Michael O’Boyle

EEG Patterns in Mild Cognitive Impairment (MCI) Patients

An emerging clinical priority for the treatment of Alzheimer’s disease (AD) is the implementation of therapies at the earliest stages of disease onset. All AD patients pass through an intermediary stage of the disorder known as Mild Cognitive Impairment (MCI), but not all patients with MCI develop AD. By applying computer based signal processing and pattern recognition techniques to the electroencephalogram (EEG), we were able to classify AD patients versus controls with an accuracy rate of greater than 80%. We were also able to categorize MCI patients into two subgroups: those with EEG Beta power profiles resembling AD patients and those more like controls. We then used this brain-based classification to make predictions regarding those MCI patients most likely to progress to AD versus those who would not. Our classification algorithm correctly predicted the clinical status of 4 out of 6 MCI patients returning for 2 year clinical follow-up. While preliminary in nature, our results suggest that automated pattern recognition techniques applied to the EEG may be a useful clinical tool not only for classification of AD patients versus controls, but also for identifying those MCI patients most likely to progress to AD.

Visual, Auditory, and Cross Modal Sensory Processing in Adults with Autism: An EEG Power and BOLD fMRI Investigation

Electroencephalography (EEG) and blood oxygen level dependent functional magnetic resonance imagining (BOLD fMRI) assessed the neurocorrelates of sensory processing of visual and auditory stimuli in 11 adults with autism (ASD) and 10 neurotypical (NT) controls between the ages of 20–28. We hypothesized that ASD performance on combined audiovisual trials would be less accurate with observable decreased EEG power across frontal, temporal, and occipital channels and decreased BOLD fMRI activity in these same regions; reflecting deficits in key sensory processing areas. Analysis focused on EEG power, BOLD fMRI, and accuracy. Lower EEG beta power and lower left auditory cortex fMRI activity were seen in ASD compared to NT when they were presented with auditory stimuli as demonstrated by contrasting the activity from the second presentation of an auditory stimulus in an all auditory block vs. the second presentation of a visual stimulus in an all visual block (AA2-VV2).We conclude that in ASD, combined audiovisual processing is more similar than unimodal processing to NTs.

Attentional Networks in Adolescents with High-functioning Autism: An fMRI Investigation

Background: Attentional deficits in Autism spectrum disorder (ASD) are often noted, but their specific nature remains unclear. Objective: The present study used the child Attentional Network Task (Child ANT) in combination with functional magnetic resonance imaging (fMRI) to determine if the consistently cited deficits of orienting attention are truly due to dysfunctions of orienting-based networks. We hypothesized that these observations are, in fact, a reflection of executive dysfunctions. As such, we expected that although ASD adolescents would perform worse on the orienting portion of the Child ANT, the strongest differences in activation between them and the neurotypical (NT) control group would be in areas classically associated with executive functioning (e.g., the frontal gyri and anterior cingulate cortex). Method: The brain activity of six high-functioning adolescents with ASD and six NT adolescents was recorded while these individuals performed the three subcomponents of the Child ANT. Results: ASDs were shown to be more accurate than NTs for the alerting, less accurate for the orienting, and similar in accuracy for the executive portions of the Child ANT. fMRI data showed increased bilateral frontal gyri recruitment, areas conventionally associated with executive control, during the orienting task for the ASD group. Conclusion: We submit that the increased activations represent neurocorrelates of signal fixation attributable to the subset of executive control responsible for sustained maintenance signals, not the main components of orienting. Therefore, excessive fixation in ASD adolescents is likely due to dysfunctions of executive control and not the orienting subcomponent of the attention network.

