Abstract—there is a growing concern that traditional neuropsychological (NS) testing tools are not sensitive to detecting residual brain dysfunctions in subjects suffering from mild traumatic brain injuries (mTBI). Moreover, most mTBI patients are asymptomatic based on anatomical brain imaging (CT, MRI), neurological examinations and patients’ subjective reports within 10 days post-injury. Our ongoing research has documented that residual balance and visual-kinesthetic dysfunctions along with its underlying alterations of neural substrates may be detected in “asymptomatic subjects” by means of Virtual Reality (VR) graphics incorporated with brain imaging (EEG) techniques. I. INTRODUCTION Concussion in sport, otherwise known as mild traumatic brain injury (MTBI) has been referred to as both the most common and the most puzzling type of traumatic brain injury [1]. It is seen during recreational activities, transportation accidents, and other situations in which the brain accelerates (or decelerates) differentially in relation to the skull. The phenomenon of concussion is puzzling in that there exists no consistent set of theoretical studies which clearly articulates its pathophysiology. Furthermore, most of the initial symptoms including balance [2] and cognitive deficits [3] usually resolve within 7-10 days post-injury. In addition, there is little evidence to suggest that current structural imaging techniques [e.g., magnetic resonance imaging (MRI)] can identify structural changes in the brain following concussion [4]. However, a variety of functional deficits observed using brain imaging studies have been noted in concussion [5,6,7]. There is no single concussion alike in terms of initial symptoms at the site of injury and therefore in symptoms resolution as an injury evolves over time. Therefore, it is our approach to examine multiple modalities (balance, neurocognitive functions and associated neural substrates) in order to properly classify the concussive episode. Accordingly, in the present report, we present a set of behavioral and brain imaging data indicating that residual functional abnormalities may be observed in “asymptomatic, based upon traditional assessment tools” subjects who have Manuscript submitted March 30, 2011. Semyon Slobounov is with Department of Kinesiology, the Pennsylvania State University (corresponding author phone: 814 863 3883; fax: 814-865- 12755; e-mail: sms18@psu.edu). Wayne Sebastianelli is with the Hershey Medical Center, Pennsylvania State University (e-mail: wsebastianelli@hmc.psu.edu ). Karl Newell is with Department of Kinesiology, the Pennsylvania State University (e-mail:kmn1@psu.edu) recently suffered from a single episode of sport-related concussion. Theoretically, this will help to clarify the nature of alteration of the cortical network following concussion. Clinically, this will help to improve the accuracy of concussion classification and to define more appropriate return-to-play criteria. We designed an EEG study using a virtual reality (VR) graphics aimed to examine the brain activation patterns preceding the loss of postural stability induced by a “Moving Room” experimental paradigm. It should be noted, that VR environment allows one to develop tasks in which the individual can control and manipulate movement along with the sense of self-motion while retaining the body fixation requirements of the fMRI environment [8]. Specifically, we developed visual perturbation balance tasks enabling (a) the subjects to experience the sense of presence [9] and (b) to track the changing brain activation patterns via EEG in both normal controls (NV) and concussed individuals during exposure to these VR-driven postural task conditions. 2. Moving Room Experiment A. Rationale: Balance abnormalities specifically evident during visual-kinesthetic tasks are the most common symptom in TBI patients suffering from sport-related concussions [2]. It should be noted that balance symptom resolution varies among TBI patients and may last up to more than one year post-injury. Our previous research has shown the presence of balance abnormalities and sensori- motor disintegration, induced by VR visual field motion up to 30 days post-injury [10]. Recent studies by Cavanaugh et al [11] have also shown that advanced methods may detect changes in postural control in subjects with “normal” postural stability and neuropsychological (NS) measures based upon conventional balance and neuropsychological testing. The VR moving room appeared to be one with the advanced tools that allow detection of residual postural abnormalities as evidenced by impaired visual-kinesthetic integration. Alterations of neural correlates associated with loss of balance due to stimulated rotations of visual field have not been examined, yet. B. Subjects: Fifteen neurologically normal student- athletes with no history of mTBI (mean age 21.3 +/- 1.5 years) and 14 student-athletes (mean age 20.8 +/- 1.7 years) who had recently suffered a sports-related mTBI (collegiate rugby, ice hockey, lacrosse, etc) were recruited for this study. The sample was 65% male and 35 % female. Academic grade average score for all subjects under study was 3.2 +/- 0.5. All injured subjects suffered from grade 1 Incorporating Virtual Reality Graphics with Brain Imaging for Assessment of Sport-Related Concussions Semyon Slobounov, Wayne Sebastianelli & Karl M. Newell