引入中立方参照：对禀赋效应的再探讨

在以往禀赋效应研究的基础上, 本研究引入中立方估价值作为参照, 在时间维度上探讨了禀赋效应的变化趋势, 并尝试延伸禀赋效应的定义。研究发现, 随着卖方拥有物品的时间延长, 买卖双方的估价呈下降趋势, 卖方的估价总是显著高于买方, 但买卖双方的估价之差不随卖方拥有物品的时间延长发生变化; 以中立方的估价为参照, 在较短的时间内卖方的估价倾向于理性, 在较长的时间内买方的估价倾向于理性; 卖方的估价在时间水平上相对于中立价格呈递增性, 而买方的估价相对于中立价格呈递减性。引入中立方再探讨禀赋效应并没有否定它的存在, 而且能够更好地解释生活中的非理性行为。     

Sequential and myopic: On the use of feedback to balance cost and utility in a simulated electricity efficiency task

While there is extensive research on feedback, little research is aimed at the use of feedback to optimise conflicting goals. A task modelled after In Home Displays for providing feedback about electricity cost was designed to investigate the effects of feedback frequency, detail, and stability, when participants try to balance cost and utility. Frequent feedback proved to be advantageous in a deterministic system, but feedback aggregated over time was advantageous in a system with noisy feedback. Surprisingly, performance was better with noisy feedback, where the probabilism, in effect, acted as a filter, highlighting the applications that are most important for the cost and the utility. Computational modelling suggested that the best-fitting model assumes that the participants are sequential, considering one goal at a time, first satisfying the cost budget, only thereafter trying to maximise the utility, and reflexive, myopically responding primarily to the feedback explicitly available on a given trial.     

One-Handed Juggling: A Dynamical Approach to a Rhythmic Movement Task

The skill of rhythmically juggling a ball on a racket was investigated from the viewpoint of nonlinear dynamics. The difference equations that model the dynamical system were analyzed by means of local and nonlocal stability analyses. These analyses showed that the task dynamics offer an economical juggling pattern that is stable even for open-loop actuator motion. For this pattern, two types of predictions were extracted: (a) Stable periodic bouncing is sufficiently characterized by a negative acceleration of the racket at the moment of impact with the ball, and (b) a nonlinear scaling relation maps different juggling trajectories onto one topologically equivalent dynamical system. The relevance of these results for the human control of action was evaluated in an experiment in which subjects (N = 6) performed a comparable task of juggling a ball on a paddle. Task manipulations involved different juggling heights and gravity conditions of the ball. The following predictions were confirmed: (a) For stable rhythmic performance, the paddle's acceleration at impact is negative and fluctuations of the impact acceleration follow predictions from global stability analysis; and (b) for each subject, the realizations of juggling for the different experimental conditions are related by the scaling relation. These results permit one to conclude that humans reliably exploit the stable solutions inherent to the dynamics of the given task and do not overrule these dynamics by other control mechanisms. The dynamical scaling serves as an efficient principle for generating different movement realizations from only a few parameter changes and is discussed as a dynamical formalization of the principle of motor equivalence.     

Self-Help for Social Anxiety: Randomized Controlled Trial Comparing a Mindfulness and Acceptance-Based Approach With a Control Group

There are many barriers to the delivery of evidence-based treatment, including geographical location, cost, and stigma. Self-help may address some of these factors but there is a paucity of research on the efficacy of self-help for many problems, including social anxiety. The present research evaluated the efficacy of a mindfulness and acceptance-based self-help approach for the treatment of social anxiety. Individuals seeking help for social anxiety or shyness were recruited from the community. Participants (N = 117) were randomly assigned to a book (n = 58) or wait-list control condition (n = 59) on a 1:1 ratio. Hierarchical linear modelling results supported the efficacy of the self-help condition with between-group effect sizes on social anxiety outcomes ranging from .74 to .79. Significant change was also observed on self-compassion, mindfulness, acceptance, and depression. Some variables, including social anxiety and acceptance, were assessed weekly for those in the book condition. Additional participants (n = 35) were recruited for the book condition increasing the sample size to 93 for the latent change score modelling analyses. A unidirectional model was supported: increases in acceptance were associated with subsequent decreases in social anxiety. Overall these results support the use of a mindfulness and acceptance-based self-help approach for social anxiety.     

