Cognitive neuroscience

Melville Joseph Wohlgemuth

Assistant Professor, Neuroscience
Member of the General Faculty
Member of the Graduate Faculty
Primary Department
Department Affiliations
Contact
520-621-6640

Work Summary

The Wohlgemuth Lab is focused on how circuits in the brain contribute to sensory-guided adaptive behaviors. The goal is to study how an integrated bottom-up and top-down cortico-fugal network controls behavior on multiple time-scales: from the rapid reactions to arriving sensing information indicative of bottom-up processing, to the longer time-scale governance of categorical behavioral control that is directed by top-down signaling. To study these phenomena, the lab uses the model system of the echolocating bat. The bat provides a way to study how the brain evolved to perform under controlled, laboratory experimentation. To research these questions, the lab employs computer modeling of behavior, multi-channel electrophysiology to relate changes in behavior to changes in brain activity, and optogenetics to test causal hypotheses about the role of different circuit components in sensorimotor integration across time-scales. By combining computational ethology and modeling, electrophysiology, calcium imaging, and optogenetics, the Wohlgemuth Lab offers new insights into circuit-level processing for both rapid control of sensory-guided adaptive behaviors and long-term goal-planning.

Research Interest

The Wohlgemuth Lab was started at University of Arizona in January, 2020. The lab combines computational ethology of natural behaviors, computational modeling of neural data, and multi-channel wireless physiology and optogenetics in freely behaving animals to understand how the brain interacts with the natural environment. Specifically, the lab is focused on the control of the echolocating bat’s natural hunting and navigation behaviors across time-scales as a general model for how the brain receives and reacts to sensory cues under real-world conditions.

Dr. Wohlgemuth’s primary goal as a scientist is to understand how circuits in the brain contribute to natural behaviors for interacting with the world on multiple timescales and dimensions (i.e. azimuth, elevation, and distance). Dr. Wohlgemuth completed his Ph.D. studying the motor control of vocal behaviors, examining how the brain of the bird controls its vocal musculature for the production of song in the laboratory of Dr. Michael Brainard at the University of California, San Francisco. This research involved chronically recording single neuron activity from the vocal motor cortex of the singing bird, relating neuronal activity with the moment-by-moment coding of individual syllables of the bird’s song, as well as overall control of global syllable sequencing. The focus was on how differences in brain activity lead to differences in motor control, and through this research, Dr. Wohlgemuth became very interested in how arriving sensory information is processed to adapt these vocal motor programs. Therefore, as a postdoctoral research Dr. Wohlgemuth chose to work on the echolocating bat because the influence of auditory information on vocal planning is a robust behavior for laboratory studies in this animal.

In his time in Dr. Cynthia Moss’s laboratory as a postdoctoral fellow, Dr. Wohlgemuth completed a variety of related projects investigating dynamic neural activity in relationship to the natural behaviors of the echolocating bat. He studied the superior colliculus (SC) because it sits at the hub of a circuit responsible for processing incoming sensory information about an object’s location into species-specific orienting behaviors. For the bat, this process involves the integration of sonar echo acoustic information into sonar vocalizations as well as adaptive ear and head movements. To research natural, adaptive behavioral control in the echolocating bat, as well as the role of the SC in these sensorimotor processes, Dr. Wohlgemuth completed several projects examining both the behavior of the bat, as well as underlying neural activity in the SC and hippocampus. The first project examined the encoding of the bat’s own sonar vocalizations in the SC. This research determined that the selectivity of auditory neurons in the more superficial sensory layers of the SC was greater than in the deeper, more motor-related layers. Interestingly, auditory selectivity was only found in response to biologically-relevant sounds, with artificial sounds failing to elicit selective responses in the SC. This result points to the importance of neuronal selectivity for sounds related to orientation by sonar, identified signals related to target selection for adaptive motor planning in the SC, and further motivated an ethological approach to understanding brain function.

