Julian Rooks Keith

• Ph.D.
• Chair at University of North Carolina Wilmington

A growing consensus among concussion experts is that a formal gait assessment is an essential component in return-to-play decisions. Concussion research illustrates that gait variables follow a pattern of recovery that may be more protracted than cognitive recovery, suggesting that gait dynamics may be more sensitive to the sequelae of concussion,...

A growing consensus among concussion experts is that a formal gait assessment is an essential component in return-to-play decisions. Concussion research illustrates that gait variables follow a pattern of recovery that may be more protracted than cognitive recovery, suggesting that gait dynamics may be more sensitive to the sequelae of concussion,...

Background Gait accelerometer (sensor) technology has proven effective in predicting several medical outcomes, but less is known regarding its prediction of concussion symptoms relative to conventional measures of gait and balance. Objective To establish the reliability and validity of gait accelerometer data. We first examine test-retest reliabil...

Drug recalls and lawsuits against pharmaceutical manufacturers are accompanied by announcements emphasizing harmful drug side-effects. Those with elevated health anxiety may be more reactive to such announcements. We evaluated whether health anxiety and financial incentives affect subjective symptom endorsement, and objective outcomes of cognitive...

Objective Brevity is critical to the broad adoption of any screening measure. We examine the efficacy of a short Conners Continuous Performance Test (CCPT 3) to screen for concussion symptoms. Method Data were from 20 U.S. sites, including university/schools conducting baseline testing (N = 817) and post-concussion assessments in medical settings (...

Background: Dangers of sports-related concussion are well documented, and those participating in sports involving significant contact are at an even higher risk relative to the general population. Despite extensive concussion education, athletes still make decisions that would be considered unsafe, such as underreporting and continuing to play des...

Objective. Chronic pain is common in military veterans with traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD). Neurofeedback, or electroencephalograph (EEG) biofeedback, has been associated with lower pain but requires frequent travel to a clinic. The current study examined feasibility and explored effectiveness of neuro-feedba...

Machine learning (ML) techniques can help harness insights from data that complement and extend those that can be attained by traditional statistical methods. The current article introduces clinicians to concepts underlying ML and explores how it can be applied within the domain of neuropsychology. Specifically, we illustrate an application of ML t...

Objective: Chronic pain is common in military veterans with traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD). Neurofeedback, or electroencephalograph (EEG) biofeedback, has been associated with lower pain but requires frequent travel to a clinic. The current study examined feasibility and explored effectiveness of neurofeedba...

Objective Sports related concussions, or mild traumatic brain injuries, have been steadily increasing over the past two decades. Effective screening and identification of concussions play a critical role in the diagnosis and rehabilitation process. Although side line assessment tools are available, there are few well validated tests available to as...

Objective: Effective screening for concussion is increasingly important, and medical professionals play a critical role in diagnostic and return-to-play decisions. However, few well-validated measures are available to assist in those decisions. This study aims to determine whether previously validated measures assessing neurocognitive and neurobeh...

The abilities to stabilize the focus of attention, notice attention lapses, and return attention to an intended object following lapses are precursors for mindfulness. Individuals diagnosed with attention-deficit hyperactivity disorder (ADHD) are deficient in the attentional and self-control skills that characterize mindfulness. The present study a...

Attention deficits are prevalent among individuals with substance use disorders and may interfere with recovery. The present study evaluated the effectiveness of an automated electroencephalogram (EEG) biofeedback system in recovering illicit substance users who had attention deficits upon admission to a comprehensive residential treatment facility...

Background/aims: AL-108-211 was a placebo-controlled, ascending-dose study that explored the safety, tolerability and efficacy of 12 weeks of treatment with AL-108 in subjects with amnestic mild cognitive impairment. Methods: A total of 144 subjects were randomized in a 2:1 drug:placebo ratio. Subjects were enrolled into the low-dose group or pl...

5-Bromo-2'-deoxyuridine (BrdU) is frequently used as a mitotic marker in studies of cell proliferation. Recent studies have reported cytotoxic effects of BrdU on neural progenitor cells in embryonic and neonatal brains in vivo and in adult tissue studied in vitro. The present study was conducted to assess whether BrdU interferes with cell prolifera...

In addition to its role in neuronal migration during embryonic development, doublecortin (DCX) plays a role in hippocampal neurogenesis across the lifespan. Hippocampal neurons exhibit a high degree of synaptic plasticity while they are in the DCX phase. While previous studies have reported that behavioral training on hippocampus-dependent tasks ca...

It is generally believed that the hippocampus is not required for simple discrimination learning. However, a small number of studies have shown that hippocampus damage impairs retention of a previously learned visual discrimination task. We propose that, although simple discrimination learning may proceed in the absence of the hippocampus, it plays...

Chronic fluoxetine increases neurogenesis in the dentate gyrus (DG). In view of the widespread clinical use of fluoxetine and the well-established role of the DG in memory, surprisingly few studies have examined the effects of fluoxetine on memory and hippocampal electrophysiology. Additionally, few studies have evaluated the potential for fluoxeti...

Long-term adrenalectomy (ADX) causes a nearly complete and selective loss of granule cells in the dentate gyrus (DG) of the hippocampus. Previously, learning and memory deficits have been observed following ADX-induced granule cell degeneration for tasks that require the hippocampus. Our objective here was to determine whether corticosterone (CORT)...

