Matching Items (5)
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- All Subjects: Bioengineering
- Creators: Helms Tillery, Stephen
Description
A previous study demonstrated that learning to lift an object is context-based and that in the presence of both the memory and visual cues, the acquired sensorimotor memory to manipulate an object in one context interferes with the performance of the same task in presence of visual information about a different context (Fu et al, 2012).
The purpose of this study is to know whether the primary motor cortex (M1) plays a role in the sensorimotor memory. It was hypothesized that temporary disruption of the M1 following the learning to minimize a tilt using a ‘L’ shaped object would negatively affect the retention of sensorimotor memory and thus reduce interference between the memory acquired in one context and the visual cues to perform the same task in a different context.
Significant findings were shown in blocks 1, 2, and 4. In block 3, subjects displayed insignificant amount of learning. However, it cannot be concluded that there is full interference in block 3. Therefore, looked into 3 effects in statistical analysis: the main effects of the blocks, the main effects of the trials, and the effects of the blocks and trials combined. From the block effects, there is a p-value of 0.001, and from the trial effects, the p-value is less than 0.001. Both of these effects indicate that there is learning occurring. However, when looking at the blocks * trials effects, we see a p-value of 0.002 < 0.05 indicating significant interaction between sensorimotor memories. Based on the results that were found, there is a presence of interference in all the blocks but not enough to justify the use of TMS in order to reduce interference because there is a partial reduction of interference from the control experiment. It is evident that the time delay might be the issue between context switches. By reducing the time delay between block 2 and 3 from 10 minutes to 5 minutes, I will hope to see significant learning to occur from the first trial to the second trial.
The purpose of this study is to know whether the primary motor cortex (M1) plays a role in the sensorimotor memory. It was hypothesized that temporary disruption of the M1 following the learning to minimize a tilt using a ‘L’ shaped object would negatively affect the retention of sensorimotor memory and thus reduce interference between the memory acquired in one context and the visual cues to perform the same task in a different context.
Significant findings were shown in blocks 1, 2, and 4. In block 3, subjects displayed insignificant amount of learning. However, it cannot be concluded that there is full interference in block 3. Therefore, looked into 3 effects in statistical analysis: the main effects of the blocks, the main effects of the trials, and the effects of the blocks and trials combined. From the block effects, there is a p-value of 0.001, and from the trial effects, the p-value is less than 0.001. Both of these effects indicate that there is learning occurring. However, when looking at the blocks * trials effects, we see a p-value of 0.002 < 0.05 indicating significant interaction between sensorimotor memories. Based on the results that were found, there is a presence of interference in all the blocks but not enough to justify the use of TMS in order to reduce interference because there is a partial reduction of interference from the control experiment. It is evident that the time delay might be the issue between context switches. By reducing the time delay between block 2 and 3 from 10 minutes to 5 minutes, I will hope to see significant learning to occur from the first trial to the second trial.
ContributorsHasan, Salman Bashir (Author) / Santello, Marco (Thesis director) / Kleim, Jeffrey (Committee member) / Helms Tillery, Stephen (Committee member) / Barrett, The Honors College (Contributor) / W. P. Carey School of Business (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Electroencephalogram (EEG) used simultaneously with video monitoring can record detailed patient physiology during a seizure to aid diagnosis. However, current patient monitoring systems typically require a patient to stay in view of a fixed camera limiting their freedom of movement. The goal of this project is to design an automatic patient monitoring system with software to track patient movement in order to increase a patient's mobility. This report discusses the impact of an automatic patient monitoring system and the design steps used to create and test a functional prototype.
ContributorsBui, Robert Truong (Author) / Frakes, David (Thesis director) / Helms Tillery, Stephen (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2014-05
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 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.
ContributorsLancaster, Jenessa Mae (Co-author) / Appavu, Brian (Co-author) / Wahnoun, Remy (Co-author, Committee member) / Helms Tillery, Stephen (Thesis director) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor) / Department of Psychology (Contributor)
Created2014-05
Description
Transcranial focused ultrasound (tFUS) is a unique neurostimulation modality with potential to develop into a highly sophisticated and effective tool. Unlike any other noninvasive neurostimulation technique, tFUS has a high spatial resolution (on the order of millimeters) and can penetrate across the skull, deep into the brain. Sub-thermal tFUS has been shown to induce changes in EEG and fMRI, as well as perception and mood. This study investigates the possibility of using tFUS to modulate brain networks involved in attention and cognitive control.Three different brain areas linked to saliency, cognitive control, and emotion within the cingulo-opercular network were stimulated with tFUS while subjects performed behavioral paradigms. The first study targeted the dorsal anterior cingulate cortex (dACC), which is associated with performance on cognitive attention tasks, conflict, error, and, emotion. Subjects performed a variant of the Erikson Flanker task in which emotional faces (fear, neutral or scrambled) were displayed in the background as distractors. tFUS significantly reduced the reaction time (RT) delay induced by faces; there were significant differences between tFUS and Sham groups in event related potentials (ERP), event related spectral perturbation (ERSP), conflict and error processing, and heart rate variability (HRV).
