Remembering remembering

We developed a laboratory analogue of the "forgot-it-all-along" effect that J. W. Schooler, M. Bendiksen, and Z. Ambadar (1997) proposed for cases of "recovered memories" in which individuals had forgotten episodes of talking about the abuse when they were supposedly amnestic for it. In Experiment 1, participants studied homographs with disambiguating context words; in Test 1 they received studied- or other-context words as cues; and in Test 2 they received studied-context cues and judged whether they had recalled each item during Test 1. In Experiment 2, retrieval cues were manipulated on both tests. In Experiment 3, both the studied- and other-context cues corresponded to the same meaning of each homograph. In Experiment 4, Test 1 was free recall, and studied- versus other-context cues were presented in Test 2. Participants more often forgot that they had previously recalled an item if they were cued to think of it differently on the two tests.     

Age-related differences in spatial memory: effects of structural and organizational context

The authors examined effects of structural and organizational spatial context on younger and older adults' memory for an arrangement of dollhouse furniture pieces. For half of the participants, landmark objects (Experiment 1) and a floor plan beneath the array (Experiment 2) served as structural context during study and replacement. Organizational context was varied by grouping items randomly or as 6 rooms in a prototypical house. Two study and replacement trials were given. In Experiment 1, landmark structural cues improved younger adults' performance, whereas both age groups benefited from the floor plan in Experiment 2. In both experiments, positive effects of organizational context and trial occurred. Higher order interactions further revealed that structural and organizational context effects varied in size across trials, suggesting that both age groups used spatial contextual cues more effectively with practice. Implications of these results for current views on cognitive compensation in adulthood are discussed.     

Overcoming Misinformation Effects in Eyewitness Memory: Effects of Encoding Time and Event Cues

Eyewitness memory is often distorted when misleading information is presented to subjects after encoding. Three experiments explored ways to overcome these misinformation effects. In Experiment 1, subjects viewed slides of a robbery, at a rate of four or seven seconds per slide. Five minutes later subjects were given a recognition test with few (1–3) or numerous (6–13) event cues. Providing numerous retrieval cues improved overall performance, but did not reduce the effects of misinformation. W ith week-long delays (Experiment 2) numerous retrieval cues did eliminate misinformation effects, but only when subjects viewed slides at the slower rate (seven seconds per slide). Experiment 3 essentially replicated this pattern, using a modified test to eliminate any biasing effects of distractors. Given adequate encoding and numerous retrieval cues, misinformation effects were eliminated, suggesting that under some conditions misinformation makes event memory inaccessible, but not unavailable.     

Cueing signals in auditory detection and frequency discrimination experiments

The effects of presenting a cueing signal during the warning interval initiating a trial were investigated in two-interval forced-choice detection and frequency-discrimination experiments. It was expected that the cueing signal would reduce the uncertainty of Ss about the stimuli being presented in these experiments. In general, it was found that performance tended to improve as the experiments progressed, both in conditions in which cues were presented and in control conditions in which no cues were presented. The improvement observed in control conditions is not usually found in similar experiments in which cues are not employed. Though performance generally improved, it was found that for some stimulus conditions the cues tended to depress average performance below the level attained without such cues.     

Cuing mechanisms in autitory signal detection

Detection of auditory signals under frequency uncertainty can be improved by presenting cues to the listeners. Since various cues have been found to differ in effectiveness, three conceivable mechanisms were considered which might account for these differences. Cuing might reduce the number and/or width of the employed auditory filters or listening bands. Also, cues could modulate the precision of frequency tuning of the filters. Psychometric functions were collected in a detection experiment with frequency uncertainty employing three kinds of cues: pure tones whose frequency was identical to that of the signal (iconic cues), complex tones with a missing fundamental equal to the signal (complex cues), and pure tones with a certain frequency relation to the signal (relative cues). Compared with a no-cue condition, all cue types improved detection performance. Fitting models to the data suggests that in the no-cue condition as well as the complex-cue condition, multiple bands were utilized, and that the iconic and relative cues induced single-band listening. There is no indication that accuracy of frequency tuning was responsible for cue-efficiency differences.     

