Reaction time to a second stimulus as a function of intensity of the first stimulus

Reaction time (RT) to the second of two stimuli presented in rapid succession was examined as a function of the intensity of the first stimulus (S₁). It was found that the delay in RT₂ was greater following a dim first stimulus than following a bright first stimulus. The magnitude of this increase corresponded to the difference in RTs to the two intensity levels of S₁. These results support the prediction of a single channel model of response selection. Examination of mean first RTs revealed a general elevation in latency of RT. However, since this increase was not influenced by the inter-stimulus interval (ISI) or by the intensity of the second stimulus (S₂), and since the same increase was found on “catch trials“ where no S₂ was presented, this increase is considered to be a function of change in set in the double response situation.     

Semantic distinctions and memory for complex sentences

This investigation studied what people remember in recalling complex sentences, whether it is certain semantic distinctions or merely transformational markers. After short intervals 24 subjects tried to recall sentences of six kinds which formed paraphrase sets: S₁ before S₂, S₁ and then S₂, After S₁ S₂, S₂ after S₁, S₂ but first S₁, and Before S₂ S₁. (S₁ and S₂ denote first and second clauses in temporal, not linguistic, order.) Subjects remembered the underlying sense of sentences with S₁-S₂ clause ordering better than those with S₂-S₁ clause ordering, regardless of transformational complexity. Subjects also showed a response bias, hence better verbatim recall, for sentences with subordinate clause second and for sentences with S₁-S₂ clause ordering. Sentence confusions indicated that subjects remembered three semantic distinctions: the temporal order, order of mention, and main-subordinate relation of the two described events. A theory of memory for marked and unmarked semantic distinctions was used to account for the results.     

Non-Informative Effects of Stimuli Functioning as Cues

The category of a first stimulus (S₁) serving as a cue may allow a subject to predict the category of a second stimulus (S₂). However, a cue may have effects on RT to S₂ that are independent of those derived from its intended role as a predictor. These non-informative effects of a cue may add to or subtract from the benefits associated with its predictive function. Two experiments demonstrate that when S₁ is in the same category as S₂ (as is frequently the case for valid cues in cueing experiments) but provides no information about S₂, RT is slower than when S₁ is in a different category from S₂. It is suggested that this category relation effect arises because inhibition of a response to S₁ is still present when S₂ arrives and that, in some cueing experiments, it may subtract from the RT benefits derived from the cue as a predictor of S₂. Also, RT to a visual but not to an auditory S₂ was faster after an auditory S₁ than after a visual S₁. It is argued that this modality combination effect is consistent with the view that auditory signals are more alerting than visual ones and that this is another factor to be taken into account in the design of cueing and other experiments.     

A dissociation between causal judgement and the ease with which a cause is categorized with its effect

The associative view of human causal learning argues that causation is attributed to the extent that the putative cause activates, via an association, a mental representation of the effect. That is, causal learning is a human analogue of animal conditioning. We tested this associative theory using a task in which a fictitious character suffered from two allergic reactions, rash (O₁) and headache (O₂). In a conditioned inhibition design with each of these two outcomes (A-O₁/AX- and B-O₂/BY-), participants were trained that one herbal remedy (X) prevented O₁ and that the other (Y) prevented O₂. These inhibitory properties were revealed in a causal judgement summation test. In a subsequent categorization task, X was most easily categorized with O_1, and Y with O₂. Thus, the categorization data indicated an excitatory X-O₁ and Y-O₂ association, the reverse of the inhibitory relationship observed on the causal judgement measure. A second experiment showed that this pattern of excitation and inhibition is dependent on intermixed A-O₁ and AX- trials. These results are problematic for the standard application of associative activation theories to causal judgement. We argue instead that the inhibition revealed in the causal judgement task reflects inferential reasoning, which relies, in part, on the ability of the cue in question to excite a representation of the outcome, as revealed in the categorization test.     

