Similarities of low-dimensional chaotic auditory attractor sequences to quasirandom noise.

The production of sequences of sounds of various pitch levels from the algebra of chaotic attractors' trajectories is relatively straightforward. Meyer-Kress (cited in Kaneko, 1986) suggested that such sequences would be distinguishable from random independent identically distributed sequences. In psychophysical terms, this is a pattern-discrimination or pattern-similarity perception task, but these two tasks are not exactly the same thing. Nine attractors from the algebras of Henon, Zaslavskii (1978), Kaplan and Yorke (1979), Lorenz, and Gregson, and the logistic and Baker transformations, were paired with 10 realizations of a random series. The identification of the random member in each pair, the confidence of identification, and the perceived pairwise similarity were recorded by 65 subjects without initial feedback and by 76 subjects with initial feedback on five trials only, for each of 20 such pairs. The results indicate varying degrees of discriminability; they can be expressed in an analog of the receiver-operating characteristics of the attractors. There is no evidence of any homogeneous basis for the discrimination, and subjects who perform better are apparently not using the same bases as those who perform poorly. The fractal dimensionality of attractors may furnish a basis for their recognition, or the consequent autoregressive spectra induced in finite (short) samples, but recent work suggests the latter spectra can be insensitive to low-dimensional attractor dynamics.     

Postidentification feedback affects subsequent eyewitness identification performance

Eyewitnesses sometimes view more than one lineup during an investigation. We investigated the effects of postidentification feedback following one lineup on responses to a second lineup. Witnesses (N=621) viewed a mock crime and, later, attempted to identify the culprit from an initial (target-absent) lineup and a second (target-present or target-absent) lineup. Prior to viewing the second lineup, some witnesses received accurate feedback stating that the initial lineup did not contain the culprit. A compound-decision, signal detection approach allowed the effects of feedback on identification responses to be described in terms of differences in discriminability and response bias. For witnesses who made an incorrect foil identification from the initial lineup, feedback (vs. no feedback) was associated with poorer discriminability on the second test. For witnesses who correctly rejected the initial lineup, feedback (vs. no feedback) was associated with greater discriminability on the second test. Only witnesses who received feedback after an initial correct rejection performed at a level comparable with a single-lineup control group, suggesting that an initial identification test can impair, but not enhance, performance on a second test involving the same culprit. From a theoretical perspective, the results are consistent with the idea that the way people use memorial information when making memory decisions is flexible. Analyses of preidentification confidence ratings, obtained in a follow-up study (N=133), suggested that the effects of feedback on identification performance may have operated via differences in witnesses' metacognitive beliefs.     

Pure feedback effects in absolute identification

To reveal the pure effects of trial-by-trial feedback on judgmental accuracy and sequential dependencies independent of global anchoring effects and other influences, we presented subjects with sequences consisting alternately (within an experimental session) of short runs of trials with feedback (feedback sequences) and without feedback (no-feedback sequences). In Experiments 1 and 2 (absolute identification of sound intensity and sound frequency, respectively), judgmental accuracy was the same in the feedback and the no-feedback sequences, contrary to previous results. Also, in the feedback sequences, the dependency of the current response on the immediately preceding stimulus was larger than that in the no-feedback sequences, while the dependency on the previous response was larger in the no-feedback sequences. In Experiment 3 (absolute identification of sound frequency), we attempted to separate the effects of the number of response categories on sequential dependencies from the effects of the number of stimuli. The results showed that the number of response categories had a larger effect than the number of stimuli on most aspects of performance, but that both affected sequential dependencies. These results are generally consistent with a theory of absolute identification in which feedback affects judgmental accuracy by improving long-term memory for judgmental anchors, while feedback affects sequential dependencies by altering response biases.     

Self-attribution of attitude as a function of belief feedback

Previous research has found that subjects listening to a communication can be persuaded more when they receive false physiological feedback concerning their emotional state than when such feedback is not presented. Such results, in conjunction with Bem's (1972) postulate that subjects infer their attitude from the external circumstances of their behavior, suggested that false feedback of belief or disbelief would affect persuasion. Subjects listened to a speech while observing their (false) reactions on a "belief meter." Half of the subjects received strong positive belief feedback, and the other half received strong disbelief feedback. Demand characteristics were varied by telling half of the subjects in each group that the meter was highly reliable and valid and the other half that is was of questionable validity. Results showed that the meter feedback affected self-attributions of attitude. Subjects receiving disbelief feedback rated their attitude the same as a control group who merely completed the attitude scale. Subjects receiving belief feedback were persuaded more than a control group receiving only the communication. The implications of the data for the construct of attitude were discussed.     