Cue combination in human spatial navigation

This project investigated the ways in which visual cues and bodily cues from self-motion are combined in spatial navigation. Participants completed a homing task in an immersive virtual environment. In Experiments 1A and 1B, the reliability of visual cues and self-motion cues was manipulated independently and within-participants. Results showed that participants weighted visual cues and self-motion cues based on their relative reliability and integrated these two cue types optimally or near-optimally according to Bayesian principles under most conditions. In Experiment 2, the stability of visual cues was manipulated across trials. Results indicated that cue instability affected cue weights indirectly by influencing cue reliability. Experiment 3 was designed to mislead participants about cue reliability by providing distorted feedback on the accuracy of their performance. Participants received feedback that their performance with visual cues was better and that their performance with self-motion cues was worse than it actually was or received the inverse feedback. Positive feedback on the accuracy of performance with a given cue improved the relative precision of performance with that cue. Bayesian principles still held for the most part. Experiment 4 examined the relations among the variability of performance, rated confidence in performance, cue weights, and spatial abilities. Participants took part in the homing task over two days and rated confidence in their performance after every trial. Cue relative confidence and cue relative reliability had unique contributions to observed cue weights. The variability of performance was less stable than rated confidence over time. Participants with higher mental rotation scores performed relatively better with self-motion cues than visual cues. Across all four experiments, consistent correlations were found between observed weights assigned to cues and relative reliability of cues, demonstrating that the cue-weighting process followed Bayesian principles. Results also pointed to the important role of subjective evaluation of performance in the cue-weighting process and led to a new conceptualization of cue reliability in human spatial navigation.     

Memory for spatial location: Cue effects as a function of field rotation

We developed theoretical extensions of Huttenlocher, Hedges, and Duncan's (1991) category-adjustment model of human spatial memory to incorporate the use of fuzzy boundariesand cue-determined prototypes. In two experiments, people reproduced locations of dots in a circle, while the number of external reference cues varied. In Experiment 1, the task field was stable and results were consistent with the use of fixed categories unaffected by number of cues. In Experiment 2, the task field was made dynamic by rotation on most trials, with results evaluated for nonrotation trials. The large cue effects observed for angular bias were consistent with the proposed cue-based fuzzy-boundary model. Large cue effects were also observed for absolute error, consistent with a model in which proximity to cues predicts stability of memory. Results point to the key role of orientation to the task environment in determining whether categorical encoding is based on cues.     

The effect of task and pitch structure on pitch-time interactions in music

Musical pitch-time relations were explored by investigating the effect of temporal variation on pitch perception. In Experiment 1, trained musicians heard a standard tone followed by a tonal context and then a comparison tone. They then performed one of two tasks. In the cognitive task, they indicated whether the comparison tone was in the key of the context. In the perceptual task, they judged whether the comparison tone was higher or lower than the standard tone. For both tasks, the comparison tone occurred early, on time, or late with respect to temporal expectancies established by the context. Temporal variation did not affect accuracy in either task. Experiment 2 used the perceptual task and varied the pitch structure by employing either a tonal or an atonal context. Temporal variation did not affect accuracy for tonal contexts, but did for atonal contexts. Experiment 3 replicated these results and controlled potential confounds. We argue that tonal contexts bias attention toward pitch and eliminate effects of temporal variation, whereas atonal contexts do not, thus fostering pitch-time interactions. Psychonomic Society, Inc.     

