The forward problem of Magnetoencephalography for an ellipsoidal inhomogeneous shell-model of the brain is considered. The inhomogeneity enters through a confocal ellipsoidal shell exhibiting different conductivity than the one of the brain tissue. It is shown that, as far as the leading quadrupolic moment of the exterior magnetic field is concerned, the complicated expression associated with t...

Incidental learning of phonological structures through repeated exposure is an important component of native and foreign-language vocabulary acquisition that is not well understood at the neurophysiological level. It is also not settled when this type of learning occurs at the level of word forms as opposed to phoneme sequences. Here, participants listened to and repeated back foreign phonologi...

Chicago, Illinois " Those who seek should not stop seeking until they find. When they find, they will be disturbed. When they are disturbed, they will rule, and when they rule, they will rest. " The Gospel of Thomas 2:1-4 iii ACKNOWLEDGMENTS My deepest gratitude goes to my advisor Prof. Arye Nehorai for his permanent support, his excellent guidance, and patience during my graduate studies. This...

Technical Note presented as a poster at the EMSE Workshop at Princeton, 7-8 Sep 2001 This technical note supplements the workshop demonstration by providing (a) pointers to issues in the literature regarding the correction of EEG (or MEG) recordings for blink and eye movement artifacts, and (b) a theoretical description of a spatial filter for removing ocular artifacts, with special attention t...

In recent years, significant progress has been made in the area of EEG/MEG source imaging. Source imaging using simple spherical models has become increasingly efficient, with consistently reported accuracy of within 5mm. In contrast, source localization on realistic head models remains comparatively modest, with sub-centimeter accuracy being the exception rather than the norm. A primary reason...

We describe a comprehensive linear approach to the problem of imaging brain activity with high temporal as well as spatial resolution based on combining EEG and MEG data with anatomical constraints derived from MRI images. The “inverse problem” of estimating the distribution of dipole strengths over the cortical surface is highly underdetermined, even given closely spaced EEG and MEG recordings...

L. Pylkkänen, A. Stringfellow, E. Flagg, and A. Marantz Department of Linguistics and Philosophy, KIT-MIT MEG Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, Mind Articulation Project, International Cooperative Research Project, Japan Science and Technology Corporation, Tokyo 113-0034, Boston University School of Medicine, Harold Goodglass Aphasia Research Center, J...

Despite intense recent research, the neural correlates of conscious visual perception remain elusive. The most established paradigm for studying brain mechanisms underlying conscious perception is to keep the physical sensory inputs constant and identify brain activities that correlate with the changing content of conscious awareness. However, such a contrast based on conscious content alone wo...

In this study, behavioral and brain measures were taken to assess the effects of training a Japanese adult subject to perceptually distinguish English /l/ and /∞/. Behavioral data showed significant improvement in identifying both trained and untrained speech stimuli. Correspondingly, neuromagnetic results showed enhanced mismatch field responses in the left hemisphere and reduced activities in...