Neural Processing to Visual Stimuli in a Three-Choice Reaction-Time Task

Some authors have suggested that certain components of the event-related potentials (ERPs) reflect underlying stages in the discrimination process. Previous studies have shown that in an auditive three-choice reaction-time task the discrimination is accomplished as a two-stage process, with the more frequently occurring stimulus discriminated at an earlier point than the rarer stimulus and the subjects could be classified as fast and slow responders in function of their response to the most frequent of the three tones. We continuously recorded the electrocerebral activity (EEG) from the scalp and the electromyographic activity (EMG) from the responding muscles in a visual three-choice reaction-time task in 10 strictly right-handed subjects. EEG and EMG responses were subsequently analyzed off-line by aligning them by the onset of either the stimulus (stimulus-synchronized) or the response (response-synchronized). The results suggest that processes of visual stimuli evaluation and response execution are continuously integrated. The discrimination and response systems to visual stimuli is accomplished as a three-stage process, one to frequent tone, another for rare 1, and the last for rare 2. The subjects were classified as fast and slow responders in function of their response to the most frequent of the three tones.     

视野位置及刺激特征对目标搜索影响的眼动研究

在视觉搜索中,注意受多种因素的影响。本研究控制了刺激呈现的3种视野位置,旨在研究在不同视野位置上,各种因素发挥作用的情况。要求被试在4个项目中搜索某一特定的靶子,记录了反应时和多种眼动指标。结果发现,在不同的视野位置上,视觉搜索过程受目标状态和刺激特征的影响程度发生了变化。并且对形状和颜色特征的加工存在时间和加工位置上的差异。     

The Role of Precues in the Preparation of Motor Responses in Humans

The authors investigated how precues about the location of an upcoming target are used by the sensorimotor system to reduce manual reaction time. In 4 experiments, participants (N = 12 in each experiment) pressed a response key as fast as possible when a precued or a nonprecued visual target appeared. Precues remained effective when a visual mask was interposed between the display of the precue and the target (Experiment 1), which suggests that precues act downstream from visual sensory memory. The precue effect was abolished when precues were presented along with a task requiring attention and a verbal response (Experiment 2) but not when presented with a task that required verbal output but had no attention demands (Experiment 3). Those findings indicate that precues must be processed attentively to become effective. When the attention-demanding task was interposed between precue and target display, the precue effect was still abolished (Experiment 4), which suggests that individuals' attention must remain in the precued area until target appearance.     

Visual Attention to Pictorial Food Stimuli in Individuals With Night Eating Syndrome: An Eye-Tracking Study

Night eating syndrome (NES) is characterized by excessive evening and/or nocturnal eating episodes. Studies indicate an attentional bias towards food in other eating disorders. For NES, however, evidence of attentional food processing is lacking. Attention towards food and non-food stimuli was compared using eye-tracking in 19 participants with NES and 19 matched controls without eating disorders during a free exploration paradigm and a visual search task. In the free exploration paradigm, groups did not differ in initial fixation position or gaze duration. However, a significant orienting bias to food compared to non-food was found within the NES group, but not in controls. A significant attentional maintenance bias to non-food compared to food was found in both groups. Detection times did not differ between groups in the search task. Only in NES, attention to and faster detection of non-food stimuli were related to higher BMI and more evening eating episodes. The results might indicate an attentional approach-avoidance pattern towards food in NES. However, further studies should clarify the implications of attentional mechanisms for the etiology and maintenance of NES.     

自闭症幼儿的视觉性自我认知实验研究

通过对平均心理年龄为23个月的6名自闭症幼儿的实验研究．甄别他们是否能从视觉上进行自我与他人的分化认知并进一步探索自闭症幼儿对镜像自我认知与录像自我认知上的差异;以秒为单位．对实验结果和过程进行了编码分析。结果表明：这6名幼儿在看自己的录像时,比看同伴的表现出更多的关注和喜悦;对录像的自我进行认知寸表现出更大的关注和积极情绪。由此推断他们已具有初步的自我认知。     

Proprioception as a Basis for the Temporal Anticipation of Motor Responses,

The present study attempted to distinguish between the proprioceptive Decay and proprioceptive Input Hypotheses of motor timing behavior. The hypothesis that an increased level of proprioceptive cues results in more proficient temporal anticipation was also tested. 90 male Ss were required to anticipate (no preview) the coincidence of a moving pointer and a stationary one. The timing response was executed with the right hand while 3 levels of proprioceptive cues were indirectly manipulated in the left arm. While results were unable to distinguish between the hypotheses, support was found for the hypothesis that an increased level of proprioceptive feedback administered during the interval can increase anticipatory response consistency.     

