Perceptual Sensitivity and Motoric Competence in 5- and 6-Month-Old Infants

The authors explored whether 5- to 6-month-old infants were sensitive to perceptual information and how they used perception as a recognition cue to search for a hidden object. In addition, the authors categorized and examined infant grasp by developmental effectiveness to determine any impact on infant search behaviors. In a within-participants design, 20 infants were presented with a toy in 2 occluder conditions. The toy was hidden under either a thick, camouflaging cloth or a thin, semitransparent cloth. The data revealed significant effects of perceptual sensitivity, age, and motor sophistication on search tasks. The results suggest that motor competence might be a limiting factor in infants' abilities to link motoric responses to notions about an object.     

Effects of translational background motion on visual localization

Three subjects were asked to judge the position of small spots of light flashed before, during or after rapid translational motion of the background grating pattern. Mislocalization of the spots was observed when the background moved during or immediately after presentation of the spot. In both cases, mislocalization always occurred in the direction of the fixation point. Furthermore, this mislocalization occurred only when the background moved in the opposite direction to the visual half-field in which the spot appeared. That is to say, a spot to the right of the fixation point was mislocalized when its background moved to the left, but not when it moved to the right, and the converse was also true. This finding was interpreted as reflecting a long-term adaptation to the optokinetic stimulation that we experience during forward and backward locomotion.     

Disfluency characteristics of 2-, 4-, and 6- yr-old males

Fluency characteristics of 36 nonstuttering males aged 2, 4, and 6 yr are presented in terms of patterns of disfluency and relationships among disfluency variables. The most frequently occuring disfluency types at each age level were revision-incomplete phrase and interjections; the least noted type was part-word repetitions for 2- and 4-yr olds and disrhythmic phonations for 6-yr-olds. Patterns of disfluency appear to be similar at all age levels studied, except that the 2-yr-old pattern showed greater magnitudes in various disfluency types. A range exists in the relationships among individual disfluency types, from moderately strong relationships between, for example, revision-incomplete phrase and interjections to lack of linear relationships between, for example, interjections and phrase repetitions. A linguistic factor may be strong within certain disfluency types. e.g., revision-incomplete phrase, interjections, and word repetitions, whereas a motor factor may be operative in others, e.g., part-word repetitions and disrhythmic phonations.     

空间距离对视觉工作记忆巩固的影响

以往研究发现,个体对不同类型的视觉信息进行视觉工作记忆巩固的模式存在差异,如对于方向信息,一次只能有一个项目被巩固进入视觉工作记忆系统,而对于颜色信息,个体则可以一次巩固两个项目进入视觉工作记忆系统。但对于视觉信息的巩固模式是否会受其他因素的影响,目前仍然没有明确的定论。本研究将探讨视觉信息的巩固模式是否可能受到记忆项目空间距离因素的影响。研究采用变化觉察范式、序列-同时呈现操作及控制记忆项目呈现间距的方法,通过3个实验考察记忆项目之间的空间距离是否能够影响个体对颜色信息和方向信息的巩固模式。在三种空间距离水平上序列呈现或同时呈现两个记忆项目,实验结果一致发现记忆项目之间的空间距离会对视觉工作记忆巩固模式产生明显影响,个体在同时呈现条件下的正确率会随着空间距离的增大而降低。这些结果表明对同一类视觉信息进行巩固的过程中所存在的项目数量限制并不是固定的,个体可以采用序列模式或有限容量的并行模式对同一类信息进行巩固,巩固的模式可能与视觉空间注意的分配以及视觉信息所能获得的注意资源有关。     

Effects of circular motion on judgment of rotation direction and depth order in visual motion

