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- All Subjects: Neuroscience
- Creators: School of Life Sciences
- Creators: Santello, Marco
Description
Motor learning is the process of improving task execution according to some measure of performance. This can be divided into skill learning, a model-free process, and adaptation, a model-based process. Prior studies have indicated that adaptation results from two complementary learning systems with parallel organization. This report attempted to answer the question of whether a similar interaction leads to savings, a model-free process that is described as faster relearning when experiencing something familiar. This was tested in a two-week reaching task conducted on a robotic arm capable of perturbing movements. The task was designed so that the two sessions differed in their history of errors. By measuring the change in the learning rate, the savings was determined at various points. The results showed that the history of errors successfully modulated savings. Thus, this supports the notion that the two complementary systems interact to develop savings. Additionally, this report was part of a larger study that will explore the organizational structure of the complementary systems as well as the neural basis of this motor learning.
ContributorsRuta, Michael (Author) / Santello, Marco (Thesis director) / Blais, Chris (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / School of Molecular Sciences (Contributor) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
ABSTRACT
Environmental and genetic factors influence schizophrenia risk. Individuals who have direct family members with schizophrenia have a much higher incidence. Also, acute stress or life crisis may precede the onset of the disease. This study aims to understand the effects of environment on genes related to schizophrenia risk. It investigates the impact of sleep deprivation as an acute environmental stressor on the expression of Htr2a in mice, a gene that codes for the serotonin 2A receptor (5-HT2AR). HTR2A is associated with schizophrenia risk through genetic association studies and expression is decreased in post-mortem studies of patients with the disease. Furthermore, sleep deprivation as a stressor in human trials has been shown to increase the binding capacity of 5-HT2AR. We hypothesize that sleep deprivation will increase the number of cells expressing Htr2a in the mouse anterior prefrontal cortex when compared to controls. Sleep deprived that mice express EGFP under control of the Htr2a promoter displayed anteroposterior gradients of expression across sagittal sections, with concentrations seen most densely within the prefrontal cortex as well as the anterior pretectal nucleus, thalamic nucleus, as well as the cingulate gyrus. Htr2a-EGFP expression was most densely visualized in cortical layer V and VI pyramidal neurons within the lateral prefrontal cortex of coronal sections. Furthermore, the medial prefrontal cortex contained significantly cells expressing Htr2a¬-EGFP than the lateral prefrontal cortex. Ultimately, the hypothesis was not supported and sleep deprivation did not result in more ¬Htr2a-EGFP expressing cells compared to basal levels. However, expressing cells appeared visibly brighter in sleep-deprived animals when compared to controls, indicating that the amount of intracellular Htr2a-GFP expression may be higher. This study provides strong visual representations of expression gradients following sleep deprivation as an acute stressor and paves the way for future studies regarding 5H-T2AR’s role in schizophrenia.
Environmental and genetic factors influence schizophrenia risk. Individuals who have direct family members with schizophrenia have a much higher incidence. Also, acute stress or life crisis may precede the onset of the disease. This study aims to understand the effects of environment on genes related to schizophrenia risk. It investigates the impact of sleep deprivation as an acute environmental stressor on the expression of Htr2a in mice, a gene that codes for the serotonin 2A receptor (5-HT2AR). HTR2A is associated with schizophrenia risk through genetic association studies and expression is decreased in post-mortem studies of patients with the disease. Furthermore, sleep deprivation as a stressor in human trials has been shown to increase the binding capacity of 5-HT2AR. We hypothesize that sleep deprivation will increase the number of cells expressing Htr2a in the mouse anterior prefrontal cortex when compared to controls. Sleep deprived that mice express EGFP under control of the Htr2a promoter displayed anteroposterior gradients of expression across sagittal sections, with concentrations seen most densely within the prefrontal cortex as well as the anterior pretectal nucleus, thalamic nucleus, as well as the cingulate gyrus. Htr2a-EGFP expression was most densely visualized in cortical layer V and VI pyramidal neurons within the lateral prefrontal cortex of coronal sections. Furthermore, the medial prefrontal cortex contained significantly cells expressing Htr2a¬-EGFP than the lateral prefrontal cortex. Ultimately, the hypothesis was not supported and sleep deprivation did not result in more ¬Htr2a-EGFP expressing cells compared to basal levels. However, expressing cells appeared visibly brighter in sleep-deprived animals when compared to controls, indicating that the amount of intracellular Htr2a-GFP expression may be higher. This study provides strong visual representations of expression gradients following sleep deprivation as an acute stressor and paves the way for future studies regarding 5H-T2AR’s role in schizophrenia.
ContributorsSchmitz, Kirk Andrew (Author) / Gallitano, Amelia (Thesis director) / Stout, Valerie (Committee member) / Maple, Amanda (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Communication amongst eusocial insect is key to their success. Ants rely on signaling to mediate many different functions within a colony such as policing and nest mate recognition. Camponotus floridanus uses chemosensory signaling in the form of cuticular hydrocarbons to regulate these functions. Each cuticular hydrocarbon profile contains numerous hydrocarbons, however it is yet to be seen if Camponotus floridanus can discriminate between linear hydrocarbons of similar length. Individual specimens were conditioned in three different ways: 5 conditioning with high concentration of sugar water (1;1 ratio), 1 conditioning with high concentration of sugar water, and 5 conditioning with low concentration of sugar water (1;4). Two linear hydrocarbons were use, C23 and C24, with C23 always being the conditioned stimulus. Specimens who were conditioned 5 times with high concentration of sugar water were the only group to show a significant response to the conditioned stimulus with a p-value of .008 and exhibited discrimination behavior 46% of the time. When compared 5 conditioning with high concentration to the other two testing conditioning groups, 1 conditioning with high concentration produced an insignificant p-value of .13 was obtained whereas when comparing it with 5 conditioning low concentration of sugar a significant p-value of .0132 was obtained. This indiciates that Camponotus floridanus are capable of discrimination however must be conditioned with high concentration of sugar water, while number of conditioning is insignificant.
