Sequential effects in absolute judgments of loudness

The effects of preceding stimuli on the judgments of current stimuli were examined in a study using absolute judgments of loudness with feedback. It was found that the response on a given trial was dependent on the stimuli in the preceding sequence of at least five trials. Both assimilation and contrast effects were observed. The form of the dependency of a response on a prior stimulus was a function of the ordinal position of the stimulus in the preceding sequence of trials. The stimulus on the immediately preceding trial had an assimilative effect on the response and preceding stimuli two to five trials removed all showed a contrast effect on a given response. The extent to which these preceding stimuli contributed to the contrast effect was an increasing function of their recency. The reversal of the dependency of the response, from assimilation to the stimulus one trial back, to contrast with the stimuli two and more trials back, indicates a unique function of the immediately preceding stimulus in this task. Since there was a reduction in the variance of responses to those stimuli similar in value to the immediately preceding stimulus, it is proposed that the stimulus and feedback on the last trial were remembered and used asa standardin judging the presented stimulus. A model is presented in which it is assumed that the memory of the magnitude of the immediately preceding stimulus is contaminated in specified ways by prior stimuli in the series. The empirical findings of assimilation and contrastare expected consequences of the proposed memorial processes.     

不同ISI下异同判断的同反应启动效应

通过改变刺激对中的第一个刺激消失到第二个刺激出现之间的间隔 (interstimulusinterval,简称ISI) ,并控制呈现的刺激前后试验不重复 ,分别进行不同形状白色图形的异同判断实验和不同颜色圆形的异同判断实验 ,系统地考察不同ISI下异同判断的同反应启动效应 ,研究异同判断的加工机制。两个实验均采用 2 (前次试验类型 :异、同 )× 2 (当前试验类型 :异、同 )× 6(ISI :1 0 0ms、2 0 0ms、30 0ms、40 0ms、50 0ms、60 0ms)重复测量设计。被试为2 1名大学本科生 ,其中男生 1 0名 ,女生 1 1名。结果发现 ,在两实验中的每一种ISI条件下 ,同反应后的试验的反应时均显著短于异反应后的试验的反应时 ,即表现出显著的同反应启动效应。实验的结果支持异同判断的双过程模型 ,并表明双加工机制可能是序列工作的     

Two types of serial dependence in visual working memory

Stimulus representations in working memory depend on memory traces of past stimuli both from previous trials and from the current trial. However, it is unclear whether the same or different mechanisms underlie this serial dependence across and within trials. We directly contrasted estimates of bias for pairs of immediately successive stimuli across and within trials. In each trial, participants memorized two consecutive motion direction stimuli (S1 and S2) and after a short delay were cued to report one of them. We found serial dependence across trials: The current S1 was attracted towards the preceding S2 when the latter had been cued for report. In contrast, within the same trial S2 was repulsed from S1. In addition, repulsion within a trial occurred for a broader range of motion direction differences between stimuli than attraction across trials. A second experiment in which 25% of trials did not require a response demonstrated that across‐trial attraction did not depend on whether the previous S2 actually had to be reported. Our findings provide evidence for two types of serial dependence operating across and within trials. They support the notion of different mechanisms integrating or segregating current from similar past memory contents depending on their task relevance.     

Functional localization and mechanisms of sequential effects in serial reaction time tasks

Reaction times (RTs) to randomly ordered stimuli are influenced in various ways by the sequence of preceding events. Depending on the response-stimulus interval and stimulus-response compatibility, cost-only or cost-benefit patterns can be observed. In order to localize these effects within the information-processing system, different sequential patterns were induced in overt performance. RTs and amplitude developments of the lateralized readiness potential (LRP) across several trials indicated the accumulation of residual traces as a possible mechanism underlying sequential effects. Analysis of LRP onsets indicated two possible loci of action of such traces. Whereas in motoric stages trace accumulation appeared to produce processing advantages only for continued event repetitions, without corresponding costs for discontinuations, cost-benefit patterns were consistently observed in premotoric stages.     

