执行意向影响事件性前瞻记忆的加工机制

本研究旨在探究不同执行意向编码形式对前瞻记忆加工机制的影响是否存在差异。结果显示在低认知负荷下,混合编码效果最好,仅执行意向编码次之,标准编码效果最差,而在高认知负荷下三种编码效果无差异。眼动指标显示在低认知负荷下混合编码的注视点数量最多,总注视时间最长;在混合编码条件下进行中任务和前瞻记忆任务的总注视时间均长于仅执行意向编码和标准编码。结果说明,执行意向编码容易受认知负荷的影响;在低认知负荷下混合编码的被试对任务刺激进行更多的监控和加工,而仅执行意向编码促进前瞻记忆任务的自动化加工。     

时间性前瞻记忆的影响因素及机制

时间性前瞻记忆是指个体记得在未来的某一时间或间隔一段时间以后做某事。与事件性前瞻记忆相比, 时间性前瞻记忆需要更多自我启动的注意资源, 并主要受到任务重要性、年龄、进行中任务的性质、时间间隔等因素的影响。时间性前瞻记忆主要与额叶有关, 对于其内部认知机制解释的理论模型主要有测试-等待-测试-退出模型以及注意阀门模型。但是时间性前瞻记忆的影响因素以及机制, 尤其是神经机制方面尚需要进一步的研究。     

Sample-stimulus discriminability and sensitivity to reinforcement in delayed matching to sample

Five pigeons were trained in a delayed matching-to-sample task with red and green stimuli. The retention interval between sample-stimulus presentation and the availability of the choice stimuli was varied between 0.01 s and 12 s within each session. The probability of food produced by correct-red and correct-green responses was varied across conditions. Sample-stimulus discriminability and response bias were measured at four different retention intervals. The results of these analyses showed an interaction between the discriminability of the sample stimuli and the control exerted by differential reinforcement. At longer retention intervals, sample discriminability decreased and sensitivity of choice behavior to changes in the red/green reinforcer ratio increased. An analogous relation has been reported in conditional discriminations in which the physical disparity of stimuli has been varied. This correspondence suggests that increasing the delay between presentation of one of two stimuli and an opportunity to respond discriminatively to it may be functionally similar to increasing the physical similarity of the two stimuli.     

Delayed stimulus control: recall for single and relational stimuli.

In a discrete-trial symbolic matching-to-sample procedure, pigeons' left-key responses were reinforced following presentation of one center-key sample, and right-key responses were reinforced following presentation of another. Recallability was measured by the difference between log ratios of left to right responses following each sample. In Experiment 1, samples were successively presented same or different wavelengths in the relational discrimination, or individual wavelengths in the single discrimination. The rate at which recallability decreased with increasing delay since sample presentation was the same for single and relational discriminations, but the initial level of performance differed, indicating that the relational discrimination was more difficult. In Experiment 2, recall functions for easy and difficult discriminations between individual wavelengths also differed in levels of initial performance but not in rate of decrement of recallability over time. Recall for stimuli differing in complexity may therefore reflect differences in discrimination difficulty.     

A ten-year prospective study of aggression in a special secure unit for dangerous patients

In a 10-year prospective study inpatient aggression was investigated in a Norwegian special secure unit covering a well-defined catchment area with a population of 240,000. The seven bed special secure unit receives dangerous, psychotic patients for long-term treatment. Only 19 patients were treated during the ten-year study lasting from 1 April 1987 to 1 April 1997. Incidents of aggressive behavior were recorded on the Report Form for Aggressive Episodes by the nursing staff. The study aimed to identify, classify and measure the occurrence of aggressive behavior, as well as the relative frequency of events preceding such behavior. A total of 2021 incidents of aggressive behavior were recorded. Seventy-five per cent of the aggressive acts were verbal or physical threats, while the remaining 25% were physical assaults directed at other persons. Four patients accounted for about 80% of the aggressive encounters. Nursing staff were victims in about 90% of the incidents. Serious physical injury was extremely rare. Situations pertaining to limit-setting and problems of communication accounted for approximately 90% of the precipitants of aggressive behavior. There were no sex differences regarding the occurrence of aggressive behavior.     

