Calibration, Information, and Control Strategies for Braking to Avoid a Collision.

This study explored visual control strategies for braking to avoid collision by manipulating information about speed of self-motion. Participants watched computer-generated displays and used a brake to stop at an object in the path of motion. Global optic flow rate and edge rate were manipulated by adjusting eyeheight and ground-texture size. Stopping distance, initiation of braking, and the magnitude of brake adjustments were influenced by both optical variables, but global optic flow rate had a stronger effect. A new model is introduced according to which braking is controlled by keeping the perceived ideal deceleration, based in part on global optic flow rate, within a "safe" region between 0 and the maximum deceleration of the brake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual control of braking: A test of the !? hypothesis.

Deceleration during braking could be controlled by (1) using the time derivative of the relative rate of optical expansion, relative to a –0.5 margin value of tau-dot (D. N. Lee, 1976) or (2) computing the required deceleration from spatial variables (i.e., perceived distance, velocity, or object size). Participants viewed closed-loop displays of approach to an object and regulated their deceleration with a brake. The object appeared on a checkerboard ground surface (providing velocity, distance, and size information) or with no background (providing only optical expansion). Mean tau-dot during braking was –0.51, and estimates of the critical value of tau-dot based on brake adjustments were –0.44 and –0.52, close to the expected value. There were no overall effects of the ground surface or object size. The results are consistent with a tau-dot strategy, where the direction and magnitude of brake adjustments are regulated using tau-dot. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What causes the face inversion effect?

What is it about the way faces are represented by the visual system that makes them so much harder to recognize when inverted? The authors tested the hypothesis that the "face inversion" effect results from the use of holistic shape representations. This suggests that the susceptibility of nonface patterns to inversion should be a function of their degree of part decomposition. In Experiment 1, this was tested and confirmed with dot patterns in which the degree of part decomposition was manipulated by grouping and segregation on the basis of dot color. The hypothesis also predicted that the face inversion effect can be eliminated with face stimuli if participants are induced to recognize the faces in terms of their component parts. In Experiment 2, this was tested and confirmed with whole, intact faces, in which the degree of part decomposition was manipulated by allowing participants to study them, initially, in either whole, intact versions or versions with parts presented separately. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of a deceleration warning light for reducing rear-end automobile collisions.

Designed an amber light, center mounted on the rear of 343 San Francisco taxicabs, to communicate information about the taxi's deceleration to following drivers. The light, activated by the use of the brake pedal, was pulsed in a controlled fashion at a rate, duty cycle, and intensity that varied exponentially with a component of deceleration. A comparison of the experimental group (with the light for 12.3 million miles) with a control group of 160 cabs (without the light for 7.2 million miles) revealed that the light prevented 5.4 collisions, 1.02 cab driver injuries, and $643 of taxicab damage per million miles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Responses to deceleration during car following: Roles of optic flow, warnings, expectations, and interruptions.

More than 25% of accidents are rear-end collisions. It is essential to identify the factors that contribute to such collisions. One such factor is a driver’s ability to respond to the deceleration of the car ahead. In Experiment 1, we measured effects of optic flow information and discrete visual and auditory warnings (brake lights, tones) on responses to deceleration during car following. With computer simulations of car-following scenes, university students pressed a button when the lead car decelerated. Both classes of information affected responses. Observers relied on discrete warnings when optic flow information was relatively less effective as determined by the lead car’s headway and deceleration rate. This is consistent with DeLucia’s (2008) conceptual framework of space perception that emphasized the importance of viewing distance and motion (and task). In Experiment 2, we measured responses to deceleration after a visual interruption. Scenes were designed to tease apart the role of expectations and optic flow. Responses mostly were consistent with optic flow information presented after the interruption rather than with putative mental expectations that were set up by the lead car’s motion prior to the interruption. The theoretical implication of the present results is that responses to deceleration are based on multiple sources of information, including optical size, optical expansion rate and tau, and discrete warnings that are independent of optic flow. The practical implication is that in-vehicle collision-avoidance warning systems may be more useful when optic flow is less effective (e.g., slow deceleration rates), implicating a role for adaptive collision-warning systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluating sex discrimination claims: The mediating role of attributions.

