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61.
We examined 5-month-olds’ responses to adult facial versus vocal displays of happy and sad expressions during face-to-face social interactions in three experiments. Infants interacted with adults in either happy-sad-happy or happy-happy-happy sequences. Across experiments, either facial expressions were present while presence/absence of vocal expressions was manipulated or visual access to facial expressions was blocked but vocal expressions were present throughout. Both visual attention and infant affect were recorded. Although infants looked more when vocal expressions were present, they smiled significantly more to happy than to sad facial expressions regardless of presence or absence of the voice. In contrast, infants showed no evidence of differential responding to voices when faces were obscured; their smiling and visual attention simply declined over time. These results extend findings from non-social contexts to social interactions and also indicate that infants may require facial expressions to be present to discriminate among adult vocal expressions of affect.  相似文献   
62.
A novel concept for selection of alloying elements based on diffusional and thermodynamic interactions is proposed. A general model to predict enhancement or reduction of diffusion flux of an element arising from the addition of another is described and specifically applied to determine the appropriate ternary alloying addition to reduce the fast precipitation kinetics observed in binary Ti–Fe based alloy. It is experimentally shown that addition of Cr and Mo decreases the kinetics of precipitation of TiFe, whereas addition of Ta and Nb enhances the kinetics, which is consistent with the predictions of the proposed model.  相似文献   
63.
Social psychological research suggests that because of concerns about being perceived in stereotypical ways, people may experience negative affect and diminished attention and cognitive capacity during interracial interactions. The authors discuss this research in relation to therapy and assessment and also offer practical suggestions for ensuring culturally competent professional practice. La investigación en el campo de la psicología social sugiere que, debido a la preocupación por ser percibida de forma estereotipada, la gente puede experimentar sentimientos negativos y un nivel reducido de atención y capacidad cognitiva durante interacciones interraciales. Los autores discuten esta investigación en relación a la terapia y evaluación, y también ofrecen sugerencias prácticas para asegurar una práctica profesional culturalmente competente.  相似文献   
64.
Two experiments were conducted to compare choices between sequences of reinforcers in pigeon (Experiment 1) and human (Experiment 2) subjects, using functionally analogous procedures. The subjects made pairwise choices among 3 sequence types, all of which provided the same overall reinforcerment rate, but differed in their temporal patterning. Token reinforcement schedules were used in both experiments and the type of exchange schedule varied across blocks of sessions. Some conditions permitted immediate exchange of tokens for consumable reinforcers (food for pigeons, video access for humans); in other conditions, tokens accumulated and were exchanged for consumable reinforcers only at the end of the sequence. Choice patterns in the immediate-exchange conditions were generally similar across species, with both pigeons and humans preferring sequences with the shortest delay to the initial reinforcer in the series. The results are broadly consistent with models of temporal discounting expanded to include the impact of sequences of delayed reinforcers acting in parallel from the time of the choice. Preferences were less consistent with discounting models in the delayed exchange conditions. Questionnaire data gathered at the end of the experiment were consistent with prior results of questionnaire studies, but showed no straightforward relation to the observed choice patterns, urging caution in the extrapolation of results from one decision-making domain to the other.  相似文献   
65.
Parallel experiments with rats and pigeons examined reasons for previous findings that in choices with probabilistic delayed reinforcers, rats' choices were affected by the time between trials whereas pigeons' choices were not. In both experiments, the animals chose between a standard alternative and an adjusting alternative. A choice of the standard alternative led to a short delay (1 s or 3 s), and then food might or might not be delivered. If food was not delivered, there was an "interlink interval," and then the animal was forced to continue to select the standard alternative until food was delivered. A choice of the adjusting alternative always led to food after a delay that was systematically increased and decreased over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Under these conditions, the indifference points for both rats and pigeons increased as the interlink interval increased from 0 s to 20 s, indicating decreased preference for the probabilistic reinforcer with longer time between trials. The indifference points from both rats and pigeons were well described by the hyperbolic-decay model. In the last phase of each experiment, the animals were not forced to continue selecting the standard alternative if food was not delivered. Under these conditions, rats' choices were affected by the time between trials whereas pigeons' choices were not, replicating results of previous studies. The differences between the behavior of rats and pigeons appears to be the result of procedural details, not a fundamental difference in how these two species make choices with probabilistic delayed reinforcers.  相似文献   
66.