Establishing auditory stimulus control over an eight-member equivalence class via conditional discrimination procedures

Two eight-member equivalence classes of visual stimuli were established during three phases of a training program. In Phase 1, two training arrangements were compared. In one, 3 subjects were taught on different trials to select from a single pair of comparison stimuli (A1, A2) in response to eight sample stimuli that were trained in pairs (B1, B2; C1, C2; D1, D2; E1, E2). In the second arrangement, subjects were taught to select from four pairs of comparisons (B1, B2; C1, C2; D3, D2; E2, E2) in response to two samples (A1, A2). Training with the single pair of comparison stimuli resulted in the development of equivalence relations (B1C1, B2C2, D1B1, D2B2, B1E1, B2E2, C1D1, C2D2, C1E1, C2E2, D1E1, D2E2, and their reciprocals) between the sample stimuli without direct training of these relations. In the other training arrangement, these relations among the comparison stimuli developed in the performance of 1 subject only. In Phase 2, three new pairs of stimuli (F1, F2; G1, G2; H1, H2) were substituted for three of the original pairs (B1, B2; C1, C2; D1, D2) and the training arrangements for the groups were reversed. Following training, the performances that showed equivalence relations on the probes in the first phase also showed equivalence relations in the second phase. If such relations did not develop in the first phase, they did not do so in the second phase. In Phase 3, relations between stimuli across the two previous phases (e.g., B1F1, B2F2, B1G1, B2H2, C1F1, etc.) were investigated. The 4 subjects whose performances showed the development of these relations were taught to select one stimulus from each class (E1 and E2) in response to a verbal label (I1 and I2) and then were tested to see if the verbal label controlled responding to the remaining members of the class (e.g., I1A1, I2A2, I1B1, I2B2, etc.). For 3 subjects, this generalized control occurred; for the 4th, generalization occurred only after verbal training with a second pair of visual stimuli (F1 and F2). In retests several months later, these auditory-visual relations were found to be intact or, if not, were recovered without direct training.     

Short-term remembering of discriminative stimuli in pigeons.

Pigeons learned to peck the left or right of two white keys depending on whether a red or a green stimulus was displayed on a third key. The opportunity to peck the white keys was then dealyed for zero to six seconds after the red or green (to-be-remembered) stimulus. On half the trials, the feeder operated during the delay to interrupt behavior that might mediate discriminated responding. No events were scheduled on the remaining trials. In a later condition, the pigeons had the opportunity to peck the white keys during the delay. In general, accuracy decreased as delay increased in all conditions, but performance was least accurate following feeder operations and most accurate when pecking was allowed during the delay. The procedures may be analogous to varying the opportunity for rehearsal in studies of human short-term memory.     

前瞻记忆的字形、语音TAP效应研究

本研究采用单因素实验设计,以30名大学生为被试,基于双重任务范式,考察了前瞻任务为材料驱动的情况下,前瞻记忆语音、字形适当迁移加工(transfer—appropriate processing,TAP)效应。结果发现：TAP效应对前瞻记忆的辨别力指标和传递效率的影响达到了显著性水平,而对于前瞻记忆判断标准的影响未达到显著水平。     

焦虑情绪和年龄因素对前瞻记忆成绩影响的研究

本研究使用了嵌入焦虑量表和前瞻记忆自评问卷的前瞻记忆测验材料．对85名初中学生和152名大学生分别进行测试。结果发现,不同水平的焦虑情绪对前瞻记忆没有显着影响．但对前瞻记忆自我评价影响显着。从年龄因素上看,大学生的前瞻记忆成绩高于初中学生。     

情绪刺激对前瞻记忆的影响

使用情绪图片作为背景任务刺激,通过两个实验来考察积极情绪和消极情绪对时间性和事件性前瞻记忆的影响。结果发现,对于背景任务的反应时,在时间性前瞻记忆和事件性前瞻记忆中,情绪的主效应都显著。而对于前瞻任务的正确率,在两种前瞻记忆中,情绪的主效应都不显著。将两个实验的数据合并分析发现,对于前瞻任务的正确率,任务类型的主效应显著,即时间性前瞻记忆的成绩显著高于事件性前瞻记忆; 而情绪的主效应不显著。结果表明,背景任务中不同的情绪刺激会对个体完成背景任务的速度产生影响,而对前瞻记忆任务的执行不会产生影响。