RT distribution analysis of category congruence effects with masked primes

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.     

After-effects of using a weighted bat on subsequent swing velocity and batters' perceptions of swing velocity and heaviness

In baseball and softball, warm-up swings with a weighted bat have been believed to increase swing velocity when an ordinary bat is used in the subsequent competitive situation. The purpose of this study was to investigate the after-effects of using a weighted bat on subsequent swing velocity and batters' perceptions of swing velocity and heaviness. Eight men in varsity softball and baseball hit a ball suspended from the ceiling 45 times (3 sets of 15 trials). For each set, the initial 5 trials were done using an ordinary 920-g wooden bat (Control condition), and the following 5 trials by a bat with an 800-g bat ring (Weighted condition), and the final 5 trials again by the ordinary bat (post-Weighted condition). Analysis of variance showed a significant decrease of 3.3% in the measured linear velocity of the bat prior to impact with the ball for the first swing of the post-Weighted condition compared with the Control condition. From the second swing the velocity returned to the level of the Control condition. Subjective judgment of the heaviness and velocity of swings for the Weighted and post-Weighted conditions by each participant showed that the ordinary bat felt lighter and swing speed felt faster for the post-Weighted condition. The advantage of the warm-up with a weighted bat was thus psychological and not biomechanical.     

Reading through a noisy channel: why there's nothing special about the perception of orthography

The goal of research on how letter identity and order are perceived during reading is often characterized as one of "cracking the orthographic code." Here, we suggest that there is no orthographic code to crack: Words are perceived and represented as sequences of letters, just as in a dictionary. Indeed, words are perceived and represented in exactly the same way as other visual objects. The phenomena that have been taken as evidence for specialized orthographic representations can be explained by assuming that perception involves recovering information that has passed through a noisy channel: the early stages of visual perception. The noisy channel introduces uncertainty into letter identity, letter order, and even whether letters are present or absent. We develop a computational model based on this simple principle and show that it can accurately simulate lexical decision data from the lexicon projects in English, French, and Dutch, along with masked priming data that have been taken as evidence for specialized orthographic representations.     

Individual differences in the biomechanical effect of loudness and tempo on upper-limb movements during repetitive piano keystrokes

The present study addressed the effect of loudness and tempo on kinematics and muscular activities of the upper extremity during repetitive piano keystrokes. Eighteen pianists with professional music education struck two keys simultaneously and repetitively with a combination of four loudness levels and four tempi. The results demonstrated a significant interaction effect of loudness and tempo on peak angular velocity for the shoulder, elbow, wrist and finger joints, mean muscular activity for the corresponding flexors and extensors, and their co-activation level. The interaction effect indicated greater increases with tempo when eliciting louder tones for all joints and muscles except for the elbow velocity showing a greater decrease with tempo. Multiple-regression analysis and K-means clustering further revealed that 18 pianists were categorized into three clusters with different interaction effects on joint kinematics. These clusters were characterized by either an elbow-velocity decrease and a finger-velocity increase, a finger-velocity decrease with increases in shoulder and wrist velocities, or a large elbow-velocity decrease with a shoulder-velocity increase when increasing both loudness and tempo. Furthermore, the muscular load considerably differed across the clusters. These findings provide information to determine muscles with the greatest potential risk of playing-related disorders based on movement characteristics of individual pianists.     

The masked onset priming effect in naming: computation of phonology or speech planning?

We investigated factors that modulate the presence of the masked onset priming effect in three naming experiments. In Experiment 1, we showed that the masked onset priming effect is found with regular words, but not with exception words, replicating the finding reported by Forster and Davis (1991). In Experiment 2, we used the conditional naming task in which words are mixed with nonwords and participants are instructed to name the item only if it is a word. The masked onset priming effect was eliminated in this experiment, but the regularity effect remained. In Experiment 3, regular and irregular words were mixed randomly, rather than in separate blocks as in Experiment 1. This reduced the size of the regularity effect, and the masked onset priming effect was again absent. We argue that these results, taken as a whole, are better interpreted within the view that the masked onset priming effect has its origin in the preparation of a speech response, rather than within the original dual-route interpretation proposed by Forster and Davis.     

Generation enhances semantic processing? The role of distinctiveness in the generation effect

The goal of the present study was to investigate the locus of the memory advantage for words that are generated according to a nonsemantic rule (letter transposition) over words that are presented intact (read words). In the first two experiments, a category instance generation task was used to test the possibility that the semantic features of generated words are more readily available than those of read words. This possibility was not supported. In Experiment 3, generation effects were found to depend on the level of meaningfulness of words in recall, but not in recognition. In Experiment 4, a between-list design eliminated the generation effect found in recall, but did not affect the generation effect in recognition. Taken together, these findings suggest that generating a target according to a letter transposition rule enhances the distinctiveness of the word along a nonsemantic dimension.     

Hypnotic memory and confident reporting

The effect of hypnosis on the relationship between confidence and accuracy of memory reports is examined. Specifically, the article reviews experimental research that has measured subjects' confidence in their hypnotically influenced memory reports. The findings of this research are discussed in terms of the factors that increase confidence without affecting accuracy, and the factors that decrease accuracy without affecting confidence. The article argues that both the experiential and social factors associated with hypnosis potentially reduce the correspondence between confidence and accuracy of memory. Finally, the article specifies the major implications for further theoretical and empirical work on hypnotic memory and confident reporting.     

Priming of abstract letter identities in the letter match task

Previous studies of letter recognition have not found priming for abstract letter identities. We used a task that required participants to decide whether a target is the same or different from a reference letter presented in opposite case, which avoids the shortcomings of tasks used in previous studies. We found robust priming effects in this task, which were the same size for letter pairs that have similar visual features across case (e.g., c/C, x/X) and dissimilar features (e.g., a/A, b/B). Also, the pattern of priming was the same whether the prime was in the same or different case as the reference. We take these findings as evidence that abstract letter identities support priming in this task. We suggest that the same-different match task is a useful tool for studying representations used to support masked priming in letter recognition and with other stimuli with limited set size.