Gideon Paul Caplovitz - US grants

DESCRIPTION (provided by applicant): Working memory (WM) serves as the 'mental workspace' permitting us to maintain and manipulate on-line mental representations of everything from a phone number to the objects around us. Given its critical importance for healthy cognition, it is not surprising that WM impairments can lead to a significant decrease in the quality of life. As such, understanding the behavioral and neuronal mechanisms that underlie healthy WM function is critical to one day developing treatments and interventions to stave off declines in WM performance. In spite of its importance for performing cognitive tasks, a surprising feature of WM is that it is severely capacity limited to ~4 items. One of the mysterie surrounding WM is how and why this capacity limitation arises. One potential source of capacity limitation may arise from how items from the environment are encoded into WM from the numerous possible items around us at any given time. Previous work has relied on behavioral and physiological measures to study factors influencing WM encoding, e.g. manipulations of encoding depth, stimulus number, or stimulus set size. However, all of these previous approaches used indirect measurements of the aggregate processing associated with performing the WM task, and none have focused directly on the processes associated with the encoding of a specific individual stimulus. Here, we propose to apply a powerful event related potential (ERP) technique: Frequency-Tagging, to directly measure the processing of individual items at encoding. This technique has been widely used in the study of visual perception, and here we propose to apply it to perform a comprehensive investigation of WM encoding. The approach entails the presentation of stimuli each flickering on and off at unique flicker rate. Intriguingly, this periodic stimulation leads to corresponding neural oscillations that can be recorded in the electroencephalogram (EEG) and analyzed in the frequency domain by looking at the frequencies at which a stimulus was flickered. The amplitudes of these 'frequency-tags' can be correlated with the behavioral outcomes of whether or not the stimulus is successfully retrieved from WM to obtain a neuronal correlate of WM encoding that is specific to an individual-stimulus. This R15/AREA grant proposal combines the theoretical and technical expertise of two researchers with years of experience studying visual perception and memory. The PIs will work closely with undergraduate and graduate students to advance our understanding of the WM encoding process. Through the proposed experiments, students will receive training in a number of areas (critical to establishing a solid foundation upon which to build future research careers in psychology and neuroscience. This innovative proposal will significantly contribute to the research and educational training goals of the University of Nevada, Reno PUBLIC HEALTH RELEVANCE: Working memory (WM) is a fundamental aspect of cognition that is highly limited in capacity. The fundamental goal of this proposal is to further our understanding of the behavioral and neural mechanisms that underlie healthy WM function. In the long-term, this research may contribute to the development of effective interventions and treatments designed to prevent or alleviate WM impairments. This R15/AREA grant proposal investigates the WM encoding process using a powerful ERP approach called frequency-tagging. We propose the collaboration between two laboratories (Caplovitz Vision Lab and the Berryhill Memory and Brain Lab) to provide student training in multiple experimental techniques to answer longstanding questions in the WM field.

Behavioral and neural investigations of spatiotemporal form integration in healthy and brain-injured persons In order to survive in a worid full of potentially life-threatening danger, the movement of objects in the visual scene must be rapidly detected and identified. Characterizing how the visual system constructs our perception of an object's form and motion is essential to understating how the visual system works in general. An understanding ofthe intact, normally functioning visual system is a fundamental starting place for diagnosing and treating the visual system when it is impaired or damaged. This proposal builds off of a growing body of evidence that our perception of a moving object is mediated by mutually interacting neural representations ofthe object's form and motion. This proposal investigates one unifying neural mechanism that may underiie such form-motion interactions: spatiotemporal form integration. Spatiotemporal form integration is the integration of neural representations of form features (i.e. the corners of an square) over space and time. The overall aim of this proposal is to investigate the properties and neural correlates of spatiotemporal form integration in mediating both form and motion perception and the possible application of this knowledge to the detection and identification of impaired neural processing in the visual system. Specific aims 1 and 2 will investigate the roles and neural correlates of spatiotempoiral form integration in mediating form and motion perception. Specific aim 3 will test the potential application of spatiotemporal form integration to serve as a metric dagnostic tool for detecting and identifying subtle neural damage and corresponding visual deficits. The project will take full advantage ofthe proposed Magnetic resonance imaging and Brain-lesioned patient database cores as well as the existing Nevada INBRE Bioinformatics core.

