Short-term memory in the pigeon: the previously reinforced response

Eighteen pigeons served in a discrete-trials short-term memory experiment in which the reinforcement probability for a peck on one of two keys depended on the response reinforced on the previous trial: either the probability of reinforcement on a trial was 0.8 for the same response reinforced on the previous trial and was 0.2 for the other response (Group A), or, it was 0 or 0.2 for the same response and 1.0 or 0.8 for the other response (Group B). A correction procedure ensured that over all trials reinforcement was distributed equally across the left and right keys. The optimal strategy was either a winstay, lose-shift strategy (Group A) or a win-shift, lose-stay strategy (Group B). The retention interval, that is the intertrial interval, was varied. The average probability of choosing the optimal alternative reinforced 80% of the time was 0.96, 0.84, and 0.74 after delays of 2.5, 4.0, and 6.0 sec, respectively for Group A, and was 0.87, 0.81, and 0.55 after delays of 2.5, 4.0, and 6.0 sec, respectively, for Group B. This outcome is consistent with the view that behavior approximated the optimal response strategy but only to an extent permitted by a subject's short-term memory for the cue correlated with reinforcement, that is, its own most-recently reinforced response. More generally, this result is consistent with “molecular” analyses of operant behavior, but is inconsistent with traditional “molar” analyses holding that fundamental controlling relations may be discovered by routinely averaging over different local reinforcement contingencies. In the present experiment, the molar results were byproducts of local reinforcement contingencies involving an organism's own recent behavior.     

The relationship between phonological and morphological deficits in Broca's aphasia: further evidence from errors in verb inflection

A previous study of 10 patients with Broca's aphasia demonstrated that the advantage for producing the past tense of irregular over regular verbs exhibited by these patients was eliminated when the two sets of past-tense forms were matched for phonological complexity (Bird, Lambon Ralph, Seidenberg, McClelland, & Patterson, 2003). The interpretation given was that a generalised phonological impairment was central to the patients' language deficits, including their poor performance on regular past tense verbs. The current paper provides further evidence in favour of this hypothesis, on the basis of a detailed analysis of the errors produced by these same 10 patients in reading, repetition, and sentence completion for a large number of regular, irregular, and nonce verbs. The patients' predominant error types in all tasks and for all verb types were close and distant phonologically related responses. The balance between close and distant errors varied along three continua: the severity of the patient (more distant errors produced by the more severely impaired patients); the difficulty of the task (more distant errors in sentence completion>reading>repetition); the difficulty of the item (more distant errors for novel word forms than real verbs). A position analysis for these phonologically related errors revealed that vowels were most likely to be preserved and that consonant onsets and offsets were equally likely to be incorrect. Critically, the patients' errors exhibited a strong tendency to simplify the phonological form of the target. These results are consistent with the notion that the patients' relatively greater difficulty with regular past tenses reflects a phonological impairment that is sensitive to the complexity of spoken forms.     

Sensitivity of time allocation to an overall reinforcer rate feedback function in concurrent interval schedules

Six pigeons were trained on concurrent variable-interval schedules in which feedback functions arranged that the overall reinforcer rate either (a) was independent of preference, (b) decreased with increasing absolute preference, or (c) increased with increasing absolute preference. In Experiment 1, the reinforcer rate in an interreinforcement interval was determined by the absolute time-allocation ratio in the previous interval. When arranged reinforcer ratios were varied, there was no evidence of control over preference by overall reinforcer rate. In Experiment 2, the feedback function arranged that reinforcer rates were an inverse function of absolute preference, and window durations were fixed times. In Phase 1, using schedules that provided a four-to-one reinforcer ratio, the window duration was decreased from 20 s to 5 s over four conditions. Then, in Phases 2 and 3, the arranged reinforcer ratios were varied. In Phase 2, the reinforcer rate in the current 5-s time window was determined by preference in the previous 5-s window, and in Phase 3, the window durations were 20 s. Again, there was no indication of control by obtained overall reinforcer rate. These data call into question theories that suggest that the process underlying matching is one of maximizing overall reinforcer rates, or that preference in concurrent aperiodic schedules is controlled to any extent by overall reinforcer rate. They also question the notion that concurrent-schedule preference is controlled by molecular maximizing.     

