Biomedical subjects

John DeLuca

Publications and source records attributed to John DeLuca.

8 recordsLinked to original sources

PubMed2003

Differentiating simple versus complex processing speed: influence on new learning and memory performance.

The current study was designed to examine how the construct of human information processing speed is conceptualized and measured, while also examining the influence of information processing speed on higher cognitive processes (i.e., learning). A mixed medical sample of 92 subjects participated in this study. Subjects underwent a broad-based neuropsychological evaluation, including measures of verbal and visuospatial new learning, spatial and verbal working memory, simple reaction time, choice reaction time, and information processing speed. Principal components factor analysis with varimax rotation resulted in a three-factor solution, comprised of: (1) simple speed/reaction time, (2) complex information processing and new learning, and (3) working memory. Notably, this factor solution identified 2 distinct forms of processing speed--simple and complex information processing speeds. In contrast to the abundance of literature grouping these two constructs together under one term (i.e., processing speed), these results indicate simple and complex speed to be distinct constructs assessed with different neuropsychological instruments. While the expected relationship between complex information processing capacities and working memory abilities was evident in this study, information processing speed also showed a significant relationship with new learning ability. The implications of this intriguing relationship are discussed.

Adult↗

PubMed2003

Can the repetition effect maximize learning in multiple sclerosis?

OBJECTIVE: The 'repetition effect' stipulates that recall ability improves as the number of learning trials that a person receives increases. While the repetition effect has been supported through many empirical investigations in healthy individuals, it has not yet been applied to clinical populations. The present study tested the hypothesis that an increased number of learning trials improves recall ability in persons with a neurological disorder, namely multiple sclerosis (MS). DESIGN: Prospective between-group design with 30-minute, 90-minute and one-week assessments. SETTING: Private, nonprofit, research facility. SUBJECTS: Sixty-four MS subjects; 20 healthy control subjects (HC). INTERVENTIONS: Subjects were given a modified Selective Reminding Test (SRT), a list of 10 words to remember in a selective reminding format. To control for the amount of information initially learned, the learning trials were repeated until the subject recalled all 10 words on two consecutive trials. MAIN OUTCOME MEASURES: SRT word recall and recognition was tested 30 minutes, 90 minutes and one week subsequent to initial acquisition. RESULTS: Interestingly, the antithesis of our hypothesis was found. That is, persons with MS who required more learning trials to reach the perfect learning criterion performed significantly worse on the recall trials. However, this was not the case in a sample of healthy individuals undergoing the same protocol. CONCLUSIONS: These results indicate that individuals with MS may not benefit from repetition in isolation, but rather require the use of more intensive cognitive rehabilitation strategies (i.e., increased organization) to help improve their depth of encoding of new information.

Adult↗

PubMed2002

Minimal neuropsychological assessment of MS patients: a consensus approach.

Cognitive impairment is common in multiple sclerosis (MS), yet patients seen in MS clinics and neurologic practices are not routinely assessed neuropsychologically. In part, poor utilization of NP services may be attributed to a lack of consensus among neuropsychologists regarding the optimal approach for evaluating MS patients. An expert panel composed of neuropsychologists and psychologists from the United States, Canada, United Kingdom, and Australia was convened by the Consortium of MS Centers (CMSC) in April, 2001. Our objectives were to: (a) propose a minimal neuropsychological (NP) examination for clinical monitoring of MS patients and research, and (b) identify strategies for improving NP assessment of MS patients in the future. The panel reviewed pertinent literature on MS-related cognitive dysfunction, considered psychometric factors relevant to NP assessment, defined the purpose and optimal characteristics of a minimal NP examination in MS, and rated the psychometric and practical properties of 36 candidate NP measures based on available literature. A 90-minute NP battery, the Minimal Assessment of Cognitive Function in MS (MACFIMS), emerged from this discussion. The MACFIMS is composed of seven neuropsychological tests, covering five cognitive domains commonly impaired in MS (processing speed/working memory, learning and memory, executive function, visual-spatial processing, and word retrieval). It is supplemented by a measure of estimated premorbid cognitive ability. Recommendations for assessing other factors that may potentially confound interpretation of NP data (e.g., visual/sensory/motor impairment, fatigue, and depression) are offered, as well as strategies for improving NP assessment of MS patients in the future.

Cognition Disorders↗

PubMed2002

Divided attention and driving: a pilot study using virtual reality technology.

BACKGROUND: Virtual reality (VR) was used to investigate the influence of divided attention (simple versus complex) on driving performance (speed control). DESIGN: Three individuals with traumatic brain injury (TBI) and three healthy controls (HC), matched for age, education, and gender, were examined. RESULTS: Preliminary results revealed no differences on driving speed between TBI and HC. In contrast, TBI subjects demonstrated a greater number of errors on a secondary task performed while driving. CONCLUSION: The findings suggest that VR may provide an innovative medium for direct evaluation of basic cognitive functions (ie, divided attention) and its impact on everyday tasks (ie, driving) not previously available through traditional neuropsychological measures.