Feedback-Induced Variability and the Learning of Generalized Motor Programs

As compared with providing extrinsic feedback on each of a set of practice trials, reducing the feedback frequency in various ways facilitates long-term retention. One explanation is that frequent feedback operates proactively on the subsequent trial, inducing excessive variability that degrades learning. We tested this view by giving or not giving feedback "reminders," where the postresponse feedback was given again just before the next attempt at a task. The reminder manipulation was examined in both blocked and randomized practice sequences during the learning of three limb-patterning tasks. Reminder feedback increased response variability during practice in both random and blocked practice. As measured in retention tests, though, feedback reminders degraded learning in random practice, but not in blocked practice. This implies that the frequently found learning advantages of random, as compared with blocked, practice might be due to feedback's facilitation of retrieval operations in blocked practice (as well as in random practice with feedback reminders); such overfacilitation of retrieval operations has been shown to degrade learning. Additional analyses revealed that random, as compared with blocked, practice enhanced the learning of the fundamental pattern of action (generalized motor program) but had little effect on the ability to scale the pattern in amplitude or time (parameterization).     

Tweaking the lexicon: organization of vowel sequences into words

The ability of listeners to distinguish between different arrangements of the same three vowels was investigated for repeating sequences having item durations ranging from 10 msec (single glottal pulses) up to several seconds/vowel. Discrimination was accomplished with ease by untrained subjects at all item durations. From 30 through 100 msec/vowel, an especially interesting phenomenon was encountered: The sequences of steady-state vowels were organized into words, with different words heard for the different arrangements of items. In a second experiment, repeating sequences of random arrangements of 10 40-msec vowels were employed. When sets of four such sequences were presented to listeners, distinctive words were heard, which permitted each arrangement to be discriminated from the others. In addition, minimal differences (reversing the order of a single contiguous pair of vowels) in the 10-item sequences could be detected via verbal mediation. Hypotheses are offered concerning mechanisms responsible for these results.     

Investigating Individual Differences in a Serial Choice Reaction Time Task: Use of Auditory Feedback and Analysis of Responses Surrounding Errors

Subjects (N = 78) performed a visual four-choice reaction time (RT) task, either with or without immediate trial-by-trial feedback, in which RT (but not accuracy) was indicated by the pitch of an auditory tone. For each feedback condition, half of the subjects (the high AH4 group) scored more than 50% on the AH4 test of fluid intelligence (Heim, 1968), whereas the remaining half (the low AH4 group) scored less than 50%. It was predicted that if low AH4 subjects were slow because they were poor at monitoring RT, they would benefit more from feedback than high AH4 subjects would. This was not supported by the data: There was some beneficial effect of feedback on RT, but only for the high AH4 group. A second possibility was that individual differences would be apparent in processes such as detecting errors and controlling RT from trial to trial. From analyses of error rates, RT distributions, and particularly sequences of responses before and after errors, there was no evidence of qualitative differences in performance between the high and low AH4 groups. It is concluded that individual differences in this task are largely determined by information-processing rate rather than by factors such as the ability to detect errors or to monitor and control RT.     

The hypercorrection effect persists over a week, but high-confidence errors return

People’s knowledge about the world often contains misconceptions that are well-learned and firmly believed. Although such misconceptions seem hard to correct, recent research has demonstrated that errors made with higher confidence are more likely to be corrected with feedback, a finding called the hypercorrection effect. We investigated whether this effect persists over a 1-week delay. Subjects answered general-knowledge questions about science, rated their confidence in each response, and received correct answer feedback. Half of the subjects reanswered the same questions immediately, while the other half reanswered them after a 1-week delay. The hypercorrection effect occurred on both the immediate and delayed final tests, but error correction decreased on the delayed test. When subjects failed to correct an error on the delayed test, they sometimes reproduced the same error from the initial test. Interestingly, high-confidence errors were more likely than low-confidence errors to be reproduced on the delayed test. These findings help to contextualize the hypercorrection effect within the broader memory literature by showing that high-confidence errors are more likely to be corrected, but they are also more likely to be reproduced if the correct answer is forgotten.     

