Response to an intervening event reverses nonspatial repetition effects in 2AFC tasks: Nonspatial IOR?

The repetition effect in two-alternatiave forced choice (2AFC) tasks is a cornerstone effect in human cognition. Yet the experiments described here show that the customary benefit of repetition reverses to a cost of repetition when participants respond to an irrelevant event between targets. In Experiments 1A-1C, participants made manual 2AFC decisions to both of two consecutive targets on a trial and, on some trials, also made a manual response to an intervening event that appeared between the two targets. A repetition benefit was observed when no intervening event appeared, whereas a repetition cost was observed when a response was required to an intervening event. Experiment 2 ruled out a solely strategic interpretation of the repetition cost effect observed on intervening event trials. In Experiments 3A and 3B, an intervening event that required a simple vocal "go" response also produced a repetition cost. In Experiment 4, a repetition cost was observed when the intervening event was changed to a tone presented aurally. In Experiment 5, the repetition benefit was observed when a response was withheld to an intervening event. A dual-process interpretation of these results is discussed, with one process related to episodic integration, and the other related to processes that produce inhibition of return.     

Changes in repeated references: Collaboration or repetition effects?

According to the Clark & Wilkes-Gibbs' collaborative model of reference, the repetition of a referential communication task produces changes in the making of references (decreasing number of words and of turns with the passing trials, increasing number of definite references and of labels), and these changes are interpreted as revealing the outgrowth of a collaborative process aiming at mutual understanding at the lowest cost. Using a repeated referential paradigm but without any physically present interlocutor, the present study aimed at answering the question of whether these changes are attributable to the mere repetition of the referential task. In adifferent addressee (DA) condition, the subjects were told before each new trial that what they would say would be presented later to another person; in asame addressee 9SA) condition, the subjects were told before each new trial that what they would say would be presented to the same person. With the passing trials, the subjects in the DA condition produced more and more words, but did not use any definite references or labels: These observations have no common point with the ones obtained within a conversational framework. The data obtained from speakers in the SA condition were only slightly different and far from being close to the ones gained in referential dialogues: The number of words remains constant, there was only a slight increase of definite references, and there were no labels. Repetition itself clearly cannot account for the changes in referring that have been reported in recent studies of how subjects cooperate in the making of references.This research was partly supported by a project grant from the National Fund for Scientific Research (Belgium) to Y. Chantraine, research assistant at the University of Louvain in Belgium.     

Why do categorization effects occur in comparative judgment tasks?

Three experiments were conducted to understand what eliminates the symbolic distance effect for reaction times (RTs) when subjects learn that items belong to categories. Artificial city locations were judged, and artificial states served as categories. In Experiment 1, whether or not categories were presented and the amount of categorization practice were manipulated. Only those subjects who had practice categorizing cities into states showed a reduced symbolic distance effect for different-state pairs. Analyses of serial position curves indicated that categorization produced faster RTs to different-as compared with their adjacent same-state pairs and it also produced faster RTs for same-state pairs closer to the category border. The border seems to serve as an anchor and facilitates RTs. In Experiments 2a and 2b, distance judgments were made by subjects who either had or had not categorized artificial cities into states. Subjects who learned categories gave larger estimates of distance between cities belonging to different states than to cities belonging to the same state. Categorization seemed to place cities from different states farther apart in psychological space, making their locations more discriminable. This, along with the use of the category border as an anchor, might explain why categorization effects occur in this location judgment task.     

Importance effects on performance in event‐based prospective memory tasks

In the present study we manipulated the importance of performing two event‐based prospective memory tasks. In Experiment 1, the event‐based task was assumed to rely on relatively automatic processes, whereas in Experiment 2 the event‐based task was assumed to rely on a more demanding monitoring process. In contrast to the first experiment, the second experiment showed that importance had a positive effect on prospective memory performance. In addition, the occurrence of an importance effect on prospective memory performance seemed to be mainly due to the features of the prospective memory task itself, and not to the characteristics of the ongoing tasks that only influenced the size of the importance effect. The results suggest that importance instructions may improve prospective memory if the prospective task requires the strategic allocation of attentional monitoring resources.     

