fMRI Applications: Non-Clinical

Room 801 A/B


Chairs: Vanessa A. Sluming and Thomas M. Talavage


Prog #

16:00 544. Brain-Computer-Interface Using Real-Time FMRI: Thought-Controlled Robot Arm

Jong-Hwan Lee1, Jeongwon Ryu2, Ferenc A. Jolesz1, Zang -Hee Cho2, Seung-Schik Yoo1

1Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA; 2Gachon Medical School, Incheon, Republic of Korea

We presented the feasibility of voluntary control of robotic arm using the thought process (regulation of the somatomotor activation via motor imagery) using real-time fMRI. Although the robotic arm was used as the means to link the thought process to the explicit tangible motion, translation into computer control commands, such as continuous cursor movement (i.e. replacing computer mouse) is also possible.

16:12 545. Parallel Real-Time FMRI with Two Connected High-Field Scanners (3T, 7T)

Tobias Moench1, Maurice Hollmann1, Ramona Grzeschik1, Michael Luchtmann1, Ralf Luetzkendorf1, Sebastian Baecke1, Johannes Bernarding1

1University of Magdeburg, Magdeburg, Germany

We enhanced a custom-made real-time fMRI software system to support the parallel usage of two or more high-field MRI scanners based on an XML-based experiment description language. We realized first experiments involving interactions between each two volunteers being measured in 3T and 7T MRI scanners in parallel. Each volunteer received feedback of his and of the opponents' current activation level. We also introduced dynamic financial rewards. Depending on the actual BOLD response of each single run (24secs) the final reward could be increased. The current financial state was continuously displayed with the activation scores to increase the volunteers' motivation.

16:24 546. Effect of Pulsed Magnetic Field on FMRI Processing of Pain

John A. Robertson1, 2, Jean Theberge1, 3, Julie Weller2, Dick J. Drost1, 3, Frank S. Prato1, 3, Alex W. Thomas1, 2

1Lawson Health Research Institute, London, Canada; 2University of Western Ontario, London, Canada; 3St. Joseph's Health Care, London, Canada

The effect of a specific pulsed magnetic field on pain processing was investigated using fMRI. Normal subjects were given acute thermal pain while imaged. Then, a pulsed magnetic field exposure (or sham condition) was given using a custom gradient program, and the functional imaging of pain repeated. The data was analyzed using Brain Voyager, and differences were found between groups in the cingulate cortex. These results demonstrate the effect of pulsed magnetic fields on neural processing.

16:36 547. Dexterity and Implicit Learning of Sequential Movements

Maite Aznárez-Sanado1, María A. Fernández-Seara1, Francis Loayza1, Maria A. Pastor1

1Center for Applied Medical Research, University of Navarra, Pamplona, Spain

The present study was designed to identify the dynamic activation changes within the basal ganglia and related motor regions during the initial learning of sequential finger movementsDexterity influences the effect of sequential movements repetition. When performing repetitive sequential movements with the right hand compared with the left hand and bimanually the recruitment of posterior parietal and premotor areas including left DLPC was greater. Cerebellar somatosensory cortex activation was also directly related with repetition.The areas attenuated with sequence repetition involved mainly the spatial attentional network needed for a visuospatial learning task, with subsequent movement sequence performance.

16:48  548. Neural Activity in Human Auditory and Sensorimotor Cortices Modulated by Passively Varied Divided Attention – an FMRI Study

Maolin Qiu1, J Arora1, Jitendra Bhawnani1, N Rajeevan1, Scott McIntyre1, Terrence W. Nixon1, R T. Constable1

1Yale University School of Medicine, New Haven, Connecticut, USA

There is much interest in human fMRI studies in understanding the impact of baseline brain activity on the activation observed. To study this, baseline is often altered with an anesthetic agent which leads to additional confounds such as pure vascular effects and attention effects that must be accounted for in order to examine the direct impact on neuronal activity. Using auditory and tactile stimulation alone and simultaneously we demonstrate that the simultaneous multi-sensory stimulation does alter the primary sensory activation indicating the equivalent of a passive attention manipulation.

17:00 549. High Resolution Functional MRI Imaging of Material-Specific Encoding in the Head, Body and Tail of the Hippocampus

Wendy Ringe1, Kaundinya Gopinath1, Sergey Cheshkov1, Subhendra Sarkar1, Richard Briggs1, Robert Haley1

1UT Southwestern Medical Center, Dallas, Texas, USA

Limited field of view, high resolution fMRI is used to demonstrated hippocampal hemisphere- and region-specific activity during a memory paradigm. Activation related to material-specific encoding is differentiated from basic material-specific visual processing for four stimuli types in the hippocampal head, body and tail: Words - bilateral (left greater than right) head, left body and tail; Nameable Objects - bilateral (right greater than left) head, left body, and right tail; Faces - bilateral head and tail; Nature Scenes left head, bilateral body and tail. High-resolution limited-coverage acquisitions is useful to study parcellation of memory processes within the hippocampus.

