Reliability and Specificity of Individual Differences In Reminiscence

In investigating Eysenck’s (1965) suggestion of the specificity of reminiscence, 50 high school boys were tested on 2 gross motorcoordination tasks—one involving tracking and the other balance. In the practice schedule, which was identical for both tasks, all Ss were given 20 50-sec. trials with a 10-sec. intertrial rest. A 5-min. interpolated rest was given after every fourth trial. The reliability of individual differences in reminiscence for both tasks was found to be extremely low. While Eysenck’s hypothesis was not necessarily weakened, doubt was cast upon the specificity of reminiscence in the usual context of the word.     

Memory for the Functional Characteristics of Climbing Walls: Perceiving Affordances

In 2 experiments, differences in visual perception of climbing routes (route finding) between 7 expert climbers, 4 novices, and 9 inexperienced participants were studied. In both experiments, participants reproduced on a scale model the locations and orientations of 23 holds of a climbing wall. The results showed that the expert climbers recalled more information and recalled clusters of information and that they focused on the functional aspects of a climbing wall, whereas they neglected its structural features. Inexperienced participants did not recall such clustered information, and they reported almost exclusively the structural features of the holds. The perception of nested affordances and the expert climbers' neglect of details are discussed.     

Slow Motor Responses to Visual Stimuli of Low Salience in Autism

ABSTRACT

The authors studied 2 tasks that placed differing demands on detecting relevant visual information and generating appropriate gaze shifts in adults and children with and without autism. In Experiment 1, participants fixated a cross and needed to make large gaze shifts, but researchers provided explicit instructions about shifting. Children with autism were indistinguishable from comparison groups in this top-down task. In Experiment 2 (bottom-up), a fixation cross remained or was removed prior to the presentation of a peripheral target of low visual salience. In this gap–effect experiment, children with autism showed lengthened reaction times overall but no specific deficit in overlap trials. The results show evidence of a general deficit in manual responses to visual stimuli of low salience and no evidence of a deficit in top-down attention shifting. Older children with autism appeared able to generate appropriate motor responses, but stimulus-driven visual attention seemed impaired.     

Motor Schema Formation and Retention in Young Children

The variability-of-practice hypothesis, a major prediction of Schmidt’s (1975) motor schema theory, was tested in an attempt to investigate motor-schema formation. In addition, schema retention was observed after a 2-week retention interval. The task involved preschool children in tossing a bean bag for appropriate distance. Four treatment groups received 100 practice trials equally divided over five days. Variation was provided by varying the weights of the bean bags. The testing situations involved tossing a criterion weighted bean bag as well as a novel weighted bean bag which none of the groups had experienced previously. In addition, all groups were tested on a new but similar task. The results supported the variability-of-practice hypothesis in terms of schema formation and transfer to novel tasks in the same movement class. After a two-week retention interval, loss in performance was significantly less for the group with variability of practice than all other groups.     

Quiet Eye Duration,Expertise, and Task Complexity in Near and Far Aiming Tasks

Skilled (n = 12) and less skilled (n = 12) billiards players participated in 2 experiments in which the relationship between quiet eye duration, expertise, and task complexity was examined in a near and a far aiming task. Quiet eye was defined as the final fixation on the target prior to the initiation of movement. In Experiment 1, skilled performers exhibited longer fixations on the target (quiet eye) during the preparation phase of the action than their less skilled counterparts did. Quiet eye duration increased as a function of shot difficulty and was proportionally longer on successful than on unsuccessful shots for both groups of participants. In Experiment 2, participants executed shots under 3 different time-constrained conditions in which quiet eye periods were experimentally manipulated. Shorter quiet eye periods resulted in poorer performance, irrespective of participant skill level. The authors argue that quiet eye duration represents a critical period for movement programming in the aiming response.     