White Matter Deterioration May Foreshadow Impairment of Emotional Valence Determination in Early-Stage Dementia of the Alzheimer Type

In Alzheimer Disease (AD), non-verbal skills often remain intact for far longer than verbally mediated processes. Four (1 female, 3 males) participants with early-stage Clinically Diagnosed Dementia of the Alzheimer Type (CDDAT) and eight neurotypicals (NTs; 4 females, 4 males) completed the emotional valence determination test (EVDT) while undergoing BOLD functional magnetic resonance imaging (fMRI). We expected CDDAT participants to perform just as well as NTs on the EVDT, and to display increased activity within the bilateral amygdala and right anterior cingulate cortex (r-ACC). We hypothesized that such activity would reflect an increased reliance on these structures to compensate for on-going neuronal loss in frontoparietal regions due to the disease. We used diffusion tensor imaging (DTI) to determine if white matter (WM) damage had occurred in frontoparietal regions as well. CDDAT participants had similar behavioral performance and no differences were observed in brain activity or connectivity patterns within the amygdalae or r-ACC. Decreased fractional anisotropy (FA) values were noted, however, for the bilateral superior longitudinal fasciculi and posterior cingulate cortex (PCC). We interpret these findings to suggest that emotional valence determination and non-verbal skill sets are largely intact at this stage of the disease, but signs foreshadowing future decline were revealed by possible WM deterioration. Understanding how non-verbal skill sets are altered, while remaining largely intact, offers new insights into how non-verbal communication may be more successfully implemented in the care of AD patients and highlights the potential role of DTI as a presymptomatic biomarker.

Spatial Attention in Binge-Drinking and Moderate-Drinking College Students: An fMRI Investigation

ABSTRACT College-age binge drinking is considered a developmental disturbance that may give rise to unique treatment challenges. The present study used functional magnetic resonance imaging (fMRI) during the completion of a spatial Stroop task to compare brain activation of 24 college-aged participants: 12 moderate drinkers (MoD) and 12 binge drinkers (BD). Overall, the BD showed a significant reduction in reaction time and accuracy in performing this task, while concurrently displaying less overall brain activation than moderate-drinking controls. In general, the BD showed decreased activity in regions related to rule discovery but hyperactivation in areas thought to mediate attention and response inhibition. Implications for treatment are discussed.

The Impact of Simulated Nature on Patient Outcomes: A Study of Photographic Sky Compositions

Objective: To examine whether incorporation of simulated nature, in the form of ceiling mounted photographic sky compositions, influences patient outcomes. Background: Previous studies have shown that most forms of nature exposure have a positive influence on patients. However, earlier studies have mostly focused on wall-hung nature representations. The emergence of simulated nature products has raised the question regarding the effects of the new product on patient outcomes. Methods: A between-subject experimental design was adopted, where outcomes from five inpatient rooms with sky composition ceiling fixture were compared to corresponding outcomes in five identical rooms without the intervention. Data were collected from a total of 181 subjects on 11 outcomes. Independent sample tests were performed to identify differences in mean outcomes. Result: Significant positive outcomes were observed in environmental satisfaction and diastolic blood pressure (BP). Environmental satisfaction in the experimental group was 12.4% higher than the control group. Direction of association for diastolic BP, nausea/indigestion medication, acute stress, anxiety, pain, and environmental satisfaction were consistent with a priori hypothesis. A post hoc exploratory assessment involving patients who did not self-request additional pain and sleep medication demonstrated confirmatory directions for all outcomes except Systolic BP, and statistically significant outcomes for Acute Stress and Anxiety—Acute Stress and Anxiety levels of the experimental group subjects was 53.4% and 34.79% lower, respectively, than that of the control group subjects. Conclusion: Salutogenic benefits of photographic sky compositions render them better than traditional ceiling tiles and offer an alternative to other nature interventions.

