The functions of resources in coalition bargaining.

An important factor that distinguishes theories of coalition formation is their assumptions regarding the role of "resources" (Rs) in coalition bargaining. Two basic functions of Rs are hypothesized: a normative function, in which Rs provide a norm or frame of reference for a fair (equitable) division of rewards, and a strategic function, in which Rs affect the number and size of winning coalitions. It is shown that minimum R theory is based entirely on the normative function; minimum power and weighted probability models are based entirely on the strategic function; and bargaining theory and equal excess model are based on both functions. An experiment was conducted with 200 male undergraduates to contrast these theories in terms of the 2 functions of Rs. Results provide the greatest support for bargaining theory and equal excess model, and it is hypothesized that a theory that ignores one or the other function is not likely to yield accurate predictions. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivational and informational functions and consequences of children's attention to peers' work.

Two studies (331 children aged 9–11 yrs) examined the proposal that the functions served by children's attention to peers' work differ both in their informational focus (whether children seek information either to improve their products or to evaluate their ability) and in their goal focus (whether information seeking serves either mastery or performance achievement strivings). In both studies responses to a self-report measure of reasons for looking at peers' work supported this hypothesis. Study 2 also examined the effect of a mastery vs a performance goal condition on reasons for looking at peers' work, subsequent information seeking, and interest in the task. Goal condition affected goal, but not informational, functions of looking at peers' work. Both goal condition and individual differences in endorsement of mastery vs performance reasons predicted later information seeking and interest. Implications for social comparison theory and for classroom learning and motivation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regulation of presynaptic NMDA responses by external and intracellular pH changes at developing neuromuscular synapses

NMDA receptors play important roles in synaptic plasticity and neuronal development. The functions of NMDA receptors are modulated by many endogenous substances, such as external pH (pHe), as well as second messenger systems. In the present study, the nerve-muscle cocultures of Xenopus embryos were used to investigate the effects of both external and intracellular pH (pHi) changes on the functional responses of presynaptic NMDA receptors. Spontaneous synaptic currents (SSCs) were recorded from innervated myocyte using whole-cell recordings. Local perfusion of NMDA at synaptic regions increased the SSC frequency via the activation of presynaptic NMDA receptors. A decrease in pHe from 7.6 to 6.6 reduced NMDA responses to 23% of the control, and an increase in pHe from 7.6 to 8.6 potentiated the NMDA responses in increasing SSC frequency. The effect of NMDA on intracellular Ca2+ concentration ([Ca2+]i) was also affected by pHe changes: external acidification inhibited and alkalinization potentiated [Ca2+]i increases induced by NMDA. Intracellular pH changes of single soma were measured by ratio fluorometric method using 2,7-bis (carboxyethyl)-5, 6-carboxyfluorescein (BCECF). Cytosolic acidification was used in which NaCl in Ringer's solution was replaced with weak organic acids. Acetate and propionate but not methylsulfate substitution caused intracellular acidification and potentiated NMDA responses in increasing SSC frequency, intracellular free Ca2+ concentration, and NMDA-induced currents. On the other hand, cytosolic alkalinization with NH4Cl did not significantly affect these NMDA responses. These results suggest that the functions of NMDA receptors are modulated by both pHe and pHi changes, which may occur in some physiological or pathological conditions.     

Eliciting effects of verbal and nonverbal cues on projective test responses.

A verbal reinforcer and 2 nonverbal immediacy cues, eye contact and body lean, were manipulated by an E under far and close conditions of interpersonal distance in a projective testing situation with 80 undergraduates. It was hypothesized that the verbal cue ("good") would be positively reinforcing at both distances but that eye contact and body lean would be reinforcing only in the far condition. As hypothesized, significant increases in the dependent measure, the number of thematic responses, were found for the verbal cue at both interaction ranges. Support for the predicted conditional effect of eye contact was found on the last trial of the testing session. Body lean did not significantly affect the number of thematic responses at either the far or close interaction distance. Implications of the results for the further study of E cues in the projective test situation are discussed. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A review and interpretation of some aspects of the infant-mother relationship in mammals and birds.

Although important research in the area of the infant-mother relationship has been increasing, research appears to be guided by an empirical orientation—a comprehensive theory is lacking. The literature is reviewed and theoretically interpreted. 2 hypotheses are proposed; in all mammals and birds: (1) novel stimuli elicit fear responses in both young and adult organisms, and (2) certain stimuli elicit a pleasant feeling in the offspring and lead to permanent reduction of fear of novel stimuli, and that these stimuli are always found in the person of the natural mother. The nature of a basic survival problem that all mammals and birds face is indicated, and it is demonstrated how the 2 hypothesized phenomena constitute a very efficient solution of the problem. (42 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Skin conductance response to punishment as a predictor and correlate of learning to avoid two classes of punishment

26 college students were exposed to a period of noxious stimulation and subsequently performed a task that incidentally involved learning to avoid 1 of 2 types of punishment. Skin conductance was recorded throughout. Magnitude of the skin conductance response both to noxious stimulation and during the avoidance task was significantly and positively correlated with the rate of learning to avoid either electric shock or loss of money. Results are interpreted as supporting both D. T. Lykken's (see record 1959-01696-001) theory of the development of sociopathic behavior and J. Aronfreed's (1968) more general conceptualization of aversive control in the human socialization process. In both, autonomically based anxiety or fear responses are given a central role. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introversion, neuroticism, rigidity, and dogmatism.

