Task-Irrelevant Context Learned Under Rapid Display Presentation: Selective Attention in Associative Blocking

In the contextual cueing task, visual search is faster for targets embedded in invariant displays compared to targets found in variant displays. However, it has been repeatedly shown that participants do not learn repeated contexts when these are irrelevant to the task. One potential explanation lays in the idea of associative blocking, where salient cues (task-relevant old items) block the learning of invariant associations in the task-irrelevant subset of items. An alternative explanation is that the associative blocking rather hinders the allocation of attention to task-irrelevant subsets, but not the learning per se. The current work examined these two explanations. In two experiments, participants performed a visual search task under a rapid presentation condition (300 ms) in Experiment 1, or under a longer presentation condition (2,500 ms) in Experiment 2. In both experiments, the search items within both old and new displays were presented in two colors which defined the irrelevant and task-relevant items within each display. The participants were asked to search for the target in the relevant subset in the learning phase. In the transfer phase, the instructions were reversed and task-irrelevant items became task-relevant (and vice versa). In line with previous studies, the search of task-irrelevant subsets resulted in no cueing effect post-transfer in the longer presentation condition; however, a reliable cueing effect was generated by task-irrelevant subsets learned under the rapid presentation. These results demonstrate that under rapid display presentation, global attentional selection leads to global context learning. However, under a longer display presentation, global attention is blocked, leading to the exclusive learning of invariant relevant items in the learning session.

How to activate students’ natural desire to test themselves

Testing oneself (i.e., doing retrieval practice) is an effective way to study. We attempted to make learners choose to test themselves more often. In Experiment 1, participants were asked how they wanted to study and were given four options: retrieval with no hint (e.g., idea: ______), a two-letter hint (e.g., idea: s____r), a four-letter hint (e.g., idea: se__er), or a presentation trial (e.g., idea: seeker). They tested themselves on the majority of trials. In Experiment 2, when the hint options were removed, they chose restudy rather than pure test on the majority of trials. These findings show that people prefer self-testing over restudy as long as they can get the answer right on the test. However, we would not recommend hints if they impaired learning compared to pure testing. Experiment 3 showed that this was not the case; the three retrieval conditions from Experiment 1 led to equivalent amounts of learning, and all three outperformed the pure presentation condition. We used different materials in Experiment 4 and found that the hints made retrieval slightly less beneficial when the hints made it possible to guess the answers without thinking back to the study phase (e.g., whip: pu__sh). In summary, hints catalyzed people’s intuitive desire to self-test, without any downside for learning, thus making their self-regulated study more enjoyable and effective.

The Nature of Error Consistency in Individuals With Acquired Apraxia of Speech and Aphasia

Purpose The primary characteristics used to define acquired apraxia of speech (AOS) have evolved to better reflect a disorder of motor planning/programming. However, there is debate regarding the feature of relatively consistent error location and type. Method Ten individuals with acquired AOS and aphasia and 11 individuals with aphasia without AOS participated in this study. In the context of a 2-group experimental design, error consistency was examined via 5 repetitions of 30 multisyllabic words. The influence of error rate, severity of impairment, and stimulus presentation condition (blocked vs. random) on error consistency was also explored, as well as between-groups differences in the types of errors produced. Results Groups performed similarly on consistency of error location; however, adults with AOS demonstrated greater variability of error type in a blocked presentation condition only. Stimulus presentation condition, error rate, and severity of impairment did not influence error consistency in either group. Groups differed in the production of phonetic errors (e.g., sound distortions) but not phonemic errors. Conclusions Overall, findings do not support relatively consistent errors as a differentiating characteristic of AOS.

Can model-free reinforcement learning operate over information stored in working-memory?

Model-free learning creates stimulus-response associations. But what constitutes a stimulus? Are there limits to types of stimuli a model-free or habitual system can operate over? Most experiments on reward learning in humans and animals have used discrete sensory stimuli, but there is no algorithmic reason that model-free learning should be restricted to external stimuli, and recent theories have suggested that model-free processes may operate over highly abstract concepts and goals. Our study aimed to determine whether model-free learning processes can operate over environmental states defined by information held in working memory. Specifically, we tested whether or not humans can learn explicit temporal patterns of individually uninformative cues in a model-free manner. We compared the data from human participants in a reward learning paradigm using (1) a simultaneous symbol presentation condition or (2) a sequential symbol presentation condition, wherein the same visual stimuli were presented simultaneously or as a temporal sequence that required working memory. We found a significant effect of reward on human behavior in the sequential presentation condition, indicating that model-free learning can operate on information stored in working memory. Further analyses, however, revealed that the behavior of the participants contradicts the basic assumptions of our hypotheses, and it is possible that the observed effect of reward was generated by model-based rather than model-free learning. Thus it is not possible to draw any conclusions from out study regarding model-free learning of temporal sequences held in working memory. We conclude instead that careful thought should be given about how to best explain two-stage tasks to participants.