The role of attributions in judgments of sex discrimination was examined in 2 laboratory experiments. In Study 1, participants read 1 of 12 brief scenarios in which limited information about the strength of evidence against a fictitious corporation and occupational gender stereotype were manipulated. Results suggested that attributions mediated the relationships between participants' gender, strength of evidence, and discrimination judgments. In Study 2, participants were provided with 1 of 3 detailed, typewritten summaries of evidence presented in a sex discrimination trial. Results indicated that jurors' gender was again significantly related to attributions and to sex discrimination judgments even in the face of substantial objective information related to the case. The variance in observers' judgments associated with gender, however, appeared to be greatest when information about the organization's guilt or innocence was equivocal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased processing enhances calibration of comprehension.

Two experiments investigated whether increased processing increases the relation between test performance predictions and test performance, i.e., increases calibration of comprehension. The amount of processing of text was manipulated by having subjects read intact text or text with deleted letters. In Experiment 1, intact versus deleted letters were manipulated within subjects, and subjects made either comprehension ease or test prediction ratings. Paragraphs with deleted letters produced higher correlations between predictions and test performance than did intact paragraphs. Better calibration with more processing was not observed for ratings of comprehension ease. In Experiment 2, in a between-subjects design, the prediction results were replicated; calibration was better for text with deleted letters than for intact text. The results show that subjects can predict performance on text material with greater than chance accuracy and that these predictions are better when subjects do more active processing during reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-efficacy theory: Implications for social facilitation and social loafing.

Two experiments indicate that the areas of social facilitation and social loafing are complementary and can be conceptualized in terms of self-efficacy theory. In Exp 1, efficacy expectancies were manipulated by false performance feedback, and outcome expectancies were manipulated by 3 group conditions (alone, coaction, and collective). In Exp 2, efficacy expectancies developed spontaneously while participants performed easy or difficult tasks, and outcome expectancies were manipulated by 3 evaluative conditions (alone, evaluation, and no evaluation). Consistent with social facilitation research, high efficacy evaluated participants performed better than alone participants, whereas low-efficacy evaluated participants performed worse than alone participants. Consistent with social loafing research, high efficacy nonevaluated participants performed worse than evaluated participants, whereas low-efficacy nonevaluated participants performed better than evaluated participants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is age irrelevant? Perceptions of young and old adult eyewitnesses

In Experiment 1, we videotaped elderly and younger adults (n = 69) reporting their memories of a crime video. The seniors were significantly less accurate than the younger adults. In Experiment 2, participants viewed the "testimony" videotapes and rated the elderly as less credible than the younger adults. In Experiment 3, participant-jurors (n = 302) evaluated transcribed testimonies provided by Experiment 1 participants. The ostensible age of the witnesses was manipulated. Thus, some participants read a senior's testimony believing it was provided by a younger adult and vice versa. Participants were apparently not biased by negative stereotypes of seniors' eyewitness capabilities.     

Lexical access without attention? Explorations using dichotic priming.

The authors used lexical decision in a dichotic listening situation and measured identity priming across channels to explore whether unattended stimuli can be processed lexically. In 6 experiments, temporal synchronization of prime and target words was manipulated, and acoustic saliency of the unattended prime was varied by embedding it in a carrier sentence or in babble speech. When the prime was acoustically salient, a cross-channel priming effect emerged, and participants were aware of the prime. When the prime was less salient, no identity priming was found, and participants failed to notice the prime. Saliency was manipulated in ways that did not degrade the prime. Results are inconsistent with models of late filtering, which predict equal priming irrespective of prime saliency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

