Matching Items (22)

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Leye (Lie) Detector \u2014 A Study of Lie Detection using Eye Tracking, Facial Gestures, and EEG

Description

Lie detection is used prominently in contemporary society for many purposes such as for pre-employment screenings, granting security clearances, and determining if criminals or potential subjects may or may not

Lie detection is used prominently in contemporary society for many purposes such as for pre-employment screenings, granting security clearances, and determining if criminals or potential subjects may or may not be lying, but by no means is not limited to that scope. However, lie detection has been criticized for being subjective, unreliable, inaccurate, and susceptible to deliberate manipulation. Furthermore, critics also believe that the administrator of the test also influences the outcome as well. As a result, the polygraph machine, the contemporary device used for lie detection, has come under scrutiny when used as evidence in the courts. The purpose of this study is to use three entirely different tools and concepts to determine whether eye tracking systems, electroencephalogram (EEG), and Facial Expression Emotion Analysis (FACET) are reliable tools for lie detection. This study found that certain constructs such as where the left eye is looking at in regard to its usual position and engagement levels in eye tracking and EEG respectively could distinguish between truths and lies. However, the FACET proved the most reliable tool out of the three by providing not just one distinguishing variable but seven, all related to emotions derived from movements in the facial muscles during the present study. The emotions associated with the FACET that were documented to possess the ability to distinguish between truthful and lying responses were joy, anger, fear, confusion, and frustration. In addition, an overall measure of the subject's neutral and positive emotional expression were found to be distinctive factors. The implications of this study and future directions are discussed.

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  • 2017-05

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The Neural Correlates of Embodied Cognition in Comprehension and Imagination

Description

The premise of the embodied cognition hypothesis is that cognitive processes require emotion, sensory, and motor systems in the brain, rather than using arbitrary symbols divorced from sensorimotor systems. The

The premise of the embodied cognition hypothesis is that cognitive processes require emotion, sensory, and motor systems in the brain, rather than using arbitrary symbols divorced from sensorimotor systems. The hypothesis explains many of the mechanisms of mental simulation or imagination and how they facilitate comprehension of concepts. Some forms of embodied processing can be measured using electroencephalography (EEG), in a particular waveform known as the mu rhythm (8-13 Hz) in the sensorimotor cortex of the brain. Power in the mu band is suppressed (or de-synchronized) when an individual performs an action, as well as when the individual imagines performing the action, thus mu suppression measures embodied imagination. An important question however is whether the sensorimotor cortex involvement while reading, as measured by mu suppression, is part of the comprehension of what is read or if it is arises after comprehension has taken place. To answer this question, participants first took the Gates-MacGinitie reading comprehension test. Then, mu-suppression was measured while participants read experimental materials. The degree of mu-suppression while reading verbs correlated .45 with their score on the Gates-MacGinitie test. This correlation strongly suggests that the sensorimotor system involvement while reading action sentences is part of the comprehension process rather than being an aftereffect.

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Date Created
  • 2016-05

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The Relationship between Neural Responses to Rejection and Depressive Symptoms in Adolescent Romantic Relationships: a Dual EEG Acquisition Study

Description

The research question this thesis aims to answer is whether depressive symptoms of adolescents involved in romantic relationships are related to their rejection sensitivity. It was hypothesized that adolescents who

The research question this thesis aims to answer is whether depressive symptoms of adolescents involved in romantic relationships are related to their rejection sensitivity. It was hypothesized that adolescents who have more rejection sensitivity, indicated by a bigger P3b response, will have more depressive symptoms. This hypothesis was tested by having adolescent couples attend a lab session in which they played a Social Rejection Task while EEG data was being collected. Rejection sensitivity was measured using the activity of the P3b ERP at the Pz electrode. The P3b ERP was chosen to measure rejection sensitivity as it has been used before to measure rejection sensitivity in previous ostracism studies. Depressive symptoms were measured using the 20-item Center for Epidemiological Studies Depression Scale (CES-D, Radloff, 1977). After running a multiple regression analysis, the results did not support the hypothesis; instead, the results showed no relationship between rejection sensitivity and depressive symptoms. The results are also contrary to similar literature which typically shows that the higher the rejection sensitivity, the greater the depressive symptoms.