The effect of vibrato on the recognition of masked vowels

Five experiments on the identifiability of synthetic vowels masked by wideband sounds are reported. In each experiment, identification thresholds (signal/masker ratios, in decibels) were measured for two versions of four vowels: a vibrated version, in which FO varied sinusoidally around 100 Hz; and a steady version, in which F0 was fixed at 100 Hz. The first three experiments were performed on naive subjects. Experiment 1 showed that for maskers consisting of bursts of pink noise, vibrato had no effect on thresholds. In Experiment 2, where the maskers were periodic pulse trains with an F0 randomly varied between 120 and 140 Hz from trial to trial, vibrato slightly improved thresholds when the sound pressure level of the maskers was 40 dB, but had no effect for 65-dB maskers. In Experiment 3, vibrated rather than steady pulse trains were used as maskers; when these maskers were at 40 dB, the vibrated versions of the vowels were slightly less identifiable than their steady versions; but, as in Experiment 2, vibrato had no effect when the maskers were at 65 dB. Experiment 4 showed that the unmasking effect of vibrato found in Experiment 2 disappeared in subjects trained in the identification task. Finally, Experiment 5 indicated that in trained listeners, vibrato had no influence on identification performance even when the maskers and the vowels had synchronous onsets and offsets. We conclude that vibrating a vowel masked by a wideband sound can affect its identification threshold, but only for tonal maskers and in untrained listeners. This effect of vibrato should probably be considered as a Gestalt phenomenon originating from central auditory mechanisms.     

Simultaneous utilization of multiple cues in judgments of learning

There is much evidence that metacognitive judgments, such as people’s predictions of their future memory performance (judgments of learning, JOLs), are inferences based on cues and heuristics. However, relatively little is known about whether and when people integrate multiple cues in one metacognitive judgment or focus on a single cue without integrating further information. The current set of experiments systematically addressed whether and to what degree people integrate multiple extrinsic and intrinsic cues in JOLs. Experiment 1 varied two cues: number of study presentations (1 vs. 2) and font size (18 point vs. 48 point). Results revealed that people integrated both cues in their JOLs. Experiment 2 demonstrated that the two word characteristics concreteness (abstract vs. concrete) and emotionality (neutral vs. emotional) were integrated in JOLs. Experiment 3 showed that people integrated all four cues in their JOLs when manipulated simultaneously. Finally, Experiment 4 confirmed integration of three cues that varied on a continuum rather than in two easily distinguishable levels. These results demonstrate that people have a remarkable capacity to integrate multiple cues in metacognitive judgments. In addition, our findings render an explanation of cue effects on JOLs in terms of demand characteristics implausible.     

Interactions Between Exogenous Auditory and Visual Spatial Attention

Six experiments were carried out to investigate the issue of cross-modality between exogenous auditory and visual spatial attention employing Posner's cueing paradigm in detection, localization, and discrimination tasks. Results indicated cueing in detection tasks with visual or auditory cues and visual targets but not with auditory targets (Experiment 1). In the localization tasks, cueing was found with both visual and auditory targets. Inhibition of return was apparent only in the within-modality conditions (Experiment 2). This suggests that it is important whether the attention system is activated directly (within a modality) or indirectly (between modalities). Increasing the cue validity from 50% to 80% influenced performance only in the localization task (Experiment 4). These findings are interpreted as being indicative for modality-specific but interacting attention mechanisms. The results of Experiments 5 and 6 (up/down discrimination tasks) also show cross-modal cueing but not with visual cues and auditory targets. Furthermore, there was no inhibition of return in any condition. This suggests that some cueing effects might be task dependent.     

Caudate-putamen lesions in the rat may impair or potentiate maze learning depending upon availability of stimulus cues and relevance of response cues

In Experiment 1 rats were required to learn a Y-maze in which reward was made available after a given response (e.g. a left turn) regardless of which arm was used as the start-box. Subjects with lesions of the caudate-putamen showed a deficit on this response-learning task compared with control subjects (unoperated animals and rats having lesions of the posterior cortex). In Experiment 2 rats with caudate-putamen lesions were unimpaired when the direction of the turn required to reach the correct goal-box (identified by means of a salient visual intra-maze cue) varied from trial to trial. In the absence of salient intramaze cues, but with enriched room (extra-maze) cues, the rats with caudate-putamen lesions were superior to controls on this task. It is argued that caudate-putamen lesions disrupt a mechanism responsible for processing information about responses, but that the other (spatial) mechanisms responsible for maze-learning remain intact and that caudate-putamen lesions may enhance performance on spatial tasks for which information about responses is irrelevant.     

