大鼠注意定势转移任务模型的深入研究：种系和检测程序的影响

注意定势转移任务(attentional set-shifting task, AST)可用于特异性检测啮齿类动物前额叶皮层及其皮层下神经通路介导的认知灵活性, 是目前研究认知灵活性及其障碍神经基础的重要模型。本研究系统调查了大鼠种系和检测程序差异对AST结果的影响。通过比较Wistar和Sprague Dawley (SD)两个种系大鼠在七阶段和五阶段两种AST检测程序中的认知表现, 研究发现：(1) SD和Wistar大鼠前额叶认知功能存在差异, 后者的总体认知表现优于前者。尤其是Wistar大鼠在逆反学习阶段的达标训练次数及错误率显著低于SD大鼠, 表明Wistar大鼠具有更高的策略转换灵活性。(2)在AST测试中逆反学习和外维度定势转移是认知灵活性评价的核心指标。这两种认知转换过程分别以前期策略和注意定势建立为基础。结果显示在两种AST检测程序中Wistar和SD大鼠在逆反学习和/或外维度定势转移等复杂学习阶段的达标训练次数和错误率均高于其它简单关联学习阶段, 表明在目前实验条件下大鼠均表现出定势形成和转换困难的反应模式, 不同认知反应间的结构关系具有稳定性。这些结果提示大鼠前额叶皮质介导的认知灵活性存在种系差异, AST各阶段认知反应间的结构效度不受目前使用的大鼠种系和检测程序差异的影响, 扩展了对AST模型的认识。     

Parametric induction of animacy experience

Graphical displays of simple moving geometrical figures have been repeatedly used to study the attribution of animacy in human observers. Yet little is known about the relevant movement characteristics responsible for this experience. The present study introduces a novel parametric research paradigm, which allows for the experimental control of specific motion parameters and a predictable influence on the attribution of animacy. Two experiments were conducted using 3D computer animations of one or two objects systematically introducing variations in the following aspects of motion: directionality, discontinuity and responsiveness. Both experiments further varied temporal kinematics. Results showed that animacy experience increased with the time a moving object paused in the vicinity of a second object and with increasing complexity of interaction between the objects (approach and responsiveness). The experience of animacy could be successfully modulated in a parametric fashion by the systematic variation of comparably simple differential movement characteristics.     

Dissociations among ABA, ABC, and AAB recovery effects

In a human predictive learning experiment, the strengths of ABA, ABC, and AAB recovery effects after discrimination reversal learning were compared. Initially, a discrimination between two stimuli (X+, Y−) was trained in Context A. During Phase 2, participants received discrimination reversal training (X−, Y+) either in Context A (Group AAB) or in Context B (Group ABA, Group ABC). Testing occurred in the reversal context and in a neutral context (Group AAB, Group ABC) or in the reversal context and in the acquisition context (Group ABA). Recovery effects were similar in ABA and ABC procedures, whereas no AAB recovery effect occurred. Furthermore, the rate of discrimination reversal learning during Phase 2 was unaffected by whether training was conducted in the same or in a different context as initial learning. Results indicate that contextual stimuli are processed before interfering information is presented. These representations, however, do not acquire the ability to control performance.     

A Note on the Aesthetics of Mirror Reversal

According to Roy Sorensen [Philosophical Studies 100 (2000) 175–191] an object cannot differ aesthetically from its mirror image. On his view, mirror-reversing an object – changing its left/right orientation – cannot bring about any aesthetic change. However, in arguing for this thesis Sorensen assumes that aesthetic properties supervene on intrinsic properties alone. This is a highly controversial assumption and nothing is offered in its support. Moreover, a plausible weakening of the assumption does not improve the argument. Finally, Sorensen’s second argument is shown to be formally flawed. As a result, the case for the aesthetic irrelevancy of orientation seems still open.     

Mom’s shadow: structure-from-motion in newly hatched chicks as revealed by an imprinting procedure

The ability to recognize three-dimensional objects from two-dimensional (2-D) displays was investigated in domestic chicks, focusing on the role of the object’s motion. In Experiment 1 newly hatched chicks, imprinted on a three-dimensional (3-D) object, were allowed to choose between the shadows of the familiar object and of an object never seen before. In Experiments 2 and 3 random-dot displays were used to produce the perception of a solid shape only when set in motion. Overall, the results showed that domestic chicks were able to recognize familiar shapes from 2-D motion stimuli. It is likely that similar general mechanisms underlying the perception of structure-from-motion and the extraction of 3-D information are shared by humans and animals. The present data shows that they occur similarly in birds as known for mammals, two separate vertebrate classes; this possibly indicates a common phylogenetic origin of these processes.     

