Fitts’ Theorem in Oculomotor Control: Dissociable Movement Times for Amplitude and Width Manipulations

The authors examined whether movement times (MT) for discrete saccades are constant given equivalent index of difficulty (ID) values (i.e., unitary nature of Fitts’ theorem). To that end, we contrasted ID/MT relations for saccades equated for ID but differing with respect to their target amplitudes and widths. Results showed that MT increased with increasing ID within amplitude and width conditions; however, the ID/MT slope was markedly steeper in the former condition. Thus, the amplitude condition imposed greater information processing demands than the width condition—a result indicating that the constituent elements of Fitts’ theorem are dissociable (i.e., nonunitary). Further, examination of saccade kinematics demonstrated that the optimal MT for a given target amplitude was largely independent of target width.     

Charting the Developmental Trajectories of Attention and Executive Function in Chinese School-Aged Children

Attention is a complex domain that has reawakened research interest in recent years. There are relatively few studies that have examined age-related changes across different attention subcomponents, such as selection, maintenance, and control, using large samples covering a wide age range. The present study assessed performance in 466 participants in order to identify the ages at which mature performance was reached across differing attention subcomponents. Furthermore, we investigated whether the nature of the attentional demands or task difficulty predicted the age at which stable levels of performance were reached. The results supported the former rather than the latter alternative.     

青少年抑郁情绪的发展轨迹:界定亚群组及其影响因素

本研究意在分性别考察中国青少年抑郁情绪的发展轨迹及其影响因素。785名男生和859名女生参加了3轮追踪研究,初始测量阶段的年龄跨度为10~16岁,平均年龄分别为12.99±1.84和12.96±1.87岁。采用流调中心抑郁量表(CES-D)简版测量青少年的抑郁情绪。模型拟合的结果显示男女生的抑郁情绪在10~19岁时段皆呈线性增长趋势,其中男生分为两个亚群组,人际关系解释了部分变异;女生分为4个亚群组,学业压力和人际关系均解释了部分变异。     

Initial validation of self-reported trajectories in military veterans

Previous research suggests that functioning after potentially traumatic events tends to follow discrete trajectories. This research is limited in that longitudinal data can be difficult to collect. The aim of the current study was to examine self-reported trajectories in military veterans using an online survey. Consistent with longitudinal work, those who reported chronic distress reported higher symptoms of PTSD and Depression, higher negative affect, lower social support, and less satisfaction with life than those on a resilient trajectory. Two change trajectories demonstrated intermediate scores on relevant measures. These results provide support for a retrospective method to assess trajectories of posttrauma functioning.     

Four themes from 20 years of research on infant perception and cognition

This paper reviews progress over the past 20 years in four areas of research on infant perception and cognition. Work on perception of dynamic events has identified perceptual constraints on perception of object unity and object trajectory continuity that have led to a perceptual account of early development that supplements Nativist accounts. Work on face processing has charted developmental changes that clarify the way innate systems are modified by experience. Research on perception of goal‐directed action and animacy has made significant progress in uncovering the roots of social cognition from 6 months onwards. New methods such as eye tracking and measures of brain activity have done much to confirm and clarify conclusions arising from more conventional looking preference methods. It is likely that future progress in theory and understanding will be made increasingly as a result of triangulation between data arising from conventional and newer methods. Copyright © 2011 John Wiley & Sons, Ltd.     

运动轨迹和方向对视觉空间关系加工的影响

视觉空间关系分为类别与数量两种表征。研究通过控制起参照作用的运动客体消失状态与定位客体出现时间,分析客体运动信息对两种关系判断的影响。结果发现:运动信息在各间隔时间对类别任务影响呈序列排列,运动方向较轨迹信息有优势,轨迹较法线信息有优势;数量表征仅在0ms间隔受运动方向促进,在其他间隔下,三种位置上的判断均无差异。结果表明运动客体类别表征比数量表征更持久;且相对类别表征,数量判断作为精确距离表征不易受运动方向和轨迹信息影响。     

Neurophysiology and neuroanatomy of reflexive and voluntary saccades in non-human primates

A multitude of cognitive functions can easily be tested by a number of relatively simple saccadic eye movement tasks. This approach has been employed extensively with patient populations to investigate the functional deficits associated with psychiatric disorders. Neurophysiological studies in non-human primates performing the same tasks have begun to provide us with insights into the neural mechanisms underlying many cognitive functions. Here, we review studies that have investigated single neuron activity in the superior colliculus (see glossary), frontal eye field, supplementary eye field, dorsolateral prefrontal cortex, anterior cingulate (see glossary) cortex and lateral intraparietal area associated with the performance of visually guided saccades, anti-saccades and memory-guided saccades in awake behaving monkeys.     

三维倾斜平面的返回抑制

以随机点立体图为实验材料,采用三维空间线索－目标范式,将刺激呈现于同一视野位置以排除眼跳因素干扰,通过观察有意注意倾斜平面和无意注意倾斜平面与测试平面间的方向一致性和角度一致性对检测平面加工的影响,探讨了注意在不同倾斜平面间的转移是否产生返回抑制。结果表明：（1）以视差线索构造的三维视觉空间中,存在与注意有关的返回抑制效应;（2）无意注意加工能导致返回抑制,注意引导平面比无意注意平面引起更大的抑制效应。本研究的结果支持Posner返回抑制是由注意转移所致的观点     

Frequency trajectory effects in Chinese character recognition: Evidence for the arbitrary mapping hypothesis

Frequency trajectory is a better measure to investigate age-limited learning effects than age of acquisition (AoA) ratings (Zevin, J. D., & Seidenberg, M. S. (2002). Age of acquisition effects in word reading and other tasks. Journal of Memory and Language, 47(1), 1-29). The current study uses frequency trajectory as a variable to investigate age-limited learning effects in Chinese character recognition, and tests predictions of the arbitrary mapping hypothesis as applied in a non-alphabetic writing system. In Experiment 1, regression analyses showed that, compared to rated AoA, frequency trajectory of characters was less affected by other lexical properties, and could explain a significant proportion of variance of AoA. In Experiment 2, the frequency trajectory and predictability from orthography to pronunciation of characters were orthogonally manipulated in a character naming task. The frequency trajectory effect appeared only for the arbitrary mapping condition. In Experiment 3, frequency trajectory and predictability from orthography to meaning of characters were manipulated in a semantic category judgment task. The frequency trajectory effects were found only when the mapping from orthography to semantic is less consistent. In summary, the study confirmed that AoA is a genuine factor affecting word processing, and the AoA effects were limited to those situations in which mapping between input and output representation was arbitrary. These results provide strong cross-linguistic evidence in support of the arbitrary mapping hypothesis.     

Does frequency trajectory influence word identification? A cross-task comparison

In a series of six experiments, the influence of frequency trajectory in visual word recognition was investigated. In Experiment 1, frequency trajectory was found to exert a strong and reliable influence on age of acquisition (AoA) ratings. In word reading (Experiment 2), lexical decision (Experiments 3 and 6), proper name decision (Experiment 4), progressive demasking (Experiment 5), and a multiple regression analysis of lexical decision times taken from the French Lexicon Project, the effect of frequency trajectory was not reliable. In contrast, in all the experiments and in the multiple regression analysis, cumulative frequency had a strong and reliable influence on word recognition times. The findings firmly establish that in alphabetic languages such as French, age-limited learning effects do not surface readily in word recognition. In contrast, the total exposure to words across the lifetime is a strong determinant of word recognition speed. The implications of the findings are discussed.