Redistributing control between the elements of a compound stimulus

Twenty-eight pigeons were given discrimination training. Four groups were run in which for 0, 2, 4 and 9 sessions of training colour was an irrelevant cue and tone was relevant. Generalization tests were given in extinction; the training colour (C₁) and another colour (C₂) were presented with tone (T) and noise (N). Responding to these four stimulus combinations, TC₁, TC₂, NC₁ and NC₂, allowed the assessment of control by colour and tone. A reduction of control by colour and an increase in control by tone were found to be positively related to the amount of training with colour irrelevant. Tests showed a strong inverse relationship between control by colour and tone.     

Conditions for a linear speed-accuracy trade-off in aimed movements

A linear speed-accuracy trade-off has been found for rapid, precisely timed movements from a home position toward a target point. In this trade-off, W_e = K₁ + K₂(D/T), where D is the distance between the home position and the target, T is a pre-specified movement time, and W_e is the standard deviation of the distances actually moved. This result differs from Fitts' law, the commonly observed logarithmic trade-off in aimed movements. A new experiment with wrist rotations was performed to determine what conditions induce the linear trade-off rather than Fitts' law. Three types of condition are considered: movement brevity, feedback deprivation, and temporal precision. The experiment yielded a linear trade-off for precisely timed movements even when their durations significantly exceeded an amount of time (200 ms) sufficient to process visual feedback. This result suggests that the linearity does not depend on movement brevity and/or feedback deprivation per se. Instead it supports a temporal-precision hypothesis that the linear trade-off occurs when aimed movements must have precisely specified durations.

A linear speed-accuracy trade-off has been found for rapid, precisely timed movements from a home position toward a target point. In this trade-off, W_e = K₁ + K₂(D/T), where D is the distance between the home position and the target, T is a pre-specified movement time, and W_e is the standard deviation of the distances actually moved. This result differs from Fitts' law, the commonly observed logarithmic trade-off in aimed movements. A new experiment with wrist rotations was performed to determine what conditions induce the linear trade-off rather than Fitts' law. Three types of condition are considered: movement brevity, feedback deprivation, and temporal precision. The experiment yielded a linear trade-off for precisely timed movements even when their durations significantly exceeded an amount of time (200 ms) sufficient to process visual feedback. This result suggests that the linearity does not depend on movement brevity and/or feedback deprivation per se. Instead it supports a temporal-precision hypothesis that the linear trade-off occurs when aimed movements must have precisely specified durations.     

The psychological refractory period as a function of performance of a first response

Proponents of a “single channel” theory of the psychological refractory period have not specified whether the single channel occupies only the decision component of the response selection, only the motor or response component, or both. In this experiment, the delay in the RT to the second of two successively presented stimuli was examined as a function of whether or not an overt motor response was made to the first stimulus, keeping the decision component constant. It was found that in both conditions RT₂ was delayed, suggesting that the decision component was a part of the single channel. However, RT₂ was delayed by a significantly greater amount if a motor response was required, indicating that the motor component is part of the single channel as well. Implications of the results for an expectancy theory of the psychological refractory period are discussed.     

What is both necessary and sufficient to maintain avoidance responding in the shuttle box?

To learn what maintains the frequency of shuttle box avoidance responses, male rats from the Berkeley S₁ strain, after 200 trials of standard discriminative avoidance training, were given 100 additional trials under one of four different conditions. Responding at the maximum rate was maintained when animals performed under the training conditions or when responses continued to terminate the warning signal immediately, even though shock was never given for failing to respond. In contrast, avoidance responding was reduced markedly if, and only if, trials were given in which the signal ceased to terminate immediately (i.e. it shut off either well before or well after a response). This decrement occurred even though avoidance responses continued to avert shock. Thus, under the conditions of this experiment prompt signal offset was both necessary and sufficient to maintain the occurrence of well-established shuttle box avoidance responses.     

