视觉监控作业中信号间隔时间和双任务对信号觉察的影响

本研究运用模拟实验,考察了以仪表显示为主的监控系统中信号间隔时间和双作业任务对人觉察信号的反应时间的影响.双作业中的主任务是要求被试同时监视4个仪表,次任务为对显示屏上一个红色亮点是否出现闪烁作简单的辨别反应.实验结果表明信号间隔时间是影响信号觉察反应时的一个重要因素.随着信号间隔时间由30-50秒延长到8-10分钟,信号觉察反应时随之先快后慢地增加.在低负荷的仪表监视作业中,通过增加一个刺激率较高而又比较简单的次任务,可使被试保持较高的唤醒水平和更好地集中注意,从而有利于提高信号觉察效率.     

学习率的心理现实性及其对项目选择的影响

项目选择一直是元认知控制研究中的热点问题。本研究以不同难度和分值的计算题为实验材料,通过两个实验探讨学习率的心理现实性及其对项目选择的影响。实验1中,在不限时条件下,被试者需要完成不同难度的计算题并赋予不同分值。实验2中,在限时条件下,通过变化计算题的难度和分值设计了三种不同学习率的项目,被试只能选择其中一种项目来计算以获得更高的分值。研究表明：第一,当项目所用时间增多时,被试对该项目所赋分值就增大,而时间（难度）与分值的比例是不变的,即学习率是相同的;第二,被试倾向于选择学习率更高的项目来完成计算任务,而当学习率相同时,被试倾向于优先选择高分困难项目。研究证实了学习率的心理现实性,并确定了学习率是项目选择的主要依据。     

唤醒水平与成年人记忆年龄差异关系的初步研究

青年与老年被试在分心与非分心条件下进行了指向记忆和逻辑故事回忆作业,同时记录了心率、指端血容和皮电等外周植物神经系统指标,以探讨成年人记忆的年龄差异与唤醒水平的关系。结果看到老年组记忆成绩明显低于青年组,同时在非分心作业时老年组血容变化率与记忆成绩明显相关,支持老年人认知成绩较差的原因是由于唤醒水平过低的假说。但在分心条件下老年组唤醒水平高于非分心条件,表明老年人唤醒水平高低可能随作业的复杂程度而变化。     

不同刺激重复量对反应抑制后效应的影响

旨在探讨不同刺激重复量对反应抑制后效应的影响。在不同刺激重复量条件下,让被试完成停止信号任务。结果发现,从总体来看,刺激重复量因素上的主效应显著,重复类型因素上主效应不显著;信号抑制条件下不同刺激重复量后无信号试次反应时与总的无信号试次反应时差异不显著;信号反应条件下不同刺激重复量后无信号试次反应时与总的无信号试次反应时差异显著。本研究表明不同刺激重复量条件下的反应抑制后效应是认知控制的执行加工而非自动化的记忆提取。     

规则多边图形的离散度与图形信号认知绩效的关系

用实验方法研究规则多边图形的离散度与图形信号认知绩效的关系。实验的自变量是图形的离散度参数,因变量是单位时间图形信号的视觉通道信息传递量。实验的刺激材料是２５个离散度为０．３～０．７的规则多边图形。刺激材料的呈现与被试的反应记录都由计算机控制。结果表明：离散度适中（０．５左右）及偏小的图形信号认知绩效较高,离散度从０．５增大到０．６,认知绩效迅速下降,离散度继续增大,认知绩效仍有下降,但趋势平缓。     

奖惩线索对停止信号任务中抑制能力和心率、皮肤电的影响

采用不同类型强化刺激(中性刺激,奖励刺激,惩罚刺激,以及奖励、惩罚刺激并存)来改变可获得奖励和惩罚的强度和频度,分别考察不同类型强化条件对停止信号任务中抑制能力、心率和皮肤电的影响.结果显示:与奖惩混合条件相比,在奖励条件下,被试的反应速度快,但正确抑制率明显低于惩罚条件和奖惩混合条件;在奖励条件下,被试在任务完成过程中的心率明显高于反馈条件、惩罚条件和奖惩混合条件.四种条件下被试的皮肤电活动无差异.     

汉字识别中部件结合率的作用:ERP研究

以汉字为实验材料,实验操纵两种部件结合率:携带位置信息的部件结合率(position-specific radical combinability,SRC)和不携带位置信息的部件结合率(position-general radical combinability,GRC)。实验中要求被试进行方位判断的同时记录被试脑电的变化。其中,实验1以假字作为填充刺激,结果发现SRC的变化引发P200效应,而GRC的变化引发了大脑半球右侧化偏向的N400效应。实验2以简单几何图形作为填充刺激,结果发现SRC所引发的P200效应消失了,但GRC所引发的大脑半球右侧化偏向的N400效应保持稳定。结果说明部件结合率可以在汉字加工中产生作用,但是携带位置信息的部件结合率在汉字加工中容易受到假字所引发的注意偏向的影响;而不携带位置信息的部件结合率在汉字加工中的作用相对稳定。     