Some classes of drugs can selectively affect learning (i.e., acquisition of behavior) at doses that do not affect performance (i.e., previously learned behavior). Some drugs (e.g., benzodiazepines) show selective effects on acquisition across a wide variety of tasks. Other drugs [e.g., N-methyl-D-aspartate (NMDA) antagonists and opiate agonists], h...

This follow-up study to Keith etal. (2002) sought to explore relations between the cognitive, neuropsychological, and psychosocial sequelae of cardiopulmonary bypass surgery (CPB) and survival. A neuropsychological test battery including the state portion of the State-Trait Anxiety Inventory (S-STAI), reaction time, visual attention (VFA), rotor pu...

The authors investigated the effects on spatial behavior of coadministrations of a benzodiazepine, chlordiazepoxide (CDP), with a noncompetitive N-methyl-d-aspartate receptor antagonist (NMDAR), dizocilpine (DZP), and a muscarinic cholinergic receptor antagonist, scopolamine (SCP). Rats solved the Morris swim task in 2 settings; 1 in which a hidden...

The purpose of this study was to determine the effects of the benzodiazepines, midazolam and chlordiazepoxide, and the barbiturate, pentobarbital, on spatial learning, in a within-subject, repeated-acquisition and performance procedure adapted to the Morris Swim Task. In the presence of one stimulus arrangement, rats learned to swim to a hidden esc...

Effects of morphine and 2 N-methyl-D-aspartate (NMDA) receptor antagonists, phencyclidine and LY235959, were studied using a within-subject, repeated-acquisition/performance procedure adapted to the Morris Swim Task. In the performance component, subjects swam to a hidden platform that was always in the same location in the pool. In the acquisition...

A morphine versus saline discrimination was demonstrated using the Morris swim task as the behavioral baseline. The apparatus was a large circular pool filled with water made opaque by floating polypropylene pellets. Rats were placed in the tank in randomly selected locations (12 trials per session) and could escape by swimming to a platform submer...

Cognitive decline after cardiopulmonary bypass (CPB) surgery has been a concern since the advent of CPB procedures. A primary focus of many studies on this topic has been to quantify the incidence of post-CPB cognitive impairment. However, studies that have used traditional parametric statistics have generally failed to confirm that long-lasting (>...

Numerous studies purport to show that cardiopulmonary bypass (CPB) surgery is associated with persistent postoperative cognitive decline. In J. R. Keith et al. (2002), the authors argued that reports of post-CPB cognitive declines have often been quantified using data analysis methods that were based on tenuous assumptions and overlooked problems a...

Shors & Matzel's conclusion that LTP is not related to learning is similar to one we reached several years ago. We discuss some methodological advances that have relevance to the issue and applaud the authors for challenging existing dogma.

The problem of learning versus performance continues to challenge researchers interested in drug effects on place learning and memory. To address this problem, the present study adapted the repeated acquisition/performance (RAP) procedure to the Morris swim task. The procedure involved training subjects to swim to a hidden platform that was always...

Place learning was assessed in three species of voles (Microtus ochrogaster, M. montanus, and M. pennsylvanicus) with the Morris swim task. The performance of all 3 species and both sexes improved with training on the hidden-platform version of the Morris swim task, which indicates that all groups were able to learn to locate a spatial goal without...

Place learning was assessed in three species of voles (Microtus ochrogaster, M. montanus, and M. pennsylvanicus) with the Morris swim task. The performance of all 3 species and both sexes improved with training on the hidden-platform version of the Morris swim task, which indicates that all groups were able to learn to locate a spatial goal without...

Elemental associations permit subjects to solve problems when the significance of the relevant stimulus elements are consistent from trial to trial but do not allow subjects to solve problems that require them to construct and use representations of stimulus conjunctions or configurations to guide their behavior. Recent research with brain-damaged...

Reexamines the empirical support for the N-methyl-D-aspartate (NMDA)-receptor-dependent long-term potentiation (LTP)/memory hypothesis and suggests that NMDA-receptor-dependent synaptic changes are not critically involved in learning and memory. The authors observe that (1) these studies did not convincingly rule out sensorimotor interpretations o...

Studied latent place learning in a novel environment, using 49 rats in a variation of the R. G. Morris (1981) water task. Ss learned to swim to an escape platform, were permitted to swim around the maze with no platform, or were placed on the platform by the experimenter. In a subsequent test, Ss that had learned to swim to the escape platform duri...

We report five experiments in which we investigated the effects of "feedback signals" on the pattern of hypoalgesia produced by inescapable shocks. A 5-s lights-out stimulus coincident with shock termination had no effect on the naltrexone-insensitive (nonopioid) hypoalgesia, which occurred after 10 inescapable shocks, but completely blocked the na...

The present study used the aggressive display of Betta splendens in response to a mirror as an index of the effects of ethanol and the opiate antagonist, naltrexone. Naltrexone produces an opiate receptor blockade and thus provided a test of the hypothesis that ethanol effects on aggression are mediated by the opioid system. Eighty fish were random...

Thesis (Ph. D.)--University of Colorado, 1990. Includes bibliographical references (leaves [98]-107).