Are three-sample tasks less sensitive than two-sample tasks? Memory effects in the testing of taste discrimination

In order to provide insights into why discrimination protocols with three stimuli sometimes tend to be less sensitive than protocols with two stimuli, two experiments were conducted. In these experiments, the relative effects of memory decay and memory interference were investigated. Both experiments involved purified water and/or solutions of low NaCl concentration. In Experiment 1, three protocols were compared: the traditional same-different test (Protocol 1), the same protocol with a rinse between the two samples (Protocol 2), and Protocol 2 with an added time delay between the first sample and the intermediate rinse (Protocol 3.) The decrease in measured d' values as time delay increased indicated that memory decay might be a factor for tests with three stimuli, such as the triangle method, rendering it less sensitive than tests with two stimuli, such as the same-different method. In Experiment 2, four protocols were compared: the traditional same-different test, the two-rinse same-different test, the triangle test, and what will be called duo same-different test. The experimental design allowed the individual consideration of memory decay and interference effects. From this last experiment, the substantial effect of memory interference was uncovered. Further experimentation will be necessary to estimate the exact relative effects of memory interference and memory decay.     

Do zoo visitors induce attentional bias effects in primates completing cognitive tasks?

Animal Cognition - While previous research has focused on the impact of visitors on zoo-housed animals’ behavior, here, we evaluated the impact of visitors on the performance of four...     

Memory cueing and instructional effects on Wason’s selection task

The present study examined the hypothesis that violation and role-playing instructions are necessary conditions for facilitation on Wason’s selection task and that facilitation due to memory cueing via thematic content is secondary. The results of a factorial experiment employing these factors did not support the hypothesis. Memory cueing was indicated as the primary factor, but violation instructions did increase the amount of facilitation observed. This interactive effect and the nature of facilitation by memory cueing are briefly discussed.     

Interference effects of stimulus–response modality pairings in dual tasks and their robustness

Recent evidence suggests that the degree of interference in dual-task situations depends crucially on the pairings of input- and output modalities of the two component tasks with increased dual-task costs for modality incompatible (i.e., visual–vocal and auditory–manual) compared to modality compatible (i.e., visual–manual and auditory–vocal) dual tasks. These effects of modality pairings in dual tasks have been related to the overlap of non-preferred processing pathways in modality incompatible tasks. Until now, modality compatibility has not yet been related to other sources of interference in a dual-task context, such as stimulus–response (S–R) compatibility or crosstalk. In the present study, we conducted two experiments using the paradigm of the psychological refractory period (PRP) to test the effects of S–R compatibility and crosstalk on the effects of modality compatibility in temporally overlapping task situations. Experiment 1 revealed an overadditive interaction between stimulus onset asynchrony and modality compatibility for tasks with S–R compatible mappings, indicating that modality compatibility effects are present in different task situations, even when S–R mappings are otherwise compatible. In Experiment 2, we aimed at pinpointing the boundaries of the effects of modality compatibility in dual-task situations. We showed that additional sources of dual-task interference in a modality compatible dual task could overwrite the pronounced PRP effect previously shown for modality incompatible tasks. Taken together, these data provide new evidence that the specific types of stimulus–response modality pairings are an additional factor that might interact with other sources of interference in dual-task situations.     

Taking the “text” out of context effects in repetition priming of word identification

Repetition priming of masked word identification is reduced when initial exposure to target words is in a text rather than in a word list. We demonstrate that there is nothing special about the text context that reduces priming. In Experiment 1, target words read in normal text or in rapid serial visual presentation (RSVP) text--either coherent or scrambled--produced similarly reduced priming, relative to the same words read aloud in a list. In Experiment 2, the delay was decreased between study and test for words presented in text, but they still displayed less priming than did words presented in a study list and tested after an equivalent delay. In Experiment 3, presenting study list words in RSVP to prevent reading each word aloud diminished priming to the same level as that in the text context. We conclude that presenting a target in context prevents it from being encoded and responded to as distinctively as when presented in isolation.     

