Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Abstract: Optical imaging of cortical activity offers several advantages over conventional electrophysiological and anatomical techniques. One can map a relatively large region, obtain successive maps to different stimuli in the same cortical area and follow variations in response over time. In the intact mammalian brain this imaging has been accomplished with the aid of voltage sensitive dyes. However, it has been known for many years that some intrinsic changes in the optical properties of the tissue are dependent on electrical or metabolic activity. Here we show that these changes can be used to study the functional architecture of cortex. Optical maps of whisker barrels in the rat and the orientation columns in the cat visual cortex, obtained by reflection measurements of the intrinsic signal, were confirmed with voltage sensitive dyes or by electrophysiological recordings. In addition, we describe an intrinsic signal originating from small arteries which can be used to investigate the communication between local neuronal activity and the microvasculature. One advantage of the method is that it is non-invasive and does not require dyes, a clear benefit for clinical applications.
Animal

Abstract: The academic achievement scores of 122 children with epilepsy were examined in relation to demographic and clinical seizure variables. As a group, these children were making less academic progress than expected for their age and IQ level. Academic deficiencies were greatest in arithmetic, followed by spelling, reading, comprehension, and word recognition. Results of the multiple regression analyses indicated a modest combined predictive significance of the demographic and clinical seizure variables for academic performance. In addition, the magnitude of these relationships varied by academic area. Among the individual variables examined the strongest correlates of academic performance were age of the child, age of seizure onset, lifetime total seizure frequency, and presence of multiple seizures (absence and tonic-clonic). These results are discussed in relation to developing an understanding of the factors which underlie academic vulnerability in children with epilepsy.
Achievement

Abstract: To calibrate an anesthetic mass spectrometer without the use of premixed gases and vapors in cylinders, we devised a gas mixer using fixed resistances of capillary needle tubings and adjustable needle valves to dilute test gases and vapors with oxygen. The dilution ratio was determined during each calibration by diluting air with oxygen and noting the reduction in the ratio of nitrogen to oxygen. Empiric correction was made by the computer for the effects of density and viscosity, relative to air, on the flow of nitrous oxide, carbon dioxide, and the saturated vapors of the three anesthetics through the capillary resistor. The computer was programmed to control solenoid valves both for calibration and for the multiplexed sampling of operating rooms. Oxygen, nitrous oxide, and carbon dioxide were used as pure gases, and halothane, enflurane, and isoflurane were vaporized at room temperature in 50-ml vaporizers. The resulting calibrations were found to be accurate to within +/- 2%.

Anesthetics