Effects of uncertainty on melodic

In three experiments, musically trained and untrained adults listened to three repetitions of a 5-note melodic sequence followed by a final melody with either the same tune as those preceding it or differing in one position by one semitone. In Experiment 1, ability to recognize the final sequence was examined as a function of redundancy at the levels of musical structurein a sequence, contour complexity of transpositions in a trial, and trial context in a session. Within a sequence, tones were related as the major or augmented triad; within a trial, the four sequences began on successively higher notes (simple macrocontour) or on randomly selected notes (complex macrocontour); and within a session, trials were either blocked (all major or all augmented) or mixed (major and augmented randomly selected). Performance was superior for major melodies, for systematic transpositions within a trial (simple macrocontours), for blocked trials, and for musically trained listeners. In Experiment 2, we examined further the effect of macrocontour. Performance on simple macrocontours exceeded that on complex, and excluded the possibility that repetition of the 20-note sequences provided the entire benefit of systematic transposition in Experiment 1. The effect of musical structure (major/augmented) was also replicated. In Experiment 3, listeners provided structure ratings of ascending 20-note sequences fromExperiment 2. Ratings onsame trials were higher than those on correspondingdifferent trials, in contrast to performance scores for augmentedsame anddifferent trials in previous experiments. The concept of functional uncertainty was proposed to account for recognition difficulties on augmented same trials. The significant effects of redundancy on all the levels examined confirm the utility of the information-processing framework for thestudy of melodic sequence perception.     

Effects of uncertainty on melodic information processing

In three experiments, musically trained and untrained adults listened to three repetitions of a 5-note melodic sequence followed by a final melody with either the same tune as those preceding it or differing in one position by one semitone. In Experiment 1, ability to recognize the final sequence was examined as a function of redundancy at the levels of musical structure in a sequence, contour complexity of transpositions in a trial, and trial context in a session. Within a sequence, tones were related as the major or augmented triad; within a trial, the four sequences began on successively higher notes (simple macrocontour) or on randomly selected notes (complex macrocontour); and within a session, trials were either blocked (all major or all augmented) or mixed (major and augmented randomly selected). Performance was superior for major melodies, for systematic transpositions within a trial (simple macrocontours), for blocked trials, and for musically trained listeners. In Experiment 2, we examined further the effect of macrocontour. Performance on simple macrocontours exceeded that on complex, and excluded the possibility that repetition of the 20-note sequences provided the entire benefit of systematic transposition in Experiment 1. The effect of musical structure (major/augmented) was also replicated. In Experiment 3, listeners provided structure ratings of ascending 20-note sequences from Experiment 2. Ratings on same trials were higher than those on corresponding different trials, in contrast to performance scores for augmented same and different trials in previous experiments. The concept of functional uncertainty was proposed to account for recognition difficulties on augmented same trials. The significant effects of redundancy on all the levels examined confirm the utility of the information-processing framework for the study of melodic sequence perception.     

Understanding priming of color-singleton search: roles of attention at encoding and "retrieval"

We investigated how the performance of a color-singleton search (the search for a single odd-colored item among homogeneously colored distractors) left a persistent memory trace (lasting up to six intervening trials or approximately 17 sec) that facilitated a subsequent color-singleton search (when the same target-distractor color combination was repeated). Specifically, we investigated the roles of attention in the encoding and "retrieval" stages of this priming effect by intermixing trials in which the target location was precued by an onset cue. We found that the encoding of both target and distractor colors was automatic in that whether or not observers had to use color in locating the target in the preceding trial did not substantially affect priming. However, priming required that the color-singleton item be attended in the preceding trial. Once a color singleton display was encoded, our results indicated that priming facilitated the direction of attention to the color-singleton target on a subsequent trial. In short, when a color-singleton item happened to be a critical item to be attended in one situation, another color-singleton item defined by the same color combination tended to attract attention in subsequent encounters.     

A search for contrast effects in discrete-trial discrimination learning by pigeons

Behavioral contrast has often been observed in free-operant experiments with pigeons, rarely in discrete-trial experiments with rats. Although Jenkins (1961) and Terrace (1963) have reported a discrete-trial contrast effect in pigeons, a series of experiments reported here found no evidence that latency of responding to S+ in a discrete-trial situation was reliably decreased by alternating reinforced trials to S+ with nonreinforced trials to S?. Latency of responding to S+ was affected neither by the length of the preceding intertrial interval (within the range of 10–60 sec), nor by whether the preceding trial had been to S+ or to S?. The results of two of these experiments suggested that the appearance of positive contrast in Jenkins's experiment was a consequence of differences in the variability of the intertrial interval experienced by control and discrimination groups. In two final experiments, employing standard free-operant procedures, contrast was observed as an increase in rate of responding to S+, but not as a decrease in latency of the first response on each S+ trial. The implication is that contrast effects are more readily observed with the rate measures of free-operant experiments than with the latency measures of discrete-trial experiments.     

The effect of ischemia on the peripheral nerve action potential in man and its relation to somatosensory magnitude coding

The amplitude and latency fluctuations of the compound action potential of the ulnar nerve were recorded percutaneously as a function of the length of time the arm was kept ischemic by means of an inflated sphygmomanometer cuff. Changes in latency and the amplitude action potential were measured for cuff positions above and below the recording electrode. The amplitude fluctuations were shown to be related to corresponding changes in the sensory threshold which has been determined in an earlier study. By manipulating the position of the cuff it was possible to determine that the amplitude fluctuations were caused by a reduced number of nerve action potentials rather than a change in the individual atonal action potential amplitude.     

