Sensory and affective components of pain: separation and synthesis.

It has become increasingly accepted that pain is not simply a sensation generated by nociceptors, but a perceptual phenomenon with particular emotional qualities. The purpose of this article is to bring together vastly different streams of research on the divisibility of pain into sensory and affective components. Empirical evidence for this divisibility is drawn from recent studies using multivariate statistics, signal detection theory, and unidimensional scaling. An important conclusion is that separable though pain components may be, they are not necessarily independent. In critiquing previous research, new criteria are derived for partitioning pain into sensory and affective components. Finally, speculations are offered as to how these same components might be synthesized on the basis of theories of perceptual organization.     

Emergenesis. Genetic traits that may not run in families.

Traits that are influenced by a configuration--rather than by a simple sum--of polymorphic genes may not be seen to be genetic unless one studies monozygotic twins (who share all their genes and thus all gene configurations) because such "emergenic" traits will tend not to run in families. Personal idiosyncrasies that have been found to be surprisingly concordant among MZ twins separated in infancy and reared apart may be emergenic traits. More speculatively, important human traits like leadership, genius in its many manifestations, being an effective therapist or parent, as well as certain psychopathological syndromes may also be emergenic. These ideas reemphasize the importance of the role played in human affairs by genetic variation.     

Scientific rewards and conflicts of ethical choices in human subjects research.

The primary responsibility of the American Psychological Association's (APA) Committee on Standards in Research (CSR) is to advise the APA on issues and standards related to the protection of human participants in psychological research. A related goal is to enhance the use of good ethical practices by APA members. The purpose of this article is to foster the view of research ethics not as an affront to the integrity of sound research, but as opportunities for scientific rewards, including increased understanding of the meaning of data, enhanced recruitment, and the inclusion of more representative samples. Three ethical practices are discussed as examples of this general premise: respect for confidentiality, use of debriefing, and assurance that participants are noncoerced volunteers. The Committee's intent is to promote consideration of these issues, not to promulgate specific guidelines or procedures.     

Injury control. A promising field for psychologists.

Injury is the fourth leading cause of death for all Americans and the most frequent cause of death for those from age 1 to 45. Moreover, injury is associated with higher treatment costs and with greater lost life-years than the other three leading causes of death. Traffic accidents are the leading cause of severe brain injury, including most paraplegic and quadriplegic cases. Because injury control is essentially psychological, there are many opportunities for psychologists to contribute, both to scientific research on the causes of injury and to clinical interventions for injury control.     

Redefining the science-practice relationship and professional training.

A revised conception of the relationship between psychological science and professional practice is proposed in the light of postmodern changes in perspectives on knowledge. Positivistic science, which has dominated the traditional interpretation of scientist-practitioner training, is considered from a constructivist point of view to be only one possible foundation of psychological knowledge. It is argued that the knowledge base of the profession should be derived with diverse methods and from multiple sources, including the knowledge of practice. The mutuality of science and practice is emphasized. An evolving framework for understanding the epistemology of practice, based on cognitive psychology, is presented. Emphasis on broadened choices of research methods, the development of reflective skills, and better linkage between teaching in the domains of research and practice are urged. Suggestions for research related to scientific training and the knowledge processes of practice are offered.     

Effects of alcohol intoxication on risk taking, strategy, and error rate in visuomotor performance.

Adult men (N = 44) participated for 2 days (alcohol vs. placebo treatment) in a double-blind, crossover experiment. Performance on the Digit Symbol Substitution Task (DSST) and a visuomotor (VM) task was measured 4 times each day. On the alcohol-treatment day, data were obtained once during ascending breath alcohol levels (BALs), once during maximal BALs (0.05 or 0.10), and twice during descending BALs. Data were collected at the same time points on the placebo-treatment day. Limited evidence for acute tolerance was obtained with the DSST, but error rates on the VM task were higher during maximal and descending BALs. Error rates remained near placebo values, and participants displayed slightly greater caution, while BALs were ascending. Strategy scores on the VM task exceeded placebo scores during maximal intoxication. Data interpretation is focused on individuals in higher level (e.g., professional) positions.     

Infants' responsiveness to the auditory and visual attributes of a sounding/moving stimulus.

Responses to unimodal and multimodal attributes of a compound auditory/visual stimulus were investigated in 4-, 6-, 8-, and 10-month-old infants. First, infants were habituated to a compound stimulus consisting of a visual stimulus that moved up and down on a video monitor and a sound that occurred each time the visual stimulus reversed direction at the bottom. Once each infant met a habituation criterion, a series of test trials was administered to assess responsiveness to the components of the compound stimulus. Response was defined as the total duration of visual fixation in each trial. In the two unimodal test trials, the rate at which the component was presented was changed while the rate of the other component remained the same, whereas in the bimodal test trial the rate of both components was changed simultaneously. Results indicated that infants at each age successfully discriminated the bimodal and the two unimodal changes and that regression to the mean did not account for the results. Results also showed that disruption of the temporal relationship that accompanied the change in rate in the two unimodal test trials was also discriminable, but rate changes appeared to play a greater role in responsiveness than did synchrony changes. Considered together with results from similar prior studies, the current results are consistent with the modality appropriateness hypothesis in showing that discrimination of temporal changes in the auditory and visual modalities is dependent on the specialization of the sensory modalities.     

Spatial attention in Ponzo-like patterns.

A variant of Ponzo's pattern was devised by drawing converging oblique lines at the ends of each of two horizontal lines that were located directly one above the other. Pairs of converging or diverging fins (either between or outside the horizontal shafts) were systematically removed. The results showed that, as predicted by integrative field theory, oblique lines between the shafts produced more distortion than did oblique lines outside the shafts. Also, it was shown that the attentive field construct in integrative field theory was crucial for predicting patterns of means and variances in this experiment. The modified Ponzo effect was shown to have much in common with the classical Müller-Lyer illusion. The subtle differences between the two were explained by proposing that the size of the optimum attentive field was larger in the Ponzo tasks than in the Müller-Lyer tasks because expansion fins are found on both shafts in the Ponzo-like figure.