Preference and reinforcer efficacy of high‐ and low‐tech items: A comparison of item type and duration of access

This study examined the interactions of stimulus type (high‐ vs. low‐tech) and magnitude (duration of access) on preference and reinforcer efficacy. Two preference assessments were conducted to identify highly preferred high‐tech and low‐tech items for each participant. A subsequent assessment examined preference for those items when provided at 30‐s and 600‐s durations. We then evaluated reinforcer efficacy for those same items when provided for a range of durations using progressive‐ratio schedules. Results suggested item type and access duration interacted to influence preference and reinforcer efficacy. Participants preferred high‐tech items at longer durations of access and engaged in more responding when the high‐tech item was provided for long durations, but these patterns were reversed for the low‐tech item. In addition, participants engaged in less responding when the high‐tech item was provided for short durations and when the low‐tech item was provided for long durations.     

A wearable vibrotactile biofeedback system improves balance control of healthy young adults following perturbations from quiet stance

Maintaining postural equilibrium requires fast reactions and constant adjustments of the center of mass (CoM) position to prevent falls, especially when there is a sudden perturbation of the support surface. During this study, a newly developed wearable feedback system provided immediate vibrotactile clues to users based on plantar force measurement, in an attempt to reduce reaction time and CoM displacement in response to a perturbation of the floor. Ten healthy young adults participated in this study. They stood on a support surface, which suddenly moved in one of four horizontal directions (forward, backward, left and right), with the biofeedback system turned on or off. The testing sequence of the four perturbation directions and the two system conditions (turned on or off) was randomized. The resulting reaction time and CoM displacement were analysed. Results showed that the vibrotactile feedback system significantly improved balance control during translational perturbations. The positive results of this preliminary study highlight the potential of a plantar force measurement based biofeedback system in improving balance under perturbations of the support surface. Future system optimizations could facilitate its application in fall prevention in real life conditions, such as standing in buses or trains that suddenly decelerate or accelerate.     

表征动量的朝向效应

本研究通过4个实验探索运动物体的朝向对表征动量的影响。4个实验均使用了2(朝向：正向vs.倒向)×2(运动方向：左vs.右/上vs.下)两因素实验设计。前3个实验使用不同的刺激材料进行水平方向的诱导运动, 结果发现, 正向运动的前移量大于倒向运动的前移量, 但这种朝向效应仅仅作用于水平向右方向, 即运动方向水平向左时朝向效应消失。实验4将运动方向改为垂直运动, 结果发现, 正向运动的前移量大于倒向运动的前移量, 但这种朝向效应仅仅作用于垂直向下方向, 即运动方向垂直向上时朝向效应消失。结论：朝向影响表征动量, 但仅作用于水平向右和垂直向下方向上, 前者可能和阅读习惯有关, 后者可能和重力作用有关。     

速度知识和表征动量

通过3个实验探索速度知识和表征动量的关系。3个实验均使用2（速度知识：快、慢）×2（运动方向：左、右）的两因素实验设计,采用诱导运动范式,因变量为偏移加权均数。实验1使用汽车和自行车作为刺激材料,发现两者的前移量无差异;实验2使用人奔跑和站立姿势作为刺激材料,发现奔跑的前移量大于站立的前移量;实验3是控制实验,发现实验2的结果不是由水平视角差异造成的。结论：在有效启动速度概念的情况下,速度知识可以影响表征动量,但其影响可能相对微弱。     

RISKY CHOICE IN PIGEONS AND HUMANS: A CROSS‐SPECIES COMPARISON

Pigeon and human subjects were given repeated choices between variable and adjusting delays to token reinforcement that titrated in relation to a subject's recent choice patterns. Indifference curves were generated under two different procedures: immediate exchange, in which a token earned during each trial was exchanged immediately for access to the terminal reinforcer (food for pigeons, video clips for humans), and delayed exchange, in which tokens accumulated and were exchanged after 11 trials. The former was designed as an analogue of procedures typically used with nonhuman subjects, the latter as an analogue to procedures typically used with human participants. Under both procedure types, different variable‐delay schedules were manipulated systematically across conditions in ways that altered the reinforcer immediacy of the risky option. Under immediate‐exchange conditions, both humans and pigeons consistently preferred the variable delay, and indifference points were generally ordered in relation to relative reinforcer immediacies. Such risk sensitivity was greatly reduced under delayed‐exchange conditions. Choice and trial‐initiation response latencies varied directly with indifference points, suggesting that local analyses may provide useful ancillary measures of reinforcer value. On the whole, the results indicate that modifying procedural features brings choices of pigeons and humans into better accord, and that human—nonhuman differences on risky choice procedures reported in the literature may be at least partly a product of procedural differences.     