时速350 km高速列车用铜基闸片材料的摩擦性能

闸片是高速列车制动系统的核心部件,本文设计了350 km·h–1高速列车用铜基闸片材料,对闸片进行了1∶1台架实验考核,重点分析了摩擦膜的性质及闸片的摩擦磨损性能。结果表明,研制闸片不仅具有优异的摩擦系数稳定性和低的磨耗,还具有不伤盘的特点。瞬时摩擦系数和平均摩擦系数均满足TJCL/307—2019标准的要求,摩擦系数稳定性为0.0015,250～380 km?h–1制动速率范围内的摩擦系数热衰退仅0.027,在380 km?h–1下的平均摩擦系数仍维持在0.35,平均磨耗仅0.06 cm3?MJ–1。闸片优异的摩擦制动性能归因于形成了高强韧、低转移速率的摩擦膜。利用大粒径摩擦组元作为外部运动障碍钉扎摩擦膜。摩擦膜中的亚微米磨屑作为摩擦膜与对偶盘的啮合点,提供摩擦阻力,以保持高速制动时的摩擦系数。添加的易氧化组元为摩擦膜源源不断提供氧化物,研磨生成的纳米氧化物作为弥散相强化摩擦膜。通过多尺度颗粒的协同增强,实现了摩擦膜的动态稳定化,赋予了闸片优异的摩擦磨损性能。      

Meta-analogical transfer: Transfer between episodes of analogical reasoning.

Meta-analogical transfer (i.e., transfer due to forming an analogy between analogies) was demonstrated in 4 experiments. Results suggest that the basis of meta-analogical transfer was transfer of predicate mappings (mappings of the concepts used to represent analogies) between separate episodes of analogical reasoning. Episodes of letter-string analogy problem solving of the form "If abc were changed into abd, how would you change kji in the same way?" were used. In Experiment 1 participants generated solutions in 2 separate analogical reasoning episodes. Order of presentation effects provided evidence of transfer of predicate mappings. Experiments 2a and 2b reinforced these findings, demonstrating transfer when mappings for the 1st analogy were directly manipulated by having participants justify an answer to the 1st analogy. Experiment 3 demonstrated that a mapping of nonidentical predicates (successor to predecessor) can also be transferred. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Approach and avoidance strength during goal attainment: regulatory focus and the "goal looms larger" effect

Three studies tested the hypothesis that regulatory focus, both as a chronic person variable and as a manipulated situational variable, differentially affects the strength of participants' approach and avoidance strategic motivations as they get closer to the goal. In 2 studies, flexion and extension arm pressure were used as on-line measures of approach and avoidance intensity, respectively. As predicted, the approach gradient was steeper for participants with a promotion focus on aspirations and gains than for participants with a prevention focus on responsibilities and nonlosses, whereas the reverse was true for the avoidance gradient. In a third study, the same pattern of results was found on a persistence measure of motivational strength. Participants with a promotion focus worked longer on anagrams closer to the goal when they were approach means for goal attainment than when they were avoidance means, whereas the reverse was true for participants with a prevention focus.     

Manipulating self-efficacy in the exercise environment in women: Influences on affective responses.

Self-efficacy was experimentally manipulated in an exercise context, and its effect on affective responses was examined. College women (N?=?46) were randomly assigned to a high- or low-efficacy condition, and efficacy expectations were manipulated by means of bogus feedback and graphs depicting contrived normative data. The manipulation successfully influenced affective responses, with participants in the high-efficacy group reporting more positive and less negative affect than did the low-efficacy group. Efficacy was significantly related to feeling-state responses during and after activity but only in the high-efficacy condition. The results suggest that self-efficacy can be manipulated and that these changes are related to the affective experience associated with exercise. Such findings may have important implications for the roles played by self-efficacy and affect in exercise adherence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When and why do ideal partner preferences affect the process of initiating and maintaining romantic relationships?

Three studies explored how the traits that people ideally desire in a romantic partner, or ideal partner preferences, intersect with the process of romantic relationship initiation and maintenance. Two attraction experiments in the laboratory found that, when participants evaluated a potential romantic partner's written profile, they expressed more romantic interest in a partner whose traits were manipulated to match (vs. mismatch) their idiosyncratic ideals. However, after a live interaction with the partner, the match vs. mismatch manipulation was no longer associated with romantic interest. This pattern appeared to have emerged because participants reinterpreted the meaning of the traits as they applied to the partner, a context effect predicted by classic models of person perception (S. E. Asch, 1946). Finally, a longitudinal study of middle-aged adults demonstrated that participants evaluated a current romantic partner (but not a partner who was merely desired) more positively to the extent that the partner matched their overall pattern of ideals across several traits; the match in level of ideals (i.e., high vs. low ratings) was not relevant to participants' evaluations. In general, the match between ideals and a partner's traits may predict relational outcomes when participants are learning about a partner in the abstract and when they are actually in a relationship with the partner, but not when considering potential dating partners they have met in person. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Overdependence on degraded gist memory in Alzheimer's disease.