Effect of the length of the runs of repetitions on the simple RT-ISI relationship

In a simple RT task the temporal organization of the preparatory processes during a given trial depends upon the time characteristics of the total experimental situation as well as upon the information gathered during one or more previous trials. The present experiment was run in order to determine whether or not these long and short term effects operate independently or interact. The effects of the preceding ISI durations on the simple RT for an ISI 1 (1.5 s) or an ISI 2 (3.0 s) are analysed in 3 experimental conditions differing in the maximum number of successive repetitions (2, 3 or 7) of trials with the same ISI. The results show that the distribution of the preparatory activity during a given trial depends firstly on the number of successive ISIs of the same duration preceding this trial, and secondly on the maximum number of repetitions. An explanation of the subjects' strategy based upon “cost of preparation” is proposed.     

Facilitating and inhibiting effects of priming and selection criteria in a sequence of dichotic listening trials

Competing models of attention make different predictions of how priming from recent stimulus processing could interact with intended selection. The present experiment examined the interaction between exogenous attention and endogenous priming across trial sequences. A sound cue directed attention to left, right or both sides before a dichotic syllable pair was presented. Participants were asked to report one syllable from each trial. Results showed that responses were slower on trials where one of the presented syllables had also been presented on the previous trial. Within these trials, the repeated syllable was selected less frequently, and the responses doing so were slower. Examined according to response choice on the preceding trial, syllables that had been ignored on the preceding trial tended to be ignored on the current trial (negative priming), while syllables that had been selected on the preceding trial tended to be selected on the current trial (positive priming). Responses that followed these selection biases were faster than responses that did not. Response selection was also influenced by the attention direction cue for the current trial, but not by the cue presented on the preceding trial. The results support an attentional model where traces from the preceding processing are retained, and current selection is biased to minimize cognitive conflict between recent and current processing. Negative priming appears to be due to after-effects of preceding processing, independently of the intentions behind that processing. The study accounts for positive and negative priming of dichotic listening sequences within an established, computationally viable biased competition framework.     

Proactive interference from items previously stored in visual working memory

This study investigates the fate of information that was previously stored in visual working memory but that is no longer needed. Previous research has found inconsistent results, with some showing effective release of irrelevant information and others showing proactive interference. Using change detection tasks of colors or shapes, we show that participants tend to falsely classify a changed item as "no change" if it matches one of the memory items on the preceding trial. The interference is spatially specific: Memory for the preceding trial interferes more if it matches the feature value and the location of a test item than if it does not. Interference results from retaining information in visual working memory, since it is absent when items on the preceding trials are passively viewed, or are attended but not memorized. We conclude that people cannot fully eliminate unwanted visual information from current working memory tasks.     

Target location probability effects in visual search: an effect of sequential dependencies

Target location probability was manipulated in a visual search task. When the target was twice as likely to appear on 1 side of the display as the other, manual button-press response times were faster (Experiment 1A) and first saccades were more frequently directed (Experiment 1B) to the more probable locations. When the target appeared with equal probability at each location in this search task, performance benefited from repetition of target location in the preceding trials (Experiment 2). When the trial sequence was constrained so that target location did not repeat within a series of 4 trials, there was no longer an advantage for more probable locations (Experiment 3). The authors conclude that the search benefits for more probable locations resulted from short-term target location repetitions.     

A feature-integration account of sequential effects in the Simon task

Recent studies have shown that the effects of irrelevant spatial stimulus-response (S-R) correspondence (i.e., the Simon effect) occur only after trials in which the stimulus and response locations corresponded. This has been attributed to the gating of irrelevant information or the suppression of an automatic S-R route after experiencing a noncorresponding trial—a challenge to the widespread assumption of direct, intentionally unmediated links between spatial stimulus and response codes. However, trial sequences in a Simon task are likely to produce effects of stimulus- and response-feature integration that may mimic the sequential dependencies of Simon effects. Four experiments confirmed that Simon effects are eliminated if the preceding trial involved a noncorresponding S-R pair. However, this was true even when the preceding response did not depend on the preceding stimulus or if the preceding trial required no response at all. These findings rule out gating/suppression accounts that attribute sequential dependencies to response selection difficulties. Moreover, they are consistent with a feature-integration approach and demonstrate that accounting for the sequential dependencies of Simon effects does not require the assumption of information gating or response suppression.     