In addition, Dr. Wohlgemuth also performed several studies evaluating the vocal and body orientation adaptations performed by a bat while it tracks moving prey and navigates through space. These experiments characterized the adaptive planning of signal design (i.e., sonar vocalizations) and signal reception (i.e., head and pinna positioning) for the bat’s active sensing systems. This work found that the bat coordinates adaptive vocal behaviors with movements of the head and ears at millisecond precision with respect, as well as over longer time-frames related to gross target motion. Additionally, this research identified how the bat must simultaneously adapt two motor behaviors (i.e., vocal and postural) in the context of its natural, active-sensing behaviors. The results of these experiments were important for additional projects examining the activity of single neurons in the SC while the bat was engaged in several naturally inspired, acoustic orienting tasks including hunting and spatial navigation behaviors. This work identified sensory, sensorimotor, and motor neurons related to each facet of adaptive sonar behaviors, and interestingly, how the activity of SC neurons is dynamically modified with respect to adaptive changes in the bat’s echolocation behaviors. This research was the first to identify 3D tuning of SC neurons (i.e., azimuth, elevation, and distance) to physical objects in the world, as well as how the spatial tuning of SC neurons sharpen as the bat increases vocal rate, thus increasing the sensory sample rate of its environment. In order to compare results discovered on egocentric tuning of SC neurons, Dr. Wohlgemuth also performed studies on the hippocampus in the echolocating bat to examine allocentric space tuning. This work demonstrated an inverse relationship between the size of hippocampal place fields and the ongoing vocal rate of the bat used to sense the environment. These results demonstrate the importance of studying the brain in a biologically-relevant context: without the bat performing its natural behaviors, it would not have been possible to uncover these novel features of the SC or hippocampus in the context of behaviors for interacting with the natural world.

Current research efforts are focused on how circuits in the brain of the bat contribute to sensory-guided adaptive behaviors. The goal is to study how an integrated bottom-up and top-down cortico-fugal network controls behavior on multiple time-scales: from the rapid reactions to arriving sensing information indicative of bottom-up processing, to the longer time-scale governance of categorical behavioral control that is directed by top-down signaling. The lab employs computational modeling behaviors and multi-channel electrophysiology to relate changes in behavior to changes in brain activity. Additionally, the lab recently developed new technologies of virus injections to both monitor (e.g., calcium imaging) and manipulate (e.g., optogenetics) circuits in the brain of the bat. These efforts will involve existing collaborations with colleagues at Johns Hopkins University (2-photon imaging in Dr. Kishore Kuchibhotla’s Lab), and with members of the Department of Biomedical Engineering at the University of Arizona (Dr. Philipp Gutruf) to develop wireless optogenetic technologies. By combining computational ethology and modeling, electrophysiology, calcium imaging, and optogenetics, the Wohlgemuth Lab will offer new insights into circuit-level processing for both rapid control of sensory-guided adaptive behaviors and long-term goal-planning.

Ying-Hui Chou

Assistant Professor, Psychology
Assistant Professor, Cognitive Science - GIDP
Assistant Professor, Evelyn F Mcknight Brain Institute
Member of the Graduate Faculty
Assistant Professor, BIO5 Institute
Primary Department
Department Affiliations
Contact
(520) 621-7447

Research Interest

My research has focused primarily on the cognitive and clinical neuroscience of aging and neurodegenerative disorders. Within this framework, my laboratory is particularly interested in integrating brain imaging and transcranial magnetic stimulation (TMS) techniques to 1) develop image-guided therapeutic TMS protocols and 2) explore TMS-derived and image-based biomarkers for early diagnosis and prediction of therapeutic outcomes for individuals with mild cognitive impairment as well as Parkinson’s disease. For past few years, I have been involved in a number of NIA-funded studies investigating brain function and its relation to cognitive performance. I am currently the Director of Brain Imaging and TMS Laboratory and teach undergraduate and graduate level courses in cognitive neuroscience, brain rehabilitation, and brain connectivity at the University of Arizona.

Dianne K Patterson

Staff Scientist, Neuroimaging
Contact
(520) 621-1644

Work Summary

I analyze MRI images to understand more about how human language works. We use functional MRI to determine which brain regions are involved in different language tasks. We also look at diffusion MRI to learn about the quality of the wiring between regions.