Twelve rats made repeated choices on an adjusting-delay schedule between a smaller reinforcer (A) that was delivered immediately after a response and a larger reinforcer (B) that was delivered after a delay which increased or decreased by 20% depending on the subject's choices in successive blocks of trials. In two phases of the experiment (100 sessions and 40 sessions), reinforcer sizes were selected which enabled theoretical parameters expressing the rate of delay discounting and sensitivity to reinforcer size to be estimated from the ratio of the indifference delays obtained in the two phases. Indifference delays, calculated from adjusting delays in the last 10 sessions of each phase, were shorter when the sizes of A and B were 14 and 25 μl of a 0.6 M sucrose solution than when they were 25 and 100 μl of the same solution. The ratio of the indifference delays was significantly smaller than that predicted on the basis of an assumed linear relation between reinforcer size and instantaneous reinforcer value, consistent with a previous proposal that this relation may be hyperbolic in form. Estimates of the rate of delay discounting based on the ratio of the two indifference delays (mean, 0.08 s(-1)) were similar to values obtained previously using different intertemporal choice protocols. Estimates of the size-sensitivity parameter (mean 113 μl) were similar to estimates recently derived from performance on progressive-ratio schedules. In both phases of the experiment, adjusting delays in successive blocks of trials were analyzed using the Fourier transform. The power spectrum obtained from individual rats had a dominant frequency that corresponded to a period of oscillation of the adjusting delay between 30 and 100 trial blocks (mean, 78). Power in the dominant frequency band was highest in the early sessions of the first phase and declined with extended training. It is suggested that this experimental protocol may have utility in neurobehavioral studies of intertemporal choice.  相似文献   
67.
Much attention has been given to enhancing the prediction of counterproductive work behavior (CWB), with a particular focus on the relationship between the five factor model of personality and CWB. Several scholars have advocated for a more complex view of this relationship, and rather than focusing simply on main effects, to examine the interaction of personality traits in predicting employee behavior. In consideration of the traits most strongly related to CWB, we examined the interaction between: (1) conscientiousness and emotional stability, (2) agreeableness and emotional stability, and (3) conscientiousness and agreeableness on CWB directed at individuals (CWB-I) and the organization (CWB-O). Results from a multi-national sample illustrate the interaction of traits increases the prediction of CWB over and above a single trait approach. The interactions suggest employees perform the least CWB when they are high on both traits (in the respective trait pairings), but low levels on either trait relate to increased CWB, and at levels comparable to individuals low on both traits. We conclude research on personality and CWB would benefit from an interactive approach as it allows for greater prediction of CWB-O and CWB-I, which is important in light of the organizational and interpersonal consequences of employee misbehavior.  相似文献   
68.
69.
Mother–infant interactions are important to infant development because they are predictive of infants’ social, cognitive, and language development (0070 and 0150). Because maternal responsive and directive behaviors are associated with differential infant outcomes, it is important to investigate influences on mothers’ provision of responsive and directive behaviors. Yet, the dyadic interaction literature is predominantly unidirectional from maternal behavior to infant outcomes. Therefore, the current study examined infant initiating behaviors and consequent maternal responses in a sample of 26 13-month-old infants and their mothers, videotaped during 5 min of free-play. Findings revealed that infants produced a variety of initiatives, and that these different infant initiatives prompted differential patterns of maternal responsive versus directive behaviors. Further, results of analyses of divergent types of maternal directive behaviors – Responsive Directives, ReDirectives, and Intrusive Directives – also may help clarify major discrepancies in the current literature regarding the positive and negative effects of maternal directiveness.  相似文献   
70.
Although studies have examined the effects of interventions focused on preterm infants, few studies have examined the effects on maternal distress (anxiety, depressive symptoms, post-traumatic stress symptoms, parenting stress) or parenting. This study examined the effects of the auditory–tactile–visual–vestibular (ATVV) intervention and kangaroo care (KC) on maternal distress and the mother–infant relationship compared to an attention control group.240 mothers from four hospitals were randomly assigned to the three groups. Maternal characteristics in the three groups were similar: 64.1% of ATVV mothers, 64.2% of KC mothers, and 76.5% of control mothers were African American; maternal age averaged 26.3 years for ATVV mothers, 28.1 for KC mothers, and 26.6 for control mothers; and years of education averaged 13.6 for ATVV and KC mothers, and 13.1 for control mothers. Mothers only differed on parity: 68.4% of ATVV and 54.7% of KC mothers were first-time mothers as compared to 43.6% of control mothers. Their infants had a similar mean gestational ages (27.0 weeks for ATVV, 27.2 for KC, and 27.4 for control) and mean birthweights (993 g for ATVV, 1022 for KC, and 1023 for control).Mothers completed questionnaires during hospitalization, and at 2, 6 and 12 months corrected age on demographic characteristics, depressive symptoms, state anxiety, post-traumatic stress symptoms, parenting stress, worry about child health, and child vulnerability (only at 12 months). At 2 and 6 months, 45-min videotapes of mother–infant interactions were made, and the HOME Inventory was scored. Behaviors coded from the videotapes and a HOME subscale were combined into five interactive dimensions: maternal positive involvement and developmental stimulation and child social behaviors, developmental maturity, and irritability.Intervention effects were examined using general linear mixed models controlling for parity and recruitment site. The groups did not differ on any maternal distress variable. Kangaroo care mothers showed a more rapid decline in worry than the other mothers. The only interactive dimensions that differed between the groups were child social behaviors and developmental maturity, which were both higher for kangaroo care infants. Change over time in several individual infant behaviors was affected by the interventions. When mothers reported on the interventions they performed, regardless of group assignment, massage (any form including ATVV) was associated with a more rapid decline in depressive symptoms and higher HOME scores. Performing either intervention was associated with lower parenting stress. These findings suggest that as short-term interventions, KC and ATVV have important effects on mothers and their preterm infants, especially in the first half of the first year.  相似文献   
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