Memory & Cognition

Bugg, Julie

doi: 10.3758/MC.36.7.1217pmid: 18927038

Compatibility effects in conflict paradigms are reduced following incompatible trials, and this effect is referred to as conflict adaptation. A perplexing pattern exists, however, with conflict-driven adaptation emerging in several paradigms (e.g., Stroop, Simon) but not consistently in the Eriksen and Eriksen (1974) flanker task. The present experiments address the seemingly elusive presence of conflict adaptation in this task. Experiment 1 shows that a negative-priming-like slowing may be masking conflict adaptation in the flanker task. In Experiment 2, conflict adaptation was revealed when a larger stimulus set designed to reduce negative priming was implemented. Taken together, the findings indicate that a consideration of processes opposing conflict adaptation in the flanker task may help reconcile prior findings.

Wohldmann, Erica; Healy, Alice; Bourne, Lyle

doi: 10.3758/MC.36.7.1228pmid: 18927039

When some perceptual-motor relationships are reversed, participants might adopt a global inhibition strategy that replaces all normal movements with reversed movements. In two experiments, participants practiced moving a cursor from a start position to target locations. In a perceptual-motor reversal condition, in which horizontal but not vertical movements were reversed, participants were trained to move only to certain locations. Testing involved moving to all locations under the same reversal condition. Training on a subset of locations yielded partial transfer to untrained locations. These results support a global inhibition hypothesis modified to include both midcourse corrective movements and training specificity.

Mattson, Paul; Fournier, Lisa

doi: 10.3758/MC.36.7.1236pmid: 18927040

Withholding an action plan in memory for later execution can delay execution of another action if the actions share a similar (compatible) action feature (e.g., response hand). We investigated whether this phenomenon, termed compatibility interference (CI), occurs for responses associated with a target as well as responses associated with distractors in a visual selection task. Participants planned and withheld a sequence of keypress responses (with their right or left hand), according to the identity of a stimulus (A), and then immediately executed a keypress response (with their right or left hand) to a second stimulus (B), according to the identity of a target letter appearing alone or among distractor letters. Distractor letters were either response compatible or incompatible with the target and appeared either simultaneously with the target (Experiments 1A and 2) or 100 msec before the target (Experiment 1B). Also, stimulus—response mapping was either 1:1 (Experiment 1) or 2:1 (Experiment 2). Results showed that the response to the Stimulus B target was delayed when it required the same response hand as Stimulus A, as opposed to a different hand. Also, the target reaction time for Stimulus B was greater when the target was flanked by incompatible distractors than when it was flanked by compatible distractors. Moreover, the degree of CI was consistent across the compatible-, incompatible-, and no-distractor conditions, indicating that CI generalizes to responses associated with a target, but not to those associated with distractors. Thus, CI occurs at a response selection, not at a response activation stage. Implications for the code occupation account for CI (e.g., Stoet & Hommel, 1999, 2002) and an alternative account for CI are discussed.

Vandierendonck, André; Christiaens, Evelien; Liefooghe, Baptist

doi: 10.3758/MC.36.7.1248pmid: 18927041

Task switching research has revealed that task changes lead to a performance switch cost. The present study focuses on the organization of task components in the task set. Three different views of task set organization have been distinguished and evidence in favor of each of these has been reported in the literature. In four experiments, we orthogonally varied the categorization task (magnitude and parity) and the stimulus dimension on which the categorization was to be made. Experiments 1, 2, and 4 used Stroop-like number stimuli, whereas Experiment 3 used global—local stimuli to define the stimulus dimension. In Experiments 2–4, the cue—stimulus interval was also varied. The findings showed that a change of any component resulted in a cost, without any reliable difference in the size of these costs. These results are consistent with the flat view on task-set organization, which assumes that the task set binds all elements in an unstructured representation, which is completely reconfigured each time a change to the task set is required. The implications of these findings are discussed in relation to other findings and the different views on task-set organization.

Maquestiaux, François; Laguë-Beauvais, Maude; Bherer, Louis; Ruthruff, Eric

doi: 10.3758/MC.36.7.1262pmid: 18927042

In this research, the controversial issue of whether the central bottleneck can be bypassed through task automatization was investigated. To examine this issue, participants received six single-task practice sessions with an auditory-vocal task (low vs. high pitch). We then assessed dual-task performance using the analytically tractable psychological refractory period (PRP) paradigm, in which the highly practiced auditory-vocal task was presented as Task 2, along with an unpracticed visual-manual Task 1. The results provide evidence of bottleneck bypass for virtually all the participants (17 out of 20). Several converging tests suggest that the bottleneck reemerged, however, in a follow-up experiment with tasks presented in the opposite order (auditory-vocal Task 1 and visual-manual Task 2). One possible explanation is that tasks greedily recruit central resources when available, even though they can operate without central resources when unavailable.

