagnosis of ADHD. Twenty-seven normal non-ADHD adults completed the Conners CPT twice: wearing -2.00 D lenses and normally (without the -2.00 D lenses) in a counterbalanced order with at least 24 h between the sessions. Simultaneous recording of participants' dynamic accommodative responses was performed from the right eye using the Grand Seiko WAM-5500 auto-refractor and electroencephalographic activity (EEG) in the left prefrontal region using the Neurosky Mindset headset. The results demonstrated a significantly greater accommodative lag in the -2.00 D stress condition and a significantly poorer performance on the Conners CPT as indexed by slower reaction time, greater standard error of hit reaction time, grater response variability, poorer stimulus detectability and a greater number of perseverations. No differences were observed on measures of EEG in the theta (4-7 Hz), alpha (8-12 Hz), and beta (12-20 Hz) bands. Moreover, when directly juxtaposed with each EEG band in multiple linear regression analyses, greater accommodative lag in the stress condition was significantly associated with a greater probability of clinical classification on the Conners CPT, and was also marginally predictive of the number of omissions recorded in the stress condition. The results demonstrated that sustained attention can be influenced by such factors as accommodative-vergence stress and suggest that bottom-up processes can contribute to and potentially exacerbate attentional problems in individuals with ADHD. The study also showed that cortical dysfunction (while sufficient) may not be a necessary condition for attentional deficits.

Effects of acute alcohol intoxication on verbal memory in young men as a function of time of day.

This experiment examined whether the time of day of alcohol administration influences alcohol metabolism and the impact of alcohol on verbal memory. It was hypothesized that circadian fluctuations in endogenous levels of testosterone in young men would differentially affect blood alcohol levels, which would consequently impair their memory performance to a different degree. Participants were administered alcohol or placebo drinks either at 8am or 6pm and recall of 4 prose passages was examined. The results indicated that recall declined for subjects administered alcohol but time of day did not moderate these effects. Nevertheless, generally alcohol breath levels changed in the predicted direction as a function of the time of the day with higher levels recorded in the morning and lower levels in the afternoon. The results suggested that observed differences in breath alcohol levels may be influenced by differences in endogenous levels of testosterone, but the effect of this presumed interaction on verbal memory appears inconclusive.