Sequential dependencies in driving

The effect of recent experience on current behavior has been studied extensively in simple laboratory tasks. We explore the nature of sequential effects in the more naturalistic setting of automobile driving. Driving is a safety-critical task in which delayed response times may have severe consequences. Using a realistic driving simulator, we find significant sequential effects in pedal-press response times that depend on the history of recent stimuli and responses. Response times are slowed up to 100 ms in particular cases, a delay that has dangerous practical consequences. Further, we observe a significant number of history-related pedal misapplications, which have recently been noted as a cause for concern in the automotive safety community. By anticipating these consequences of sequential context, driver assistance systems could mitigate the effects of performance degradations and thus critically improve driver safety.     

目标性意图与执行性意图调节情绪反应的效果比较

目标性意图和执行性意图作为目标的不同形式,对情绪调节的影响有待探讨。本研究试图考察目标性意图和执行性意图与表达抑制相结合之后,在调节情绪反应方面的作用。实验采用主观报告和生物反馈的方法对58名大学生进行测试。结果发现：（1）执行性意图组被试在观看负性和中性图片时对自身情绪唤醒度的评价均显著低于目标性意图组,在观看负性图片时其情绪唤醒度也显著低于控制组。（2）执行性意图组被试在各项生理反应指标上均显著低于目标性意图组和控制组,主要表现为形成执行性意图的个体在皮肤电导增加量、皮温降低量和指脉增加量上均显著低于形成目标性意图或不形成任何意图的个体。上述结果表明,相较于仅仅给出情绪体验下调目标的目标性意图,与表达抑制结合在一起的执行性意图能有效下调个体的负性情绪反应。     

Informational constraints shape emergent functional behaviours during performance of interceptive actions in team sports

Objectives

This study aimed to explain how defenders intercept the trajectory of a passing ball by understanding how they coupled their actions to critical information sources in a competitive performance setting in team sports.

Design

Time series data on movement displacements of fifteen senior male futsal performers were recorded and digitized during nine competitive futsal games.

Method

Performance was recorded by a digital camera and digitized with TACTO software. The spatial-temporal dynamics of performers during ten intercepted and ten non-intercepted passes were compared. Time to ball interception was calculated by the difference between the time of each defender to an interception point in ball trajectory and the time of the ball’s arrival at the same interception point. Initial distances between defenders and ball and velocity data of defenders and ball over time were also recorded.

Results

Time to ball interception revealed positive values when passes were not intercepted, and negative to zero values when passes were intercepted. At the moment of pass initiation defenders’ distances to the ball constrained their possibilities for successful interception. Analysis of defenders’ adaptations to the environment revealed that continuous changes in the defenders’ velocities constrained their success of the interception.

Conclusions

Intercepted passes seemed to be influenced by the continuous regulation of a defender’s velocity relative to the ball’s trajectory. Time to ball interception is a variable that captured the emergent functional behaviours of players attempting to intercept the trajectory of a pass in the team sport of futsal.     

On the law of Regular Minimality: Reply to Ennis

Ennis's critique touches on issues important for psychophysics, but the points he makes against the hypothesis that Regular Minimality is a basic property of sensory discrimination are not tenable.(1) Stimulus variability means that one and the same apparent stimulus value (as measured by experimenter) is a probabilistic mixture of true stimulus values. The notion of a true stimulus value is a logical necessity: variability and distribution presuppose the values that vary and are distributed (even if these values are represented by processes or sets rather than real numbers). Regular Minimality is formulated for true stimulus values. That a mixture of probabilities satisfying Regular Minimality does not satisfy this principle (unless it also satisfies Constant Self-Similarity) is an immediate consequence of my 2003 analysis. Stimulus variability can be controlled or estimated: the cases when observed violations of Regular Minimality can be accounted for by stimulus variability corroborate rather than falsify this principle. In this respect stimulus variability is no different from fatigue, perceptual learning, and other factors creating mixtures of discrimination probabilities in an experiment.(2) Could it be that well-behaved Thurstonian-type models are true models of discrimination but their parameters are so adjusted that the violations of Regular Minimality they lead to (due to my 2003 theorems) are too small to be detected experimentally? This is possible, but this amounts to admitting that Regular Minimality is a law after all, albeit only approximate: nothing in the logic of the Thurstonian-type representations per se prevents them from violating Regular Minimality grossly rather than slightly. Moreover, even very small violations predicted by a given class of Thurstonian-type models can be tested in specially designed experiments (perhaps under additional, independently testable assumptions). The results of one such experiment, in which observers were asked to alternately adjust to each other the values of stimuli in two observation areas, indicate that violations of Regular Minimality, if any, are far below limits of plausible interpretability.     

Effects of diazepam on schedule-controlled and schedule-induced behavior under signaled and unsignaled shock.