Ecological Factors Impacting Provider Attitudes Towards Human Service Delivery Reform

Although reform efforts are substantially altering the structural operations and guiding ideological framework of the human service delivery system, little empirical work has been done to systematically examine these transformations. This study examines providers' attitudes regarding two reform elements that are being widely implemented: an increased emphasis on inter-agency collaboration and a shift from a medical model service delivery philosophy, that focuses on client deficits, to one that emphasizes consumer strengths. Through survey data collected from 186 providers from 32 human service agencies in one county, the relationship between providers' perceptions of contextual support for human service delivery reform and providers' attitudes towards these initiatives is explored. The findings from this study support the importance of attending to the ecology in which we initiate system reform efforts. For both reform elements, working within contexts that are perceived as providing ideological and functional support for change was associated with positive provider attitudes towards those changes. Staffs' perceptions of the external environment played the most critical role in shaping staff attitudes. Interestingly, unique aspects of providers' work environments were related to positive attitudes towards the two different reforms. The implications of these findings for the success of human service delivery reform are discussed.     

Prenatal maternal stress and prematurity: a prospective study of socioeconomically disadvantaged women.

Developed and tested a biopsychosocial model of birthweight and gestational age at delivery using structural equation modeling procedures. The model tested the effects of medical risk and prenatal stress on these indicators of prematurity after controlling for whether a woman had ever given birth (parity). Subjects were 130 women of low socioeconomic status interviewed throughout pregnancy in conjunction with prenatal care visits to a public clinic. The majority of women were Latino or African-American. Half were interviewed in Spanish. Lower birthweight was predicted by earlier delivery and by prenatal stress. Earlier delivery was predicted by medical risk and by prenatal stress. Parity was not related to time of delivery or to birthweight. Implications of results for the development of biopsychosocial research on pregnancy and on stress are discussed.     

Mixed Picture of Readiness for Adoption of Evidence-Based Prevention Programs in Communities: Exploratory Surveys of State Program Delivery Systems

An emerging literature highlights the potential for broader dissemination of evidence‐based prevention programs in communities through existing state systems, such as the land grant university Extension outreach system and departments of public education and health (DOE–DPH). This exploratory study entailed surveying representatives of the national Extension system and DOE–DPH, to evaluate dissemination readiness factors, as part of a larger project on an evidence‐based program delivery model called PROSPER. In addition to assessing systems’ readiness factors, differences among US regions and comparative levels of readiness between state systems were evaluated. The Extension web‐based survey sample N was 958 and the DOE–DPH telephone survey N was 338, with response rates of 23 and 79 %, respectively. Extension survey results suggested only a moderate level of overall readiness nationally, with relatively higher perceived need for collaborative efforts and relatively lower perceived resource availability. There were significant regional differences on all factors, generally favoring the Northeast. Results from DOE–DPH surveys showed significantly higher levels for all readiness factors, compared with Extension systems. Overall, the findings present a mixed picture. Although there were clear challenges related to measuring readiness in complex systems, addressing currently limited dissemination resources, and devising strategies for optimizing readiness, all systems showed some readiness‐related strengths.     

Interpretation bias and social anxiety: does interpretation bias mediate the relationship between trait social anxiety and state anxiety responses?

