Parameters affecting conscious versus unconscious visual discrimination with damage to the visual cortex (V1).

When the visual (striate) cortex (V1) is damaged in human subjects, cortical blindness results in the contralateral visual half field. Nevertheless, under some experimental conditions, subjects demonstrate a capacity to make visual discriminations in the blind hemifield (blindsight), even though they have no phenomenal experience of seeing. This capacity must, therefore, be mediated by parallel projections to other brain areas. It is also the case that some subjects have conscious residual vision in response to fast moving stimuli or sudden changes in light flux level presented to the blind hemifield, characterized by a contentless kind of awareness, a feeling of something happening, albeit not normal seeing. The relationship between these two modes of discrimination has never been studied systematically. We examine, in the same experiment, both the unconscious discrimination and the conscious visual awareness of moving stimuli in a subject with unilateral damage to V1. The results demonstrate an excellent capacity to discriminate motion direction and orientation in the absence of acknowledged perceptual awareness. Discrimination of the stimulus parameters for acknowledged awareness apparently follows a different functional relationship with respect to stimulus speed, displacement, and stimulus contrast. As performance in the two modes can be quantitatively matched, the findings suggest that it should be possible to image brain activity and to identify the active areas involved in the same subject performing the same discrimination task, both with and without conscious awareness, and hence to determine whether any structures contribute uniquely to conscious perception.

WormBase: network access to the genome and biology of Caenorhabditis elegans

WormBase (http://www.wormbase.org) is a web-based resource for the Caenorhabditis elegans genome and its biology. It builds upon the existing ACeDB database of the C.elegans genome by providing data curation services, a significantly expanded range of subject areas and a user-friendly front end.

Providing health information to the general public: a survey of current practices in academic health sciences libraries*

A questionnaire was mailed to 148 publicly and privately supported academic health sciences libraries affiliated with Association of American Medical Colleges (AAMC)–accredited medical schools in the United States and Canada to determine level of access and services provided to the general public. For purposes of this study, “general public” was defined as nonaffiliated students or health care professionals, attorneys and other nonhealth-related professionals, patients from affiliated or other hospitals or clinics, and general consumers. One hundred five (71%) libraries responded. Results showed 98% of publicly supported libraries and 88% of privately supported libraries provided access to some or all of the general public. Publicly supported libraries saw greater numbers of public patrons, often provided more services, and were more likely to circulate materials from their collections than were privately supported libraries. A significant number of academic health sciences libraries housed a collection of consumer-oriented materials and many provided some level of document delivery service, usually for a fee. Most allowed the public to use some or all library computers. Results of this study indicated that academic health sciences libraries played a significant role in serving the information-seeking public and suggested a need to develop written policies or guidelines covering the services that will be provided to minimize the impact of this service on primary clientele.