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Date Created
  • 2015-05

Joint Action Produces Super Mirror Neurons

Description

Abstract: Behavioral evidence suggests that joint coordinated movement attunes one's own motor system to the actions of another. This attunement is called a joint body schema (JBS). According to the

Abstract: Behavioral evidence suggests that joint coordinated movement attunes one's own motor system to the actions of another. This attunement is called a joint body schema (JBS). According to the JBS hypothesis, the attunement arises from heightened mirror neuron sensitivity to the actions of the other person. This study uses EEG mu suppression, an index of mirror neuron system activity, to provide neurophysiological evidence for the JBS hypothesis. After a joint action task in which the experimenter used her left hand, the participant's EEG revealed greater mu suppression (compared to before the task) in her right cerebral hemisphere when watching a left hand movement. This enhanced mu suppression was found regardless of whether the participant was moving or watching the experimenter move. These results are suggestive of super mirror neurons, that is, mirror neurons which are strengthened in sensitivity to another after a joint action task and do not distinguish between whether the individual or the individual's partner is moving.

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Date Created
  • 2015-12

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Using Transcranial Alternating Current Stimulation to Entrain Cortical Oscillations

Description

Transcranial Current Stimulation (TCS) is a long-established method of modulating neuronal activity in the brain. One type of this stimulation, transcranial alternating current stimulation (tACS), is able to entrain endogenous

Transcranial Current Stimulation (TCS) is a long-established method of modulating neuronal activity in the brain. One type of this stimulation, transcranial alternating current stimulation (tACS), is able to entrain endogenous oscillations and result in behavioral change. In the present study, we used five stimulation conditions: tACS at three different frequencies (6Hz, 12Hz, and 22Hz), transcranial random noise stimulation (tRNS), and a no-stimulation sham condition. In all stimulation conditions, we recorded electroencephalographic data to investigate the link between different frequencies of tACS and their effects on brain oscillations. We recruited 12 healthy participants. Each participant completed 30 trials of the stimulation conditions. In a given trial, we recorded brain activity for 10 seconds, stimulated for 12 seconds, and recorded an additional 10 seconds of brain activity. The difference between the average oscillation power before and after a stimulation condition indicated change in oscillation amplitude due to the stimulation. Our results showed the stimulation conditions entrained brain activity of a sub-group of participants.

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Date Created
  • 2020-05

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Analysis of Brain Activity in Elite Golfers

Description

It is unknown which regions of the brain are most or least active for golfers during a peak performance state (Flow State or "The Zone") on the putting green. To

It is unknown which regions of the brain are most or least active for golfers during a peak performance state (Flow State or "The Zone") on the putting green. To address this issue, electroencephalographic (EEG) recordings were taken on 10 elite golfers while they performed a putting drill consisting of hitting nine putts spaced uniformly around a hole each five feet away. Data was collected at three time periods, before, during and after the putt. Galvanic Skin Response (GSR) measurements were also recorded on each subject. Three of the subjects performed a visualization of the same putting drill and their brain waves and GSR were recorded and then compared with their actual performance of the drill. EEG data in the Theta (4 \u2014 7 Hz) bandwidth and Alpha (7 \u2014 13 Hz) bandwidth in 11 different locations across the head were analyzed. Relative power spectrum was used to quantify the data. From the results, it was found that there is a higher magnitude of power in both the theta and alpha bandwidths for a missed putt in comparison to a made putt (p<0.05). It was also found that there is a higher average power in the right hemisphere for made putts. There was not a higher power in the occipital region of the brain nor was there a lower power level in the frontal cortical region during made putts. The hypothesis that there would be a difference between the means of the power level in performance compared to visualization techniques was also supported.