Sequential congruency effects in implicit sequence learning

We deal with situations incongruent with our automatic response tendencies much better right after having done so on a previous trial than after having reacted to a congruent trial. The nature of the mechanisms responsible for these sequential congruency effects is currently a hot topic of debate. According to the conflict monitoring model these effects depend on the adjustment of control triggered by the detection of conflict on the preceding situation. We tested whether these conflict monitoring processes can operate implicitly in an implicit learning procedure, modulating the expression of knowledge of which participants are not aware. We reanalyze recently published data, and present an experiment with a probabilistic sequence learning procedure, both showing consistent effects of implicit sequence learning. Despite being implicit, the expression of learning was reduced or completely eliminated right after trials incongruent with the learned sequence, thus showing that sequential congruency effects can be obtained even when the source of congruency itself remains implicit.     

冲突观察能诱发冲突适应

重复启动效应和一致试次所占的比例都会影响冲突适应效应。采用词-色Stroop任务, 本研究在控制了重复启动效应和一致试次的比例之后, 通过三个实验共同探讨反应执行和冲突观察对冲突适应效应的影响。实验一发现当前试次的Stroop干扰效应, 但没有得到冲突适应效应; 在实验二中, 先前试次为四选一的选择反应时任务, 当前试次为词-色Stroop任务, 得到反转的冲突适应效应; 实验三和实验一程序相似, 但在先前试次上不执行反应, 得到了稳定的冲突适应效应。这些结果证明, 冲突观察能够诱发冲突适应机制, 提升当前的操作表现。     

Sequence effects by non-predictive arrow cues

Previous studies have found that attention orienting is influenced by the orienting processes of previous trials in a spatial cueing paradigm. This study mainly investigated whether this sequence effect could happen for a non-predictive arrow cue and whether it was influenced by the cue-target SOAs in previous and current trials. A significant sequence effect was observed for arrow cues even when voluntary control was not required, and it was significantly influenced by the SOAs of previous trials. The present results support the automatic memory check hypothesis and may reflect some temporal characteristics of the memory mechanism in sequential processes. In addition, contrary to the previous findings, we found an overall response facilitation following a catch trial, suggesting that the influence of preceding catch trials may be sensitive to experimental contexts.     

Discrete-trial alternation in the rat

The acquisition and maintenance by rats of single alternation, double alternation, and four other repeating patterns of reinforced and non-reinforced trials was studied in a discrete-trial lever-pressing situation. The rats learned all these patterns in a small number of experimental sessions. Single alternation was learned more rapidly than the more complex patterns. Rate of learning single and double alternation decreased moderately as inter-trial interval increased. Abrupt changes in the scheduling of trials, either by doubling the inter-trial interval or by shifting from fixed to variable trial spacing, temporarily disrupted the patterned performance. Two hypotheses concerned with the means by which the rats could have learned to conform to the pattern were examined: (1) “timing” of the interval between successive reinforcements; and (2) control of responding on a trial by the outcome of preceding trials, depending on the consistency with which these outcomes were associated with reinforced or non-reinforced trials in the pattern and on how many trials back these outcomes occurred. The second hypothesis accounted for the relative frequency of errors on trials at various locations in the sequences, and predicted most of the changes in error frequency observed in experiments in which “inter-trial stimuli” were added to the sequences.     

Contextual control over lexical and sublexical routines when reading English aloud

Are the processes responsible for reading aloud single well-formed letter strings under contextual control? Despite the widespread contention that the answer to this question is “yes,” it has been remarkably difficult to provide a compelling demonstration to that effect. In a speeded naming experiment, skilled readers read aloud exception words (such asPint) that are atypical in terms of their spelling sound correspondences and nonwords (such asFlad) that appeared in a predictable sequence. Subjects took longer to name both words and nonwords when the item on the preceding trial was from the other lexical category, relative to when the preceding item was from the same lexical category. This finding is consistent with the relative contributions of lexical and sublexical knowledge being controlled. We note a number of different ways that this control could arise and suggest some directions for future research.     

Sequence effects in a spatial cueing task: Endogenous orienting is sensitive to orienting in the preceding trial

In a spatial cueing paradigm it was investigated whether endogenous orienting is sensitive to orienting processes in the previous trial. Specifically, the effect of the previous cue direction, the previous trial type (valid, invalid, neutral, catch) and target alternation effects were studied. Strategic effects were shown as attentional costs and benefits were larger after a valid than after an invalid trial. Following catch trials, an overall response slowing was observed, but costs and benefits were unaffected. This was interpreted as a reduction in alertness and as support for the dissociation between spatial and temporal attentional mechanisms. Repetition of target position per se had no effect, but in neutral trials responses were slower to targets appearing at the location that was cued in the previous trial, independent of validity of the preceding trial. This suggests that long-term inhibition-of-return can occur between trials when attention is controlled endogenously.