Research Interest

I do neuroimaging, specifically fMRI and DTI. I am especially interested in brain networks and developments in neuroimaging software. We use independent component analysis to identify separate networks in the brain related to processing and learning language. My colleagues and I worked to improve fMRI analysis, display and data sharing options. Beginning with a web-based workbench designed for the dynamic exploration of map-based data, we worked to develop brain maps that could be similarly explored and demonstrated that this approach yielded results similar to those achieved by much more laborious and manual exploration techniques. This has improved our ability to streamline analyses, extract insights from our data and share data online. I have also worked on DWI analysis of the language system for the past 8 years. This has resulted in contributions to tract analyses (Wilson et al., 2011) and to the development of a novel technique (Patterson et al., 2015) to extract not only information about the properties of each tract but also information about the size and location of connected grey matter regions. We continue to explore the implications of these new measures. Keywords: fMRI, DWI, Language, Neuroimaging, MRI

Aneta Kielar

Assistant Professor, Speech/Language and Hearing
Assistant Professor, Cognitive Science - GIDP
Assistant Professor, BIO5 Institute
Contact
(520) 621-1644

Work Summary

My research examines neural factors which affect language functions, and how these change across life-span and are influenced by stroke, brain injury and neurodegenerative disorders. In my work, I use combination of cognitive measures and multimodal neuroimaging techniques (fMRI, EEG/ERPs, MEG). I am also interested in recovery of function, and treatment approaches involving speech-language therapy in combination with noninvasive brain stimulation techniques.

Research Interest

My research program is centered on investigating the neurobiology of healthy language system, and changes in cognitive and language processing associated with stroke and neurological disorders. My interests include incorporating cognitive measures and multimodal neuroimaging methods, with a goal to understand the relationship between language and other aspects of cognition, as well as the neural dynamics related to brain damage, resilience, and recovery. My research efforts are directed towards identifying factors which affect language comprehension and production, and how these change with development and are influenced by aging, stroke, brain injury, and neurodegenerative disorders, including Primary Progressive Aphasia (PPA) and Alzheimer’s disease (AD). I study language processing at the multiple levels, using behavioral experiments and both structural (DTI, lesion-symptom mapping, voxel-based morphometry) and functional neuroimaging (fMRI, EEG, MEG). In addition, I am interested in neuroplasticity and application of noninvasive brain stimulation techniques (e.g., TMS, tDCS) to the treatment of aphasia and dementia. The long-term goal of my research is to understand the cognitive and neural processes that support recovery of cognitive and language functions after stroke. Keywords: stroke, aphasia, dementia, MRI, EEG, Language

Matthew Dennis Grilli

Assistant Professor, Psychology
Assistant Professor, Evelyn F Mcknight Brain Institute
Assistant Professor, Neurology
Assistant Professor, Cognitive Science - GIDP
Assistant Professor, BIO5 Institute
Primary Department
Department Affiliations
Contact
(520) 621-7447

Work Summary

My research interests are broadly focused on understanding how and why we store and retrieve memories. The clinical and cognitive neuroscience research conducted in my laboratory combines neuropsychological, cognitive, social psychological, and neuroimaging approaches. An emphasis of my current research is autobiographical memory, which refers to memories of personal experiences. Ongoing projects are investigating how autobiographical memory is affected in several populations, including older adults at risk for Alzheimer’s disease and individuals with acquired brain injury. We also are interested in understanding how changes to autobiographical memory impact other aspects of cognition, and we seek to develop new interventions to improve autobiographical memory and everyday functioning.

Research Interest

My research interests are broadly focused on understanding the reciprocal relations of self and memory. How does the self influence learning and memory retrieval? How does memory contribute to one's sense of self? Uncovering the ways in which the self and memory interact may advance understanding of identity, elucidate the conditions and experiences that modify the self, and inspire clinical interventions that improve quality of life and wellbeing for people who have neurological or mental health conditions. Ongoing projects are investigating how to improve memory through self-referential encoding strategies in individuals with traumatic brain injury and other neuropsychological conditions. My current research also is investigating how individuals with amnesia (a profound learning and memory impairment) construct a sense of self and experience a sense of continuity in life.