Common features of the “repetition” and “same-different” effects in reaction time experiments

Using comparable stimulus and response sets, and the same Ss, the “repetition” and “same-different” effects were studied in two experiments involving several reaction-time (RT) tasks. In Experiment 1, these effects were examined at a 2-sec interval between successive stimuli in the simple (SRT), the recognition (RRT), the choice (CRT), the same-different recognition(S-DRRT),and the same-different choice (S-DCRT) tasks. In Experiment 2, the effects were studied at a 1 O-sec interval in the CRT and S-DCRT tasks. The results suggest the following mainconclusions: (1)The positive repetition effect (i.e., shorter reaction times on “repeated” trials than on “nonrepeated” trials) is not only a feature of the CRT task but may also occur in the SRT and RRT tasks. (2) With increasing intertrial interval, the magnitude of the positive repetition effect diminishes and then reverses into a negative repetition effect. (3) The positive same-different effect (ie., shorter reaction times on “same” trials than on “different” trials) is affected by an increase in interstimulus interval ina manner that parallels the effect of intertrial interval on the positive repetition effect, suggesting that the processes underlying the two effects are mainly the same. (4) These changes in the magnitude and direction of the repetition and same-different effects are probably a function of discrimination difficulty.     

How does processing affect storage in working memory tasks? Evidence for both domain-general and domain-specific effects

Two studies that examine whether the forgetting caused by the processing demands of working memory tasks is domain-general or domain-specific are presented. In each, separate groups of adult participants were asked to carry out either verbal or nonverbal operations on exactly the same processing materials while maintaining verbal storage items. The imposition of verbal processing tended to produce greater forgetting even though verbal processing operations took no longer to complete than did nonverbal processing operations. However, nonverbal processing did cause forgetting relative to baseline control conditions, and evidence from the timing of individuals' processing responses suggests that individuals in both processing groups slowed their responses in order to "refresh" the memoranda. Taken together the data suggest that processing has a domain-general effect on working memory performance by impeding refreshment of memoranda but can also cause effects that appear domain-specific and that result from either blocking of rehearsal or interference.     

A short‐term perceptual priming account of spacing effects in explicit cued‐memory tasks for unfamiliar stimuli

Memory for repeated items improves when presentations are spaced during study. This effect is found in explicit memory tasks using different types of material, different experimental paradigms, and in different subject populations. Two experiments are described where the spacing effect was assessed on a yes/no recognition memory task using words and nonwords as targets. The main results showed that changing the font between repeated occurrences of targets at study did not affect the spacing effect for words, even under shallow encoding conditions, but effectively removed the spacing effect with nonwords. In both experiments, the font manipulation was made between subjects, ruling out explanations in terms of differential attention to particular font conditions. These results provide further support for short‐term perceptual priming accounts of the spacing effect: Semantically‐based repetition priming affects memory for words; perceptual priming mechanisms affect memory for nonwords.     

Peripheral spatial cues modulate spatial congruency effects: Analysing the “locus” of the cueing modulation

The spatial Stroop effect (slower left/right responses to left/right pointing arrows when they appear at spatially incongruent than at congruent locations) has often been used to examine the processing of irrelevant spatial information. We present data from two experiments in which the magnitude of such location-based interference is drastically reduced when the location of the arrow is precued by a spatial noninformative cue. The main aim of the present study was to clarify whether such modulation takes place at perceptual or at response-related stages of processing. First, we manipulated the spatial compatibility between the direction of the arrow and the location of the response so that each subject would respond with spatially compatible vs. incompatible key presses for each half of the experiment. We found that such manipulation did not have any effect on the standard reduction of the congruency effect by peripheral cues. In a second experiment, subjects made left/right key presses to directional arrows pointing bottom/up, which could appear equally often at left/right/bottom/up locations. In cued trials, we found a reduction of the congruency effect on the vertical axis (stimulus location-direction congruency), whereas congruency was unaffected by cueing in targets presented on the horizontal axis (stimulus-response location congruency). According to these results, we conclude that spatial noninformative cues modulate spatial Stroop interference by reducing the conflict between stimulus dimensions at perceptual- rather than motor-related stages of processing.     

Who is susceptible in three false memory tasks?