Two studies aimed to examine whether high socially anxious individuals are more likely to negatively interpret ambiguous social scenarios and facial expressions compared to low socially anxious individuals. We also examined whether interpretation bias serves as a mediator of the relationship between trait social anxiety and state anxiety responses, in particular current state anxiety, bodily sensations, and perceived probability and cost of negative evaluation pertaining to a speech task. Study 1 used ambiguous social scenarios and Study 2 used ambiguous facial expressions as stimuli to objectively assess interpretation bias. Undergraduate students with high and low social anxiety completed measures of state anxiety responses at three time points: baseline, after the interpretation bias task, and after the preparation for an impromptu speech. Results showed that high socially anxious individuals were more likely to endorse threat interpretations for ambiguous social scenarios and to interpret ambiguous faces as negative than low socially anxious individuals. Furthermore, negative interpretations mediated the relationship between trait social anxiety and perceived probability of negative evaluation pertaining to the speech task in Study 1 but not Study 2. The present studies provide new insight into the role of interpretation bias in social anxiety.     

Individual reactions to a multisensory immersive virtual environment: the impact of a wind farm on individuals

The aim of this study was to assess the impact of a wind farm on individuals by means of an audio-visual methodology that tried to simulate biologically plausible individual-environment interactions. To disentangle the effects of auditory and visual components on cognitive performances and subjective evaluations, unimodal (Audio or Video) and bimodal (Audio + Video) approaches were compared. Participants were assigned to three experimental conditions that reproduced a wind farm by means of an immersive virtual reality system: bimodal condition, reproducing scenarios with both acoustic and visual stimuli; unimodal visual condition, with only visual stimuli; unimodal auditory condition, with only auditory stimuli. While immersed in the virtual scenarios, participants performed tasks assessing verbal fluency, short-term verbal memory, backward counting, and distance estimations (egocentric: how far is the turbine from you?; allocentric: how far is the turbine from the target?). Afterwards, participants reported their degree of visual and noise annoyance. The results revealed that the presence of a visual scenario as compared to the only availability of auditory stimuli may exert a negative effect on resource-demanding cognitive tasks but a positive effect on perceived noise annoyance. This supports the idea that humans perceive the environment holistically and that auditory and visual features are processed in close interaction.     

Costs in searching for two targets: dividing search across target types could improve airport security screening

The cost of searching for two visual targets simultaneously was compared against two separate single‐target searches using exposure time and accuracy measures within a staircase procedure. Dual‐target search for all stimuli (colour, shape and orientation) exhibited a loss of accuracy for one target. For orientation and shape, this dual‐target cost in accuracy was extreme, with chance‐level performance on one target. For colour, dual‐target search exhibited an additional cost in search time, with search requiring a longer exposure than the summed time required for two single‐target searches. An additional search‐time cost was also found for orientation targets when irrelevant colour variation was added to the display. In conclusion, dual‐target search for dissimilar targets is accompanied by an accuracy cost. Furthermore, colour variation, whether task‐relevant or not, leads to an additional cost in processing speed. The results suggest that a divided‐effort strategy would improve performance in search tasks such as X‐ray baggage screening. Copyright © 2006 John Wiley & Sons, Ltd.     

Controlling experiments with a general-purpose time-sharing system

For many experiments in the behavioral and biomedical sciences, there is no substitute for an experimental-control computer with true real-time capabilities. However, if an experimenter can tolerate timing errors of several seconds, then he can reap the benefits of computer control by buying time on a general-purpose time-sharing system. There can be little doubt that a self-contained computer-controlled laboratory will be more economical if a fair number of experiments are contemplated. But when only a few experiments are planned, the researcher may find that he can run them with a general-purpose time-sharing system at only a fraction of the cost of establishing a     

An analysis of timeout and response cost in a programmed environment

A group of mildly retarded adolescents with high rates of antisocial behavior was exposed to two parameters of timeout and response cost within the context of a programmed environment. For five of the six subjects, the two higher values (30 tokens response cost or 30 min timeout) were significantly more suppressive than the lower values (five tokens or 5 min). For the one remaining subject, there was a strong relationship in the opposite direction. Also, the timeout and response cost of higher value became increasingly more suppressive over time, whereas those of lower value did not. There were few appreciable differences between the timeout and response cost of similar magnitude. A discussion of these results is presented in support of the notion that the functional aversiveness of timeouts (and response costs) appears to be critically dependent upon interactions with the environmental conditions in which they are implemented and the reinforcement histories of the subjects.     

