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ERPs were recorded from 24 undergraduates as they read sentences known to differ in syntactic complexity and working memory requirements, namely Object and Subject Relative sentences. Both the single-word and multiword analyses revealed significant differences due to sentence type, while multiword ERPs also showed that sentence type effects differed for(More)
Repeated exposure to words leads to plastic changes in the nervous system throughout the lifespan, with the consequence that common words are processed more rapidly and accurately than rare words. Most behavior time measures correlate highly with the logarithm of a stimulus word's experiential frequency. Here, we demonstrate similar but earlier changes in(More)
Sentence-length event-related potential (ERP) waveforms were obtained from 23 scalp sites as 24 subjects listened to normally spoken sentences of various syntactic structures. The critical materials consisted of 36 sentences each containing one of two types of relative clauses that differ in processing difficulty, namely Subject Object (SO) and Subject(More)
Although persistent drought in West Africa is well documented from the instrumental record and has been primarily attributed to changing Atlantic sea surface temperatures, little is known about the length, severity, and origin of drought before the 20th century. We combined geomorphic, isotopic, and geochemical evidence from the sediments of Lake Bosumtwi,(More)
AC amplifiers can introduce significant distortions into the low frequency and DC components of recorded electrophysiological data such as event-related potentials (ERPs). Methods for correcting such distortions (i.e., estimating the waveform of the original data) after the data have been amplified and recorded rely on an accurate estimate of the(More)
or any information storage and retrieval system, without permission in writing from the publisher. Supercritical fluid extraction (SFE) is a relatively new technique in the field of analytical chemistry, having evolved in the last decade as an alternative method of preparing samples prior to analysis. SFE offers many advantages to the analyst that are not(More)
Late Cretaceous climatic cycles are reflected in lithological and magnetic variations in carbonate sediments from South Atlantic Deep-Sea Drilling Project site 516F at a paleolatitude of roughly 30 degrees S. Magnetic susceptibility cycles 20 to 60 centimeters in length appear to be controlled by the precession of the equinoxes. Cyclicity is particularly(More)
Water, in its subcritical state, can be used as both a solvent and reactant for the hydrolysis of triglycerides. In this study, soybean, linseed, and coconut oils were successfully and reproducibly hydrolyzed to free fatty acids with water at a density of 0.7 g/mL and temperatures of 260-280 " C. Under these conditions the reaction proceeds quickly, with(More)