Abstract:  The rotation direction and depth order of a rotating sphere consisting of random dots often reverses while it is viewed under orthographic projection. However, if a short viewing distance is simulated under perspective projection, the correct rotation direction can be perceived. There are two motion cues for the rotation direction and depth order. One is the speed cue; points with higher velocities are closer to the observer. The other is the vertical motion cue; vertical motion is induced when the dots recede from or approach the observer. It was examined whether circular motion, which does not have any depth information but induces vertical velocities, masks the vertical motion cue. In Experiment 1, the effects of circular motion on the judgment of the rotation direction of a rotating sphere were examined. The magnitude of the two cues (the speed cue and the vertical velocity cue) as well as the angular speed of circular motion was varied. It was found that the performance improved as the vertical velocity increased and that the speed cue had slight effects on the judgment of the rotation direction. It was also found that the performance worsened as the angular speed of the circular motion was increased. In Experiment 2, the effects of circular motion on depth judgment of a rotating half sphere were investigated. The performance worsened as the angular speed of the circular motion increased, as in Experiment 1. These results suggest that the visual system cannot compensate perfectly for circular motion for the judgment of the rotation direction and depth order.     

A comparison of disconfirmatory, confirmatory and control strategies on Wason's 2-4-6 task

Attempts to instruct subjects to falsify on inference tasks designed to model scientific problem-solving have indicated that, in most cases, falsification does not lead to improved performance. The only study in which instructions to falsify did improve performance was done with groups, using a novel inference task. The present study is an attempt to replicate the success of falsification in the group study with subjects run individually on an inference task that has been used extensively in the literature: Wason's 2-4-6 problem. Each subject was run in one of three strategy conditions: confirmatory, disconfirmatory or control (no-strategy).

Results indicated that subjects in the disconfirmatory condition solved the 2-4-6 problem significantly more often than subjects in other conditions. The superior performance of disconfirmatory subjects was explained by the fact that they deliberately sought and obtained significantly more falsificatory information than subjects in other conditions.

The critical difference between this study and previous attempts to instruct individual subjects to falsify on the 2-4-6 task is that subjects in the present study were given no feedback as to whether their guesses were right or wrong until the experiment was over. The implications of this result for scientific problem-solving are discussed.     

Effects of visual information on adults' and infants' auditory statistical learning

Infant and adult learners are able to identify word boundaries in fluent speech using statistical information. Similarly, learners are able to use statistical information to identify word-object associations. Successful language learning requires both feats. In this series of experiments, we presented adults and infants with audio-visual input from which it was possible to identify both word boundaries and word-object relations. Adult learners were able to identify both kinds of statistical relations from the same input. Moreover, their learning was actually facilitated by the presence of two simultaneously present relations. Eight-month-old infants, however, do not appear to benefit from the presence of regular relations between words and objects. Adults, like 8-month-olds, did not benefit from regular audio-visual correspondences when they were tested with tones, rather than linguistic input. These differences in learning outcomes across age and input suggest that both developmental and stimulus-based constraints affect statistical learning.     

Interactions of reading and semantics along the ventral visual processing stream

Converging evidence supports a distributed-plus-hub view of semantic processing, in which there are distributed modular semantic sub-systems (e.g., for shape, colour, and action) connected to an amodal semantic hub. Furthermore, object semantic processing of colour and shape, and lexical reading and identification, are processed mainly along the ventral stream, while action semantic processing occurs mainly along the dorsal stream. In Experiment 1, participants read a prime word that required imagining either the object or action referent, and then named a lexical word target. In Experiments 2 and 3, participants performed a lexical decision task (LDT) with the same targets as in Experiment 1, in the presence of foils that were legal nonwords (NW; Experiment 2) or pseudohomophones (PH; Experiment 3). Semantic priming was similar in effect size regardless of prime type for naming, but was greater for object primes than action primes for the LDT with PH foils, suggesting a shared-stream advantage when the task demands focus on orthographic lexical processing. These experiments extend the distributed-plus-hub model, and provide a novel paradigm for further research.     

Effects of approach velocity and foot-target characteristics on the visual regulation of step length.