Cost containment as professional challenge

Cost containment by means of prospective payment and other mechanisms is widely seen as a challenge to modern medicine; but the challenge is seldom articulated clearly in terms of core professional values and the moral content of a claim to professionalism. Medical ethics, as it has evolved as a field of study in the past twenty years, has contributed little to the concept of professionalism in medicine. For an investigation of professionalism in the face of cost containment to evolve fruitfully, several things must occur. The true nature of today's challenge to medicine must be appreciated. The balance between tradition and response to social change in defining a professional value system must be appreciated. Physician income must be explicitly addressed as a moral issue. And practical strategies for investigating and affirming core professional values must be developed for health delivery systems and medical education settings.     

An experimental analysis of the cost of food in a closed economy.

Rats lived in individual chambers in which the only food available was delivered for lever pressing. During Stage I, a fixed number of presses was required for each food pellet. As this fixed ratio of presses per food pellet was increased daily, a rat's daily intake of food was reduced. During Stage II, the cost of a food pellet was increased by replacing each fixed ratio with its interval equivalent. Each interval was a rat's mean time between the first press of a ratio and the delivery of a pellet during Stage I. During Stage II, only two presses were every required for a food pellet: The first press initiated a delay and the second activated the pellet dispenser after that delay elapsed. Food intakes for the series of fixed ratios and a rat's series of delay equivalents were very similar when plotted as a function of delay, but not when plotted as a function of presses per pellet. Consequently, the fixed ratio reduced food intake because larger ratios increased delay to food from the first press of a ratio. Observations and an analysis of interresponse times further revealed that as the fixed ratio increased, and local as well as overall rate of food intake decreased, lever pressing became more stereotyped. Because this increased stereotypy resulted in greatly increased rates of lever pressing, delay to food was minimized, and perhaps more importantly, so too was the reduction of a rat's baseline daily intake.     

Learning categories at different hierarchical levels: a comparison of category learning models

Three formal models of category learning, the rational model (Anderson, 1990), the configural-cue model (Gluck & Bower, 1988a), and ALCOVE (Kruschke, 1992), were evaluated on their ability to account for differential learning of hierarchically structured categories. An experiment using a theoretically challenging category structure developed by Lassaline, Wisniewski, and Medin (1992) is reported. Subjects learned one of two different category structures. For one structure, diagnostic information was present along a single dimension (1-D). For the other structure, diagnostic information was distributed across four dimensions (4-D). Subjects learned these categories at a general or at a specific level of abstraction. For the 1-D structure, specific-level categories were learned more rapidly than general-level categories. For the 4-D structure, the opposite result was observed. These results proved highly diagnostic for evaluating the models—although ALCOVE provided a good account of the observed results, the rational model and the configural-cue model did not.     

Time Costs for Genetic Counseling in Preconception Carrier Screening with Genome Sequencing

Advances in technology and the promise of personalized health care are driving greater use of genome sequencing (GS) for a variety of clinical scenarios. As health systems consider adopting GS, they need to understand the impact of GS on the organization and cost of care. While research has documented a dramatic decrease in the cost of sequencing and interpreting GS, few studies have examined how GS impacts genetic counseling workloads. This study examined the time needed to provide genetic counseling for GS in the context of preconception carrier screening. Genetic counselors prospectively reported on the time spent in the results disclosure process with 107 study participants who were part of the NextGen study. We found that the median time for results disclosure was 64 min (ranged from 5 to 229 min). Preparation work was the most time-consuming activity. Qualitative data from journal entries, debrief interviews with genetic counselors, and detailed case conference notes provided information on factors influencing time for results disclosure and implications for practice. Results suggest that expanded carrier screening could require significant increases in genetic counseling time, unless we are able to generate new resources to reduce preparation work or develop other strategies such as the creation of new models to deliver this type of service.     

