Perceptual integration of identity,location and colour

Summary Different properties of the visual array are encoded in the brain in a variety of different, specialized subsystems. Some of these subsystems are spatiotopically organized; others appear not to be. The question arises as to how information regarding different properties of the same visual object, encoded in different spatiotopic and non-spatiotopic subsystems, is co-ordinated or integrated in the selective control of action. In our experiments, subjects are instructed to name selectively just one object among a briefly presented, and pattern-masked, array of other objects; the object to be named is specified either in terms of its colour and/or in terms of its relative location in the array. We also manipulate the categorical relation between the target object and its surrounding non-targets. Our results indicate that, even at quite short exposures (short masking SOA), categorical identity information is available, but that this information has not yet been co-ordinated with information about relative position or colour. Integration of identity and relative position information begins to appear in the selective control of action only at relatively long masking SOAs and continues over several hundred milliseconds. Even when the target is the only member of the designated response-set in the display, other items surrounding the target interfere with target selection. Outer items in a spatial cluster of items may be segmented earlier than central items, and the integration of identity and position information appears earlier for outer positions. We put forward a preliminary outline model of visual attribute integration in the selective control of action and in the creation of episodic memory.Paper contributed to Symposium on Visual Attention and Action at the Centre for Interdisciplinary Research (ZIF), University of Bielefeld, Federal Republic of Germany, July 1985     

Validation of the Clance Imposter Phenomenon Scale

The Clance Impostor Phenomenon Scale (CIPS; Clance, 1985) was compared to the newly developed Perceived Fraudulence Scale (Kolligian & Sternberg, 1991). The two scales were found to have high internal consistency and to correlate in a similar manner with other measures. Further, discriminant validity evidence for the Impostor Phenomenon (IP) was provided by comparing the CIPS to measures of depression, self-esteem, social anxiety, and self-monitoring. The IP was related to, but substantially discriminable from, these constructs. Finally, construct validity evidence for the CIPS was provided through principal components analysis that yielded three stable factors: Fake, Discount, and Luck.     

Central localization of plasticity involved in appetitive conditioning in Lymnaea

Learning to associate a conditioned (CS) and unconditioned stimulus (US) results in changes in the processing of CS information. Here, we address directly the question whether chemical appetitive conditioning of Lymnaea feeding behavior involves changes in the peripheral and/or central processing of the CS by using extracellular recording techniques to monitor neuronal activity at two stages of the sensory processing pathway. Our data show that appetitive conditioning does not affect significantly the overall CS response of afferent nerves connecting chemosensory structures in the lips and tentacles to the central nervous system (CNS). In contrast, neuronal output from the cerebral ganglia, which represent the first central processing stage for chemosensory information, is enhanced significantly in response to the CS after appetitive conditioning. This demonstrates that chemical appetitive conditioning in Lymnaea affects the central, but not the peripheral processing of chemosensory information. It also identifies the cerebral ganglia of Lymnaea as an important site for neuronal plasticity and forms the basis for detailed cellular studies of neuronal plasticity.