Stefaniak, Nicolas; Willems, Sylvie; Adam, Stéphane; Meulemans, Thierry

doi: 10.3758/MC.36.7.1283pmid: 18927043

The aim of this study was to explore the role of prior explicit sequence knowledge by comparing its influence on serial reaction time (SRT) performance with either a deterministic or a probabilistic sequence. The results confirm that, with a deterministic sequence, preliminary explicit learning improves SRT performance. On the other hand, with a probabilistic sequence, the results show no advantage for SRT performance in explicitlearning conditions. In addition, by using the process dissociation procedure (Jacoby, 1991), we show that performance on a subsequent generation task was more sustained by controlled processes for participants in the explicit-learning conditions than for those in the incidental condition. On the whole, these results, showing that the influence of explicit knowledge can be suppressed in certain specific conditions, are consistent with the intervention of both implicit and explicit mechanisms in SRT tasks, and the results also show that their relative influence can be modulated by the particular demands of the task.

Perruchet, Pierre; Desaulty, Stéphane

doi: 10.3758/MC.36.7.1299pmid: 18927044

A number of studies have shown that people exploit transitional probabilities between successive syllables to segment a stream of artificial continuous speech into words. It is often assumed that what is actually exploited are the forward transitional probabilities (given XY, the probability that X will be followed by Y ), even though the backward transitional probabilities (the probability that Y has been preceded by X) were equally informative about word structure in the languages involved in those studies. In two experiments, we showed that participants were able to learn the words from an artificial speech stream when the only available cues were the backward transitional probabilities. Learning is as good under those conditions as when the only available cues are the forward transitional probabilities. Implications for some current models of word segmentation, particularly the simple recurrent networks and PARSER models, are discussed.

Chen, Lillian; Boland, Julie

doi: 10.3758/MC.36.7.1306pmid: 18927045

Two eyetracking-during-listening experiments showed frequency and context effects on fixation probability for pictures representing multiple meanings of homophones. Participants heard either an imperative sentence instructing them to look at a homophone referent (Experiment 1) or a declarative sentence that was either neutral or biased toward the homophone’s subordinate meaning (Experiment 2). At homophone onset in both experiments, the participants viewed four pictures: (1) a referent of one homophone meaning, (2) a shape competitor for a nonpictured homophone meaning, and (3) two unrelated filler objects. In Experiment 1, meaning dominance affected looks to both the homophone referent and the shape competitor. In Experiment 2, as compared with neutral contexts, subordinate-biased contexts lowered the fixation probability for shape competitors of dominant meanings, but shape competitors still attracted more looks than would be expected by chance. We discuss the consistencies and discrepancies of these findings with the selective access and reordered access theories of lexical ambiguity resolution.

Kinoshita, Sachiko; Hunt, Louise

doi: 10.3758/MC.36.7.1324pmid: 18927046

Macquarie University, Sydney, New South Wales, Australia In the number magnitude decision task (“Is the number bigger/smaller than 5?”), response to a target (e.g., 3) is faster following a masked prime congruent with the target (e.g., 1) than it is following an incongruent prime (e.g., 9). This category congruence effect has been reported to be “interference-dominant” relative to a neutral prime (e.g., the # sign, the number 5) on the basis of the analysis of mean response time (RT). Using RT distribution analysis as well as mean RTs, we identified two bases for this pattern. One relates to the choice of neutral baseline: The # prime, unlike the digit prime, does not factor in the cost of perceptual transition between the prime and target, and therefore underestimates facilitation and overestimates the interference effect. The second basis of the interference-dominant pattern is a disproportionate slowdown of congruent trials in the slow RT bins. Furthermore, this slowdown is greater for primes that had been used as targets than it is with “novel” primes that have not been responded to as targets. We interpret the results as suggesting that the category congruence effect has two components with different time courses—one based on stimulus-response mapping, and the other on semantic categorization.

Harris, Harlan; Murphy, Gregory; Rehder, Bob

doi: 10.3758/MC.36.7.1335pmid: 18927047

New concepts can be learned by statistical associations, as well as by relevant existing knowledge. We examined the interaction of these two processes by manipulating exemplar frequency and thematic knowledge and considering their interaction through computational modeling. Exemplar frequency affects category learning, with high-frequency items learned more quickly than low-frequency items, and prior knowledge usually speeds category learning. In two experiments in which both of these factors were manipulated, we found that the effects of frequency are greatly reduced when stimulus features are linked by thematic prior knowledge and that frequency effects on single stimulus features can actually be reversed by knowledge. We account for these results with the knowledge resonance model of category learning (Rehder & Murphy, 2003) and conclude that prior knowledge may change representations so that empirical effects, such as those caused by frequency manipulations, are modulated.