A framework for designing socially assistive robot interactions

Robots are increasingly tested in different socially assistive scenarios. Future applications range from dieting, coaching, tutoring to autism therapy. In such applications the success of the system is commonly evaluated by the ability to encourage the user to keep up with a task. Hence, one important requirement for supportive systems is to have an interactional motivational model that formalizes the way how users can be assisted. In this paper we describe our framework for coordinating motivational interaction scenarios with socially assistive robots (SAR) in the context of sport assistance. We exemplify three different sport scenarios where we have used the same motivational interaction model. Furthermore, we show how this model can be used to systematically test the different aspects of motivation in the context of SAR in sport domains. Therefore, we have conducted an experiment to evaluate the importance of acknowledgement from SAR for human interaction partners. The results show that users exercise longer if acknowledgment is included into the motivational model.     

Escalation behavior in domains related and unrelated to decision makers' academic background

Based on Staw and Ross's (1987) analysis of escalation behavior it was hypothesized that (a) those who are involved with projects related to their academic background will tend to persist in a losing course of action and to judge the situation as reversible more than those who have to make decisions in areas unrelated to their specialty; (b) providing information that the loss is irreversible will decrease the tendency to invest additional resources. A secondary goal of the study was to examine whether there would be any difference in sunk cost decisions when the resource invested is financial as compared to time. Using a 2 × 2 × 2 factorial design, a total of 296 students were given eight different scenarios in which relatedness of decision subject-matter to academic background, reversibility of the situation, and type of resources (time or money) were the independent variables, and commitment to a course of action was the dependent variable. The results confirmed the hypotheses. No significant main effect for type of resources (time vs. money) was found. Theoretical and practical implications of the results are discussed.The authors thank Dr. Michael Hoffman for his valuable contribution in preparing this paper.     

Children's evaluations of provocation between peers

The present study examined children's evaluations of potentially conflictual situations between peers. Eight- and 11-year-olds evaluated two hypothetical target children in three scenarios which differed as to the intent of a provocative act (Accidental, Ambiguous, Hostile). In addition to grade and sex, relationship between targets was manipulated as a between-subjects variable with targets portrayed as either Best Friends Acquaintances, or Enemies. Children evaluated targets in terms of attributions of intentions, behavior response, affective state of targets, and mutual liking between targets. Results indicated that aggressor's intentions and victim's behavior response were evaluated as positive for the Accidental scenario and as negative for the Hostile scenario regardless of target relationship. When aggressor's intentions were unclear (e.g., Ambiguous), interactions between Best Friends and interactions between Acquaintances were evaluated as positive while interactions between Enemies were perceived as negative. Further, while all children predicted a negative response by the victim during the Hostile situation, younger children predicted the victim's response would be less negative than did older children. Children reported Best Friends and Acquaintances as liking each other more before the provocation situation started than after it occurred while liking between Enemies remained unchanged, thus indicating a belief that provocations may hurt a positive or neutral relationship. Targets were perceived to be in negative affective states during the Accidental and Ambiguous scenarios and the aggressor was perceived to be in a neutral affective state during the Hostile scenario. Results are discussed in terms of previous research on response to provocation and implications for research on children's peer conflicts. Aggr. Behav. 23:417–431, 1997. © 1997 Wiley-Liss, Inc.     

Additional validation of the attitudes toward Seeking Professional Psychological Help Scale

To provide information on the construct validity of the Attitudes Toward Seeking Professional Psychological Help scale, relationships between prior treatment experiences and scores on the scale were evaluated. Participants were 270 students recruited from undergraduate psychology courses at a medium-sized university in the midwestern USA. 79% were women: their ages ranged from 18 to 53 years (M= 19.0, SD=4.4). In addition to completing the scale, the subset of 76 participants who reported prior mental health care treatment also evaluated these experiences using a rating scale anchored by 0: very dissatisfied and 4: very satisfied. For the total sample, prior experience with the mental health care delivery system was associated with higher scores on the scale, denoting more positive attitudes. In the subgroup with prior treatment experience, evaluation ratings were also associated with treatment attitudes, accounting for 17% of the variance in their scale score. These results provide additional support for the construct validity of this scale.