The second study used the same behavioral paradigm, but targeted tFUS to the right anterior insula/frontal operculum (aIns/fO). The aIns/fO is implicated in saliency, cognitive control, interoceptive awareness, autonomic function, and emotion. tFUS was found to significantly alter ERP, ERSP, conflict and error processing, and HRV responses.
The third study targeted tFUS to the right inferior frontal gyrus (rIFG), employing the Stop Signal task to study inhibition. tFUS affected ERPs and improved stopping speed. Using network modeling, causal evidence is presented for rIFG influence on subcortical nodes in stopping.
This work provides preliminarily evidence that tFUS can be used to modulate broader network function through a single node, affecting neurophysiological processing, physiologic responses, and behavioral performance. Additionally it can be used as a tool to elucidate network function. These studies suggest tFUS has the potential to affect cognitive function as a clinical tool, and perhaps even enhance wellbeing and expand conscious awareness.
The second study used the same behavioral paradigm, but targeted tFUS to the right anterior insula/frontal operculum (aIns/fO). The aIns/fO is implicated in saliency, cognitive control, interoceptive awareness, autonomic function, and emotion. tFUS was found to significantly alter ERP, ERSP, conflict and error processing, and HRV responses.
The third study targeted tFUS to the right inferior frontal gyrus (rIFG), employing the Stop Signal task to study inhibition. tFUS affected ERPs and improved stopping speed. Using network modeling, causal evidence is presented for rIFG influence on subcortical nodes in stopping.
This work provides preliminarily evidence that tFUS can be used to modulate broader network function through a single node, affecting neurophysiological processing, physiologic responses, and behavioral performance. Additionally it can be used as a tool to elucidate network function. These studies suggest tFUS has the potential to affect cognitive function as a clinical tool, and perhaps even enhance wellbeing and expand conscious awareness.
ContributorsFini, Maria Elizabeth (Author) / Tyler, William J (Thesis advisor) / Greger, Bradley (Committee member) / Santello, Marco (Committee member) / Kleim, Jeffrey (Committee member) / Helms Tillery, Stephen (Committee member) / Arizona State University (Publisher)
Created2020
Description
Electrical nerve stimulation is a promising drug-free technology that could treat a variety of ailments and disorders. Methods like Vagus Nerve Stimulation have been used for decades to treat disorders like epilepsy, and research with non-invasive vagus nerve stimulation has shown similar effects as its invasive counterpart. Non-invasive nerve stimulation methods like vagus nerve stimulation could help millions of people treat and manage various disorders.
This study observed the effects of three different non-invasive nerve stimulation paradigms in human participants. The first study analyzed the safety and efficacy of transcutaneous auricular vagal nerve stimulation in healthy humans using a bilateral stimulation protocol with uniquely designed dry-hydrogel electrodes. Results demonstrate bilateral auricular vagal nerve stimulation has significant effects on specific parameters of autonomic activity and is safe and well tolerated. The second study analyzed the effects of non-invasive electrical stimulation of a region on the side of the neck that contains the Great Auricular Nerve and the Auricular Branch of the Vagus Nerve called the tympanomastoid fissure on golf hitting performance in healthy golfers. Results did not show significant effects on hitting performance or physiological activity, but the nerve stimulation had significant effects on reducing state-anxiety and improving the quality of feel of each shot. The third study analyzed the effects of non-invasive nerve stimulation of cervical nerves on the back of the neck on putting performance of yips-affected golfers. Results demonstrated that cervical nerve stimulation had significant effects on improving putting performance but did not have significant effects on physiological activity. Data from these studies show there are potential applications for non-invasive electrical nerve stimulation for healthy and athletic populations. Future research should also examine the effects of these stimulation methods in clinical populations.
This study observed the effects of three different non-invasive nerve stimulation paradigms in human participants. The first study analyzed the safety and efficacy of transcutaneous auricular vagal nerve stimulation in healthy humans using a bilateral stimulation protocol with uniquely designed dry-hydrogel electrodes. Results demonstrate bilateral auricular vagal nerve stimulation has significant effects on specific parameters of autonomic activity and is safe and well tolerated. The second study analyzed the effects of non-invasive electrical stimulation of a region on the side of the neck that contains the Great Auricular Nerve and the Auricular Branch of the Vagus Nerve called the tympanomastoid fissure on golf hitting performance in healthy golfers. Results did not show significant effects on hitting performance or physiological activity, but the nerve stimulation had significant effects on reducing state-anxiety and improving the quality of feel of each shot. The third study analyzed the effects of non-invasive nerve stimulation of cervical nerves on the back of the neck on putting performance of yips-affected golfers. Results demonstrated that cervical nerve stimulation had significant effects on improving putting performance but did not have significant effects on physiological activity. Data from these studies show there are potential applications for non-invasive electrical nerve stimulation for healthy and athletic populations. Future research should also examine the effects of these stimulation methods in clinical populations.
ContributorsHool, Nicholas (Author) / Tyler, William J (Thesis advisor) / Crews, Debbie (Committee member) / Muthuswamy, Jitendran (Committee member) / Helms Tillery, Stephen (Committee member) / Sebold, Brent (Committee member) / Arizona State University (Publisher)
Created2020