The Effects of Feedback Equivocality on Escalation of Commitment: An Empirical Investigation of Decision Dilemma Theory1

The effects of feedback equivocality on escalation of commitment were examined in a laboratory study. Subjects had multiple opportunities to allocate money to market a software product. During the initial phase, subjects received feedback that was of either low or high equivocality. Half of the subjects in each equivocality level were given a standard by which to judge the feedback. In the second phase, all subjects received negative feedback. Consistent with Bowen's (1987) decision dilemma theory, subjects who received low equivocality feedback did not escalate allocations, and subjects who received high equivocal feedback escalated allocations. The presence of a standard or goal attenuated escalation. These results are consonant with a dynamic, temporally based account of escalation and are discussed in a synthesis of the literatures in behavior analysis, economics, forecasting, and psychology.     

Memory for lateral orientation of slides in picture stories

Three picture stories were constructed by taking slides of people involved in three different activities. Two sequences of these slides were presented. Subjects were asked whether or not each slide in the second sequence was in the same lateral orientation as in the first sequence. Experiment 1 presented the slides in correct or random sequence and in correct or random lateral orientation (2 by 2 design). The two groups who received correct orientation excelled in recognition of orientation in the test series. Experiment 2 replicated the random orientation condition, found that pre-warning of the recognition task had no effect on performance, and suggested that these subjects did not make use of the events in determining laterality. Experiment 3 replicated the correct order and orientation condition and further revealed that new but appropriate slides in the test series were accurately judged as to lateral orientation which fit the context of the original stories.     

The Role of Task Experience and Prior Knowledge for Detecting Invalid Augmented Feedback while Learning a Motor Skill

Two hypotheses were investigated. These were generated from results reported by Buekers, Magill, and Sneyers (1994) and an uncertainty account of those and other effects on skill learning of erroneous knowledge of results (KR). The first hypothesis proposes that if experienced performers have developed the capability of detecting and correcting errors, then they should not be influenced by erroneous KR in the same way as novices. The second proposes that if information about the invalid feedback is given to subjects prior to the beginning of the practice trials, then the capability for assessing feedback can be accelerated such that subjects who receive this advance information should not be misled by the erroneous KR. The first hypothesis was investigated in Experiment 1 by having subjects practise an anticipation timing task for 450 trials. One group received correct KR on all trials, and another group received no KR. Half of the subjects in each group were unexpectedly switched to erroneous KR after 400 trials. Results indicated that the erroneous KR influenced both groups during acquisition and on a retention test one minute later. However, on a retention test given one week later, only the group that had practised with no KR before being switched to erroneous KR continued to show the negative influence of the invalid KR. The second hypothesis was examined in Experiment 2 by telling subjects prior to beginning practice trials that it was possible that the KR they received would be erroneous. Results showed that this intervention strategy was effective on the no-KR retention tests only for subjects who had no-KR trials alternated with trials on which they received the erroneous KR. The results of these experiments provide evidence that uncertainty about the validity of sensory feedback increases the likelihood that subjects will be misled by invalid augmented feedback. Moreover, this uncertainty can be overcome by increased experience or by providing advance knowledge about the nature of the invalid feedback.     

Parallel non-verbal enumeration is constrained by a set-based limit

Adults can represent approximate numbers of items independently of language. This approximate number system can discriminate and compare entities as varied as dots, sounds, or actions. But can multiple different types of entities be enumerated in parallel and stored as independent numerosities? Subjects who were prevented from verbally counting watched an experimenter hide sequences of objects in two locations. The number of object types, which contrasted in category membership, color, shape, and texture, varied from 1 to 5, and object types were completely temporally intermixed. Subjects were then asked how many objects of each type were in each location. In three experiments, subjects successfully enumerated the objects of each type in each location when 1-3 types were presented, but failed with 4 or 5 types, regardless of the total number of objects seen. Thus, adults can perform simultaneous enumeration of multiple sets that unfold in temporally intermixed fashion, but are limited to 3 such sets at a time. Furthermore, they perform these parallel enumerations in the absence of training or instruction, and can do so for sets of objects that are hidden in distinct locations. The convergence of this 3-set capacity limit with the 3-item capacity limit widely observed in studies of working memory suggests that each enumeration requires a single slot in memory, and that storage in memory is required before enumeration can occur.     