Adult↗

PubMed2002

Driving behaviors following brain injury: self-report and motor vehicle records.

BACKGROUND: This study examined both objective and subjective measures of driving behaviors occurring in the past 5 years for 47 individuals with traumatic brain injury (TBI) and 22 healthy controls (HC), matched for age, gender, education, and years of driving experience. RESULTS: Overall, subtle descriptive differences in driving characteristics were observed between the two groups. However, comparison of self-reported and documented reports of aberrant driving behaviors did not reveal a significantly greater number of accidents or violations among TBI participants compared with HC drivers. The results suggest that individuals with TBI, who successfully complete a driving evaluation program, are able to reintegrate into the driving community with minimal difficulty.

Accidents, Traffic↗

PubMed2002

Telerehabilitation needs: a survey of persons with acquired brain injury.

OBJECTIVE: To survey individuals with acquired brain injury to assess multiple facets of interest, access, and familiarity necessary to implement new telerehabilitation technologies. DESIGN: Anonymous mail survey. SETTING: Community. PARTICIPANTS: Seventy-one respondents to a survey. These individuals had experienced acquired brain injury (predominantly severe traumatic brain injury [TBI]) and were living in the community. Surveys were mailed by a state chapter of the Brain Injury Association to a random selection of members with acquired brain injury. MAIN OUTCOME MEASURE: Survey designed specifically for this investigation. RESULTS: The survey responses indicate that there is great interest in the possibility of accessing telerehabilitative services among individuals with acquired brain injury. In particular, there was strong interest expressed in services that could be used to assist with problems in memory, attention, problem-solving, and activities of daily living. CONCLUSIONS: Telemedicine, and more specifically telerehabilitation, holds great promise as an adjunct to traditional clinical service delivery. Little research in this area has been applied, however, to individuals with acquired brain injuries. Although on the surface, telerehabilitation seems to be an appropriate assessment and treatment modality for individuals with brain injury, it will only succeed if those individuals have the interest-and the access-necessary to use new and evolving technologies.

Adolescent↗

PubMed2002

Functional magnetic resonance imaging technology and traumatic brain injury rehabilitation: guidelines for methodological and conceptual pitfalls.

OBJECTIVES: To illuminate the current methodological and conceptual pitfalls inherent in conducting functional magnetic resonance imaging (fMRI) research with individuals who have sustained traumatic brain injury (TBI) and to discuss appropriate remedies. The aim is describe fMRI research, its limitations, and how to best use this technology to examine TBI. DISCUSSION: The topics discussed in this article include issues regarding signal detection, brain activation measurement, head movement, and sources of signal artifact. Issues surrounding data interpretation and the importance of analyzing the brain as a connected neural network is also discussed. Finally, problems with spatial normalization when examining individuals with TBI are reviewed. CONCLUSIONS: To date, there is a scarcity of research applying fMRI technology to the study of TBI. However, because it is a noninvasive procedure with high availability in hospital settings across the country, the next decade of TBI research will likely include a proliferation of this form of investigation. At this time, much work is needed to better understand how to optimally use this technology to examine the effects of TBI on behavior. For fMRI to enhance TBI research it will be imperative to establish valid research protocols and reliable methods of data interpretation.

Brain Injuries↗

PubMedDate not supplied

Dissociating basal forebrain and medial temporal amnesic syndromes: insights from classical conditioning.

In humans, anterograde amnesia can result from damage to the medial temporal (MT) lobes (including hippocampus), as well as to other brain areas such as basal forebrain. Results from animal classical conditioning studies suggest that there may be qualitative differences in the memory impairment following MT vs. basal forebrain damage. Specifically, delay eyeblink conditioning is spared after MT damage in animals and humans, but impaired in animals with basal forebrain damage. Recently, we have likewise shown delay eyeblink conditioning impairment in humans with amnesia following anterior communicating artery (ACoA) aneurysm rupture, which damages the basal forebrain. Another associative learning task, a computer-based concurrent visual discrimination, also appears to be spared in MT amnesia while ACoA amnesics are slower to learn the discriminations. Conversely, animal and computational models suggest that, even though MT amnesics may learn quickly, they may learn qualitatively differently from controls, and these differences may result in impaired transfer when familiar information is presented in novel combinations. Our initial data suggests such a two-phase learning and transfer task may provide a double dissociation between MT amnesics (spared initial learning but impaired transfer) and ACoA amnesics (slow initial learning but spared transfer). Together, these emerging data suggest that there are subtle but dissociable differences in the amnesic syndrome following damage to the MT lobes vs. basal forebrain, and that these differences may be most visible in non-declarative tasks such as eyeblink classical conditioning and simple associative learning.

Amnesia↗