Aspects of the theory of comprehension, memory and attention

This paper proposed a two-stage model to capture some basic relations between attention, comprehension and memory for sentences. According to the model, the first stage of linguistic processing is carried out in short-term memory (M₁) and involves a superficial analysis of semantic and syntactic features of words. The second stage is carried out in long-term memory (M₂) and involves application of transformational rules to the analyses of M₁ so as to determine the deep or underlying relations among words and phrases. According to the theory, attention is an M₂ process: preliminary analyses by M₁ are carried out even for unattended inputs, but final analyses by M₂ are only carried out for attended inputs. The theory was shown to be consistent with established facts concerning memory, attention and comprehension, and additional support for the theory was obtained in a series of dichotic listening experiments.     

Violation of the scalar property for time perception between 1 and 2 seconds: evidence from interval discrimination, reproduction, and categorization

According to the hypothesis of a scalar property for time, the variability to time ratio should be constant. Three experiments tested the validity of this hypothesis in a restricted range of durations (standard values = 1, 1.3, 1.6, and 1.9 s). In each experiment, time intervals to be discriminated, reproduced, or categorized were presented with 2, 4, or 6 brief successive auditory signals marking 1, 3, or 5 intervals, respectively. In Experiment 1, participants were asked to indicate whether the interval(s) within a second series of sounds were shorter or longer than those of the first. In Experiment 2, the standard interval had to be reproduced. In Experiment 3, after 10 presentations of the standard, participants had to categorize each comparison interval as shorter or longer than the standard. In addition to showing that performance was generally poorer when only 1 interval was presented and remained about the same regardless of whether 3 or 5 intervals were presented (Experiments 1 and 3), the results demonstrated that the variability to time ratio is not constant across the standard interval conditions. Overall, the ratio is higher at 1.9 than at 1 s. This violation of scalar timing occurs whatever the method used and does not interact with the number-of-interval variable.     

Studies in auditory timing: 2. Rhythm patterns

Listeners discriminated between 6-tone rhythmic patterns that differed only in the delay of the temporal position of one of the tones. On each trial, feedback was given and the subject's performance determined the amount of delay on the next trial. The 6 tones of the patterns marked off 5 intervals. In the first experiment, patterns comprised 3 "short" and 2 "long" intervals: 12121, 21121, and so forth, where the long (2) was twice the length of a short (1). In the second experiment, patterns were the complements of the patterns in the first experiment and comprised 2 shorts and 3 longs: 21212, 12212, and so forth. Each pattern was tested 45 times (5 positions of the delayed tone x 3 tempos x 3 replications). Consistent with previous work on simple interval discrimination, absolute discrimination (delta t in milliseconds) was poorer the longer the intervals (i.e., the slower the tempo). Measures of relative discrimination (delta t/t, where t was the short interval, the long interval, or the average of 2 intervals surrounding the delayed tone) were better the slower the tempo. Beyond these global results, large interactions of pattern with position of the delayed tone and tempo suggest that different models of performance are needed to explain behavior at the different tempos. A Weber's law model fit the slow-tempo data better than did a model based on positions of "natural accent" (Povel & Essens, 1985).     

Parametric coupling and generalized decoupling revealed by concurrent and successive isometric contractions of distal muscles

In two experiments we examined the hypothesis of transient parametric coupling during the specification of peak forces of isometric contractions produced by the left and right hand. In the first experiment participants had to produce bimanual contractions with same and different target forces as rapidly as possible in response to an auditory signal; target forces were cued visually with variable cueing intervals. At short cueing intervals reaction times were longer when different peak forces had to be specified than when same peak forces were cued, and this reaction-time difference declined as the cueing interval was increased. Independent of the cueing interval intermanual correlations of peak forces, rise times, and reaction times were smaller in conditions with different peak forces than in those with same peak forces. In the second experiment imperative signals for left-hand and right-hand contractions were separated in time. Target forces for the first response were cued with variable cueing intervals, while for the second response the cues were presented simultaneously with the second imperative signal. Reaction time of the second response was longer when target forces for the two successive responses were different rather than same, and this reaction-time difference declined when the delay of the second signal was increased as well as when the cueing interval for the first response became longer. These results are consistent with the hypothesis of a transient cross-talk between concurrent processes of peak-force specifications; in addition they indicate generalization of the decoupling required to specify different peak forces concurrently to the specification of temporal response characteristics and to processes of response initiation.     

