[Show abstract][Hide abstract] ABSTRACT: Processing speed, working memory, and attention deficits are some of the most common cognitive deficits associated with traumatic brain injury (TBI). Cognitive rehabilitation has been proven to be an effective method to remediate cognitive deficits in adults with TBI; however, little research has considered the effects of TBI severity on such interventions. The present study examines changes in cognition following a computerized training program in adults with mild/moderate TBI and adults with severe TBI. Fourteen participants (ages 26-68; M = 45, SD = 13.95) with a history of TBI were separated into a mild/moderate group (n = 6) and a severe group (n = 8). Over a period of 12 weeks, participants underwent 40 hours of computerized cognitive training using Brain Fitness Program (POSIT Science) software. Baseline and follow-up neuropsychological assessments were administered to all participants. Neuropsychological scores were submitted to a 2x2 mixed design ANOVA, in which severity group (mild/moderate versus severe) served as the between-subjects variable and time (baseline versus follow-up) served as the within-subjects variable. Results indicate significant group differences on various cognitive measures including increased performance on a memory composite, F(1,11) = 7.06, p = .022; visual memory, F(1,12) = 8.13, p = .015; working memory, F(1,12) = 4.93, p = .046; continuous performance task, F(1,12) = 5.24, p = .041; and shifting attention test, F(1,12) = 8.85, p = .012. Our findings suggest that cognitive rehabilitation techniques may be especially beneficial to adults with severe TBI. Following administration of a computerized training program, adults with severe TBI showed significant improvements in cognitive performance relative to adults with mild/moderate TBI.
International Neuropsychological Society, Denver, CO; 02/2015
[Show abstract][Hide abstract] ABSTRACT: During the acute and post acute period following a mild traumatic brain injury (mTBI) multiple cognitive processes are negatively affected. Prior studies have reported numerous cognitive domains affected during the acute and post-acute period. Studies have demonstrated cognitive recovery, with subjective and objective assessments, that within days to weeks these cognitive abilities are recovered. This study examines the recovery of neurocognitive functions longitudinally.
Archives of clinical neuropsychology : the official journal of the National Academy of Neuropsychologists. 09/2014; 29(6):596.
[Show abstract][Hide abstract] ABSTRACT: Recent studies indicate that processing speed deficits form the basis for deficits of other higher order cognitive abilities. Therefore, improvements in auditory processing speed will likely positively impact multiple areas of cognition, including verbal learning and memory, working memory, and executive functions. This study examines the effect of a computerized training program to improve processing speed in adults with a TBI.
Archives of clinical neuropsychology : the official journal of the National Academy of Neuropsychologists. 09/2014; 29(6):589.
[Show abstract][Hide abstract] ABSTRACT: Verbal memory is one of the most common cognitive deficits following a traumatic brain injury (TBI). Cognitive rehabilitation techniques have been proven to be effective methods to remediate verbal memory in TBI. The present investigation aims to determine whether verbal memory can be remediated with a computerized auditory training program as a cognitive remediation technique. Following comprehensive baseline neuropsychological assessments, 32 participants (18 males, 14 females; ages 24-68, M = 45.81, SD = 13.81) with a history of TBI were placed into the experimental or control group. Fifteen experimental participants were administered 40 hours of cognitive training using the Brain Fitness Program software over eight weeks, and 17 participants were in a no treatment control group. All participants in experimental and control groups were administered follow-up neuropsychological assessments identical to the baseline tests to determine changes in performance of verbal memory. The results demonstrate that the experimental group compared to the control group, showed higher improvement in verbal memory. The impact of cognitive training on verbal memory is indicated by large effect size of baseline and follow-up difference scores for Logical Memory (d = 4.33 for immediate; d = 3.43 for delayed recall), CVLT-II (d = 2.09 for delayed recall; d = 4.68 for delayed recognition), and a composite verbal memory index (d = 2.70) determined by the CNS Vital Signs program. Our results demonstrate that verbal memory impairments in individuals with a TBI can be remediated by employing a systematically recurrent auditory training program.
The 133rd annual meeting of the American Psychological Association, Washington, DC; 08/2014
[Show abstract][Hide abstract] ABSTRACT: The present study utilized functional near infrared spectroscopy (fNIRS) to detect neural activation differences in the orbitofrontal brain region between individuals with multiple sclerosis (MS) and healthy controls (HCs) during a working memory (WM) task. Thirteen individuals with MS and 12 HCs underwent fNIRS recording while performing the n-back WM task with four levels of difficulty (0-, 1-, 2-, and 3-back). Subjects were fitted with the fNIRS cap consisting of 30 'optodes' positioned over the forehead. The results revealed different patterns of brain activation in MS and HCs. The MS group showed an increase in brain activation, as measured by the concentration of oxygenated hemoglobin (oxyHb), in the left superior frontal gyrus (LSFG) at lower task difficulty levels (i.e. 1-back), followed by a decrease at higher task difficulty (2- and 3-back) as compared with the HC group. HC group achieved higher accuracy than the MS group on the lower task loads (i.e. 0- and 1-back), however there were no performance differences between the groups at the higher task loads (i.e. 2- and 3-back). Taken together, the results suggest that individuals with MS experience a task with the lower cognitive load as more difficult than the HC group, and the brain activation patterns observed during the task confirm some of the previous findings from functional magnetic resonance imaging (fMRI) studies. This study is the first to investigate brain activation by utilizing the method of fNIRS in MS during the performance of a cognitive task.