Determining the Temporal Limits of a Visual Sample for Visual Regulation

The author examined the minimum amount of time needed for vision to increase aiming accuracy and decrease movement duration. Participants selected when they would receive a visual sample during aiming movements by pressing a switch held with the left hand. The sample was one of the following durations: 40 ms, 30 ms, 20 ms, 10 ms, or 0 ms (no vision). Decreased accuracy in the no-vision condition compared to the vision conditions was observed when the duration of the impending sample was unknown (Experiment 1). Samples 40 ms in duration were sufficient to decrease endpoint variability when the duration of the sample was known before the movement (Experiment 2). These results indicate that short visual samples can be used to decrease movement time and increase accuracy and that knowledge of the impending visual context can impact the individual's subsequent behavior.     

Movement-Produced Feedback as a Mechanism For The Temporal Anticipation of Motor Responses

That part of the input hypothesis of motor timing behavior which postulates that movement-produced feedback can serve as a mechanism for the temporal anticipation of motor responses was tested. 32 male college Ss temporally anticipated (no preview) the coincidence of a moving pointer with a stationary one and executed the timing response with his right hand while either a high (HFB) or low (LFB) level of movement-produced feedback was indirectly manipulated in the left arm. The HFB group temporally anticipated with greater accuracy than the LFB group which supported that part of the input hypothesis being tested. Apparently, Ss were relying on proprioceptive feedback about the position of their left arm movement to cue the timing response of their right hand.     

Fear of Failure Biases Affective and Attentional Responses to Lexical and Pictorial Stimuli

The purpose of this investigation was to examine whether attentional biases would be noticed among individuals differing in levels of fear of failure (FF) as they viewed pictorial and lexical stimuli depicting various affective content. Indices of natural selective attention, namely, viewing time and self-reported affect, were assessed in 137 college students during free viewing picture and word presentation conditions. As hypothesized, FF was (a) negatively associated with self-reported dominance and valence for failure- and unpleasant-themed stimuli, and (b) positively associated with arousal ratings for unpleasant pictures. Although initially suppressed by neuroticism, partial correlation coefficients revealed a significant positive relationship between FF and viewing time for failure pictures. Results are discussed in the context of current theories of emotional reactivity and attentional biases pertaining to the nature of FF. Recommendations are provided for future research to elaborate the mechanisms involved in detrimental effects of FF.     

Aging and Visual Attention

ABSTRACT— Older adults are often slower and less accurate than are younger adults in performing visual-search tasks, suggesting an age-related decline in attentional functioning. Age-related decline in attention, however, is not entirely pervasive. Visual search that is based on the observer's expectations (i.e., top-down attention) is relatively preserved as a function of adult age. Neuroimaging research suggests that age-related decline occurs in the structure and function of brain regions mediating the visual sensory input, whereas activation of regions in the frontal and parietal lobes is often greater for older adults than for younger adults. This increased activation may represent an age-related increase in the role of top-down attention during visual tasks. To obtain a more complete account of age-related decline and preservation of visual attention, current research is beginning to explore the relation of neuroimaging measures of brain structure and function to behavioral measures of visual attention.     

Sex Differences in Simple Visual Reaction Time: A Historical Meta-Analysis

To test the hypothesis that the magnitude of sex differences in simple visual reaction time (RT) has narrowed across time, a meta-analysis was conducted on 72 effect sizes derived from 21 studies (n=15,003) published over a 73-year period. The analysis provided strong evidence for the hypothesized change. In addition, the analysis indicated that the sex difference in RT was on average smaller with non-U.S. samples than with U.S. samples. No relation was found between the magnitude of the sex difference in RT and age or presence vs. absence of a warning signal. Two factors–-participation in fast-action sports and driving–-are proposed as having been responsible for the decrease in the magnitude of the sex differences in simple visual RT across time.     

