Electrobehavioral characteristics of epileptic rats following photothrombotic brain infarction.

The goal of this study was to characterize the electroencephalographic (EEG) and behavioral properties of young adult rats during extended video-EEG monitoring following photothrombotic brain infarction. Two-month-old male Sprague-Dawley rats underwent photothrombotic brain infarction of the left sensorimotor cortex with the photosensitive dye rose bengal (n=10) or were used as controls (n=9). Qualitative and quantitative EEG analysis was performed on digital video-EEG records obtained during 6 months of recording. The main finding of this study was that 5/10 (50%) lesioned animals developed focal epileptic seizures ipsilateral to the cortical infarct characterized by rhythmic spike-wave discharges with or without behavioral change. Epileptic animals demonstrated increased delta, theta, and low beta-range power ipsilateral to the infarct that reliably distinguished them from lesioned nonepileptic and control animals. Lesioned animals (epileptic and nonepileptic) also demonstrated a distinct pattern of focal rhythmic theta activity before or after generalized high beta-range discharges. Electrical and behavioral characteristics common to both lesioned and control animals included: (1) focal rhythmic theta activity in either hemisphere; (2) focal low beta-range discharges in either hemisphere; (3) generalized high beta-range discharges; (4) absence seizures; (5) generalized pseudoperiodic spike discharges associated with mild multifocal body jerks; (6) tonic-clonic seizures (one nai;ve control; one lesioned animal). Cresyl violet staining of lesioned animals' brains showed consistent infarcts of the sensorimotor cortex extending to the subcortical white matter. These results provide an expanded electrobehavioral description of young adult rats following photothrombotic brain infarction and augment further investigation into the molecular, cellular, and network alterations that contribute to the establishment of post-stroke epilepsy.

Form and content: looking at visual features of television.

Television viewing at home by 50 individuals in 5 age groups (2-, 5-, 8-, 12-year-olds, and adults) was recorded on 1-s time-lapse videotapes over 10-day periods. Coding was based on 5-min point samples. Analysis examined looking at the TV screen in relation to the visual presence of the features cuts, movement, animation, man, woman, child, and nonhuman; content features were child vs. adult programming and overt purposeful character behavior. Cuts, movement, and overt purposeful character behavior were positively related to looking independent of child vs. adult programming. Associations with looking for the remaining features depended on the viewer's age or sex or type of content within which they occurred.

Early childhood television viewing and adolescent behavior: the recontact study.

In this Monograph, we report the follow-up of 570 adolescents who had been studied as preschoolers in one of two separate investigations of television use. The primary goal of the study was to determine the long-term relations between preschool television viewing and adolescent achievement, behavior, and attitudes. Using a telephone interview and high school transcripts, we assessed adolescent media use; grades in English, science, and math; leisure reading; creativity; aggression; participation in extracurricular activities; use of alcohol and cigarettes; and self-image. In each domain, we tested theories emphasizing the causal role of television content (e.g., social learning, information processing) as contrasted with those theories positing effects of television as a medium, irrespective of content (e.g., time displacement, pacing, interference with language). The results provided much stronger support for content-based hypotheses than for theories emphasizing television as a medium; moreover, the patterns differed for boys and girls. Viewing educational programs as preschoolers was associated with higher grades, reading more books, placing more value on achievement, greater creativity, and less aggression. These associations were more consistent for boys than for girls. By contrast, the girls who were more frequent preschool viewers of violent programs had lower grades than those who were infrequent viewers. These associations held true after taking into account family background, other categories of preschool viewing, and adolescent media use. One hypothesis accounting for the sex differences is that early experiences, such as television viewing, have greater effects when they counteract normative developmental trends and predominant sex-typed socialization influences than when they reinforce them. Adolescents in the study used both television and print media to support ongoing interests. Television content (e.g., entertainment, sports, or world events) predicted extracurricular activities, role models, and body image. The only evidence for possible effects of television as a medium was the positive relation of total viewing to obesity for girls. The medium of television is not homogeneous or monolithic, and content viewed is more important than raw amount. The medium is not the message: The message is.