Blocking and overshadowing between intra-maze and extra-maze cues: A test of the independence of locale and guidance learning

Rats were trained on an elevated maze where the rewarded alternative was defined either in terms of intra-maze cues (rubber or sandpaper flooring on rewarded and unrewarded arms, regardless of their position) or in terms of extra-maze cues (the correct arm always pointed toward a particular corner of the room, and was sometimes covered with rubber and sometimes with sandpaper), or where both sets of cues were simultaneously relevant. In Experiment 1 rats pretrained with either intra-maze or extra-maze cues alone relevant learned less about the other set of cues than non-pretrained control groups, when, in a second phase of the experiment, both sets of cues were simultaneously relevant. Experiment 2 confirmed that intra-maze cues could block extra-maze cues, and ruled out one alternative explanation of the results of Experiment 1. Experiment 3 showed that extra-maze cues overshadowed intra-maze cues, but that there was no reciprocal overshadowing of extra-maze by intra-maze cues. This was despite the fact that animals learned the intra-maze discrimination significantly faster than the extra-maze discrimination. Experiment 3 also suggested that rats did not solve the extra-maze discrimination by learning to approach or avoid specific extra-maze cues, but rather by locating the correct arm by reference to the entire set of extra-maze cues. The results suggest that locale or place learning and cue or guidance learning, in O'Keefe and Nadel's (1978) terminology, interact with one another in much the same way as does learning about any pair of stimuli in a Pavlovian conditioning experiment.     

Young children’s age-of-acquisition estimates for spoken words

This study was concerned with the impact of stimulus familiarity on young children's ability to recognize spoken words and make explicit judgments about them. In Experiment 1, 5-year-olds made age-of-acquisition (AOA) estimates for a set of words that were very similar to estimates made by older children and adults. In Experiment 2, young children's picture recognition, mispronunciation detection, and vocabulary monitoring performance all varied systematically with these AOA estimates and with a stimulus-type (intact-mispronounced) manipulation. Subjective AOA estimates (whether from children or from adults) proved to be a better predictor of performance than did two objective familiarity measures and subjective imageability. These results point to considerable metalexical knowledge on the part of young children or explicit sensitivity regarding their own vocabulary knowledge. In addition, the results lend some support to the notion that actual AOA contributes to subjective AOA estimates.     

Place learning in scopolamine-treated rats: the roles of distal cues and catecholaminergic mediation

Experiments 1 and 2 tested the hypothesis that cholinergic receptor antagonists impair place learning in a water maze by interfering with the processing of distal, visual cues. Extramaze cues were offered to rats in the form of geometrical patterns arranged on the inner circumference of a curtain surrounding the water maze. In Experiment 1 the animals were offered both the distal cues and proximal cues in the form of pingpong balls in fixed positions on the surface of the water while only distal cues were present in Experiment 2. Animals were injected with either scopolamine (0.5 mg/kg body wt) or saline 20 min prior to the daily place learning sessions. Upon reaching criterion level performance the animals were tested on "rotation" sessions on which the distal cues were displaced. The outcome of such "rotations" demonstrated that-regardless of the presence or absence of proximal cues-scopolamine-treated rats relied at least as much as normal animals on the distal cues. The acquisition phase of both Experiments 1 and 2 demonstrated an almost complete lack of scopolamine-associated impairment in acquisition and performance of the place learning task. In Experiment 3 (when scopolamine was no longer administered) the subjects of Experiment 2 were exposed to a series of pharmacological "challenges" of their place learning performance and eventually to surgical ablation of the anteromedial prefrontal cortex. The outcome of the pharmacological challenges and the postoperative test of task performance demonstrated that the place learning performance of animals which had acquired the task under scopolamine was mediated by a neural substrate dissimilar to the substrate of task performance in normal animals. Rats acquiring the task while deprived of the cholinergic system demonstrated above-normal contributions to task mediation from catecholaminergic-probably dopaminergic-mechanisms and tentative results pointed to a "shift" toward prefrontal task mediation.     

