Continuous versus discrete dimensions of reinforcement schedules: An integrative analysis

An approach to reinforcement-schedule contingencies is presented that accommodates continuous as well as discrete effective dimensions of responses and reinforcers. College students' wheel turning was reinforced by projected reading material according to four schedule contingencies that incorporated either a discontinuous (count) or continuous (duration) dimension of the response and the reinforcer. The contingencies arranged a 1:1 correspondence between (a) response count and consequent stimulus count, (b) response duration and stimulus count, (c) response count and stimulus duration, and (d) response duration and stimulus duration. Contingencies incorporating response count produced moderate to high rates of very short-duration responses. Contingencies incorporating response duration produced very low-rate, long-duration responding. The dimension of the reinforcer had minimal or no additional effect. We suggest that incorporating duration and other continuous dimensions into schedule contingencies may improve our understanding of both laboratory and nonlaboratory behavior.     

Effects of stimulus frequency and reinforcement variables on reaction time

Pigeons pecked at one of two black forms, “+” or “O,” either of which could appear alone on a white computer monitor screen. In baseline series of sessions, each form appeared equally often, and two pecks at it produced food reinforcement on 10% of trials. Test series varied the relative probability or duration of reinforcement or frequency of appearance of the targets. Peck reaction times, measured from target onset to the first peck, were found to vary as a function of reinforcement probability but not as a function of relative target frequency or of reinforcement duration. Reaction times to the two targets remained approximately equal as long as the probability of reinforcement, per trial, was equal for the targets, even if the relative frequency of the targets differed by as much as 19 to 1. The results address issues raised in visual search experiments and indicate that attentional priming is unimportant when targets are easy to detect. The results also suggest that equalizing reinforcement probability per trial for all targets removes differential reinforcement as an important variable. That reaction time was sensitive to the probability but not the duration of reinforcement raises interesting questions about the processes reflected in reaction time compared with rate as a response measure.     

Distinguishing between haloperidol's and decamethonium's disruptive effects on operant behavior in rats: use of measurements that complement response rate.

The behavioral effects of haloperidol (0.04 to 0.16 mg/kg) and nonparalytic doses of decamethonium (0.2 to 0.8 mg/kg) were studied with operant methods that permitted the measurement of response rate, peak force of response, duration of response, and duration of the rat's head entry into the reinforcement dipper well. Type of operant response topography (forelimb press or forelimb grasp-and-pull) and peak force (low or high) required for reinforcement delivery were independent variables. The low-force, press-topography condition yielded qualitatively different profiles for the two drugs. Haloperidol increased peak force and duration of operant response, increased maximum head entry duration, and temporally dissociated forelimb and head entry behavior. Decamethonium decreased force and duration of operant response, did not appreciably affect maximum head entry duration, and did not influence the normal temporal coupling of forelimb and head entry responses. The haloperidol effects were seen as reflections of pseudo-Parkinsonism, not muscle weakness, which appeared to be the primary source of decamethonium's behavioral effects.     

Running and responding reinforced by the opportunity to run: effect of reinforcer duration.

The present study investigated the effect of reinforcer duration on running and on responding reinforced by the opportunity to run. Eleven male Wistar rats responded on levers for the opportunity to run in a running wheel. Opportunities to run were programmed to occur on a tandem fixed-ratio 1 variable-interval 30-s reinforcement schedule. Reinforcer duration varied across conditions from 30 to 120 s. As reinforcer duration increased, the rates of running and lever pressing declined, and latency to lever press increased. The increase in latency to respond was consistent with findings that unconditioned inhibitory aftereffects of reinforcement increase with reinforcer magnitude. The decrease in local lever-pressing rates, however, was inconsistent with the view that response strength increases with the duration of the reinforcer. Response rate varied inversely, not directly, with reinforcer duration. Furthermore, within-session data challenge satiation, fatigue, and response deprivation as determinants of the observed changes in running and responding. In sum, the results point to the need for further research with nonappetitive forms of reinforcement.     

