The CMCP is designed to emphasize a multi-disciplinary approach to identifying, locating, and analyzing the different types of memory in the primate brain. The Center will provide behavioral, imaging, neurophysiological and computational components to the study of memory and cortical plasticity. Imaging studies will help identify areas of the brain active during object memory tasks, location memory tasks, and time memory tasks in non-human primates. These results, combined with predictions from computational modeling, will be used to target single cell recordings in areas associated with different kinds of memories in non-human primates in order to get real time data on physiological responses to different memory formation. The intent is to understand mechanisms of normal memories, determine the types of memory compromised by disease or injury, and target treatment for environmentally induced memory loss (e.g., Post Traumatic Stress Disorder) or drug addiction.
The Beauchamp Laboratory studies multisensory integration and visual perception in the living human brain using a variety of techniques. The main technique is blood-oxygen level dependent functional magnetic resonance imaging (BOLD fMRI). Using BOLD fMRI, the PI has shown that the human superior temporal sulcus (STS) is important for integrating visual, auditory and multisensory integration. The PI has also shown that the same region of STS responds to social stimuli such as emotional faces. Therefore, it may be an important brain target for treating disorders of language such as dyslexia. Because BOLD fMRI offers only an indirect measure of neuronal activity, it is important to combine fMRI with other measures of brain function. Transcranial magnetic stimulation (TMS) allows for the creation of a temporary lesion in a brain area. By combining TMS with fMRI, the necessity of a brain area for a cognitive function can be examined. For instance, the PI has shown that the parietal lobe is important for integrating information from the visual and tactile modalities. When subject receives a faint touch on their hand, they are much better able to detect it when they are able to see the touch. Interrupting parietal activity with TMS eliminates this behavioral advantage.
Dr. Dragoi's laboratory is currently engaged on several lines of research to understand how individual neurons and networks in the visual cortex of behaving monkey construct real-time representations of incoming stimuli, how internal representations are updated as new information is acquired, and how neuronal coding relates to visual behavior. To achieve these goals, the lab employs state-of-the-art electrophysiological and behavioral techniques that allow the simultaneous recording of the activity of multiple neurons in the visual cortex of alert monkeys during specific behavioral tasks, in combination with computational models of network function to understand how neural circuits produce emergent properties relevant for visual behavior. The research in Dr. Dragoi's lab on the neural coding of dynamic image representations has the potential to advance our understanding of the neuronal mechanisms underlying visual perception and learning, and, at the same time, help develop chronically-implantable human cortical prostheses to assist visually impaired people.
The Felleman laboratory studies the functional organization of visual cortex in non-human primates using a variety of neuroimaging, neurophysiological, and neuroanatomical pathway tracing techniques. Over the last 15 years, the Felleman laboratory has used intrinsic cortical optical imaging to study the modular organization of cortical areas V1, V2, and V4. These studies have revealed systematic maps of color in areas V2 and V4, as well as systematic maps of object shape in areas V1, V2, and V4. Current studies are investigating how multiple low level cues are combined in area V4 and beyond to form representations of objects utilized in higher order temporal lobe object processing areas. Neurophysiological studies, using single electrode and multiple-electrode arrays are then conducted to determine how single cell properties contribute to the observed functional maps. Neuroanatomical pathway tracing techniques are used in the Felleman laboratory to determine how specific cortical modules or areas are interconnected in an effort to determine the flow of visual information in the non-human primate. At the level of cortical modules, intrinsic cortical imaging is first performed to identify specific color, brightness, or shape modules. These modules are then injected with distinguishable neuroanatomical tracers to determine how information from these specific modules are “broadcast” actors the visual cortical hierarchy. Quantitative analysis of anterograde and retrograde lebeling from neuroanatomical tracer injections into area V4 has revealed a complex array of cortical subdivisions throughout inferotemporal cortex that are likely to be play critical, yet differential roles in visual processing and visual object memory.
The research in the Sereno laboratory covers a broad array of methodologies to address higher cognitive function in humans and nonhuman primates with the long-term goals of understanding attention and memory. The laboratory is highly interdisciplinary and includes research techniques utilizing eye-tracking technology, nonhuman primate electrophysiology, behavioral testing, and computational modeling. The laboratory has four basic lines of experimental and theoretical investigation: 1) neurophysiological investigations of shape and spatial processing, 2) neurophysiological investigations of attention and working memory, 3) investigations of eye movements in human clinical populations and 4) theoretical and computational models. This research will allow design of better methods for diagnosis of higher cognitive dysfunctions, to improve evaluation of treatment effects on cognitive function, prediction and development of individualized treatments, and development of biomarkers of cognitive dysfunction in human disorders. The research will provide both an overarching framework to guide the experimental studies and a quantitative method of testing these neurally based hypotheses.
Dr. Wright’s research programs investigate basic processes and mechanisms underlying learning and memory in monkeys, pigeons, and humans. One research program involves abstract concept learning (e.g., identity, nonidentity and matching to sample) with pigeons showing, for the first time, concept learning in an avian species. Processes responsible for concept learning are being explored. In another research program processes by which subjects make decisions is being studied: how they compare the choices available, and what strategies they use to decide which choice to choose. The analytic framework uses a mathematical model and has shown promise in the investigation of early learning stages with pigeons and comparisons to humans. In memory research programs, procedures have been developed for animals to perform comparable to humans in list memory tasks. List memory tests allow exploration of memory phenomena not possible with single memory items. Interference and other memory processes are being researched to determine how memory changes over time. Pigeons, monkeys, and humans are being tested in change-detection tasks to compare visual working memory capacity and object memory to location memory.