热手谬误？赌徒谬误？ ——随机序列知觉中近因效应的格式塔现象研究

通过两个实验来探讨随机序列中的近因效应。在实验1中,采用传统实验范式,让被试进行一系列的抛掷硬币结果的猜测并给予反馈,结果发现：（1）在最近连续几次硬币呈现的结果不同时,人们通常把各个结果分别作为独立的单元来看待,大部分情况下做出随机性的预期;（2）在最近连续几次硬币呈现的结果相同时,人们通常把连续几次相同的结果作为一个认知单元来看待,在最近猜测对错两种情况下分别出现了截然相反的两种近因效应。当最近1次猜对时,对下一结果的预期出现正近因效应即热手谬误,但是最近几次连续猜对时谬误减少乃至消失;当最近1次猜错时,对下一结果的预期出现负近因效应即赌徒谬误,并且最近几次连续猜错时负近因效应并未受到太大影响。实验2在实验1范式的基础上,把硬币抛掷的结果人为分组,发现被试对每一组的第一个结果做出预期时,实验1中的各种效应均消失,该现象支持关于随机序列知觉的“格式塔理论”。     

Distortions in Eyewitnesses' Recollections: Can the Postidentification-Feedback Effect Be Moderated?

Giving eyewitnesses confirming feedback after they make a lineup identification (e.g., "Good. You identified the actual suspect.") inflates not only their recollections of how confident they were at the time of the identification, but also other testimony-relevant judgments, such as how good their view was, how much attention they paid during witnessing, and how quickly they identified the suspect. We replicated this postidentification-feedback effect with eyewitnesses who had made false identifications (N = 156), adding critical conditions in which after the identification but prior to the feedback, some eyewitnesses were given instructions to privately think about their confidence, their view, and other matters. Other eyewitnesses were given the same thought instructions subsequent to the feedback manipulation. Prior thought served to mitigate the effects of feedback, but subsequent thought did not. In addition, even without feedback, privately thinking about confidence had some confidence-inflating properties of its own.     

Multilevel coordination stability: integrated goal representations in simultaneous intra-personal and inter-agent coordination

The influence of integrated goal representations on multilevel coordination stability was investigated in a task that required finger tapping in antiphase with metronomic tone sequences (inter-agent coordination) while alternating between the two hands (intra-personal coordination). The maximum rate at which musicians could perform this task was measured when taps did or did not trigger feedback tones. Tones produced by the two hands (very low, low, medium, high, and very high) could be the same as, or different from, one another and the (medium-pitched) metronome tones. The benefits of feedback tones were greatest when they were close in pitch to the metronome and the left hand triggered low tones, while the right hand triggered high tones. Thus, multilevel coordination was facilitated by tones that were easy to integrate with, but perceptually distinct from, the metronome, and by compatibility of movement patterns and feedback pitches.     

Judgement of lateral orientation for previously seen and unseen photographs of faces

In Study 1, 56 undergraduates judged whether each member of two sets of unseen photographs of faces was shown in the original or reversed orientation. Performance was at chance level, indicating that they could not perform this task. In Studies 2 and 3, the first of which involved unanalyzed data from previously-published work, an investigation was made of identification of orientation for faces which had been laterally reversed in the course of experiments on recognition memory. For a total of 406 subjects, over-all identification accuracy was about 60%, which was above chance. However, subjects were correct more often on normal (unchanged) than on reversed (changed) faces and were generally more likely to identify a face as normal when they were certain than when they were uncertain in their initial recognition judgement. It was concluded that identification performance could largely be accounted for by a response strategy model in which subjects judged orientation on the basis of their subjective familiarity with the face. Together, these studies demonstrate that subjects could not usually detect the lateral orientation of previously-seen or of unseen photographs of faces.     