An evaluation of the value of choice-making opportunities in single-operant arrangements: simple fixed- and progressive-ratio schedules

The current study compared the effects of choice and no-choice reinforcement conditions on the task responding of 3 children with autism across 2 single-operant paradigm reinforcer assessments. The first assessment employed simple fixed-ratio (FR) schedules; the second used progressive-ratio (PR) schedules. The latter assessment identified the differential strength of choice-making conditions in promoting task responding relative to no-choice conditions for 2 participants; no differential findings were obtained during the FR assessment.     

Further examination of video‐based preference assessments without contingent access

The first purpose of this study was to attempt to replicate previous findings that video‐based preference assessments without access to selected stimuli may accurately predict relative reinforcing efficacy of stimuli. To do this, we conducted a concurrent operant reinforcer assessment in which we evaluated the relative reinforcing value of highly preferred and less preferred items identified in a video‐based preference assessment. The second purpose of this study was to begin to evaluate the potential behavioral mechanisms responsible for the validity of this assessment. To conduct this analysis, we evaluated the relative reinforcing value of those same stimuli depicted in video format and then compared results to results obtained during the reinforcer assessment for tangible stimuli. For all five participants, stimuli identified as highly preferred functioned as reinforcers, and four of five participants, responding during the reinforcer assessment was similar in the presence of tangible stimuli and videos depicting those stimuli.     

Relative preferences for edible and leisure stimuli in children with autism

Prior researchers have reported a tendency for individuals with developmental disabilities to select edible items more often than leisure items when those items are presented together in stimulus preference assessments. However, children with autism spectrum disorders (ASD), with whom many behavior analysts currently practice, are underrepresented in this body of literature. We conducted a replication of prior research with 26 children with ASD. Results indicated that edible items were more likely than leisure items to rank highly in our preference assessments, in concurrence with prior research. However, leisure items were also selected more often overall than in prior research, and significant individual variation was observed. These results suggest that preference assessments containing both edible and leisure stimuli can yield useful information for behavior analysts providing services to children with ASD, and the degree of preference for edible items noted in prior work may not be reflected in this contemporary population.     

Assessing preference for types of social interaction

To date, few researchers have evaluated methods for assessing preference for social interactions. Due to concerns that commonly used stimulus preference assessment methods may be inappropriate, or at least cumbersome, for the assessment of social reinforcers, we developed and evaluated a new method of assessing preference for social interactions. A social interaction preference assessment (SIPA) and a concurrent operant reinforcer assessment were conducted with five participants diagnosed with autism spectrum disorder. A differentially preferred and reinforcing social interaction was identified for all five participants. The SIPA procedures, results, and the implications of these results are discussed.     

飞行场景中表征动量的地标吸引效应和排斥效应

设置了安全和危险两种地标, 采用诱导运动范式考察了飞行场景中运动目标和关联地标的相对关系、目标运动方向及关联地标的意义特征和呈现时间对运动目标位置判断的影响。结果显示: (1)飞行场景中飞机的表征动量较强; (2) 趋近安全地标的表征动量大于远离安全地标的表征动量, 趋近危险地标的表征动量小于远离危险地标的表征动量, 安全地标呈现出地标吸引效应, 而危险地标呈现出地标排斥效应; (3) 高关联的安全和危险地标使飞机的表征动量不受运动方向影响; (4) 保持间隔期间呈现的安全和危险地标使飞机的表征动量增加。结论 :表征动量的地标效应受制于地标意义特征, 表征动量受到目标和地标之间的因果关系和情景意义的影响。