Schedule-controlled lever pressing and schedule-induced licking were studied in rats under a multiple fixed-interval fixed-interval schedule of food reinforcement upon which was superimposed a multiple variable-time variable-time schedule of electric-shock delivery. Shocks were signaled in one component of the multiple schedule and unsignaled in the other. The effects of diazepam upon the suppression of behavior during the signal (conditioned suppression) and during signaled and unsignaled shock (differential suppression) were studied under several shock intensities (Experiment 1) and at increased body weight (Experiment 2). In each study, diazepam led to dose-dependent increases in the rate of pressing and licking during signaled and unsignaled shock, but had little effect on conditioned suppression. the rate-enhancing effects of diazepam depended upon the intensity of shock, nature of the response, and whether or not shocks were signaled. The data was discussed in terms of (1) implications for understanding the effects of signaled and unsignaled shock on behavior, (2) the effects of diazepam on behavior suppressed by response-independent shock, and (3) comparison between operant and schedule-induced behavior.     

Schedule-induced defecation.

Excessive defecation, typically considered to be a concomitant of stress, was experimentally induced or eliminated under specific schedules of positive reinforcement of lever pressing by rats. The schedules were, by and large, those under which polydipsia is typically induced. In the first of three experiments, rats under fixed-interval 32-second schedules and variable interval 32-second schedules for food and water reinforcers defecated profusely, but not under fixed-interval one-second schedules or other small interval schedules. Somewhat higher rates of defecation were observed on variable interval 32-second schedules than on fixed-interval 32-second schedules. In a second experiment, fixed-ratio schedules were used, some of which resulted in responding such that reinforcement densities were similar to those on the interval schedules that induced defecation. Defecation was not systematically induced by these ratio schedules. In a third experiment, fixed-time schedules of food presentations were utilized. High rates of defecation were induced comparable to those induced by interval schedules of the same time parameter. No other behavior commonly termed "emotional" was observed in any of these experiments.     

THE EXPERIMENTAL MODIFICATION OF SONOROUS BREATHING

Loud snoring is a noxious habit and potential personal health risk. We are reporting the first experimental study of simple behavioral techniques for the modification of chronic snoring. Twenty-four volunteers participated in a repeated measures, randomized group design over 2 weeks of intervention and one-month follow-up. Treatment groups included a contingent-awakening and breathing retraining (self-control) condition. Both treatment groups were compared to a no-treatment control. Despite considerable intrasubject variability and the lack of an adequate attention-placebo control group, objective assessment indicated a substantial reduction in snoring amplitude and frequency in both treatment groups. Follow-up assessments further demonstrated maintenance of change. This study has implications for modification of sleep habit disorders and learning without awareness.     

加工水平对不同类型内隐记忆测试的影响

许多内隐记忆研究表明 ,加工水平影响外显记忆而不影响内隐记忆 ,这样的实验结果被一些研究者认为是外显记忆与内隐记忆系统分离的重要依据之一。实际上 ,内隐记忆研究中的加工水平问题一直存在争议 ,加工水平效应作为两类记忆系统分离的依据是不充分的。在我们的这项实验中 ,结果表明 ,加工水平影响概念样例生成这种内隐记忆测试而不影响知觉辨认测试。     

Estimates of shape by eye, or, The little invariant that could

Five experiments were conducted to test the hypothesis that observers apprehend specific constancies under change in perspective. The constancies were projective properties of ellipses pictured to slant and tilt in depth. Observers were asked to reproduce the static upright view of a moving pair of ellipses, using a computer graphics display and interface. Projective invariants for pairs of conics were computed on the observers’ productions. A few experimental conditions revealed near-perfect performance. When pairs of coplanar ellipses were viewed under dynamic transformation in perspective, then invariants calculated on the observers’ productions were a match – in value on average – to the invariants of the transforming ellipse pairs. It is proposed that measures of projective properties afford a family of techniques that can be applied to gauge acuity for complex shapes in the study of visual form perception.     

Attenuation of latent inhibition after compound conditioning

Using a conditioned suppression procedure with rats, three experiments examined the effects of compound conditioning on the degree of latent inhibition. Experiment 1 suggested that latent inhibition of the preexposed target was not enhanced but rather attenuated when a second stimulus was presented in compound conditioning. Experiment 2 showed that a similar result was obtained when, in subjects given only compound conditioning, the salience of the target was reduced to the level where it was overshadowed by the second stimulus. Experiment 3 proved that addition of the second stimulus only during preexposure, or during both preexposure and conditioning, did not attenuate the latent inhibition to the target. These results are difficult to explain by any model of Pavlovian conditioning which assumes that both latent inhibition and overshadowing effects are a consequence of acquisition deà cit; other possible accounts are discussed.