Integration of noxious stimulation across separate somatosensory communications systems: a functional theory of pain

Functional measurement analyses and psychophysical techniques were used to assess how separate, cross-modal, aversive events are integrated in judgements of pain. Subjects made magnitude estimations of noxious stimuli produced by a 6 X 6 factorial design of electric shocks and loud tones. Group data and most of the individual results were consistent with a model of linear pain summation: The estimates of pain approximated the linear sum of the pain estimates of the individual electrocutaneous and auditory components. The relation between painful sensation and current intensity could be described by a mildly expansive power function with an exponent of about 1.1. Auditorily produced painful sensation related to sound pressure level by a mildly compressive power function with an exponent of about 0.90 as a representative figure. Results are interpreted in terms of a functional theory of pain. Noxious events are first transformed to psychological scale values via stimulus-specific psychophysical transfer functions. The outputs of these functions are then combined with other pain-related internal representations of either sensory or cognitive origin, according to simple algebraic models.     

Visual control of step length during running over irregular terrain

Running over uneven ground requires visually regulating step length to secure proper footing. To examine how this is achieved, we studied subjects running on a treadmill on a series of irregularly spaced targets. The movements of their lower limbs and coccyx relative to the targets were monitored opto-electronically by a Selspot system. The results indicated that step length was adjusted to strike the targets primarily by varying the vertical component of impulse applied to the ground during the stance phase. In contrast, horizontal impulse was not varied significantly, and changing the reach forward of the foot on landing contributed little to variation in step length. Changing the vertical impulse simply altered the step time proportionately. Thus the data are consistent with a time-based model in which vertical impulse is modulated by the optic variable delta tau (Lee, 1976) specifying the time gap that has to be bridged by the runner between two targets.     

Fluctuations and phase symmetry in coordinated rhythmic movements

Pendular, clocking movements typify mammalian terrestrial locomotion. They can be investigated with a procedure in which people swing hand-held pendulums at the wrists, comfortably and rhythmically. Pendular, clocking behavior was examined for in-phase and out-of-phase coordinations. The periodic timing and powering of rhythmic movements in the comfort state follow from different laws (Kugler & Turvey, 1986). One law guides the assembling of the reference frame for "clocking." Another law guides the assembling of the muscular, escapement processes determining the cycle energy. Wing and Kristofferson's (1973) method for parsing periodic-timing variance into independent "clock" and "motor" sources was applied. Mean periodicity was unaffected by phase. "Clock" fluctuations, however, were larger out of phase than in phase. "Motor" fluctuations were indifferent to phase but reflected the departures of individual wrist-pendulum systems from their preferred periods. It appears that an intended phase relation is realized as a constraint on "clock" states. These states are more stable under the in-phase constraint than under the out-of-phase constraint.     

Multidimensional scaling reveals two dimensions of thermal pain

The Individual Differences Scaling (INDSCAL) model of multidimensional scaling was used to explore the dimensions of thermal pain. The observers made 66 similarity judgments to all pairs of 12 different thermal stimulus intensities ranging from zero to noxious. Analysis of the data revealed a two-dimensional group stimulus space. The major dimension ordered the stimuli with respect to their intensity. This quantitative, strength-of-sensation dimension may be interpreted as indicating how weak or strong a stimulus feels, apart from any secondary qualities of warmth or pain. The second dimension was related to the qualitative aspects of the stimuli. This bipolar dimension contained two attributes: a pain attribute ranging from just detectable warmth to painful, and a warm-hot attribute running from just detectable warmth to hot. This study demonstrates the utility of the INDSCAL approach to the understanding of pain and offers a new technique for answering the age-old question concerning the number and qualities of the dimensions underlying the pain experience.     

The facial muscle patterning of posed and imagery-induced expressions of emotion by expressive and nonexpressive posers

Much research on emotional facial expression employs posed expressions and expressive subjects. To test the generalizability of this research to more spontaneous expressions of both expressive and nonexpressive posers, subjects engaged in happy, sad, angry, and neutral imagery, and voluntarily posed happy, sad, and angry facial expressions while facial muscle activity (brow, cheek, and mouth regions) and autonomic activity (skin resistance and heart period) were recorded. Subjects were classified as expressive or nonexpressive on the basis of the intensity of their posed expressions. The posed and imagery-induced expressions were similar, but not identical. Brow activity present in the imagery-induced sad expressions was weak or absent in the posed ones. Both nonexpressive and expressive subjects demonstrated similar heart rate acceleration during emotional imagery and demonstrated similar posed and imagery-induced happy expressions, but nonexpressive subjects showed little facial activity during both their posed and imagery-induced sad and angry expressions. The implications of these findings are discussed.     