Alzheimer's disease (AD) reduces associative effects on false recognition in the Deese-Roediger-McDermott task, either due to impaired memory for gist or impaired use of gist in memory decisions. Gist processes were manipulated by blocking or mixing studied words according to their associations and by varying the associative strength between studied and nonstudied words at test. Both associative blocking and associative strength had smaller effects on false recognition in AD patients than in control participants, consistent with gist memory impairments. However, unlike the case with control participants, blocking influenced true and false recognition equally in AD patients, demonstrating an overdependence on gist when making memory decisions. AD also impaired item-specific recollections, relative to control participants, as true recognition of studied words was reduced even when the two groups were equated on gist-based false recognition. We propose that the overdependence on degraded gist memory in AD is caused by even larger impairments in item-specific recollections. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Affective and cardiovascular effects of experimentally-induced social status.

Objective: Observational research suggests subordinate social status is associated with negative mental and physical health outcomes. However, observational studies have limitations, including confounding of social status with other factors, limited ability to infer causality, and difficulty of obtaining detailed affective and physiologic data. This study used experimental methods to test the hypothesis that subordinate social status per se causes psychological distress and cardiovascular arousal. Design: Forty-four women were randomly assigned to an induced subordinate or dominant status condition. Social status was manipulated using a procedure derived from status construction theory. Main Outcome Measures: Affective responses were assessed via self-report. Cardiovascular responses were assessed by measures of systolic and diastolic blood pressures obtained with an automated blood pressure machine. Results: Participants in the subordinate condition perceived themselves as lower in status; the reverse was true for dominant condition participants. Compared with induced dominant status, induced subordinate status produced increased negative affect and systolic blood pressure over the course of the study. Conclusion: Findings suggest social status can be experimentally manipulated and short-term induction of subordinate status can have adverse effects on affect and stress-related physiological systems. Results have implications for understanding how socioeconomic status "gets under the skin" to influence health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Shifts in evaluations of participants following intergroup competition.

"Intergroup competition was simulated by having two-man teams compete against two stooges on several tasks. Winning and losing was manipulated by having the stooges win against half the teams and always lose against the other half. The difference in favorability of a team's before and after ratings of the other participants on 27 personality traits was the dependent variable… the hypothesis that 'liking' is increased by interaction received… support." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Encoding conditions and the list-strength effect.

The list-strength effect occurs when "strong" items within a list are remembered at the expense of "weak" items within that same list. Two experiments (using 185 college student Ss) showed that variably encoded words were remembered better than words repeated with the same encoding context, whether memory was measured by free recall, frequency estimates, or recognition d'. However, there was little or no evidence from any of the measures that the variably encoded words were recollected in the mixed lists at the expense of the similarly encoded words. This pattern held even though, in Exp 2, there was a list-strength effect on free recall, when list strength was manipulated by increasing the number of presentations of a word. It is concluded that the free recall results could not be accommodated by the model of memory postulated by R. M. Shiffrin et al (see record 1990-13917-001) to account for the effects of list strength. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of memory strength in reality monitoring decisions: evidence from source attribution biases

Reality monitoring of verbal memories was compared with decisions about pictorial memories in this study. Experiment 1 showed an advantage in memory for imagined over perceived words and a bias to respond "perceived" on false alarms. Experiment 2 showed the opposite pattern: an advantage in memory for perceived pictures and a bias to respond "imagined" on false alarms. Participants attribute false alarms to whichever class of memories has the weakest trace strengths. The relative strength of memories of imagined and perceived objects was manipulated in Experiments 3 and 4, yielding changes in source attribution biases that were predicted by the strength heuristic. All 4 experiments generalize the mirror effect (an inverse relationship between patterns of hits and false alarms commonly found on recognition tests) to reality monitoring decisions. Results suggest that under some conditions differences between the strength of memories for perceived and imagined events, rather than differences in qualitative characteristics, are used to infer memory source.