Can Hospital Form Trigger Fear Response

Objective: To examine whether exposure to curve versus sharp contours in the built healthcare setting produces systematic and identifiable patterns of amygdala activation and behavioral response in healthy adults. Background: Recent studies in cognitive neuroscience suggest that humans prefer objects with a curved contour compared with objects that have pointed features and a sharp-angled contour. An implicit perception of threat represented by sharp objects, in humans, was hypothesized to explain this bias. Method: The study adopted a within-subject experimental design, where 36 subjects (representing three age-groups and both sexes) were exposed to a randomized order of 312 real-life images (objects, interiors, exteriors, landscape, and a set of control images). Amygdala activation was simultaneously captured using functional magnetic resonance imaging technology. Subjects’ preference (like/dislike) data were also collected while in the scanner. Data were collected in 2013. Results: In case of images depicting landscape and healthcare objects, brain scans show significant higher amygdala activation associated with sharp contours. However, in relation to images depicting hospital interiors and exterior envelops, brain scans show significant higher amygdala activation associated with curve contours. These activations pertain to exposure during the precognitive stages of the subjects’ perception. Conclusion: Hospital forms do have systematic impact on fear response during precognitive stages of human perception. Whether this first impression colors the subsequent experience of an actual patient with real illness or injury is unknown.

Different cognitive functions discriminate gait performance in younger and older women: A pilot study

AIM Cognitive dysfunction is associated with slower gait speed in older women, but whether cognitive function affects gait performance earlier in life has yet to be investigated. Thus, the objective of this study was to test the hypothesis that cognitive function will discriminate gait performance in healthy younger women. METHODS Fast-pace and dual-task gait speed were measured in 30 young to middle-aged (30-45y) and 26 older (61-80y) women without mild cognitive impairment. Visuoperceptual ability, working memory, executive function, and learning ability were assessed using neuropsychological tests. Within each age group, women were divided by the median into lower and higher cognitive function groups to compare gait performance. RESULTS Younger women with higher visuoperceptual ability had faster fast-pace (2.25±0.30 vs. 1.98±0.18m/s, p≤0.01) and dual-task gait speed (2.02±0.27 vs. 1.69±0.25m/s, p≤0.01) than women with lower visuoperceptual ability. The difference in dual-task gait speed remained significant (p=0.02) after adjusting for age, years of education, and other covariates. Dividing younger women based on other cognitive domains showed no difference in gait performance. In contrast, working memory and executive function discriminated dual-task gait speed (p<0.05) in older women after adjusting for age and education. CONCLUSION To our knowledge, this is the first study to show that poorer cognitive function even at a relatively young age can negatively impact mobility. Different cognitive functions discriminated gait performance based on age, highlighting a possible influence of aging in the relationship between cognitive function and mobility in women.

Hyper-brain connectivity in binge drinking college students: a diffusion tensor imaging study

ABSTRACT The current study used diffusion tensor imaging to examine patterns/degree of brain connectivity in 12 college-aged binge drinking (BD) and 12 moderate drinking individuals. Voxel-level and region-of-interest analyses revealed increased connectivity of the BD brain in the right corona radiata, right external capsule, and both the right and left cingulum. Also, fractional anisotropy and axial diffusivity values of these regions correlated with a number of drinking behaviors of the BD as well as both groups combined. It is hypothesized that increased connectivity in the BD may produce difficulties with regulatory control, contributing to their propensity to binge.

Cognitive profiles of Post-traumatic Stress Disorder and depression in children and adolescents

Background/Objective: Several diagnostic criteria of Post-traumatic Stress Disorder (PTSD) are remarkably similar to symptoms reported by individuals with depression, particularly as they manifest as cognitive processing deficits in children. Because of this overlap in profile and the high rate of comorbidity of PTSD and depression (48% to 69%), pinpointing similarities/differences in cognitive processes related to each of these disorders is essential to accurate diagnosis. This study aims to examine cognitive performance profiles of 23 children who have been victims of PTSD and to compare their results with 23 children with depression and 24 controls. Method: Empirical study, observational and descriptive methodologies were performed using several neuropsychological tests to assess IQ, attention, memory and executive function. Statistical comparisons between groups were made using the non-parametric Kruskall-Wallis test and post-hoc analyses were conducted using a Mann Whitney U test, as well as Quades co-variance analysis. Results: Data show different profiles of cognitive performance in those with PTSD compared to those with depression and controls. Conclusions: The findings suggests that PTSD and depressed children differ somewhat in their cognitive profiles, and the differences in IQ found between those with PTSD and those without are not necessarily a confounding variable, but may rather be a consequence of their traumatic experience.