Brain Imaging and Behavior 06/2014; · 2.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Diffusion tensor imaging (DTI) has widely been used to investigate the microstructural damage of white matter tracts that occur in individuals with traumatic brain injury (TBI). In the current review, we discuss the white matter regions which are commonly affected in adults with TBI. We also describe the current literature that has utilized DTI to investigate the relationship between microstructural integrity with neuropsychological performance and clinical outcome measures. Finally, a model is presented of the potential utilization of DTI as a biomarker of efficacy in neurorehabilitation for individuals with TBI.
[Show abstract][Hide abstract] ABSTRACT: The current study examined the relationship between two separate but complementary methods of assessing executive functions in individuals with multiple sclerosis (MS): (1) a neurocognitive approach with the Tower of London(-DX) (TOL-DX) test and (2) a functional top-down approach with the Executive Function Performance Test (EFPT). Sixty-eight individuals with MS (79% female) and 38 healthy controls (68% female) were administered both the TOL-DX test and the EFPT. For the group with MS, significant differences were found on the TOL-DX test and the EFPT executive components and functional tasks. For the group with MS, the number of moves to complete the TOL-DX tasks was significantly positively correlated to the Organization and Sequencing executive components of the EFPT and the Simple Cooking and Bill Payment tasks of the EFPT. The results demonstrate the relationship of executive function behavior and performance of instrumental activities of daily living tasks.
OTJR Occupation Participation Health 01/2011; 31(1):S30-7. · 0.80 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The premise of this report is that functional Near Infrared Spectroscopy (fNIRS) imaging data contain valuable physiological information that can be extracted by using analysis techniques that simultaneously consider the components of the measured hemodynamic response [i.e., levels of oxygenated, deoxygenated and total hemoglobin (oxyHb, deoxyHb and totalHb, respectively)]. We present an algorithm for examining the spatiotemporal co-variations among the Hb components, and apply it to the data obtained from a demonstrational study that employed a well-established visual stimulation paradigm: a contrast-reversing checkerboard. Our results indicate that the proposed method can identify regions of tissue that participate in the hemodynamic response to neuronal activation, but are distinct from the areas identified by conventional analyses of the oxyHb, deoxyHb and totalHb data. A discussion is provided that compares these findings to other recent studies using fNIRS techniques.
[Show abstract][Hide abstract] ABSTRACT: Multiple Sclerosis (MS) is a disease of the central nervous system affecting millions of people worldwide. In addition to the disabling physical symptoms of MS, roughly 65% of individuals with MS also experience significant cognitive dysfunction, especially in the domains of learning/memory, processing speed (PS) and working memory (WM). The purpose of this review is to examine major topics in research on cognitive dysfunction, as well as review recent functional magnetic resonance imaging (fMRI) studies focusing on cognitive dysfunction in MS. Additionally, directions for future research are discussed.
Frontiers in Bioscience 02/2009; 14:1730-44. · 3.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An essential component for a practical noninvasive brain-computer interface (BCI) system is data recording technology that
can access the information-processing activity of the brain with high fidelity and throughput. Functional near-infrared spectroscopic
(fNIRS) imaging is a methodology that shows promise in meeting this need, having a demonstrated sensitivity to both the slow
hemodynamic response that follows neuroactivation and to the lower amplitude fast optical response that is considered a direct
correlate of neuroactivation. In this report we summarize the technology integration strategy we have developed that permits
detection of both signal types with a single measuring platform, and present results that document the ability to detect these
data types transcranially in response to two different visual paradigms. Also emphasized is the effectiveness of different
data analysis approaches that serve to isolate signals of interest. The findings support the practical utility of NIRS-based
imaging methods for development of BCI applications.
Foundations of Augmented Cognition. Neuroergonomics and Operational Neuroscience, 5th International Conference, FAC 2009 Held as Part of HCI International 2009 San Diego, CA, USA, July 19-24, 2009, Proceedings; 01/2009
[Show abstract][Hide abstract] ABSTRACT: We have developed a method for dividing the hemoglobin signal into six discrete categories that correspond to different states of vascular autoregulation. Here we use it to reveal physiologically meaningful differences among three subject groups.