Performance of normal and neurological mutant mice on radial arm maze and active avoidance tasks

The objectives of the present study are to assess the import of gene-imposed structural alterations on behavioral performance and obtain performance data preliminary to studies of experimental mouse chimera behavior. Reeler, staggerer, and weaver neurological mutant, and control B6C3 and ichthyosis mice were tested on radial arm maze and active avoidance tasks. Weaver mice had incapacitating seizures while performing the radial arm maze task and were, therefore, removed from further testing. Staggerer mice displayed a significant deficit on both tasks compared to control mice. Homozygous reeler mice (rl/rl) also had a significant deficit on the active avoidance task compared to +/rl control mice but not significantly poorer than ichthyosis mice. However, their performance on the radial arm maze task, while initially poor, improved so that they performed the task similar to wild-type controls. Three of the reeler mice reached criterion for solving the radial arm maze task. None of the staggerer mice reached criterion. These data are discussed in terms of the value of using neurologically mutant mice in dissecting structural-functional relationships. It is suggested that the behavior of these mutants might point toward specific components of cerebellar involvement in behavioral acts.     

The imperfect attainment of intimacy: a key concept in marital therapy

The intense though transient intimacy of romantic love is contrasted with the more durable and sustained intimacy of conjugal love. The latter, it is argued, requires that the partners have each attained an adequate degree of separateness and at the same time are able to allow themselves to become physically and emotionally close. Relationships which are not intimate are characterized by excessive degrees of dependence, directiveness or detachment. The equilibrium in a non-intimate relationship is maintained by fears in the respective partners about the other becoming too separate, too close, too influential, too assertive, too capable etc. Therapy involves persuading each to try cautiously giving ground in one direction whilst the other is giving ground in a complementary direction. Intimacy will follow if neither is too controlling from above nor too clinging from below and both partners are able to relate on an equal adult to adult basis.     

Sex differences in the effects of gonadectomy on amphetamine-induced rotational behavior in rats

The effects of gonadectomy on amphetamine-induced rotational behavior were studied in male and female rats. Different systemic doses were used to produce equivalent brain concentrations of the drug in each group, thereby controlling for sex differences in the metabolism of amphetamine. Ovariectomy of female rats significantly attenuated amphetamine-induced rotation, whereas castration of males was without effect. The results support the idea that in females, the endogenous gonadal hormones facilitate functional activity in the mesostriatal dopamine system.     

Impact of a preventive social problem solving intervention on children's coping with middle-school stressors

Children receiving 1 year or 1/2 year of a preventive social problem solving program in elementary school were compared with each other and with a no-treatment group upon entry into middle school. One year of training was significantly related to reductions in the severity of a variety of middle-school stressors. Most importantly, a clear mediating role for social problem solving (SPS) skills was found. Children lacking in SPS skills were more likely to experience intense stressors; however, possessing the skills was not necessarily predictive of adjustment to stressors. The results are discussed in terms of the implications of this asymmetry and the strong support given to the value of social problem solving as a preventive intervention for children.     

Assessment of anxiety and achievement in kindergarten and first-and second-grade children

The psychometric properties of the State-Trait Anxiety Inventory for Children (STAIC) and relationships between STAIC T-Anxiety scores and standardized measures of achievement were determined for 948 kindergarten and first-and second-grade children. The T-anxiety scores of kindergarten children were lower than those of first-and second-graders. Internal consistency of the STAIC scales was higher in individual testing sessions than in small group administrations. Small but significant negative correlations were found between STAIC T-Anxiety scores and measures of school achievement. It was concluded that the STAIC is a potentially useful measure of state and trait anxiety in kindergarten through sixth-grade children, but it must be administered individually at the kindergarten and first-grade levels.The research was performed while the senior author was a senior research scientist at the Dallas Independent School District.