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Date Created
  • 2016-05

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Electroencephalography Feature Extraction of Neural Stimuli

Description

Many mysteries still surround brain function, and yet greater understanding of it is vital to advancing scientific research. Studies on the brain in particular play a huge role in the

Many mysteries still surround brain function, and yet greater understanding of it is vital to advancing scientific research. Studies on the brain in particular play a huge role in the medical field as analysis can lead to proper diagnosis of patients and to anticipatory treatments. The objective of this research was to apply signal processing techniques on electroencephalogram (EEG) data in order to extract features for which to quantify an activity performed or a response to stimuli. The responses by the brain were shown in eigenspectrum plots in combination with time-frequency plots for each of the sensors to provide both spatial and temporal frequency analysis. Through this method, it was revealed how the brain responds to various stimuli not typically used in current research. Future applications might include testing similar stimuli on patients with neurological diseases to gain further insight into their condition.

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Date Created
  • 2016-05

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Optimizing Biofeedback and Learning in an EEG-Based Brain-Computer Interface

Description

Brain-computer interface technology establishes communication between the brain and a computer, allowing users to control devices, machines, or virtual objects using their thoughts. This study investigates optimal conditions to facilitate

Brain-computer interface technology establishes communication between the brain and a computer, allowing users to control devices, machines, or virtual objects using their thoughts. This study investigates optimal conditions to facilitate learning to operate this interface. It compares two biofeedback methods, which dictate the relationship between brain activity and the movement of a virtual ball in a target-hitting task. Preliminary results indicate that a method in which the position of the virtual object directly relates to the amplitude of brain signals is most conducive to success. In addition, this research explores learning in the context of neural signals during training with a BCI task. Specifically, it investigates whether subjects can adapt to parameters of the interface without guidance. This experiment prompts subjects to modulate brain signals spectrally, spatially, and temporally, as well differentially to discriminate between two different targets. However, subjects are not given knowledge regarding these desired changes, nor are they given instruction on how to move the virtual ball. Preliminary analysis of signal trends suggests that some successful participants are able to adapt brain wave activity in certain pre-specified locations and frequency bands over time in order to achieve control. Future studies will further explore these phenomena, and future BCI projects will be advised by these methods, which will give insight into the creation of more intuitive and reliable BCI technology.

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Date Created
  • 2014-05

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Effects of Neurofeedback and Vagus Nerve Stimulation on Archery Performance: A Pilot Study

Description

The purpose of this study was to determine the effects of EEG neurofeedback training and vagus nerve stimulation on archery performance in elite recurve bow archers. Archers were assessed using

The purpose of this study was to determine the effects of EEG neurofeedback training and vagus nerve stimulation on archery performance in elite recurve bow archers. Archers were assessed using performance measures including, quality of feel, target scoring ring score, heart rate, and electroencephalographic (EEG) measures. Results showed significant changes in quality ratings, heart rate and brain activity. Though there was not enough evidence to show a significant change in target ring scores, the results indicated physiological changes that could result in performance score changes with consistent use.

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Date Created
  • 2019-12

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Specificity of Auditory Modulation during Speech Planning

Description

Previous research has showed that auditory modulation may be affected by pure tone
stimuli played prior to the onset of speech production. In this experiment, we are examining the
specificity

Previous research has showed that auditory modulation may be affected by pure tone
stimuli played prior to the onset of speech production. In this experiment, we are examining the
specificity of the auditory stimulus by implementing congruent and incongruent speech sounds in
addition to non-speech sound. Electroencephalography (EEG) data was recorded for eleven adult
subjects in both speaking (speech planning) and silent reading (no speech planning) conditions.
Data analysis was accomplished manually as well as via generation of a MATLAB code to
combine data sets and calculate auditory modulation (suppression). Results of the P200
modulation showed that modulation was larger for incongruent stimuli than congruent stimuli.
However, this was not the case for the N100 modulation. The data for pure tone could not be
analyzed because the intensity of this stimulus was substantially lower than that of the speech
stimuli. Overall, the results indicated that the P200 component plays a significant role in
processing stimuli and determining the relevance of stimuli; this result is consistent with role of
P200 component in high-level analysis of speech and perceptual processing. This experiment is
ongoing, and we hope to obtain data from more subjects to support the current findings.

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Created

Date Created
  • 2020-05