Event-related potentials in neuropsychological studies of language

Experiments are described in which event-related potentials (ERPs) are employed to study the specialization of functions between and within the cerebral hemispheres during the performance of language and nonlanguage tasks by normal adults. Similar studies of deaf subjects suggest that the functional organization of the brain may be altered after different early language and sensory experiences. Studies of patients with alexia without agraphia suggest that the ERP may be a valuable tool with which to study cerebral reorganization after brain damage.     

Religious Symbolism at the Limits of Human Engagement

This article explores the triadic semiotics of C.S. Peirce as a resource for the interdisciplinary dialogue between science and theology. His pragmatic theory of interpretation was explicitly linked to a non-dualistic metaphysics and epistemology, and avoids the temptation to treat religious symbolism reductionistically. This philosophical model can facilitate dialogue across disciplines about questions of ultimate religious significance in a way that overcomes some of the pernicious dualisms that reinforced the popular imagery that science and theology are (at worst) enemies in warfare or (at best) indifferent and irrelevant to one another.     

Event-related potential studies of cerebral specialization during reading: I. Studies of normal adults

A number of methodological features were incorporated in a paradigm designed to maximize the likelihood of finding reliable event-related potential (ERP) signs of functional specializations between and within the cerebral hemispheres. Every subject was more accurate in identifying words presented to the right than to the left visual field. The morphology of the ERPs elicited by these words varied considerably as a function of electrode position both within and between the hemispheres. Amplitude asymmetries of ERP components recorded from occipital regions of the two hemispheres varied systematically with the position of the word in the visual field. On the other hand, ERPs from more anterior (temporal and frontal) regions displayed large asymmetries which were in the same direction regardless of the visual field of word presentation. The most prominent such asymmetry was in the negativity in the region 300–500 msec (N410) which was larger in the left than the right hemisphere in every subject. These results demonstrate that in this paradigm which demands specialized language processing ERPs are sensitive to aspects of cerebral organization both within and between the two hemispheres.