Precision hypothesis and the end-state comfort effect

Recently, motor control research has emphasized the planning of macroscopic aspects of control. In object manipulation studies, when participants complete a movement in a comfortable posture, an end-state comfort effect is attained. One explanation for this effect is the precision hypothesis, which states that precision increases when participants are in a comfortable position. This research directly tests the precision hypothesis in two experiments. In Experiment 1, participants picked up a dowel and touched a large or small target on a wall. For the second experiment, the same procedure was followed using a pinpoint target. The probability analyses of the first experiment indicated that the end-state comfort effect was magnified in the small target condition and that the point-of-change effect (Short and Cauraugh, 1997) appeared only when end-state comfort was magnified. Error analyses in Experiment 2 showed that participants were more accurate when in a more comfortable position. The present findings indicate that the precision hypothesis plays a significant role in the end-state comfort effect.     

贝叶斯因子及其在JASP中的实现

统计推断在科学研究中起到关键作用, 然而当前科研中最常用的经典统计方法——零假设检验(Null hypothesis significance test, NHST)却因难以理解而被部分研究者误用或滥用。有研究者提出使用贝叶斯因子(Bayes factor)作为一种替代和(或)补充的统计方法。贝叶斯因子是贝叶斯统计中用来进行模型比较和假设检验的重要方法, 其可以解读为对零假设H₀或者备择假设H₁的支持程度。其与NHST相比有如下优势：同时考虑H₀和H₁并可以用来支持H₀、不“严重”地倾向于反对H₀、可以监控证据强度的变化以及不受抽样计划的影响。目前, 贝叶斯因子能够很便捷地通过开放的统计软件JASP实现, 本文以贝叶斯t检验进行示范。贝叶斯因子的使用对心理学研究者来说具有重要的意义, 但使用时需要注意先验分布选择的合理性以及保持数据分析过程的透明与公开。     

The effect of simulation exercises on the control of aggressive behaviour in children

Abstract.— The subjects consisted of two. matched, extremely aggressive (experimental = ExG and control = CoG) groups of twelve 8–year-old boys. and of one criterion group (CrG) of extrovert, well-controlled boys. Video-tape recording of behaviour was used both in pretest (T₁) and post-test (T₂). Between T₁ and T₂ the ExG was submitted to simulation exercises of 8 lessons given in a period of four weeks. The exercises consisted in social problem solutions on the purely cognitive (imaginary and symbolic) level and in role-playing (behavioral level). The hypothesis was that the combination of cognitive training and observational learning with the aim of making children realise alternatives to aggression in coping with thwarting situations and their after-effects. would influence individuals with strong aggressive habits to abandon theiraggressive reactions in favour of more constructive behaviour. As to aggression, the results supported the hypothesis. For constructive behaviour, (1) the ExG maintained the samelevel of control of social behaviour in T₁ and T₂, while a significant drop occurred in the GoC, and (2) the strategies of problem solution improved significantly in the ExG. In T₂, the behaviour of the ExG resembled more closely that of the CoG than the behaviour of the CrG, as hypothesized.     

Sequential effects in pigeon delayed matching-to-sample performance

Pigeons were tested in a three-alternative delayed matching-to-sample task in which second-choices were permitted following first-choice errors. Sequences of responses both within and between trials were examined in three experiments. The first experiment demonstrates that the sample information contained in first-choice errors is not sufficient to account for the observed pattern of second choices. This result implies that second-choices following first-choice errors are based on a second examination of the contents of working memory. Proactive interference was found in the second experiment in the form of a dependency, beyond that expected on the basis of trial independent response bias, of first-choices from one trial on the first-choice emitted on the previous trial. Samples from the previous trial were not found to exert a significant influence on later trials. The magnitude of the intertrial association (Experiment 3) did not depend on the duration of the intertrial interval. In contrast, longer intertrial intervals and longer sample durations did facilitate choice accuracy, by strengthening the association between current samples and choices. These results are incompatible with a trace-decay and competition model; they suggest strongly that multiple influences act simultaneously and independently to control delayed matching-to-sample responding. These multiple influences include memory for the choice occurring on the previous trial, memory for the sample, and general effects of trial spacing.     