Influence of a tone’s tonal function on temporal change detection

Music cognition research has provided evidence that the tonal function of a musical event influences perception and memory. Our study investigated whether tonal function influences a basic temporal judgment, notably the detection of a temporal change disrupting a sequence’s regularity. The sequences consisted of six musical events presented in isochrony (or with the fifth event occurring earlier or later): Three chords (instilling a tonal context) were followed by a tone (repeated three times). The tones fulfilled one of two tonal functions in the tonal context. Participants had to detect whether the sequence contained a temporal change and were not informed about tonal manipulations. Discrimination performance (as measured by d’) showed an influence of tonal function on temporal change detection: Performance was better for the tonic tone (having the most important tonal function in the key) than for the unstable leading tone, the less stable mediant tone, and even than the stable dominant tone. The outcome shows the influence of listeners’ tonal knowledge on a perceptual time judgment and suggests that processing of tonal and temporal structures interact at some stage of processing.     

Assigning Grammatical Gender During Word Production

The present study was designed to examine the processes by which grammatical gender is assigned during word production. French words varied in strength of sublexical cues, based on whether the word ending was typical for one gender rather than neutral about gender, and lexical cues, derived from the associated definite article being uninformative about gender for words beginning with a vowel, but informative for words beginning with a consonant. In Experiment 1, when native French speakers classified the gender of mentally evoked names of pictures, no effects of these cues were obtained. Experiment 2 used an improved methodology, with participants classifying the gender of words translated from English. English-speaking learners of French were influenced strongly by lexical and sublexical cues, while French speakers showed a weaker influence. However, for both speaker groups, words whose gender was classified slowly during recognition were also classified slowly during production, and error rates were similarly correlated across tasks. The conclusion was that gender is not equally available for all words once the associated “lemma” is accessed. Current models of language production may have to incorporate mechanisms allowing differential speed of access to gender information depending on a word’s formal properties.     

Influence of a tone's tonal function on temporal change detection

Music cognition research has provided evidence that the tonal function of a musical event influences perception and memory. Our study investigated whether tonal function influences a basic temporal judgment, notably the detection of a temporal change disrupting a sequence's regularity. The sequences consisted of six musical events presented in isochrony (or with the fifth event occurring earlier or later): Three chords (instilling a tonal context) were followed by a tone (repeated three times). The tones fulfilled one of two tonal functions in the tonal context. Participants had to detect whether the sequence contained a temporal change and were not informed about tonal manipulations. Discrimination performance (as measured by d') showed an influence of tonal function on temporal change detection: Performance was better for the tonic tone (having the most important tonal function in the key) than for the unstable leading tone, the less stable mediant tone, and even than the stable dominant tone. The outcome shows the influence of listeners' tonal knowledge on a perceptual time judgment and suggests that processing of tonal and temporal structures interact at some stage of processing.     

The phenomenology of endogenous orienting

Can we build endogenous expectations about the locus of occurrence of a target without being able to describe them? Participants performed cue-target detection tasks with different proportions of valid and invalid trials, without being informed of these proportions, and demonstrated typical endogenous effects. About half were subsequently able to correctly describe the cue-target relationships ('verbalizers'). However, even non-verbalizer participants showed endogenous orienting with peripheral cues (Experiments 1 and 3), not depending solely on practice (Experiment 2). Explicit instructions did not bring about dramatic advantages in performance (Experiment 4). With central symbolic cues, only verbalizers showed reliable endogenous effects (Experiment 5). We concluded that endogenous orienting with peripheral cues can occur independently of participants developing explicit hypotheses about the cue-target relationships.     

Tonal expectations influence pitch perception

In this study, we investigated the influence of tonal relatedness on pitch perception in melodies. Tonal expectations for target tones were manipulated in melodic contexts while controlling sensory expectations, thus allowing us to assess specifically the influence oftonal expectations on pitch perception. Three experimentsprovided converging evidence that tonal relatedness modulates pitch perception in nonmusician listeners. Experiment 1 showed, with a rating task, the influence of the tonal relatedness of a target tone on listeners' judgments of tuning/mistuning. Experiment 2 showed, with a priming task, that pitch processing of in-tune tones was faster for tonally related targets than for less related targets. Experiment 3 showed, with a comparison task, that discrimination performance for small mistunings was better when the to-be-compared tones were tonally related to the melodic context. Findings are discussed in relation to psychoacoustic research on contextual pitch perception and to studies showing facilitation of early processing steps via knowledge- and attention-related processes.