过犹不及：情绪的效价-唤醒度冲突在动机倾向上的分离

本研究通过两个实验考察不同效价度和唤醒度的情绪刺激是否存在动机倾向上的分离模式。实验1要求被试对表情图片的动机倾向（趋近/回避）进行主观评分,发现被试对低唤醒表情或积极表情有更加趋近的倾向。实验2以运动的线索启动动机倾向（趋近/回避）,完成情绪词效价判断任务,从内隐的角度考察情绪刺激是否存在动机倾向上的分离模式,结果发现,被试对动机倾向一致的情绪刺激的反应时更快。趋近的消极情绪词比趋近的积极情绪词的N2波幅更大,远离的低唤醒情绪词比趋近的低唤醒情绪词的LPC波幅更大。结果说明积极或者低唤醒的情绪刺激引发趋近倾向,而消极或高唤醒的情绪刺激引发回避倾向。     

关于短时记忆搜索时间的年龄差异及其与唤醒水平关系的实验研究

本研究对24名老年人(平均65岁)和24名青年人(平均24岁)进行短时记忆搜索实验,同时记录了休息及作业过程中被试的心率、指端血容和皮电的变化,以探讨搜索时间的年龄差异和唤醒水平之间的关系。结果表明,所有被试的搜索反应时均随搜索项目的增多而增加,老年被试的搜索反应时明显慢于青年被试。在作业条件下,老年被试的心率、血容与皮电的反应性明显低于青年被试,表现为唤醒水平较低和适应较快的倾向。在血容、皮电反应性与搜索反应时之间存在着显著相关,这表明老年人唤醒水平较低可能是其搜索反应较慢的原因之一,也可能二者均由某一共同的中枢因素的年老变化所引起。     

不同愉悦度面孔阈下情绪启动效应:来自ERP的证据

采用事件相关电位技术,研究阈下情绪启动效应。实验中的因素是阈下呈现的情绪启动面孔的愉悦度,分为高、低两个水平。被试的任务是对中性靶刺激面孔进行情绪判断。结果发现:被试在对靶刺激进行情绪判断时出现与启动刺激愉悦度趋于一致的启动效应;低愉悦度面孔作启动刺激条件下N1和P2的波幅显著大于高愉悦度面孔作为启动刺激的条件;不同愉悦度情绪面孔的阈下启动效应是由于启动刺激影响了对靶刺激的知觉加工所致。     

在不同事件率条件下人格倾向类型对认知性警戒的影响

本研究采用两种事件率 ,考察了人格倾向类型对认知性警戒的影响。实验结果表明 :(1 )事件率是影响作业绩效的一个重要因素。事件率与人格倾向存在着交互作用。 (2 )认知性警戒作业的应激效应与事件率有关 ,随着事件率的上升 ,受试者在作业过程中的应激水平明显增高。 (3 )根据对被试自觉疲劳的测量结果 ,在认知性警戒作业中 ,内倾者与外倾者间应激水平存在差异。     

Effects of shifts in the rate of repetitive stimulation on sustained attention

The effects of shifts in the rate of presentation of repetitive neutral events (background event rate) were studied in a visual vigilance task. Four groups of subjects experienced either a high (21 events/min) or a low (6 events/min) event rate for 20 min and then experienced either the same or the alternate event rate for an additional 40 min. The temporal occurrence of critical target signals was identical for all groups, irrespective of event rate. The density of critical signals was 12 signals/20 min. By the end of the session, shifts in event rate were associated with changes in performance which resembled contrast effects found in other experimental situations in which shift paradigms were used. Relative to constant event rate control conditions, a shift from a low to a high event rate depressed the probability of signal detections, while a shift in the opposite direction enhanced the probability of signal detections.     

Test anxiety and visual vigilance

Twenty male and 20 female subjects, previously classified as high or low in test anxiety, participated in an experiment on visual vigilance under conditions designed either to enhance or minimize feelings of being tested. Detection rate declined across the 36 min of the task among subjects high in test anxiety who believed that they were being tested and in subjects low in test anxiety who did not. False detection rates revealed no significant differences among conditions. Analysis of sensitivity to signals according to statistical decision theory revealed low sensitivity in both the high-anxiety test and low-anxiety/no-test conditions than in the other two. Analysis of decisional criteria showed that subjects in the high-anxiety test condition were more conservative in setting a criterion than subjects in the other three conditions. No sex differences were found. The results are discussed in terms of an elaboration of Sarason's (1978) model of test anxiety.     