ContributorsDamari, Ben Aviv (Author) / Liebig, Juergen (Thesis director) / Ghaninia, Majid (Committee member) / Pratt, Stephen (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (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
Collaborative learning is a potential technique for teachers to use to meet the diverse learning needs of the students in their classrooms. Previous studies have investigated the contexts in which the benefits of collaborative learning show greater presence. The most important factor found was the quality of the interactions. Studies have suggested that high achieving students are capable of improving the quality of interactions. This bears the question if prior knowledge plays an influence in the learning outcome of students in collaborative learning. Results show that high prior knowledge students do not face a detriment in having low prior knowledge students as a partner comparing to having another high prior knowledge student and that low prior knowledge students show significantly higher learning outcome when partnered with a high prior knowledge partner than with another low prior knowledge student. It is therefore likely that having a high prior knowledge student within a dyad improves the quality of interaction, resulting in greater learning outcome through collaborative learning.
ContributorsKeyvani, Kewmars (Author) / Chi, Michelene (Thesis director) / Wylie, Ruth (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / School of Life Sciences (Contributor)
Created2014-05
ContributorsSavarese, Erica (Author) / Robert, Jason (Thesis director) / Hurlbut, Ben (Committee member) / Verrelli, Brian (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
The role of retention and forgetting of context dependent sensorimotor memory of dexterous manipulation was explored. Human subjects manipulated a U-shaped object by switching the handle to be grasped (context) three times, and then came back two weeks later to lift the same object in the opposite context relative to that experience on the last block. On each context switch, an interference of the previous block of trials was found resulting in manipulation errors (object tilt). However, no significant re-learning was found two weeks later for the first block of trials (p = 0.826), indicating that the previously observed interference among contexts lasted a very short time. Interestingly, upon switching to the other context, sensorimotor memories again interfered with visually-based planning. This means that the memory of lifting in the first context somehow blocked the memory of lifting in the second context. In addition, the performance in the first trial two weeks later and the previous trial of the same context were not significantly different (p = 0.159). This means that subjects are able to retain long-term sensorimotor memories. Lastly, the last four trials in which subjects switched contexts were not significantly different from each other (p = 0.334). This means that the interference from sensorimotor memories of lifting in opposite contexts was weaker, thus eventually leading to the attainment of steady performance.
ContributorsGaw, Nathan Benjamin (Author) / Santello, Marco (Thesis director) / Helms Tillery, Stephen (Committee member) / Buneo, Christopher (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
With the overall health of the environment rapidly declining \u2014 mostly due to human behaviors, solving the problem of nature deficit disorder and getting more children interested and aware of nature could be paramount to improving the environmental health of our planet. In this study, the relationship between children's learning and emotion is explored. Pre- and post-tests were given to children attending a week-long summer freshwater ecology camp; their knowledge of and emotional connection to different ecological concepts were measured. Two separate ecosystems were tested \u2014 a freshwater ecosystem that was taught over the course of the week, and a marine ecosystem for comparison. Increases in knowledge and emotion were seen in every freshwater ecosystem concept. Additionally, the knowledge and emotion scores were correlated, suggesting a positive relationship between them. The marine ecosystem did not show improvements in concrete knowledge, but showed increases in abstract learning, indicating that the abstract concepts learned about the freshwater ecosystem were able to transfer to the marine. Overall results show the ability of a hands-on learning experience to foster an emotional connection between a child and the subject matter. However, long-term studies are needed to track the relationship between children and their knowledge of and emotional connection to the subject matter.
ContributorsMossler, Max Vaughn (Author) / Pearson, David (Thesis director) / Smith, Andrew (Committee member) / Berkowitz, Alan (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a devastating illness that causes the degeneration of both upper and lower motor neurons, leading to eventual muscle atrophy. ALS rapidly progresses into paralysis, with patients typically dying due to respiratory complications within three to five years from the onset of their symptoms. Even after many years of research and drug trials, there is still no cure, and current therapies only succeed in increasing life-span by approximately three months. With such limited options available for patients, there is a pressing need to not only find a cure, but also make new treatments available in order to ameliorate disease symptoms. In a genome-wide association study previously conducted by the Translational Genomics Research Institute (TGen), several single-nucleotide polymorphisms (SNPs) upstream of a novel gene, FLJ10968, were found to significantly alter risk for ALS. This novel gene acquired the name FGGY after publication of the paper. FGGY exhibits altered levels of protein expression throughout ALS disease progression in human subjects, and detectable protein and mRNA expression changes in a mouse model of ALS. We performed co-immunoprecipitation experiments coupled with mass spectrometry in order to determine which proteins are associated with FGGY. Some of these potential binding partners have been linked to RNA regulation, including regulators of the splicesomal complex such as SMN, Gemin, and hnRNP C. To further validate these findings, we have verified co-localization of these proteins with one another. We hypothesize that FGGY plays an important role in ALS pathogenesis, and we will continue to examine its biological function.
ContributorsTerzic, Barbara (Author) / Jensen, Kendall (Thesis director) / Francisco, Wilson (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2014-05
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