内隐序列学习表征方式的实验研究

采用Lewicki等人创造的“矩阵扫描”任务,对内隐序列学习的表征方式进行了研究。结果发现：规则试验的反应时显著低于随机试验,说明被试能够内隐地掌握复杂规则,没有证据表明这与“运动”频率的大小和序列样例的记忆有关;此外,序列结构也是影响内隐序列学习的因素之一。     

情感启动行为研究概述

在西方心理学界,情感启动的研究是近20年来的一个比较活跃的研究领域,研究者们采用多种实验任务和研究方法进行了大量实验,取得了一定的研究成果,证明了人的态度能够被自动激活,并提出了三种对情感启动效应的理论解释：激活扩散机制,反应冲突机制,情感匹配机制。但到目前为止,不同的研究之间仍然存在着一定的分歧。今后的研究应该重点探讨评价自动激活的内在机制,从而促进情感启动的无意识研究。     

有关镜像神经元起源问题上的争论

文章阐述了镜像神经元起源问题上的争论及其最新进展。镜像神经元的独特之处在于,它在动作知觉和动作执行两个阶段皆被激活。这一知觉和操作的匹配机制究竟是怎样形成的?遗传论观点认为镜像神经元的匹配机制是有机体适应环境的结果,由于镜像神经元具有理解他人动作意图的特殊功能,因而被自然选择,通过遗传而得到传递。联结论则主张这种匹配机制只不过是大脑皮层动作神经元对感觉刺激形成的一种条件反射,是个体经验的结果。镜像神经元的"进化-发展观"则采纳渐成论的观点,认为镜像神经元的起源和进化不可能是联结学习单独造就的,而是进化的、生物的、发展性的、社会认知方面的和基于经验的各种因素的联合作用。     

Knowledge with and Without Belief

This article argues for the thesis that the distinction between propositional and doxastic justification should be extended to knowledge. A consequence of this thesis is that there is a type of knowledge that requires belief and a type that does not. A familiar example strikingly similar to the sort of example used to introduce the propositional/doxastic justification makes a prima facie case. Additional theoretical advantages are revealed when the distinction is applied within the context of some recent epistemological debates. These include debates over the knowledge account of assertion, testimonial knowledge, self‐deception, and the question of whether knowledge can be essentially based on falsehood. It is contended that the sort of distinction offered here provides a way to settle these debates and, at the same time, acknowledge what is correct in the opposing positions.     

Encoding instructions and stimulus presentation in local environmental context-dependent memory studies

Murnane and Phelps (1993) recommend word pair presentations in local environmental context (EC) studies to prevent associations being formed between successively presented items and their ECs and a consequent reduction in the EC effect. Two experiments were conducted to assess the veracity of this assumption. In Experiment 1, participants memorised single words or word pairs, or categorised them as natural or man made. Their free recall protocols were examined to assess any associations established between successively presented items. Fewest associations were observed when the item-specific encoding task (i.e., natural or man made categorisation of word referents) was applied to single words. These findings were examined further in Experiment 2, where the influence of encoding instructions and stimulus presentation on local EC dependent recognition memory was examined. Consistent with recognition dual-process signal detection model predictions and findings (e.g., Macken, 2002; Parks & Yonelinas, 2008), recollection sensitivity, but not familiarity sensitivity, was found to be local EC dependent. However, local EC dependent recognition was observed only after item-specific encoding instructions, irrespective of stimulus presentation. These findings and the existing literature suggest that the use of single word presentations and item-specific encoding enhances local EC dependent recognition.     

The Probability of Iterated Conditionals

Iterated conditionals of the form If p, then if q, r are an important topic in philosophical logic. In recent years, psychologists have gained much knowledge about how people understand simple conditionals, but there are virtually no published psychological studies of iterated conditionals. This paper presents experimental evidence from a study comparing the iterated form, If p, then if q, r with the “imported,” noniterated form, If p and q, then r, using a probability evaluation task and a truth‐table task, and taking into account qualitative individual differences. This allows us to critically contrast philosophical and psychological approaches that make diverging predictions regarding the interpretation of these forms. The results strongly support the probabilistic Adams conditional and the “new paradigm” that takes this conditional as a starting point.     

Behavioral control by the response–reinforcer correlation

Using a discrete‐trials procedure, two experiments examined the effects of response–reinforcer correlations on responding while controlling molecular variables that operated at the moment of reinforcer delivery (e.g., response–reinforcer temporal contiguity, interresponse times preceding reinforcement). Each trial consisted of three successive components: Response, Timeout, and Reinforcement, with the duration of each component held constant. The correlation between the number of responses in the Response component and reinforcer deliveries in the Reinforcement component was varied. In the Positive‐correlation condition, a larger number of responses in the Response component programmed a higher reinforcement rate (Experiment 1) or a shorter time to reinforcement (Experiment 2) in the Reinforcement component. Although programmed in this way, the actual reinforcer delivery was dependent on, and occurred immediately after, a response in the Reinforcement component. In the Zero‐correlation condition, the programmed rates of reinforcement (Experiment 1) or the times to reinforcement (Experiment 2) in the Reinforcement component of each trial were yoked to those in the preceding Positive‐correlation condition. Responding in the Response component was higher in the Positive‐ than in the Zero‐correlation condition, without systematic changes in molecular variables. The results suggest that the response–reinforcer correlation can be a controlling variable of behavior.