Directional collisions during a route-following task

Neurologically normal people tend to collide with objects on the right side more frequently than with objects located on the left side of space. This phenomenon could be attributable to pseudoneglect wherein individuals selectively attend to the left field. The current study investigated this effect using a virtual route-following task that was presented centrally, in the lower field, and in the upper field. Handedness was also examined. Fifty-two participants (four left handed) completed this task, and when presented in the lower field, more left-side collisions emerged. In the upper condition, this bias reversed direction to the expected rightward bias. In the central condition, there was no significant directional bias in collision behavior. An interaction between handedness and presentation condition indicated that left-handed participants experienced more right-side collisions in the central condition. Collectively, these results suggest that directional biases (i.e., left vs. right) in collision behavior are modulated by both location in the visual field (central, upper, or lower) and handedness. (JINS, 2009, 15, 225–230.)

Expanding retrieval practice: An effective aid to preschool children's learning

The benefits of expanding retrieval practice for preschool children were explored in two experiments. In Experiment 1, three groups learned names for six plush toy pigs using expanding retrieval practice, a reward incentive, or a control condition. Reward did not significantly improve learning but retrieval practice doubled recall. In Experiment 2, three groups learned names to soft toys, comparing recall following massed elaborative study with either expanding retrieval practice or expanding re-presentation. Recall was tested after 1 minute, 1 day, and 2 days. A very large effect size ( d = 1.9) indicated the very considerable benefit from expanding retrieval practice over the elaboration condition. Comparison with the re-presentation condition suggested that half of the benefit of expanding retrieval practice came from spaced scheduling and half from retrieval practice. Expanding retrieval practice provides an effective method to improve learning by young children.

Dissociation between Visual Perception of Allocentric Distance and Visually Directed Walking of its Extent

Walking without vision to previously viewed targets was compared with visual perception of allocentric distance in two experiments. Experimental evidence had shown that physically equal distances in a sagittal plane on the ground were perceptually underestimated as compared with those in a frontoparallel plane, even under full-cue conditions. In spite of this perceptual anisotropy of space, Loomis et al (1992 Journal of Experimental Psychology: Human Perception and Performance18 906–921) found that subjects could match both types of distances in a blind-walking task. In experiment 1 of the present study, subjects were required to reproduce the extent of allocentric distance between two targets by either walking towards the targets, or by walking in a direction incompatible with the locations of the targets. The latter condition required subjects to derive an accurate allocentric distance from information based on the perceived locations of the two targets. The walked distance in the two conditions was almost identical whether the two targets were presented in depth (depth-presentation condition) or in the frontoparallel plane (width-presentation condition). The results of a perceptual-matching task showed that the depth distances had to be much greater than the width distances in order to be judged to be equal in length (depth compression). In experiment 2, subjects were required to reproduce the extent of allocentric distance from the viewing point by blindly walking in a direction other than toward the targets. The walked distance in the depth-presentation condition was shorter than that in the width-presentation condition. This anisotropy in motor responses, however, was mainly caused by apparent overestimation of length oriented in width, not by depth compression. In addition, the walked distances were much better scaled than those in experiment 1. These results suggest that the perceptual and motor systems share a common representation of the location of targets, whereas a dissociation in allocentric distance exists between the two systems in full-cue conditions.

The Influence of Multiple Presentations on Judgments of Children's Phonetic Accuracy

Two experiments examined whether listening to multiple presentations of recorded speech stimuli influences the reliability and accuracy of judgments of children's speech production accuracy. In Experiment 1, 10 listeners phonetically transcribed words produced by children with phonological impairments after a single presentation and after the word was played 7 times. Inter- and intratranscriber reliability in the single- and multiple-presentation conditions did not differ significantly. In Experiment 2, 18 listeners provided binary correct/incorrect judgments of /s/ accuracy in single- and multiple-presentation conditions. There was no systematic effect of presentation condition on either accuracy or intrarater reliability. However, greater interrater reliability was noted in the multiple-presentation condition, particularly for tokens of /s/ that were incorrect or acoustically intermediate between an incorrect and a correct /s/. Taken together, the results suggest that multiple presentations have no measurable effect on the accuracy and intrarater reliability of judgments of children's phonetic accuracy, but that they do have a small effect on interrater reliability. Clinical implications are discussed.

Effects of Bilingual and Monolingual Presentations and Time on Concept- and Language-Matching Tasks

Balanced Turkish-English bilingual participants viewed word pairs, presented both monolingually (English-English or Turkish-Turkish) or bilingually (English-Turkish or Turkish-English) and both for short and long durations. They made decisions on whether the simultaneously presented words in a pair were in the same language or not, or whether they denoted the same concept or not. In the short presentation condition, we found no evidence for subliminal processing. In cases in which both words were consciously identified, participants were more accurate, although not faster in the long than in the short presentation condition for both language and concept decisions. In the long presentation condition, language decisions were more accurate than concept decisions, although not faster. In addition, language decisions were not affected by whether the words were synonyms (concept identity), and concept decisions were not affected by whether the presentation was monolingual or bilingual (language identity), although in the monolingual conditions, “same” decisions were faster but not more accurate, and in the bilingual conditions a speed-accuracy trade-off was observed in that “same” decisions were faster but “different” decisions were more accurate.