ABSTRACT

Decades of research show that people are susceptible to developing false memories. But if they do so in one task, are they likely to do so in a different one? The answer: “No”. In the current research, a large number of participants took part in three well-established false memory paradigms (a misinformation task, the Deese-Roediger-McDermott [DRM] list learning paradigm, and an imagination inflation exercise) as well as completed several individual difference measures. Results indicate that many correlations between false memory variables in all three inter-paradigm comparisons are null, though some small, positive, significant correlations emerged. Moreover, very few individual difference variables significantly correlated with false memories, and any significant correlations were rather small. It seems likely, therefore, that there is no false memory “trait”. In other words, no one type of person seems especially prone, or especially resilient, to the ubiquity of memory distortion.     

Similarity among tasks is the key to show generalization of cognitive training effects in Alzheimer’s disease: a case study

Cognitive training can allow patients with Alzheimer’s disease (AD) to reinforce individual cognitive abilities. In the present case study, we investigated the generalizability of trained cognitive skills to novel tasks, and their stability over time.

One AD patient underwent a structured cognitive training using the GEO (Geographical Exercise for cognitive Optimization) task, whereas eight AD patients underwent a control cognitive intervention. Participants’ performances on the GEO task, on a similar untrained cognitive task, and on a different untrained cognitive task were recorded before and after the intervention, and at the follow-up. On both the trained and the similar untrained tasks patients’ and controls’ performance significantly differed from one another. Our preliminary evidence shows that a cognitive training could allow patients to improve and maintain their performance not only on the trained task, but also on a similar task.     

What's in a cue? The role of cue orientation in object displacement tasks

The current study looked at two theoretical proposals explaining toddlers’ abilities to use cue information for recovering a hidden object that had rolled down a ramp behind an occluded screen. These two approaches, the theory of object directed attention and a landmark-based account, make different predictions regarding the efficacy of an obliquely aligned cue to object position. Accordingly, the search by forty 24-month olds, forty-two 30-month olds, and forty-one 36-month olds for a hidden toy that was cued using either a short versus a long cue, or a vertically aligned versus an obliquely aligned cue, were compared. Analyses of search accuracy revealed that children were more successful when faced with short as opposed to long cues, and when using vertical as opposed to oblique cues. These findings support a landmark-based approach, as opposed to an object-directed attention account, and are discussed with reference to their implications for spatial orientation more generally.     

Attentional difficulties in children: Weakness in executive function or problems in coping with difficult tasks?

Two groups of children, one with good attention and one with poor attention, as rated by teachers, carried out a computerized visual search task. There were no differences between groups on an easy search for a single target, but when the task was made more difficult by including foils very similar to the targets or requiring alternating search for two different targets, the poor attention group made significantly more errors than the good attention group. The nature of these increases in errors was examined to discover whether they were due to errors specifically on the foils similar to the targets and errors due to failure to alternate. It was found that as well as making more errors of these types, the children with poor attention also showed a greater increase in other types of error (shape confusions, repetitions etc.) from the simple task to the more difficult ones. It is concluded that these findings do not support an explanation of poor attention solely in terms of weaknesses in specific executive functions, but suggest that supplementary or alternative explanations are needed, for example reduced processing capacity or problems in motivation or arousal when coping with difficult tasks.     

What causes the spacing effect? Some effects of repetition,duration, and spacing on memory for pictures

Three experiments examined effects of the spacing of repetitions on memory for pictures. In Experiment I, the duration of the first presentation (P(1)) was manipulated, as was P(1)-P(2) spacing. The effect of spacing on judged frequency was independent of P(1) duration. In Experiment II, pictures were given M massed presentations just prior to the P(M)-P(M+1) spacing interval. The form of the spacing curve was independent of M. Neither experiment confirmed the prediction of "overhabituation," derived from the habituation-recovery explanation of the spacing effect. In Experiment III, subjects made both duration and frequency judgments. The duration judgment results were not consistent with the notion that subjects remember multiple massed presentations as single occurrences of especially long duration. Some evidence from Experiments I and III suggests that an interrupted stimulus is recognized better than one that is not interrupted-a finding that, if replicable, would support the habituation-recovery account of the spacing effect.