1,720,997 research outputs found
Identifying Neural Signatures of Satisfaction of Sleep Need
No full textSleep consists of multiple stages: S1, S2, slow-wave-sleep (SWS), and rapid eye movement (REM). Do these stages serve complementary, different functions, or the same function but with different magnitudes? During non-REM (S1àS2àSWS), the brain signal progressively slows and becomes larger: Slow-wave oscillation (SWO: 0-1Hz) and signal in delta band (1-4Hz) in non-REM are the most unlike wake and are more prominent following sleep deprivation and during SWS [1,2]. Low-frequency power is thought to be an indicator of sleep need being met. Our studies, based on overnight, scored sleep data and brain signal from 5000+ subjects (8000+ nights) [3] suggest low-frequency power in S2 and in SWS and SWS duration, but not S2 duration, indicate sleep need being met: increased delta energy in S2 means less SWS duration (rs=-0.9145, p<<.00001), but not less S2 duration, i.e. more efficient sleepers can fulfill sleep need with increased delta power without getting to SWS. In fact, increased S2 delta power means shorter S2 durations, i.e. with greater sleep need, an individual will transition from S2 into SWS quicker. Increased delta power in SWS means shorter S1,2 durations suggesting that sleep need is not met by increasing S1,2 durations. Within-subject analyses for subjects for whom a second night of data was recorded corroborate all our results, affirming our conclusion that delta power across non-REM sleep and SWS duration are indicators of sleep need. Thus, S1,2 appear to be transitional stages for satisfying sleep need and may not have a distinct function from SWS after all.Honors CollegeElectrical and Computer Engineering, Department o
How to Increase Confidence Without Improving Performance
No full textSo far, we have determined and adjusted experiment design and written the code for the experiment. We are currently collecting data from test subjects and working on creating related experiments for the future. The experiment code was written in MATLAB, using PsychToolbox 3 and a toolbox from CARLsim 3.0 that we modified. We are already planning similar experiments for the project, including testing with a modified form of volatility, a sleep study, and directional bias. This research should allow us to better understand the perceptual decision-making process in humans.Electrical and Computer Engineering, Department ofHonors Colleg
Reading Your Mind Through Your Eyes: Using Eye Scan Patterns and Machine Learning to Predict Number Choice
No full textEye tracking technology measures eye movements in real time. Studies have shown that eye movement patterns can express spatial cognitive thoughts, confirming the existence of the eye-cognition link. The purpose of this experiment is to determine a correlation between spatial cognition and number processing. If a correlation exists, features suggesting this correlation will be identified to predict a subject’s response using machine learning. Fifty subjects were asked to look at a screen and respond to the following auditory prompt: “Think of a number x/y/z and say it out loud”. These intervals were named Number Line, Pre-prompt, Mid-prompt, and Post-prompt. A predicted model was created by training a Random Forest (RF) Algorithm. Results indicate a strong correlation between saccade vector and participants’ response, suggesting subjects made saccades toward the direction of response in mind. A strong correlation was also identified between Fixation X and participants’ response as these fixations were made in relative locations of the given numbers on a number line. Test accuracy of 90.5% for Trial 1 was obtained with 50 trees. All ten trials resulted in a mean accuracy of 89%. Our future plans involve determining the existence of a vertical component of spatial cognition.Honors CollegeElectrical and Computer Engineering, Department o
An Electrical Circuit Model of Circle of Willis to Predict Stroke
No full textIs it possible to predict which individuals are more prone to stroke years before they actually get one? An affirmative answer to this question has big implications for public health. The Circle of Willis (CoW), a ring of arteries that distributes blood flow to the two hemispheres of the brain, is only completely present in ~50% of all people. We hypothesized that the differences in the variations explain the differences in the relative probability of individuals suffering a blockage owing to a stroke. To address this, it is necessary to model these variations and to introduce blockages in these modeled variations and observe how it affects blood flow, temporarily or permanently. This research modeled the CoW using different parameters of the biological structure with electrical components. Biological data from empirical, clinical studies constrained our circuit model. High-Performance-Computing was utilized to match electrical current ratios to blood flow ratios obtained from empirical studies to compute biologically plausible circuit models where the values of the circuit components match the anatomical values. Approximately 215 million potential solution models were computed and compared with clinical data, of which 3,000+ models with flow rates matching clinical data for complete and two incomplete variations of the CoW were found. Then the circuit model was simplified and the changes in blood flow across variations were analyzed. We anticipate our solution models to be the starting point for in-depth analyses of the variations or blockages in the CoW for which there are no clinical data readily available.Electrical and Computer Engineering, Department ofHonors Colleg
Exploring the Role of Heritability in Disease
No full textThe heritability (h2) of a disease is the proportion of phenotypic variance that is due to genetics. The goal of my research is to determine if a trend exists between the heritability of a particular disease and its earliest age of onset. Common genetic wisdom suggests that diseases with greater heritability will have an earlier age of onset, but this has not been heavily tested yet. We collected heritability values for diseases based on ACE model estimates because this divides the total phenotypic variance into additive genetic effects, shared environmental effects, and unique environmental effects. We found values for 97 diseases and categorized them based on ICD-11 classifications before performing a Spearman correlation. Our results suggest that common genetic wisdom might be incorrect, but these results were inconclusive because we have only scratched the surface of possible diseases to test. We will add to our list of diseases before we make any definitive claims about disease onset and heritability. Gathering more data will also allow us to determine whether certain organ systems are genetically predisposed to disease. Inspired by heritability and the ACE model, we also plan to incorporate the environmental components and search for trends with age of onset, prevalence, incidence, and NIH funding allocated for a particular disease. Changes in genetic and environmental proportions and incidence and prevalence could determine the effectiveness of current public health interventions and research studies and potentially motivate reason to change the way we combat disease.Electrical and Computer Engineering, Department ofHonors Colleg
Circle of Willis: Accessing the Possibility of Ruptured Aneurysm
No full textElectrical and Computer Engineering, Department ofHonors Colleg
How is Rapid Eye Movement (REM) Sleep Related to Deep Slow-Wave Sleep (SWS) in Humans?