There are two problems concerning the often hypothesized relationship between neuroticism and behavioral rigidity. First, are there personality dimensions other than neuroticism which affect the relationship? Eysenck (1947) hypothesized that introverted neurotics are rigid, but that extroverted neurotics are not. Second, Rokeach (1960) offered a distinction between rigidity and dogmatism, in which rigidity can be defined as the inability to produce novel or changed responses while dogmatism can be defined as an inability to utilize novel responses which have been produced. Which of these two types of inflexibility characterizes neurotics? To explore for answers for these two questions, a 2 × 2 experimental design was set up. Two conclusions follow from this study. The first is that it is inappropriate to speak loosely of the "rigidity" or "inflexibility" of neurotic behavior, as it was shown that neurotics are not different from non-neurotics in their ability to produce novel responses, but only in their ability to utilize such responses. Secondly, not all neurotics manifest this inability; it is shown by introverted neurotics only. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vulnerability to depressive mood reactions: Toward a more powerful test of the diathesis–stress and causal mediation components of the reformulated theory of depression.

To provide a more powerful test of the diathesis–stress component of the reformulated theory of depression (Abramson, Seligman, & Teasdale, 1978), we extended and refined the Metalsky, Abramson, Seligman, Semmel, and Peterson (1982) study and examined whether the content of college students' attributional styles (hypothesized attributional diathesis) as measured at Time 1 interacted with the outcomes students received on a class midterm exam to predict their subsequent depressive mood responses. In addition, to test the mediation component of the theory, we examined whether the relation between the hypothesized attributional diathesis and failure students' subsequent depressive mood responses to their low midterm grades was mediated by the particular causal attributions these students made for their low grades. The results partially corroborated the current statement (Abramson, Alloy, & Metalsky, 1986; Abramson, Metalsky, & Alloy, 1986a, 1986b) of the diathesis–stress component of the theory. Whereas students' immediate depressive mood reactions were predicted solely by the outcomes they received on the class midterm exam, their enduring depressive mood reactions were predicted solely by the hypothesized Attributional Diathesis?×?Outcome on Midterm Exam interaction. The direction and form of the interaction were in line with prediction. The results corroborated predictions derived from the mediation component of the theory as they applied to students' enduring mood responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of children's understanding of ambivalence and causal theories of emotions.

Investigated a 4-stage developmental sequence in children's understanding of ambivalence. At the highest level of this sequence, children understand that contradictory feelings can coexist at the same time toward the same target in terms of a framework in which it is recognized that the 2 feelings influence one another. 20 4–5 yr olds, 20 7–8 yr olds, and 20 10–11 yr olds were presented with 2 tape-recorded stories in which the protagonist could be construed as feeling happy and sad or anger and love. Raters scored the Ss' responses to a structured interview about the stories in terms of the proposed sequence. Separate parts of the protocols were assessed independently with respect to a proposed sequence in children's causal theories of emotions. According to this sequence, children's understanding of feelings develops from an externally based theory in which feelings are wedded to events to an internally based theory in which feelings largely depend on memories, thoughts, and attitudes. Results support both hypothesized developmental progressions and show significant relationships between the 2 domains of Ss' understanding of emotions. Findings suggest that internal states' mediation of emotional responses may be an important component in understanding ambivalence and that the motivation to integrate conflicting feelings may play a role in promoting the external to internal shift in children's causal theories of emotions. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physical activity play: the nature and function of a neglected aspect of playing

In this review, we consider the nature and possible developmental functions of physical activity play, defined as a playful context combined with a dimension of physical vigor. We distinguish 3 kinds of physical activity play, with consecutive age peaks: rhythmic stereotypies peaking in infancy, exercise play peaking during the preschool years, and rough-and-tumble play peaking in middle childhood. Gender differences (greater prevalence in males) characterize the latter 2 forms. Function is considered in terms of beneficial immediate and deferred consequences in physical, cognitive, and social domains. Whereas most theories assume that children's play has deferred benefits, we suggest that forms of physical activity play serve primarily immediate developmental functions. Rhythmic stereotypies in infancy are hypothesized to improve control of specific motor patterns. Exercise play is hypothesized to function primarily for strength and endurance training; less clear evidence exists for possible benefits for fat reduction and thermoregulation. In addition, there may be cognitive benefits of exercise play that we hypothesize to be largely incidental to its playful or physical nature. Rough-and-tumble play has a distinctive social component; we hypothesize that it serves primarily dominance functions; evidence for benefits to fighting skills or to emotional coding are more equivocal. Further research is indicated, given the potentially important implications for children's education, health, and development.     