Two questions emerge from the literature concerning the perceptual-motor processes underlying the visual regulation of step length. The first concerns the effects of velocity on the onset of visual control (VCO), when visual regulation of step length begins during goal-directed locomotion. The second concerns the effects of different obstacles such as a target or raised surface on step length regulation. In two separate experiments, participants (Experiment 1 & 2: n=12, 6 female, 6 male) walked, jogged, or sprinted towards an obstacle along a 10 m walkway, consisting of two marker-strips with alternating black and white 0.50 m markings. Each experiment consisted of three targeting or obstacle tasks with the requirement to both negotiate and continue moving (run-through) through the target. Five trials were conducted for each task and approach speed, with trials block randomised between the six participants of each gender. One 50 Hz video camera panned and filmed each trial from an elevated position, adjacent to the walkway. Video footage was digitized to deduce the gait characteristics. Results for the targeting tasks indicate a linear relationship between approach velocity and accuracy of final foot placement (r=0.89). When foot placement was highly constrained by the obstacle step length shortened during the entire approach. VCO was found to occur at an earlier tau-margin for lower approach velocities for both experiments, indicating that the optical variable 'tau' is affected by approach velocity. A three-phase kinematic profile was found for all tasks, except for the take-off board condition when sprinting. Further research is needed to determine whether this velocity affect on VCO is due to 'whole-body' approach velocity or whether it is a function of the differences between gait modes.     

The lateral effects of Dohsa-method relaxation on visual and auditory responses

The effects of relaxation training, using the Dohsa method, on visual and auditory responses were examined. Twelve college students underwent relaxation training either to the left shoulder, left side of the waist, and the left foot, or to the right side. The measures used in this study were weight-bearing, body perception and external perception, visual field, and visual and hearing acuity. Weight-bearing significantly increased for the foot undergoing relaxation training, compared with the untreated foot, indicating that the subjects stood more firmly on the ground on the relaxed foot. Subjects could also perceive positive changes in their "sense of standing firmly on the ground,""sense of activity in the body,""sense of muscular relaxation," and "sense of fullness in the abdomen" on the side of the body receiving relaxation training. There were positive changes in external perception such as "vividness of the external world,""breadth of the visual field," and "active impression of the external world" for subjects' vision on the side receiving relaxation training. Furthermore, visual and hearing acuity on the side on which relaxation training was administered improved significantly.     

Disconfirmation and dual hypotheses on a more difficult version of wason's 2-4-6 task

This paper reports two experiments in which subjects worked to solve a more difficult version of Wason's 2-4-6 task: instead of the usual “numbers must ascend in order of magnitude” rule, a more general rule, “the three numbers must be different”, was used. The first experiment established that instructing subjects to disconfirm on the “three different numbers” did not significantly improve their performance, as compared with confirmatory and control groups. Disconfirmatory subjects did try to propose more triples at variance with their hypotheses but were unable to obtain the necessary disconfirmatory information.

To help subjects represent the task in a way that facilitated disconfirmation, the second experiment utilized a procedure in which subjects were told that they were looking for two rules, Dax and Med-the Dax rule corresponding to “three different numbers” and the Med rule to its complement, i.e. two or more numbers the same. Of subjects in the Dax-Med condition, 88% solve the rule, as opposed to 21% of subjects in a control condition. Dax-Med subjects tended to search for positive instances of the Med rule, which, in turn, forced them to test the limits of the Dax rule. It was concluded that the Dax-Med manipulation did facilitate a different mental representation of the task than the normal procedure.     

Effects of contextual interference, task difficulty, and levels of processing on pursuit tracking

Based on an activity questionnaire, 48 females without experience in open sports skills were selected to track a moving light beam through either a circle, square, or triangular target area on a pursuit rotor. Contextual interference was created by presenting 5 velocities in either a random or a blocked context during acquisition. Level of processing was manipulated by having half of all subjects classify acquisition velocities by a predetermined numerical code. Time-on-target (TOT) was measured after each acquisition, retention, and transfer trial. Subjects tracking the circle produced higher TOTs than those who tracked the square or triangle (which did not differ from one another) across all three phases of the experiment; blocked and random acquisition groups were not significantly different from one another in acquisition, retention, or transfer. Subjects who classified acquisition velocities and tracked the circle under the blocked acquisition context produced significantly higher retention scores than those who tracked the circle but did not classify acquisition velocities. Transfer was facilitated for subjects who tracked the triangle in a random transfer context and classified velocities during acquisition. Results were discussed as providing support for the manipulation of the level of cognitive processing during the initial stage of learning. In addition, manipulating task difficulty was discussed.     