A note on cue probability learning: what conditioning data reveal about cue contrast

In a probabilistic learning task with two complementary cues (C₁ and C₂) and two events (E₁ and E₂) the subject has a tendency to infer that E₂ will occur when C₂ occurs after he/she has observed that E₁ frequently goes with C₁. This phenomenon was termed cue contrast because it reflects the belief that C₂ contrasts with C₁ and should indicate E₂. Two kinds of predictions following from the notion of cue contrast were tested on response proportions from the first block of trials in four previously published experiments on cue probability learning. Of a total of 15 independent observations (eight within-group comparisons; seven between-group comparisons) 13 confirmed the predictions (sign test, p<0.005). It was concluded that cue utilization is both an inductive process based on association between cues and events and an inferential process based on contrast.     

The role of attention in children's time perception.

This study tested the role of attention in 7- to 9-year-old children's time estimation. Based on an attentional model of time estimation, it was hypothesized that prospective estimates of short intervals are a function of the degree to which a child is occupied with the passage of time and is focusing his or her attention on estimating the exposure time of a stimulus. Two experiments with two different manipulations on attentional focus were conducted. Eighty children were exposed to two types of light bulbs, one a big bulb kindled with high intensity and the other a small one kindled with low intensity. The light bulbs were kindled for different intervals ranging from 3 to 10 s. In both experiments children estimated the lighting time of the bulbs in each condition by a reproduction method. In the first experiment prospective time estimates were found to be significantly longer than retrospective ones. In the second experiment children gave shorter time estimates when their attention was attracted away from the time estimation task than when it was not. In both experiments the attentional hypothesis was supported. In addition, support for the "more is more" hypothesis was obtained. Implications for understanding children's time perception processes are discussed.     

The effects of postconditioning revaluation of CS1 and UCS following pavlovian second-order electrodermal conditioning in humans

An experiment is described which uses various inferential post-conditioning revaluation techniques in order to clarify the associative substructure underlying Pavlovian electrodermal conditioning in human subjects. This study established a second-order skin conductance response (SCR) by pairing a CS₁ with an aversive 115 dB tone (UCS), and then pairing a different stimulus (CS₂) with CS₁. The second-order SCR survived post-conditioning extinction of the response to CS₁, but was abolished when (i) a post-conditioning habituation procedure resulted in a favourable revaluation of the tone UCS, or (ii) when subjects were given instructions which informed them that there would be no more UCS presentations. These results suggest that in the second-order electrodermal conditioning paradigm described, CR₂ is not mediated by S-R links--as it appears to be in second-order aversive conditioning in nonhuman animals--but is affected by manipulations which modify the subject's cognitions concerning the UCS.     

音乐训练促进诗句韵律整合加工的神经过程

本研究采用ERP技术, 考察音乐训练组和对照组完成诗句押韵判断任务时, 在绝句末对韵律信息(含声调和韵母两个维度)的整合加工过程。结果发现, 在100~300 ms, 仅音乐训练组在声调/韵母合适条件下, 对韵母/声调的一致性进行深入分析, 并诱发了更大的正波; 在韵母违反条件下, 声调违反相比声调合适诱发了更小的正波。在300~750 ms, 两组被试均在绝句末对诗句内出现的韵母和声调违反进行整合分析并诱发了广泛分布的负波。不过, 对照组仅在声调/韵母合适条件下进行, 而音乐训练组则在声调/韵母违反条件下完成此过程。综上, 音乐训练组和对照组均会在诗句末完成押韵信息的整合加工, 但是音乐训练组对韵律信息(尤其是声调)的加工更敏感和快速, 并且对不同类型的违反有更精细的差异性反应