17:12 550. ASL Perfusion FMRI to Image Psychomotor Vigilance Time-On-Task Effects in the Human Brain

Hengyi Rao1, 2, Julian Lim1, Wenchau Wu1, Jiongjiong Wang1, John A. Detre1, David F. Dinges1

1University of Pennsylvania, Philadelphia, Pennsylvania, USA

ASL perfusion fMRI was used to examine the neural correlates of performance decline and mental fatigue induced by a continuous 20-minute psychomotor vigilance test (PVT). Elevated subjective report of fatigue scores were associated with global CBF changes from the beginning to the end of the task, while prolonged reaction times were associated with regional CBF changes in the thalamus-parietal-cingulate-frontal network both during task and baseline periods. These findings demonstrate the feasibility and utility of ASL perfusion fMRI for imaging time-on-task effects, and provide a neural basis for the dissociation between subjective mental fatigue and objective performance stability.

17:24 551. Using FMRI to Explore Secondary Somatosensory Areas in the Lateral Sulcus of Squirrel Monkeys

Na Zhang1, Limin Chen1, Gregory H. Turner1, R. Friedman2, A. W. Roe2, John C. Gore1, Malcolm J. Avison1

1Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA; 2Vanderbilt University, Nashville, Tennessee, USA

While primary somatosensory cortex (SI) in non-human primates has been extensively mapped using electrophysiology (Kaas), optical imaging of intrinsic signal (OIS; Chen), and fMRI (Chen), less is known about the fine scale topographic organization of secondary somatosensory cortex (SII), due in large part to its inaccessibility for optical imaging. We previously demonstrated that somatotopic maps collected using high field BOLD fMRI are in close agreement with those obtained in the same animal using OIS and electrophysiology.  We further demonstrated the ability of high field BOLD fMRI to resolve submillimeter shifts in cortical activation that are the neural correlates of the sensory funneling illusion in SI.  We have now used the same BOLD fMRI methods to examine the fine somatotopic organization of digits in SII of squirrel monkey, and to determine whether similar cortical correlates of sensory funneling are present in SII. Our results revealed that each digit activated distinct somatotopically organized anterior and posterior areas of SII. This organization in SII was consistently reproducible within and across animals.  These studies demonstrate the ability of high field BOLD fMRI to map the functional organization of the non-human primate brain at submillimeter resolution in areas that are inaccessible to optical imaging techniques, and require the sacrifice of the animal for electrophysiological mapping studies.  Furthermore, they represent some of the first data suggesting that sensory funneling may have neural correlates beyond SI.

17:36 552. Linking Genes to Brain Function: Expression of Serotonin 5-HT1A Receptors in Specific Neuronal Populations Results in Divergent PhMRI Responses to the Selective Agonist 8-OH-DPAT

Alessandro Gozzi1, Adam Schwarz1, Valerio Crestan1, Theodoros Tsetsenis2, Enrica Audero2, Luisa Lo Iacono2, Cornelius thilo Gross2, Angelo Bifone1

1GlaxosmithKline Medicine Research Centre, Verona, Italy; 2EMBL, Monterotondo, Italy

Transgenic mouse lines selectively expressing the serotonin 5-HT1A receptor in specific brain regions have been recently developed to investigate the role of discrete forebrain circuits in anxiety and depressive disorders. Here we have applied phMRI to characterize brain functionality in wild-type, serotonin 5-HT1A knockout mice (KO), and in transgenic lines selectively expressing the receptor in the central amygdala. Results highlighted divergent functional roles of distinct receptor populations belonging to the same neurotransmitter system. This study demonstrates the potential of phMRI as a tool to phenotype genetically engineered animals and to explore the correlation between genes and brain function in vivo.

17:48 553. Behavioral Correlates of Negative BOLD Signal Changes in the Primary Somatosensory Cortex

Juergen Baudewig1, Andreas Kastrup1, Sonja Schnaudigel1, Lars Becker1, Jan Martin Sohns1, Peter Dechent1

1Georg-August-University Goettingen, Goettingen, Germany

Aside from positive BOLD signals there is converging evidence that neuronal responses also induce negative signals. Although it is believed that these negative BOLD signals reflect suppression of neuronal activity direct evidence for this assumption is lacking. The aim of this study was to determine the functional significance of negative BOLD responses during unilateral electrical median nerve stimulation. Positive BOLD changes were observed in the contralateral, whereas negative BOLD changes could be detected in the ipsilateral primary somatosensory cortex. Additional psychophysiological experiments revealed that these focal cortical fMRI signal decreases reflect a functionally effective inhibition in the somatosensory system.