Effects of angularity of the figures with sharp and round corners on visual evoked potentials

Following a study in which equilateral triangles elicited larger visual evoked potentials (VEPs) than either squares or circles, we examined the effect of single-line angular figures with a sharp or a round corner at angles of 45°, 90°, 135° or 180°. VEPs were recorded monopolarly at four locations on the midline of scalp for 10 subjects, while the figure was tachiscopically presented to the lower visual field. Subtracted waves were obtained between figure and control (blank) conditions. N1 (peak latency 135–142 ms) and P2 (235–237 ms) waves were identifiable. N1 amplitude tended to decrease as a function of angularity, irrespective of orientation (angle pointing up or down). The effect of the sharpness/roundness of the corner was much smaller than that of its angularity. These findings suggest that the greater VEP response with triangles than with squares and circles may be attributable to the acute angularity of triangles. Related cortical processes and VEP components are also discussed.     

Comparison of chemosensory, auditory and visual event-related potential amplitudes

To enhance understanding of neuropsychological processing underlying chemosensory event-related potentials (CSERPs), the objective of the present study was to compare CSERPs with auditory (AERPs) and visual event-related potentials (VERPs), and to approach the question of similarities in neuropsychological processing by means of correlation and cluster analyses. A multisensory ERP protocol was used, in which olfactory/chemosomatosensory (pyridine), auditory (1000-Hz tone) and visual (white circle) stimuli were presented in a pseudo-randomized sequence to 18 young, healthy adults. The results show (1) a morphological relation between P2 and P3 components that is different for the chemosensory than for the auditory and visual modalities, (2) a relatively weak association between the chemosensory and auditory/visual modalities for P3 in terms of both correlation and cluster, and (3) a P2/P3 cluster for the chemosensory but not auditory or visual modality. This supports the claim that the chemosensory P2 and P3 components reflect similar neuropsychological processes.     

Creativity and inductive reasoning: The relationship between divergent thinking and performance on wason's 2-4-6 task

This study was an investigation of the relationship between potential creativity—as measured by fluency scores on the Alternate Uses Test—and performance on Wason's 2-4-6 task. As hypothesized, participants who were successful in discovering the rule had significantly higher fluency scores. Successful participants also generated higher frequencies of confirmatory and disconfirmatory hypotheses, but a multiple regression analysis using the stepwise method revealed that the frequency of generating disconfirmatory hypotheses and fluency scores were the only two significant factors in task outcome. The results also supported earlier studies where disconfirmation was shown to play a more important role in the later stages of hypothesis testing. This was especially true of successful participants, who employed a higher frequency of disconfirmatory hypotheses after receiving feedback on the first announcement. These results imply that successful participants benefited from the provision of feedback on the first announcement by switching to a more successful strategy in the hypothesis-testing sequence.     

The effect of inversion on 3- to 5-year-olds’ recognition of face and nonface visual objects

This study compared the effect of stimulus inversion on 3- to 5-year-olds’ recognition of faces and two nonface object categories matched with faces for a number of attributes: shoes (Experiment 1) and frontal images of cars (Experiments 2 and 3). The inversion effect was present for faces but not shoes at 3 years of age (Experiment 1). Analogous results were found for boys when faces were compared with frontal images of cars. For girls, stimulus inversion impaired recognition of both faces and cars at 3 to 4 years of age, becoming specific to faces only at 5 years of age (Experiments 2 and 3). Evidence demonstrates that the ability to extract the critical cues that lead to adults’ efficient face recognition is selectively tuned to faces during preschool years.     

The Effects of Relaxation and Postural Training on External Perception: Improvement of Visual Acuity, Visual Field, and Hearing Acuity

This study examined the effects of muscular relaxation and postural training on external perception using a visual acuity test, a visual field test, and a hearing acuity test. Eighteen undergraduate students were randomly assigned to experimental and control groups. The experimental group underwent muscular relaxation and postural training. Each subject in this group was administered the tests before and after the training. Each subject in the control group carried out the tests before and after participating in a 30-min conversation with the experimenter. On all three tests, the experimental group improved significantly more than the control group.