The role of stimulus factors in making categorical and coordinate spatial judgments

We report three experiments which investigate the lateralization of categorical and coordinate processing. In all experiments, participants judged the position of a dot relative to a line. We manipulated display luminance (controlling for contrast), polarity (black-on-white versus white-on-black displays), and exposure duration (100, 150, and 200 ms). The results showed a left visual field-right hemisphere advantage for coordinate judgments, but only under highly prescribed conditions. We argue that stimulus and procedural factors are critical in determining the hemisphere by task interaction.     

Measurement of the texture-coherence limit for bandpass arrays

Casual observation suggests that when the elements of a visual array are packed at a sufficiently high density they cohere to generate the percept of a texture. This 'texture-coherence limit' has been quantified by using arrays composed of Gabor functions, sixth Gaussian derivatives, or differences of Gaussians. In all cases the texture-coherence limit was a power-law function of the size of the elements as quantified by their space constants with an exponent averaging 0.7. Furthermore, the texture-coherence limit was independent of both element spatial frequency and contrast over a considerable range. A quantitative fit to the data is provided by a model in which the texture-coherence limit is determined by activation of complex cells, which pool a spatial range of subunit inputs, throughout the stimulus region. Possible extensions to two dimensions are considered.     

Eye movements measured with a solid state photodiode matrix

The apparatus described uses the corneal reflex technique to measure horizontal and vertical eye movements with a metal oxide semiconductor matrix array of 64 by 64 photodiodes. A simple optical system forms a reflex image on the array and also determines the device range, which can vary from ±25 deg to ±3 deg; sensitivity is 50 arc min and 6 arc min, respectively. Mounted on a simple lightweight headband complete with universal mechanical adjusters, the instrument weighs less than 100 g, excluding connecting cable, and samples eye movements every 5 msec.     

Last rights: the ethics of research on the dead

People often have strong views about being the subjects of research after their deaths. Should these views be given any weight and, if so, how much? How could we find out what the views are and what should we do if we cannot? This paper defends the idea of posthumous interests and discusses the significance of those interests for research ethics. It argues that we can be guided by a symmetry between the interests of living and dead people and uses posthumous privacy as an example. It also claims that the weight of those interests might not decline even over long periods of time. The arguments have important implications for the ethics of (amongst others) biomedical, archaeological, anthropological, historical, and sociological research.     

Parental consent and the use of dead children's bodies

It has recently become known that, in Liverpool and elsewhere, parts of children's bodies were taken postmortem and used for research without the parents being told. But should parental consent be sought before using children's corpses for medical purposes? This paper presents the view that parental consent is overrated. Arguments are rejected for consent from dead children's interests, property rights, family autonomy, and religious freedom. The only direct reason to get parental consent is to avoid distressing the parents, which carries implications for the consent process, secret harvesting of body parts, and the weight to be given to parental feelings.     

Pigeons discriminate continuous versus discontinuous line segments

Three experiments examined various facets of the perception of continuous and discontinuous line segments in pigeons. Pigeons were presented with 2 straight lines that were interrupted by a gap. In some instances, the lines were the same angle and were positioned so that they appeared (to human observers) to form a continuous line. In other instances, the lines were different angles or the same angle but spatially misaligned. The birds were trained to classify each stimulus as continuous or discontinuous using a go/no-go procedure. A series of tests followed in which the birds received novel discontinuous displays made up of familiar line segments, continuous and discontinuous stimuli made up of novel line segments (novel straight lines or curved lines), and familiar displays in which the gap was covered with a gray square. Results from the tests indicated that 2 of the 3 pigeons had learned a continuous-discontinuous categorization and that they appeared to use the relationship between the 2 line segments in discriminating the displays.     

The Impact of Breast Cancer Genetic Risk Assessment on Intentions to Perform Cancer Surveillance Behaviors

One hundred and fifty-four women undergoing breast/ovarian cancer genetic risk assessment completed questionnaires at entry into the Cancer Genetic Service for Wales (CGSW) assessment program and following risk provision, mapping the strength of intentions to engage in a number of preventive/surveillance behaviors, including seeing specialists, breast self-examination, and involvement in screening programs, including mammography. A number of potential predictors of intentions were also assessed, including participants' mood and emotional response to receiving risk information, the perceived benefits (in terms of reassurance and early disease detection) of engaging in each preventive behavior, and the perceived desires of their family and General Practitioner. Intentions to self-examine did not change following risk provision, although strength of intentions to engage in some other preventive behaviors did lessen. Family and General Practitioners appeared to be strong social influences on behavioral intentions, as were the perceived benefits of gaining reassurance and/or early detection of disease.     

Spatial learning and memory in the tortoise (Geochelone carbonaria)

A single tortoise (Geochelone carbonaria) was trained in an eight-arm radial maze, with the apparatus and general procedures modeled on those used to demonstrate spatial learning in rats. The tortoise learned to perform reliably above chance, preferentially choosing baited arms, rather than returning to arms previously visited on a trial. Test sessions that examined control by olfactory cues revealed that they did not affect performance. No systematic, stereotyped response patterns were evident. In spite of differences in brain structure, the tortoise showed spatial learning abilities comparable to those observed in mammals.     

Why do Managers Engage in Trustworthy Behavior? A Multilevel Cross‐Cultural Study in 18 Countries

Drawing on theories of generalized exchange and the norm of indirect reciprocity, we conceptualize subordinates’ organizational citizenship behavior directed toward the organization (OCBO) and directed toward peers (OCBI) as antecedents of managerial trustworthy behavior and examine how managers’ affective trust in subordinates mediates this relationship. We also investigate the extent to which this mediation is moderated by the level of collectivism in a society. Data were collected from 741 managers and 2,111 subordinates in 18 countries representing all major cultural regions of the world. We find support for our hypothesized moderated mediation in that managers’ affective trust in subordinates mediates the relationships between both subordinates’ OCBO and managerial trustworthy behavior, and subordinates’ OCBI and managerial trustworthy behavior across the different countries studied. Further, managers’ affective trust in subordinates only mediates the relationships between both types of citizenship behavior and managerial trustworthy behavior when collectivism is low to medium but not when it is high. Implications for research on cross‐cultural psychology, trust, and organizational citizenship behavior are discussed.