Differential role of vasoactive prostanoids in porcine and human isolated pulmonary arteries in response to endothelium-dependent relaxants

The pig is increasingly being used in medical research, both as a model of the human cardiovascular system, and as a possible source of organs for xenotransplantation. However, little is known about the comparative functions of the vascular endothelium between porcine and human arteries. We have therefore compared the effects of two endothelium-dependent vasorelaxants, acetylcholine (ACh) and the Ca2+-ATPase inhibitor, cyclopiazonic acid (CPA) on the porcine and human isolated pulmonary artery using isometric tension recording. ACh and CPA produced endothelium-dependent relaxations of both the human and porcine pulmonary arteries. In the porcine pulmonary artery, the cyclo-oxygenase inhibitor, flurbiprofen had no effect on relaxations to ACh (Emax: control 67.8+/-8.8% versus 72.4+/-9.5% (n=11)) or CPA (Emax: control 79.6+/-5.0% versus 94.0+/-10.6% (n=7)). The nitric oxide synthase inhibitor, L-NAME converted relaxations to both ACh and CPA into contractile responses (maximum response: ACh 30.0+/-11.1% (n = 10); CPA 80.4+/-26.2% (n = 8) of U46619-induced tone). These contractile responses in the presence of L-NAME were abolished by flurbiprofen. In the human pulmonary artery, L-NAME and flurbiprofen partly attenuated relaxations to ACh (Emax: control: 45.1+/-12.1%; flurbiprofen: 33.4+/-13.5%; L-NAME: 10.1+/-7.2%) and CPA (Emax: control: 78.1+/-5.5%; flurbiprofen: 69.6+/-7.2%; L-NAME 37.9+/-10.7% of U46619-induced tone). These responses were abolished by the combination of both inhibitors. We have demonstrated that while the release of nitric oxide is important in responses to endothelium-dependent vasorelaxants in both human and porcine pulmonary arteries, in the human arteries, there is an important role for vasorelaxant prostanoids whilst in the porcine arteries, vasoconstrictor prostanoids are released.     

Individual differences in the regulation of intergroup bias: The role of conflict monitoring and neural signals for control.

[Correction Notice: An erratum for this article was reported in Vol 94(3) of Journal of Personality and Social Psychology (see record 2008-01768-011). In this article, there was an error in Figure 4. The corrected figure is provided in this erratum.] Low-prejudice people vary considerably in their ability to regulate intergroup responses. The authors hypothesized that this variability arises from a neural mechanism for monitoring conflict between automatic race-biased tendencies and egalitarian intentions. In Study 1, they found that low-prejudice participants whose nonprejudiced responses are motivated by internal (but not external) factors exhibited better control on a stereotype-inhibition task than did participants motivated by a combination of internal and external factors. This difference was associated with greater conflict-monitoring activity, measured by event-related potentials, when responses required stereotype inhibition. Study 2 demonstrated that group differences were specific to response control in the domain of prejudice. Results indicate that conflict monitoring, a preconscious component of response control, accounts for variability in intergroup bias among low-prejudice participants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduced hypoxic chemosensitivity in partially paralysed man. A new property of muscle relaxants?

BACKGROUND: It was hypothesized that non-depolarizing neuromuscular blocking agents impair hypoxic chemosensitivity in man. METHODS: In thirty randomly allocated male volunteers the hypoxic and hypercarbic ventilatory responses were measured during partial paralysis (TOF ratio 0.70) due to either atracurium (n = 10), pancuronium (n = 10) or vecuronium (n = 10). RESULTS: Hypoxic ventilatory responses were depressed by 306, 287 and 296% (mean SD) at steady-state infusion of atracurium, pancuronium and vecuronium, respectively. At a TOF ratio of > 0.90, the HVR was not different from control measurements. CONCLUSION: It is concluded that non-depolarizing neuromuscular blocking agents impair hypoxic ventilatory regulation. Further experimental studies are warranted to fully describe the mechanism(s) responsible for this interaction.     

S-R compatibility between response position and destination of apparent motion: Evidence of the detection of affordances.