Visual Feedback of Target Position Affects Accuracy of Sequential Movements at Even Spaces

The role of visual feedback during movement is attributed to its accuracy, but findings regarding the utilization of this information are inconsistent. We developed a novel dot-placing task to investigate the role of vision in arm movements. Participants conducted pointing-like movements between two target stimuli at even spaces. In Experiment 1, visual feedback of targets and response positions was manipulated. Although visual loss of target stimuli hindered accuracy of movements, the absence of the position of previously placed dots had little effect. In Experiment 2, the effect of movement time on accuracy was assessed, as the relationship between these has been traditionally understood as a speed/accuracy trade-off. Results revealed that duration of movement did not impact movement accuracy.     

From One to Two: Can Visual Feedback Improve the Light Touch Effects on Postural Sway?

The postural control is improved by implicit somatosensory information from lightly touching a rigid bar or explicit visual information about the postural sway. Whether these two additional sources provided at the same time further reduce the postural sway is still unknown. Participants stood on a force plate as quiet as possible lightly touching the bar while received or not visual feedback of the center of pressure position on a monitor screen. Postural sway reduced similarly with the light touch regardless of the additional visual feedback. The findings suggested that providing explicit visual feedback of the center of pressure does not increase the light touch effects on the postural sway. The importance of the implicit somatosensory information on postural control is discussed.     

Atypical Neuropsychological Profile in a Boy with 22q11.2 Deletion Syndrome Keywords:

In this article the general and specific cognitive impairments of the boy R.H. with a de novo deletion 22q11.2 are described. His full-scale IQ was 73, and he obtained only slightly better verbal than non-verbal subtest scores. Neuropsychological assessment revealed specific impairments in perceptual categorization of objects presented suboptimal, matching of unfamiliar faces, and verbal learning and memory. In contrast, he performed in accordance with his intelligence level on other visual perceptual tasks, on non-verbal learning and memory tasks, and on attention tasks. Voxel-wise statistical comparison of a high-resolution T1-weighted magnetic resonance image of R.H’s brain with similar images obtained from 14 normal control children revealed as major abnormalities a reduction of the right inferior parietal and superior occipital lobe, and a bilateral reduction of deep white matter behind the inferior frontal gyrus. These cognitive impairments and MRI abnormalities are not commonly described in 22q11.2 Deletion Syndrome and may indicate a larger heterogeneity in the neurocognitive phenotype than currently evidenced. At least in this boy the microdeletion seems to have interfered with the development and functioning of particular neural subsystems, while the structure and functioning of other subsystems was left intact.     

COPY AND RECALL PERFORMANCE OF 6–8-YEAR-OLD CHILDREN AFTER STANDARD VS. STEP-BY-STEP ADMINISTRATION OF THE REY-OSTERRIETH COMPLEX FIGURE

Turner syndrome (TS) is a genetic disorder in females characterized by the complete or partial absence of one X chromosome. Its most consistent physical features include short stature and ovarian dysgenesis. TS individuals demonstrate a characteristic neurocognitive profile involving weaknesses in visuospatial processing. The hypothesis of defective right hemisphere specialization has been offered to explain the visuospatial deficits in TS. In contrast, an alternative explanation proposes a more uniform dysfunction of the left and right hemispheres, based on findings of symmetrical abnormalities. This article presents an overview of the two hypotheses, along with relevant findings on hemispheric specialization with respect to TS. The impact of the genetic and hormonal mechanisms on the neurocognitive profile of TS is also discussed and directions for further empirical research are identified.     

外源性视觉选择性注意的时空特征

使用与目标出现位置无关的外周空现刺激作为线索,研究在不同刺激呈现间隔（ＳＯＡ）下它对不同偏心 视觉目标的辨别反应时的影响,以考察外源性觉选择性注意的加工特生,并下三种注意空间分布模型对选择性注意时空特征的不同预测,结果表明：１．外周突现刺激能够不随意地吸引注意,符合自动加工特性;２．注意转移以注意中心连续移动的方式进行,支持探照灯模型,不支持透镜模型和静态的空间梯度模型,并在注意移动速率进行了估计