2004 — 2005 |
Ganis, Giorgio |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Dot and Fmri Studies of Visual Perception and Imagery @ Massachusetts General Hospital
DESCRIPTION (provided by applicant): Diffuse optical imaging (DOI) is a non-invasive and inexpensive imaging technique that uses near-infrared light (NIR) to probe tissue optical properties. In its most common application, DOI can measure regional changes in the concentration of oxy- and deoxy-hemoglobin with excellent sampling rates (exceeding 100 Hz, given suitable hardware). In diffuse optical topography (DOT), numerous light sources and detectors are employed, resulting in spatial maps of oxy- and deoxy-hemoglobin concentration changes. To date, there have been numerous demonstrations in adults that modulations of diffuse optical imaging signals elicited by perceptual and cognitive tasks can be detected non-invasively at the scalp. Yet, there has not been a systematic validation of DOT with more established techniques, leaving unresolved the issue of the true potential and limitations of DOT as a cognitive neuroscience tool. The general goals of the proposed research are to conduct such a systematic validation in adults by recording simultaneously DOT and fMRI data during established visual stimulation paradigms. The critical importance of conducting such a validation becomes apparent if one considers some of the potential benefits of DOT as a cognitive neuroscience tool: (1) DOT can be used safely with pediatric populations of any age; this is especially important for healthy infants and young children, in which fMRI cannot easily be used without extreme physical restraint measures (e.g., sedation); (2) The DOT equipment is portable and so can be used in settings where fMRI cannot (e.g., realistic settings such as driving a vehicle); (3) DOT monitors brain activation in a less intrusive manner than fMRI since acquisition is silent and subjects are only minimally constrained physically; (4) DOT is over an order of magnitude less expensive than fMRI; and (5) DOT can measure physiological parameters that are complementary to those measured by fMRI. Thus, the development and validation of DOT for the noninvasive study of brain function may result in an additional technique available to cognitive neuroscientists to investigate brain function and dysfunction in adults and especially in pediatric populations.
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2004 — 2008 |
Kosslyn, Stephen [⬀] Ganis, Giorgio |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Fmri and Doi Investigations of Deception
This project has three main goals. The first is to investigate the neural basis of deception. This goal will be achieved by using established neuroimaging technologies (fMRI), thus going beyond the traditional approaches based on the measurement of peripheral variables such as skin conductance, which have not proven highly valid. The second goal is to validate a novel taxonomy of lies based on prior research conducted in the PI's laboratory. The idea of subdividing lies into different categories and studying these categories separately is a major conceptual advance in the study of deception because the traditional approach has treated deception as a unitary phenomenon: either one is lying or one is telling the truth. In the proposed taxonomy, lies are divided according to two dimensions: 1) whether they are spontaneous or memorized in advance, and 2) whether they are isolated (i.e., unrelated to each other) or fit into a coherent story. The different types of lies are conceptualized in terms of the cognitive processes they are likely to engage. One of the methodological strengths of the proposed approach is that the brain regions supporting the hypothesized cognitive processes engaged during the different types of lies will be independently identified for each participant (by using a set of "neurocognitive localizer" tasks). These additional data will provide important constraints for the interpretation of the results in the deception conditions. The third goal is to use the resulting knowledge to develop a new technology for detecting the neural processes associated with different types of lies. This technology is known as diffuse optical imaging (DOI), and relies on measuring the absorption of near-infrared light in the cerebral cortex to track cortical processes. Although in its infancy, DOI has the advantage of being relatively inexpensive and portable.
A better understanding of the brain processes that underlie deception can potentially benefit society in several ways. First, it is likely to advance our knowledge (and consequently collective awareness) of the limitations and potential of lie detection methods. Second, the understanding gained in this work about the neural processes underlying deception may lead to more effective lie detection methods; this could be very important in forensic settings. Third, the development of an affordable technology (DOI) that can be used to study the neural correlates of deception could eventually revolutionize the field of lie detection.
This project will strengthen the collaboration between researchers whose main area of expertise is cognitive neuroscience and researchers whose expertise is in physics and engineering. Such collaborations weaken traditional barriers between disciplines and allow scientists in training (students, assistants, postdocs) to acquire a greater range of skills and experience. The PI's lab has a long history of training scientists who have gone on to make independent contributions, and that practice will be continued. This project offers educational opportunities for students and junior researchers. On the technical side, they will not only acquire training in fMRI, but also have the unique opportunity to learn the novel DOI technology and participate in its development at various levels; on the content side, these studies cut across several lines of research that are often not integrated. In doing so, they provide students and junior scientists with an unusual breadth as well as an opportunity to learn to integrate what appear to be parallel research domains. In order to disseminate the results of the research as broadly as possible, significant findings will be reported primarily as journal articles, and preliminary data will be discussed with other investigators at scientific meetings.
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2009 — 2010 |
Ganis, Giorgio |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Sger: Neural Correlates of Action Videogame Training: An Exploratory Fmri Study @ Massachusetts General Hospital
Vision is the dominant sensory modality that people use to interact with the external environment and to learn about it. There is behavioral evidence that even relatively short periods of training with action video games can improve performance on some kinds of visual abilities, especially those that allow people to analyze spatial relationships among objects in the environment. For example, after action video game training, people are able to keep track of more objects moving around in the visual world than they could before. This exploratory research addresses three gaps in current understanding. First, the full range of visual abilities that can be improved by action video game training remains unknown. Second, it is not known whether such training could improve learning speed itself during visual tasks, such as those that involve predicting sequences of spatial locations. Third, little is known about the brain changes that enable such improvements. The proposed research will measure performance and brain activation in a group of participants (using functional magnetic resonance imaging) on a battery of visual tasks before and after a two-week action video game training period. The pattern of performance and brain activation changes will reveal the specific visual and learning abilities and brain networks that are modified by video game training.
The proposed study will provide preliminary data potentially leading to training-based applications that are important for society. Specifically, the visuospatial abilities that can be improved after action video game practice are used in a broad range of professions. For instance, mathematicians, engineers, architects and many other individuals routinely engaged in tasks that require performing complex mental spatial transformations may benefit from action video game training. This research may be eventually lead to developing effective training video games that maximally take advantage of adult brain plasticity. Information about the precise neural bases of these processes may also lead to innovative educational practices that enhance learning abilities themselves, help people with visuospatial learning disabilities, as in attention deficit disorder, or even to future pharmacological methods to improve performance.
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