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.     

Are insomniacs sleepy during the day? A pupillometric assessment.

A biodevelopmental model of insomnia is articulated specifying coordinated nighttime (disturbed sleep pattern) and daytime (no excessive daytime sleepiness) characteristics defining an insomnoid classification in at-risk groups: short sleepers and older adults. Pupillometry is proposed as a useful means of discriminating degree of daytime sleepiness to aid in the differential diagnosis of insomnia and insomnoid states, and the present study tested the discriminative validity of this approach. Noninsomniac (n = 34) and insomniac (n = 29) college students submitted to four 10 min pupillometry sessions tracking daytime sleepiness from morning arising to bedtime. Pupil diameter proved to be an able discriminator of these two groups though substantial overlap of the two distributions was also noted. The results supported the sensitivity of pupillometry in detecting daytime sleepiness, but yielded alternative interpretations. We observed statistical differentiation in insomniac and noninsomniac daytime sleepiness, but substantial, functional overlap between these groups. Assessment and treatment implications arising from the biodevelopmental model were hypothesized.     

Reaction time to threat stimuli in panic disorder and social phobia

Two studies assessed response time among clinically anxious subjects and normal controls when presented with threat, positive and neutral stimuli under perceptual (lexical decision) and semantic (category decision) task conditions. In Study 1, panic disorder subjects' (n = 14) performance was compared to that of matched normal controls (n = 14) while in Study 2 social phobic subjects (n = 24) were compared to matched normal controls (n = 24). Relative to matched normal controls, panic disorder subjects but not social phobics tended to show greater slowing in performance on the more cognitively complex (category) task. A second finding, consistent across both studies was that, compared to the normal control groups, both panic and social phobic groups showed significantly slowed responses to threat words in both the perceptual and semantic tasks. Such findings are directly counter to the predictions of a mood congruence hypothesis. This apparent contradiction is resolved by a review of the literature which indicates that mood-related facilitation effects are obtained only in tasks which tap awareness of threat information rather than speed of response. It is suggested that while anxiety may produce enhanced awareness of threat, it may inhibit responsiveness to it. The results of these studies are seen as consistent with ethological theories of inhibited motoric responses under certain threat conditions. Furthermore, the findings suggest that caution is indicated in interpreting slowed reaction time to threat stimuli in tasks such as the Stroop color naming task as purely the result of attentional processes.     

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.