Effects of contextual interference, task difficulty, and levels of processing on pursuit tracking

Based on an activity questionnaire, 48 females without experience in open sports skills were selected to track a moving light beam through either a circle, square, or triangular target area on a pursuit rotor. Contextual interference was created by presenting 5 velocities in either a random or a blocked context during acquisition. Level of processing was manipulated by having half of all subjects classify acquisition velocities by a predetermined numerical code. Time-on-target (TOT) was measured after each acquisition, retention, and transfer trial. Subjects tracking the circle produced higher TOTs than those who tracked the square or triangle (which did not differ from one another) across all three phases of the experiment; blocked and random acquisition groups were not significantly different from one another in acquisition, retention, or transfer. Subjects who classified acquisition velocities and tracked the circle under the blocked acquisition context produced significantly higher retention scores than those who tracked the circle but did not classify acquisition velocities. Transfer was facilitated for subjects who tracked the triangle in a random transfer context and classified velocities during acquisition. Results were discussed as providing support for the manipulation of the level of cognitive processing during the initial stage of learning. In addition, manipulating task difficulty was discussed.     

Response patterns and cardiovascular effects during response sequence acquisition by humans.

The effects of temporal delays imposed between successive responses and of vitamin C administration were examined on the acquisition of response sequences and on cardiovascular reactivity during sequence acquisition. Thirteen adult subjects (6 female, 7 male), in good health, gave written consent prior to participating in 12 weekly 45-min sessions. Points, exchanged for money after each session, were presented when subjects completed 15-response sequences on a touch-sensitive three-response keypad. A position counter increased from 0 to 14 as subjects emitted correct responses in the sequence. Four novel 15-response sequences were presented each session. No delays were imposed between successive responses during the acquisition of one sequence; delays were imposed immediately following each response during the acquisition of a second sequence, thereby delaying response feedback; delays were imposed following feedback during acquisition of a third sequence, resulting in the removal of the stimulus correlated with sequence position; and, as a control condition, delays were imposed following feedback, but stimuli correlated with sequence position were reinstated prior to the next response during acquisition of a fourth sequence. Subjects were exposed to one of two delay durations (0.2 and 0.5 or 0.5 and 1.0 s) each session, and delay durations alternated every session. During Weeks 5 to 8, subjects received 3 grams of vitamin C per day, whereas during Weeks 1 to 4 and 9 to 12, subjects received placebo under single-blind conditions. All subjects acquired the sequences, as evidenced by decreasing percentages of incorrect responses across trials. When temporal delays were imposed between successive responses during sequence acquisition, acquisition efficiency was enhanced. Examination of response latencies suggested that the status of preceding responses (i.e., correct or incorrect) rather than the status of the position counter influenced subsequent responding. Cardiovascular effects were inversely related to the length of the temporal delay. Neither cardiovascular reactivity or sequence acquisition were related to vitamin C administration.     

Auditory temporal discrimination by trained listeners

Previous reports from this laboratory have shown that untrained listeners cannot name the order of sounds in extended sequences of unrelated items such as hisses, tones, and buzzes at item durations of 200 msec, even though identification of order for the sounds of speech and music is accomplished readily at much shorter item durations. The present study indicates that under appropriate conditions subjects can be trained to distinguish between and to identify permuted orders within sequences of nonrelated sounds each lasting only 10 msec or less. Evidence is presented suggesting that much of what passes for direct identification of order is actually based on prior identification of a larger pattern. Two principal mechanisms seem to mediate discrimination of auditory temporal order: (1) fine resolution (requiring prior training) permitting identification of over-all patterns and capable of operating with item durations of only a few msec; (2) coarse resolution (special prior training not required) allowing naming of order of items having minimal durations usually above 200 msec for unfamiliar sequences.     

Delayed sensory feedback in the learning of a novel motor task

Summary Generally the therapeutical effect of EMG feedback is viewed in terms of the immediate contiguity between response and information. According to this view any feedback delay would deteriorate the result. In this article the validity of this notion has been investigated. Three groups of normal subjects were required to perform a difficult movement under three feedback conditions: immediate EMG feedback, delayed EMG feedback, and a control (no EMG feedback) condition. The results indicated a significant difference between the EMG feedback groups and the control condition. However, no such difference was found between the immediate and delayed feedback conditions. The results suggested that the immediacy of the feedback is not the main factor in EMG feedback, but the specificity of the information.This study was supported by Grant no. 15-35-03 from the Netherlands Organization for the Advancement of Pure Research