In choice reaction time, stimuli and responses in some combinations (e.g., based on spatial arrangement) are faster than in other combinations. To test whether motion toward a position yields faster responses at that position, a computer-generated square in front of one hand appeared to move either toward that hand or toward the other hand. Compatible responses (e.g., motion toward left hand/left response) were faster than incompatible responses, even when that opposed traditional positional compatibility. In Experiment 2, subjects responded to the same stimuli but with both hands left, right, or on the body midline. Medial responses were the fastest, showing that destination, rather than mere relative position, was a critical variable. It was suggested that spatial compatibility effects are not unique to position but apply to a variety of task situations, describable by J. J. Gibson's theory of affordances, in which he claims that one perceives the actions (e.g., catching) permitted in a situation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The functions of aggression by male teenagers.

A selectionist theory states that violence by males toward male peers originally served specific functions and violence to female peers served others. Differences in self-reported victimization and perpetration in studies of 1,452 high school students were hypothesized. In Study 1, male-to-male aggression was reported to be more prevalent than male-to-female aggression. For male-to-male aggression, perpetrator reports agreed with or exceeded victim reports, and victims were more often strangers than close friends. In contrast, for male-to-female aggression, there were consistently fewer reports from perpetrators than from victims, and victims were less often strangers than girlfriends. Study 2 obtained similar findings for reported frequency, number of victims and perpetrators, and sexual aggression. Study 3 showed that girls' aggression contrasted with that by boys with respect to intra- versus intersex aggression and perpetrator–victim agreement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Process learning time as an adaptive design variable in concept learning using computer-based instruction.

Investigated the effects of manipulating the display time of interrogatory examples in a concept-learning experiment according to individual processing needs. Extending the (see PA, Vols 66:6674 and 70:6652), 2-stage concept-learning theory by R. D. Tennyson et al it was hypothesized that prototype formation (Stage 1) requires an increase in the amount of information in the initial instructional period, whereas classification skill development (Stage 2) requires an increase in "reasonable" processing time in the latter instructional period. Data analyses using posttest and retention test scores showed that, for 96 9th-grade students studying 3 biological concepts via computer-based instruction, decreasing display time of interrogatory examples for incorrect answers (thereby increasing the amount of information) and increasing display time for correct answers (thereby increasing processing time) was better than several alternative procedures. These alternatives are (1) decreasing display time for correct answers and increasing it for incorrect answers (reversal of hypothesis), (2) controlling display time but without adjustment for responses, and (3) allowing for learner control of display time. Findings are discussed in reference to information processing theory and use of instructional display time as an adaptive design variable. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suppressors of an Arabidopsis thaliana phyB mutation identify genes that control light signaling and hypocotyl elongation

Ambient light controls the development and physiology of plants. The Arabidopsis thaliana photoreceptor phytochrome B (PHYB) regulates developmental light responses at both seedling and adult stages. To identify genes that mediate control of development by light, we screened for suppressors of the long hypocotyl phenotype caused by a phyB mutation. Genetic analyses show that the shy (short hypocotyl) mutations we have isolated fall in several loci. Phenotypes of the mutants suggest that some of the genes identified have functions in control of light responses. Other loci specifically affect cell elongation or expansion.     

Group support and the behavior of leaders and nonleaders.

In order to observe systematic behavioral differences between leaders, joiners, and nonjoiners, 17 Ss in each category were placed in a condition of group support followed by one of group nonsupport. In both conditions, 1 S from 1 of the 3 categories interacted with 3 paid participants in an attempt to solve a relatively unstructured task. As hypothesized, leaders made significantly more positive affect responses than nonjoiners across both situations and leaders made significantly fewer negative responses under support and significantly more negative responses under nonsupport than nonjoiners. 1 major hypothesis was not substantiated: Leaders did not make significantly more task oriented responses than either of the other categories under support or nonsupport. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suppression of T-cell proliferation by CD8+ T cells induced in the presence of protoscolices of Echinococcus multilocularis in vitro

Immunoregulatory influences of protoscolices (PSC) of Echinococcus multilocularis on murine T-lymphocyte functions have been examined in an in vitro system. Proliferative responses of spleen cells stimulated with concanavalin A (ConA) or anti-CD3 monoclonal antibodies were depressed by the addition of PSC. In the presence of PSC, both interleukin-2 (IL-2) production and IL-2 receptor (IL-2R) expression by lymphocytes stimulated with ConA were significantly reduced. However, exogenous IL-2 reconstituted both the ConA-stimulated proliferative responses and IL-2R expression. These findings suggest that PSC of E. multilocularis can suppress lymphoid cell responses via influences on IL-2 production. Indeed, addition of CD(8+)-enriched cells from cultures stimulated with ConA plus PSC to fresh spleen cells showed marked suppression of the ConA responses. IL-2 production as well as IL-2R expression on the spleen cells so treated were suppressed. These findings reveal a suppressive immunologic function induced by E. multilocularis PSC that involves inhibition of IL-2 production and reduction of IL-2R expression. The PSC-induced CD8+ cells appear to play a key role in the suppressive regulation of host immune responses against E. multilocularis.