Influence of two types of information trials on the formation of a discrimination-reversal learning set in Japanese monkeys

Abstract: Three groups of male adult Japanese monkeys were trained in 30 discrimination-reversal learning-set (LS) problems using the Wisconsin General Test Apparatus. A control group ( N = 3) was trained in the standard procedure: acquisition of up to 12 consecutive correct responses, reversal to the same criterion, and then shift to a new problem. To the other two groups, three information trials signaling the stimulus value in reversal were given after they reached the criterion in acquisition. Subjects in the positive-stimulus information (PSI) group ( N = 4) were exposed only to the reversal positive stimulus, and a response to it was rewarded. Subjects in the negative-stimulus information (NSI) group ( N = 4) were exposed only to the reversal negative stimulus, and any response to it was not rewarded. Information trials reduced reversal errors and NSI trials were more effective than PSI trials in error reduction ( p < .05). Information trials also aided in acquisition: the NSI and PSI groups learned the acquisition phase of the problems with significantly fewer errors than control group ( p < .01) in the last stage of training. The implications of these results are discussed in relation to strategy learning and attention learning in LS formation.     

Perceptual unit formation in simple motion patterns

The present study investigated the proximal constraints that determine perceptual unit formation under minimal stimulus conditions. Projections of three moving dots, which could form two possible two-dot configurations, were presented to naive observers. In a forced-choice situation, their task was to report which two-dot configuration was perceived as a distinct perceptual unit. The results showed that common motions (arbitrary translations and rigid rotations in the frontoparallel plane) have stronger grouping power as compared to different relative motions (expansions/contractions, or simultaneous expansions/contractions and deformations in the frontoparallel plane). It was found that proximal changes of distances between elements in two-dot structures reduce grouping power. Changes of proximal directions, however, did not affect unit formation in two-dot structures at all. The effect of vector algebraic combinations on grouping power in three-dot strutures was also investigated. Evidently, visual vector analysis splits up motion combinations into their constituents, and in come cases this contributes to additive effects.     

Relax and try this instead: abbreviated habit reversal for maladaptive self-biting.

We evaluated the effectiveness of an abbreviated habit reversal procedure to reduce mal-adaptive oral self-biting in an adolescent boy in residential care. Treatment involved a combination of relaxation and two competing responses. Results of a withdrawal design and two posttreatment medical evaluations indicated that the intervention eliminated the biting and the tissue damage it caused.     

MODIFYING LETTER AND NUMBER REVERSALS IN ELEMENTARY SCHOOL CHILDREN1

Children from regular and special-education classes were exposed to tutoring procedures designed to modify letter and number reversals. In Experiment I, two students showed reversals during letter-naming (e.g., saying p for q) and two-digit number (e.g., writing 31 for 13) exercises. In Experiment II, one subject made two-digit reversals, while the other child reversed single-digit numbers (e.g., 9 written with circle on right side of stem). The subject in Experiment III emitted letter reversals under naming, dictation, and copying exercises. The child in Experiment IV showed written letter reversals on both sides of the “body midline” under dictation procedures. Basic treatment procedures during all experiments involved modelling of correct and incorrect symbol formation, and differential experimenter feedback following student responses. During Experiments I and II, subjects were praised for each correct response, and informed when a reversal occurred. Experiment III included a Modelling Only Phase before these feedback procedures. Besides praise, treatment conditions in Experiment IV consisted of additional feedback following correct responses (e.g., charting correct responses), and temporal delays imposed between dictated letters and student responses. Except for occasional letter-naming reversals of one subject (Experiment I), and letter dictation errors of another (Experiment IV), reversals were eliminated when all experiments terminated. The Modelling Only Phase in Experiment III also reduced reversals to a low level. These findings suggest that a variety of reversal problems may be effectively assessed and remediated via simple modelling and reinforcement procedures. In addition, postcheck observations indicated that the effects were enduring. The present procedures should be easily implemented by school personnel.     

Sensitivity to reinforcer duration in a self-control procedure

In a concurrent-chains procedure, pigeons' responses on left and right keys were followed by reinforcers of different durations at different delays following the choice responses. Three pairs of reinforcer delays were arranged in each session, and reinforcer durations were varied over conditions. In Experiment 1 reinforcer delays were unequal, and in Experiment 2 reinforcer delays were equal. In Experiment 1 preference reversal was demonstrated in that an immediate short reinforcer was chosen more frequently than a longer reinforcer delayed 6 s from the choice, whereas the longer reinforcer was chosen more frequently when delays to both reinforcers were lengthened. In both experiments, choice responding was more sensitive to variations in reinforcer duration at overall longer reinforcer delays than at overall shorter reinforcer delays, independently of whether fixed-interval or variable-interval schedules were arranged in the choice phase. We concluded that preference reversal results from a change in sensitivity of choice responding to ratios of reinforcer duration as the delays to both reinforcers are lengthened.