Effects of two teacher-presentation rates on off-task behavior, answering correctly, and participation

Off-task behavior, correct answering, and participation during beginning reading instruction were recorded for two low-achieving first-grade children during two different rates of teacher presentation. A slow-rate presentation (A) was compared with a fast-rate presentation (B) in an ABABAB design. In slow-rate presentation, there was a delay between the children's response and introduction of the next task. In fast-rate presentation, there was no delay. A new teacher taught during the final AB phases, which allowed for a brief replication. Both teachers were reminded on a fixed-interval 90-sec schedule throughout all phases of the experiment to praise the subjects, thus preventing a confounding of social praise and rate of teacher presentation. Fast-rate presentation was accompanied by a lower per cent occurrence of off-task behavior for both Subjects 1 and 2. For Subject 1, correct answering and participation were more frequent during all three fast-rate phases. For Subject 2, correct answering and participation were more frequent during the fast-rate phases after the first reversal.     

Dimensional stimulus control following brief wavelength training

Pigeons with extensive training pecking a key illuminated by a white line then had brief training with the key illuminated by 555 nanometers. This was immediately followed by a wavelength generalization test in extinction. Dimensional stimulus control about the training wavelength increased with the duration and number of reinforcements given on variable-interval 30-sec and variable-interval 10-sec schedules in Experiment I. In Experiment II, dimensional stimulus control was obtained after only 4 min of wavelength training from birds with prior and independent discrimination training. Experiment III provided groups equated in number of reinforcers with groups in Experiment I and two 8-min duration groups. Analyses, which included results from both Experiments I and III, showed that dimensional stimulus control increased: (a) more rapidly as a function of the duration of variable-interval 10-sec than variable-interval 30-sec reinforcement; (b) at the same rate across variable-interval reinforcement schedules, as a function of the number of reinforcers available during brief wavelength training.     

Stimulus control of differential-reinforcement-of-low-rate responding

Five pigeons were given single-stimulus training on an 8-sec differential-reinforcement-of-low-rate schedule followed by steady-state generalization training using 12 wavelength stimuli. Three birds had a high percentage of reinforced responses on the training schedule and flat generalization gradients of total responses. The birds with fewer reinforced responses had much steeper generalization gradients. Generalization gradients plotted as a function of both stimulus wavelength and interresponse time showed that for most birds, stimulus control was restricted to responses with long interresponse times. Responses with very short interresponse times were not under stimulus control and there was some evidence of inhibitory control of short interresponse times. Interresponse-times-per-opportunity functions, plotted as a function of stimulus wavelength, showed that stimulus wavelength controlled the temporal distribution of responses, rather than the overall rate of response. The data indicate that the differential-reinforcement-of-low-rate schedule generates several response categories that are controlled in different ways by wavelength and time-correlated stimuli, and that averaging responses regardless of interresponse-time length obscures this control.     

On computing time-to-collision for automation scenarios

Time to collision (TTC) has been a key vehicle safety metric for decades. With the increasing prevalence of advanced driver assistance systems and vehicle automation, TTC and many related metrics are being applied to the analysis of more complicated scenarios, as well as being integrated into automation algorithms. While the TTC metric was originally conceived to be inclusive of generic two-dimensional situations, its applications has been mostly limited to one-dimensional scenarios. This paper derives general equations and algorithms using two-dimensional information. Additionally, methods from computational geometry, a field that didn’t exist when TTC was first used, are employed for the general case of computing TTC between bounding boxes. Parametric equations for lines play a prominent role and offer an elegant way to express the geometry of the scenarios described in this paper. Throughout, the approach is not to derive specific algebraic conditions as in previous efforts. Rather, the focus in on developing general algorithms for computation. The techniques presented are not necessary for traditional car following scenarios; but offer options for more complex situations that trade off analytic solutions for computational flexibility.     

Murray Sidman: fostering progress through foundational choices

The contributions of Murray Sidman to the field of behavior analysis have helped to put the field on a progressive path. In this paper we describe three areas as examples, drawn from the larger set of his notable contributions: the analysis of stimulus equivalence in a way that has fostered a behavior-analytic approach to derived stimulus relations and symbolic meaning; the observation and measurement of individual behavior through time; and his stance against punitive applied methods. In each of these areas Sidman was a dedicated behaviorist, avoiding appeals to mentalistic or transcendental forces, opposing hypothetical mediational accounts, and taking a functional and contextual approach. Clarity of assumptions was at the heart of Sidman's effective scientific practices and there is no reason to think that those same assumptions will not carry us further, as evidence mounts in support of these views on psychological research and practice.     

Training sequence effects on emergent conditional discriminations: Replication and extension to selection-based training

We examined the replicability and generality of a previously reported training sequence effect on emergent conditional discriminations in the intraverbal naming task. In Experiment 1, a tact–intraverbal (TI) group learned first to vocally label 6 visual patterns and then to intraverbally relate pairs of verbal labels, whereas an intraverbal–tact (IT) group received the same training in the opposite sequence. Emergent conditional discriminations among pattern stimuli were assessed in match-to-sample (MTS) format. Experiment 2 was identical, except vocal tact and intraverbal training were replaced with selection-based training in which the verbal labels were text stimuli. Compared to the IT sequence, the TI sequence resulted in greater mean accuracy at test (Experiment 1), higher yields (Experiment 2), and shorter reaction times (Experiment 2). Experiment 2 data suggested the TI group's performance might be less dependent on intact intraverbal relations relative to the IT group, but related to participants' reports of visualization during intraverbal training. The results suggest the sequence effect is replicable and occurs in experimental preparations commonly used to study derived stimulus relations. They also provide novel support for the hypothesis that participant behavior during training alters sources of stimulus control available at test.     

激活水平和呈现方式对错误记忆的影响

随机抽取80名大学生参与实验,采用DRM(Deese-Roediger-Mcdermott)范式,探讨了激活水平和呈现方式对错误记忆的影响。结果发现:(1)在随机呈现条件下,关键诱饵的错误再认率显著低于分组呈现条件,但学过项目的正确再认率在两种条件下无差异。(2)在高激活水平条件下,学过项目的正确再认率明显低于低激活水平条件,但关键诱饵的错误再认率在两种激活条件下的差异不够明显。这表明,呈现方式对关键诱饵的错误再认率有显著影响,而激活水平的影响则不显著。由此可知,人们的记忆可以在没有任何外界信息干扰的情况下因内在联想过程而自发地发生改变。     

The social dynamics involved in recovery and return to sport following a sport-related concussion: A study of three athlete-teammate-coach triads

An athlete's connection to their team and team members is an important part of their sport experience. However, researchers currently know little about the nature of these social dynamics with respect to concussed athletes. Our study explored athletes' recovery and reintegration into the team environment following a sport-related concussion. We conducted semi-structured interviews with each member of three athlete-teammate-coach triads (N = 9). We analysed the data using thematic narrative analysis and present the results as three stories that focused on each athlete's experience. For Cassie, we found two major plot points in her story: the transition in her role (and shift in identity) from athlete to student assistant coach/team manager and, once recovered, back to an athlete on the team. For Jess, we found that the main plot in her story was “pressure”. Specifically, the interplay between internal (placed on herself) and external (perceived from teammates and coaches) pressures to return to sport. In the third and final story, the main plot point was the tensions that arose from Jaden's preferences for social support and the type of support that his teammates and coaches believed he needed during his recovery. Our results highlight the interplay between athlete's personal and social identities, feelings of pressure to return and readiness, and the challenges of providing the right amount and type of social support. This research contributes to our limited understanding of the social dynamics involved in athletes' return to sport following a concussion.