No full textSleep consists of two broad phases: rapid eye movement (REM), and non-REM sleep, and the deepest stage of non-REM sleep is slow-wave sleep (SWS). SWS and REM sleep are believed to be related, but exactly how is not known. As SWS has been studied and believed to be essential to brain restoration, REM sleep could hold an important function that needs to be explored. This research analyzed the electroencephalogram data of over 5,000 subjects to find the relationship between various parameters within REM sleep and other stages of sleep. The data was recorded by Sleep Heart Health Study and analyzed by MATLAB. The main parameters which were studied are power spectra, sleep time, percentage of total sleep time, REM density, and nasal air temperature. Using Borbely study as the reference, parameters were paired and taken Spearman correlation coefficients for all subjects on first visit, only healthy subjects on first visit, and all subjects that continued follow-up visit (1). Instead of getting a contrasting relationship between SWS and REM sleep as suggested in previous studies, the result shows a complementary relationship for SWS and REM sleep.Electrical and Computer Engineering, Department ofHonors Colleg
What is a Clear Picture? Human Sensitivity to Noise in Natural Images.
No full textThis study examines the neurological underpinnings that are responsible for human's perceptions of clarity, through the identification and classification of various image features that influence this perception. A total of 100 subjects were used to identify image features, through the administration of a visual test that allowed the subject to choose the clearest image from a set of identical images with different noise distortions. Two tests were administered that consisted of a consecutive series of these choices for each subject.Honors CollegeElectrical and Computer Engineering, Department o
Visual Characteristics of Maternal Gesturing and the Role in Early Attentional Organization
No full textMany researchers have focused on the types of gestures parents make that are most prevalent during a word learning task, that are most relevant to word learning, and the social benefits surrounding the understanding of gesture behavior. Though we know so much about parental use of gestures and the benefits they have on a child’s word learning, we know little about the visual consequences that gestures provide and the processes underlying the benefit. The characteristics of parental gesturing that is relevant to language development have yet to be explored. The current study asks how parents gesture with their infants in a word learning interaction task, and how infants capture and attend to this input. Furthermore, the study looks at object size changes due to gesturing, which may provide perceptually meaningful information that may support word learning, and the impacts that parental gesturing have on an infants’ sustained attention.
To address these aims, the proposed study will look at seven types of parental gestures and hand motions, including deictic, symbolic, shaking, looming, upwards, downwards, and other (conventional and beat). Eleven infants ages 5 to 7 months (prelexical group) and eleven infants ages 9 to 11 months (early lexical group) and their parents participated in the study. Parents and children sat across from each other while wearing eye-tracking devices during a word learning play session involving a set of toys. Parents taught their infant eight words they heard over a recording using any toy they choose from toys that were provided, with 40 seconds given for each word.
Results showed that there were no differences in the way parents gestured towards prelexical and early lexical infants, but that they used each gesture type at different frequencies. It was also found that infants attended to relevant cues (hands, objects, or face) differently and that objects were looked at the most compared to parent hands, child hands, and face for both groups. Interestingly, gestures guided the attention of the prelexical group to relevant cues more than the early lexical group. Results also showed that though sustained attention moments for infants in both groups did not account for a significant portion of their looking behavior, a significant portion of these sustained moments were a result of parent gesture. Lastly, there were no significant differences in object size changes in relation to parent gesture, but results suggest that when the size changes more, infants look at a relevant cue more. The thesis concludes with a general discussion of the findings, limitations that may have impacted data analysis, and interesting future directions.Psychology, Department o
Effects of Distance and Grouping on Visual Attention for Static and Dynamic Displays
No full textNaturally, our visual system receives a staggering amount of information from the environment. Mechanisms are needed to filter irrelevant information and select the most significant for our task. Since the static stimuli have been intensely researched, we are focusing mainly on dynamic stimuli. The goal of this research was to investigate the deployment of exogenous attention to the dynamic stimuli forming perceptual groups. We conducted three experiments both in dynamic and in static conditions with novel features. Particularly, we examined how attention spreads within or outside of a moving object and how perceptual grouping by color and motion affects the allocation of attention. The results demonstrate clearly the effects of distance, color and motion on the allocation of visual attention. Exogenous attention follows the reference frame moving with the stimulus. Also the exogenous attention is allocated not just to the cued element but also to all elements forming the group.Electrical and Computer Engineering, Department o
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