自闭症幼儿自主性共同注意的实验研究

为探索和发现自闭症幼儿的自主性共同注意的特征,以6名自闭症幼儿,以及在心理年龄与之匹配的弱智和正常儿童各6名作为研究对象,以实验和准实验的方法,进行此研究。同时还以秒为单位对实验过程与结果进行编码分析。结果表明,自闭症幼儿的自主性视觉方向所及目标物多于人,而人的目标中叉更多地锁定同伴而非教师。自闭症幼儿在唤起他人共同注意时多以“拉”和“抱”来替代指点行为。自主性共同注意的发生率与情绪有密切关系。     

视觉注意选择性的空间位置效应的研究

采用注意线索技术探讨颜色、角度和空间位置对视觉选择性注意的影响。研究结果表明 :( 1 )目标与干扰刺激颜色相同时 ,表现出明显的注意空间位置效应 ;( 2 )目标与干扰刺激颜色不同时 ,空间位置效应明显弱化 ;( 3 )整体而言 ,注意加工速度从左到右均表现出明显的“V”字形效应。     

基于空间和基于物体的选择注意在信号检测中的作用

先前的研究认为基于空间和基于物体的注意选择都是存在的,但是很少有研究探讨这两者的关系,即两者是存在交互作用还是单独作用的。因此本研究采用Egly等修正的线索提示实验范式,探讨基于物体和基于空间的注意选择机制在信号检测任务中的关系。实验采用2(两种物体)×2(两种空间)×3(有效线索、物体内无效线索和物体间无效线索)的被试内设计。16名大学生被试参加实验。结果表明:(1)对有效线索的反应快于无效线索,且物体内无效线索快于物体间无效线索;(2)在不同材料之间,两类无效线索反应时之差存在显著差异;(3)空间因素和物体因素的作用是独立的。结论提示:基于空间和基于物体的选择性注意都是存在的,且两者独立作用于注意的选择过程。     

Facilitation of return in voluntary orienting to visual attributes1

Abstract: The present study examined the effects of voluntary and automatic orienting after a relatively long interval in an attentional cueing paradigm. Facilitation of return was observed after the voluntary orienting to a designated color (Experiment 1) and motion direction (Experiment 2), whereas inhibition of return was observed after the automatic orienting to an abrupt stimulus onset (Experiment 1). These results suggest that the voluntary orienting to a visual attribute modulates subsequent processes differently from the automatic orienting to an abrupt onset. In the voluntary orienting to visual attributes, it would be advantageous to return attention to the previously attended location, which is a potential source of information.     

Specificity of Learning in a Video-Aiming Task: Modifying the Salience of Dynamic Visual Cues

The authors investigated whether the salience of dynamic visual information in a video-aiming task mediates the specificity of practice. Thirty participants practiced video-aiming movements in a full-vision, a weak-vision, or a target-only condition before being transferred to the target-only condition without knowledge of results. The full- and weak-vision conditions resulted in less endpoint bias and variability in acquisition than did the target-only condition. Going from acquisition to transfer resulted in a large increase in endpoint variability for the full-vision group but not for the weak-vision or target-only groups. Kinematic analysis revealed that weak dynamic visual cues do not mask the processing of other sources of afferent information; unlike strong visual cues, weak visual cues help individuals calibrate less salient sources of afferent information, such as proprioception.     

A Comparison of Least-to-Most Prompts and Progressive Time Delay on the Disruptive Behavior of Students with Autism

We compared the effects of two instructional strategies on the frequency of errors and episodes of disruptive behavior of 4 students with autism. In Phase I, easy and difficult tasks were presented to determine whether the tasks were associated with differential rates of disruptive behavior. Phase II compared the effects of a least-to-most prompting procedure (LTM) to a progressive time delay procedure (PTD) on errors and disruptive behavior when difficult tasks were presented. Observers sequentially recorded instructor instructions, response prompts, prompts for appropriate sitting, and feedback statements; and student disruptive, correct, error, and no responses during 1:1 sessions. Results showed PTD produced fewer errors than LTM for all 4 students, and lower rates of disruptive behavior for 2 students. When PTD was implemented as the final phase with 2 of the students, rates of disruptive behavior associated with the task previously taught with LTM immediately decreased. Conditional probability statements indicated that disruptive behavior occurred infrequently with all 4 students when effective response prompts were used.     

空间方位及SOA对视觉选择注意的影响

该文采用注意线索技术探讨颜色、角度和空间方位对视觉选择性注意的影响。研究结果表明:1)随着突现刺激呈现角度的变化,表现出从左至右的明显的倒“V”字型效应,当突现刺激特征显著时(颜色明显变化),“V”字型效应消失;2)随着SOA的延长,空间角度对选择注意加工的影响越来越显著;3)综合处理空间角度结果表明,被试对“上”方目标的反应速度最快,其次是左和右,对“下”的目标的反应速度最慢,而且相对受SOA的影响较小。