Cast shadows in wide perspective.

We investigated the apparent spatial layout of cast shadows up to very wide fields of view. We presented up to 130 degrees wide images in which two 'flat poles' were standing on a green lawn under a cloudless blue sky on a sunny day. The poles threw sharp cast shadows on the green, of which one was fixed.

Phenomenal transparency at X-junctions.

Phenomenal transparency was studied in a stimulus geometry that differs markedly from the conventional Metelli configuration, namely four squares that abut at a common vertex. In case of subjective transparency one perceives either a bipartite square ground overlaid with a uniform transparent rectangle, or a uniform square background overlaid with a pair of mutually orthogonal, uniform, transparent rectangular regions. Thus, the generic interpretations are limited to "left", "right", "lower", or "upper" transparent rectangles or (when no subjective transparency occurs) "mosaic".

Surface gradients, contours and the perception of surface attitude in images of complex scenes.

Sophisticated computer graphics were used to generate images of three-dimensional blocks-world scenes to investigate the perception of surface attitude. Three types of surface primitive (planar blocks, cylinders, and ellipsoids) were combined to form structured settings. The experiments were designed to investigate whether surface-based information such as gradients in shading and texture provide any significant advantage in attitude judgments over information derived from object contours.

Continuous monitoring by microprocessor from the operating room to the intensive care unit.

The "Chronicler" is made up of a microcomputer (the CPU is a Motorola 6809), an alphanumeric-graphic display with keyboard and a printer. The system is connected to several physiological signal monitors and in our application to a mechanical ventilator under electronic control. It collects every 5 seconds - or at each breathing cycle if required - all the data supplied by the various measuring devices including those in the mechanical ventilator.