Health-related Internet use, coping, social support, and health indicators in people living with HIV/AIDS: preliminary results from a community survey.

Widespread Internet use has revolutionized health information and patient education for persons with chronic illnesses. The authors surveyed 147 HIV-positive persons to examine factors associated with Internet use and associations between Internet use and health. Information, motivation, and behavioral skills associated with using the Internet were related to Internet use. The authors found that health-related Internet use was associated with HIV disease knowledge, active coping, information seeking coping, and social support among persons who were using the Internet. These preliminary findings suggest an association between using the Internet for health-related information and health benefits among people living with HIV/AIDS, supporting the development of interventions to close the digital divide in HIV/AIDS care.     

Effects of chlordiazepoxide on pausing during rich-to-lean transitions

Extended pausing during discriminable transitions from rich-to-lean conditions can be viewed as escape (i.e., rich-to-lean transitions function aversively). Thus, an anxiolytic drug would be predicted to mitigate the aversiveness and decrease pausing. In the current experiment, pigeons' key pecking was maintained by a multiple fixed-ratio fixed-ratio schedule of rich (i.e., larger) or lean (i.e., smaller) reinforcers. Intermediate doses (3.0-10.0 mg/kg) of chlordiazepoxide differentially decreased median pauses during rich-to-lean transitions. Relatively small decreases in pauses occurred during lean-to-lean and rich-to-rich transitions. Effects of chlordiazepoxide on pausing occurred without appreciable effects on run rates. These findings suggest that signaled rich-to-lean transitions function aversively.     

Carryover bias in visual assessment.

Carryover of stimuli in sequential judgments was studied for a visual assessment task involving estimation of the percentage cover of black circles on a white image. Seven image types with different levels of cover density were arranged in a sequentially balanced design in which each image type was preceded the same number of times by all image types. In the absence of carryover, when images were preceded by images with the same cover density, the response scores were well fitted by a power function of percentage cover with a mean exponent of 0.73 over subjects. Carryover took the form of an assimilation, so that the cover estimate for a target image was generally higher when preceded by an image with higher cover, and lower when preceded by an image with lower cover. However, the magnitude of the carryover effect showed little evidence of increasing with difference in cover between successive images. Nonparametric and parametric methods for testing for carryover are presented. The need for development of psychological models to explain the proposed statistical models is discussed.