Bar press and bar release as avoidance responses

Two experiments were performed in which rats had to avoid shock by both pressing and releasing a bar within specified intervals. When the release-shock interval was held constant and the press-shock interval was increased, response rate decreased and bar holding increased. When the press-shock interval was held constant and the release-shock interval was increased, both response rate and bar holding decreased.     

Contrast and autoshaping in multiple schedules varying reinforcer rate and duration

Thirteen master pigeons were exposed to multiple schedules in which reinforcement frequency (Experiment I) or duration (Experiment II) was varied. In Phases 1 and 3 of Experiment I, the values of the first and second components' random-interval schedules were 33 and 99 seconds, respectively. In Phase 2, these values were 99 seconds for both components. In Experiment II, a random-interval 33-second schedule was associated with each component. During Phases 1 and 3, the first and second components had hopper durations of 7.5 and 2.5 seconds respectively. During Phase 2, both components' hopper durations were 2.5 seconds. In each experiment, positive contrast obtained for about half the master subjects. The rest showed a rate increase in both components (positive induction). Each master subject's key colors and reinforcers were synchronously presented on a response-independent basis to a yoked control. Richer component key-pecking occurred during each experiment's Phases 1 and 3 among half these subjects. However, none responded during the contrast condition (unchanged component of each experiment's Phase 2). From this it is inferred that autoshaping did not contribute to the contrast and induction findings among master birds. Little evidence of local contrast (highest rate at beginning of richer component) was found in any subject. These data show that (a) contrast can occur independently from autoshaping, (b) contrast assays during equal-valued components may produce induction, (c) local contrast in multiple schedules often does not occur, and (d) differential hopper durations can produce autoshaping and contrast.     

回溯式时间记忆特点的实验研究

实验研究在2个月的时间内探索了回溯式时间记忆的特点,实验选取15个影视片断和8个新闻事件,影视片段播放的时间和新闻事件的发生同期,要求被试回忆影视片段和新闻事件的时点、时距和时序。结果表明：（1）在时序上,影视片段时序的准确性高于新闻事件;在时距上,7分钟和15分钟的准确性高于30分钟,7分钟时距倾向于高估,30分钟时距倾向于低估;在时点上,影视片段的准确性高于新闻事件。（2）时点的回溯式记忆受到被试自我卷入程度的影响。（3）回溯式时距估计受到真实时距的长短和延迟时间长短的交互影响。（4）事件序列关系一般倾向于具有网络层次的特征,在无充足思考时间条件下,倾向于具有线形模型的特征。     

汉语普通话句子重音在时长方面的声学表现

研究包括2部分。在第一部分,通过对由10个发音人发音的148条句子中的4个词时长方面的声学特征的分析发现：（1）当句子重音强调词时,时长的增加主要集中在这个词的重读音节上;（2）当句子重音强调词的某个音节时,时长的延长主要集中在这个音节上。在第二部分,通过使用上述语句的知觉实验发现,句子重音强调词的语句和句子重音强调这个词的重读音节的语句相对于它们的语境是可以相互替换的, 这种相互可替换性起因于这两种语句声学表现方面的相似性     

几何解题过程的眼动及视觉工作记忆模型:OGRE模型

简要介绍了一个几何解题过程的眼动及视觉工作记忆模型——跟动的几何推理引擎模型（OGRE）,对该模型的特点及其在其它认知过程中的应用进行了讨论。     

科普杂志目录编排效果的眼动研究

该研究探讨了读者在阅读科普杂志目录时的眼动特征。实验仪器为美国应用科学实验室生产的Model504型眼动仪。实验设计为2(插图颜色:彩色、黑白)×2(插图注解:有、无)×2(文字颜色:黑、蓝)。被试为大学生。研究发现:(1)被试对彩色插图的注视时间和注视次数比黑白插图的多;(2)被试对有注解的插图注视时间和注视次数要比无注解插图的多。实验结果表明,所阅读目录中的信息量决定读者的注意力。