Equating tasks and sustaining attention in children and adults: the methodological and theoretical utility of d' matching

The present study develops a method to create task equivalency for children and adults in vigilance research. Experiment 1 employed the signal detection index of perceptual sensitivity (d') to calibrate vigilance tasks for 32 children (ages 7-8) and 32 adults. The results of Experiment 1 suggest that task equivalency across groups can be attained, and a vigilance decrement was observed for children. In Experiment 2, the task parameter of event rate was manipulated across two vigils. Again, 32 children (ages 7-8) and 32 adults participated. The results suggest that a reverse event rate effect emerged for both children and adults. In addition, developmental differences in response to the event rate manipulation and with respect to the vigilance decrement emerged: Children benefited less from the manipulation and were more likely to demonstrate a vigilance decrement than were adults. No developmental differences emerged for the sensitivity decrement. The results are explained with reference to how task demands interact with participant arousal, and implications for development and for future research are discussed.     

Equating tasks and sustaining attention in children and adults: The methodological and theoretical utility ofd’ matching

The present study develops a method to create task equivalency for children and adults in vigilance research. Experiment 1 employed the signal detection index of perceptual sensitivity (d’) to calibrate vigilance tasks for 32 children (ages 78) and 32 adults. The results of Experiment 1 suggest that task equivalency across groups can be attained, and a vigilance decrement was observed for children. In Experiment 2, the task parameter of event rate was manipulated across two vigils. Again, 32 children (ages 78) and 32 adults participated. The results suggest that a reverse event rate effect emerged for both children and adults. In addition, developmental differences in response to the event rate manipulation and with respect to the vigilance decrement emerged: Children benefited less from the manipulation and were more likely to demonstrate a vigilance decrement than were adults. No developmental differences emerged for the sensitivity decrement. The results are explained with reference to how task demands interact with participant arousal, and implications for development and for future research are discussed.     

Effects of anxiety on attentional allocation and task performance: An information processing analysis

An information processing signal detection methodology was employed to examine attentional allocation and its correlates in both normal comparison (NC) and generalized anxiety disorder (GAD) participants. In particular, the impact of neutral distractor and negative feedback cues on performance of an attention vigilance task was investigated. Individuals with GAD (N = 15) evidenced impaired performance on an attention vigilance task relative to NC participants (N = 15) when neutral distractor cues were presented. Contrary to prediction, no group differences in performance were detected under conditions in which participants were presented negative feedback cues they were told were relevant to their performance. Instead, GAD participants exhibited improvement during the experimental task such that their performance was equivalent to NC participants. Across trials, the clinically anxious group endorsed significantly higher levels of worry and negative affectivity; however, they failed to respond with concomitant physical arousal (e.g. increased muscle tension). These data are discussed within the context of Eysenck and Calvo's (1992, Cognition and Emotion, 6, 409–434) processing efficiency theory. Additionally, the results of this investigation provide support for Barlow's (1988, Anxiety and its disorders: The nature and treatment of anxiety and panic) conceptualization of anxiety as requiring the interaction of cognitive schema and physiological arousal.     

Body movement and inattention in learning-disable and normal children

Four experiments were conducted to test various aspects of an optimal level of arousal model of hyperactivity in learning-disabled children. Vigilance performance and level of body movement were measured while learning-disabled and control children performed in an auditory vigilance task. The results suggested that body movement increased throughout the vigilance task, increased rates of external stimulation result in decreased level of body movement, and learningdisabled children differed from controls in showing higher levels of body movement and poorer vigilance performance. The results were discussed in terms of changes in arousal level and compensatory stimulus-seeking behavior.     

Effects of social influence in a recognition task of auditory intensity: a temporary shift in criterion.

The effects of responses of another person or a computer occurring prior to the subjects' responses in tasks to recognition model which assumed that subjects shifted their decision criteria temporarily on each trial. A parameter representing the amount of criterion shift reliably estimated sensitivity to social influence. When the social sensitivity parameter was estimated from the data, discriminative ability, defined as d', was unaffected by the presence of social influence. Principal components analyses suggested that social sensitivity and discriminative ability represented essentially orthogonal components of subjects' decision behavior.     

Skill development in vigilance: effects of event rate and age.

Thirty-six young (19-27 years), middle-aged (40-55 years), and old (70-80 years) adults performed a 30-min vigilance task at low (15 per min) and high (40 per min) event rates for 20 sessions. Skill-acquisition curves modeled on power, hyperbolic, and exponential functions were predicted. With extensive practice, hit rates increased and false-alarm rates decreased to virtually asymptotic levels. Skill development was best described by the hyperbolic function. Practice reduced but did not eliminate the vigilance decrement in all subjects. The event-rate effect--the decrease in hit rate at high event rates--was reduced with practice and eliminated in young subjects. Hit rates decreased and false-alarm rates increased with age, but there was little attenuation of age differences with practice. Implications for theories of vigilance, skill development, and cognitive aging are discussed.     

The effect of sleep deprivation on signal detection parameters

Twelve subjects performed a high signal rate vigilance task, once after a night's sleep, and once after a night without sleep. Raw scores were transformed into the signal detection parameters, d' and β. After sleep deprivation, detection performance was significantly impaired. This was reflected in a fall of d', whereas β was not significantly altered. Analysing the control data alone for comparison with other vigilance studies revealed a decrement in % signals detected and d', and an increase in β from the first to the second half of the test.