The octopus is a social animal, with high intelligence and problem-solving skills, that is very distant from humans in terms of its evolution. This project aims to fabricate neuroelectric sensors and experimental protocols that would enable studying visual and higher level cognitive processes in the octopus while they are engaged in natural behaviors in an underwater environment. This will necessitate development of new engineering solutions for crafting electroencephalography (EEG) sensors that can record signal underwater, new solutions for removing noise artifacts from these highly complicated recordings, as well as careful design of experiments that could study such behaviors in a virtual-reality environment. While the brain of the octopus is very different from that of the human, it does support well-defined cognitive functions. Therefore, understanding whether and how octopuses' brains implement processes such as learning, attention, habituation, and surprise can produce new and important understandings of how neurobiological systems can support function. This research might reveal that the neural substrates of cognitive function in the octopus are organized according to principles that differ drastically from those found in in humans.

This EAGER project has several aims. It will develop the first underwater EEG, first testing well-validated paradigms on humans performing task underwater and benchmarking against known waveforms. The electrodes will be constructed so that they do not corrode in salt water. It will also develop high-quality virtual reality stimulation that could impact octopuses' behavior in an underwater environment. It will utilize EEG frequency-tagging techniques to determine processing of environmental stimulus by the octopus. This will allow studying whether octopuses present characteristic responses that are analogous to surprise, adaptation, working memory and attention effects (in primates and other vertebrates). The study will also allow answering how and in what manner do octopuses sleep. All data, artifacts and modeling software will be made publicly available and constitute an important resource for the community. The results of this study could impact our general understanding of how brains support complex cognitive functions, with direct relevance to artificial intelligence efforts.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Complex brains have evolved in only three lineages on planet earth: chordates, such as ourselves, arthropods, such as honeybees, and molluscs. Among the molluscs the octopus stands out as the brainiest and smartest. In fact, an octopus has about half a billion neurons, which is comparable to the number of neurons in the cortex of a dog. Just as wings evolved many times, in the birds, bats and pterodons, complex brains have evolved to solve similar problems, such as vision and planning, in convergent ways. To understand universal principles of neural organization and computation, it would be beneficial to learn about the commonalities and differences between our brains and perhaps the most different brain on the planet, that of the octopus. While some anatomical work has moved in this direction, there has been a relative paucity of work looking at octopus cognition. Because octopuses cannot talk, Behavior and objective measurements of their neural activity is one way to assess their cognition. A great deal of work has focused on observing octopus behavior. Relatively little research has focused on octopus neurophysiology, primarily because it is a technically difficult issue to either place invasive electrodes inside an octopus, or to place non-invasive electrodes on slippery octopus skin, especially when they can easily remove them with their arms.

This project will focus on developing a non-invasive way to get measurements of octopus neural activity using underwater electroencephalography (EEG). Researchers will place the octopuses on densely packed, fixed electrodes on the floor of a container, rather than attempting to place electrodes on the octopus, as one does in human EEG. This approach takes advantage of the fact that octopuses naturally want to occupy a small crevice and peer out onto the scene, because they are opportunistic and stealthy ambush hunters, rather like cats, who themselves have to avoid being eaten. The goal of the present work is to continue to develop co-PI Besio’s tripolar electrode technology in an interactive cycle with EEG experiments that ask questions about octopus cognition. To date, the team has struggled with various technical problems such as corrosion caused by saltwater, or artifacts in the EEG signal introduced by water. The team’s goal is to develop a fully functioning octopus EEG system over the next two years of funding, to gather sufficient preliminary data to put in a larger proposal concerning octopus cognition using EEG in the future. This project will allow the scientific community to learn how the most 'alien' brain on earth functions, potentially teaching scientists about universal principles of neural computation, which could shed light on how human brains work and also inform design in artificial intelligence systems that could benefit society.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.