No abstract

We present a functional MRI experiment investigating the neural basis of feature-based attention in humans using the Stroop task. Cortical areas specifically involved in color processing and word reading were first identified in individual participants using independent tests. These areas were then probed during the Stroop task (in which participants must selectively attend to the font color of a word while ignoring the word itself). We found that activation in functionally defined color areas increased during the task relative to a neutral color-naming task while activation in functionally defined word areas decreased. These results are consistent with a biased competition model of feature-based attention in which the processing of attended features is enhanced and the processing of ignored features is suppressed.

sufficient rigor, coverage, and readability so that a beginner can, with reasonable ease, learn the subject well from the text alone. This book can be wholeheartedly recommended either for a first course or for t.he engineer ~'ho needs to learn or review t he subject on his own. As an introductory text, this work should provide a standard of comparison for some years to corne.

No abstract

invasion of muscle coats, serosa, or lymphatics as indications for further surgery. However, Dent et al.5 found residual neoplasm in lymph nodes and in the appendiceal stump in 2 of 8 patients subjected to hemicolectomy after discovery of a carcinoid tumor at appendectomy. None of their patients has had recurrence or late metastases. Since the 2 carcinoids with lymph node metastases were the only 2 (in their series of 29) over 1 cm in diameter, they recommend right colectomy for neoplasms of this size or greater.There is thus lack of agreement concerning the degree of potential malignancy of this neoplasm and its appropriate treatment. Since pediatric patients have such a long life expectancy, the opportunity of followup makes the likelihood of detecting late recurrences of neoplasms of low malignant potential greater in this age group. This study was undertaken to determine the behavior of appendiceal carcinoids in pediatric patients, especially in relation to size and extent of invasion. MATERIALS AND METHODST h e files of the Armed Forces Institute of Pathology were searched for all cases of carcinoid tumors in children under 15 years of age. Twenty-six acceptable cases were found, all of which were appendiceal The majority of these patients were military dependents. Histologic sections and some clinical information were available for all cases. Slides were reviewed by two of us (SER, RMD) to evaluate depth of invasion by neoplasm and presence or absence of perineural involvement. Followup information was obtained on 23 of the 26 patients by contacting families and attend- 1538