Response bias and the discrimination of stimulus duration

Pigeons discriminated stimulus duration in a psychophysical choice situation. Following presentation of any duration from a set of short duration (11 to 15 sec), responses on a red key were reinforced intermittently. Following presentation of any duration from a set of long durations (16 to 22 sec), responses on a green key were reinforced intermittently. Relative reinforcement rates were manipulated for choice responses across conditions. As relative reinforcement rates were varied, psychometric functions showed shifts in green-key responses at all durations. A signal-detection analysis showed that sensitivity remained roughly constant across conditions while response bias changed as a function of changes in relative reinforcement rate. Relative error rates tended to match relative reinforcement rates.     

颞叶皮层在灵长类不变性知觉和原型表征中的重要作用

如果要走出人工智能在感知觉领域的困境．就必须认识到人类特有的受生物现实约束的认知特点。综合分析各种证据表明,知觉和客体识别的本质不是分析千差万别的局部特征,而是提取环境中的大范围不变量（早期为拓扑特性检测）,形成并存贮一定原型表征;颞叶皮层在灵长类这种不变性知觉和原型表征中具有重要作用。     

Detection and discrimination of optical flow components

Observers viewed animation sequences consisting of random dots, some of which moved coherently in a given direction (signal dots) and the rest of which moved randomly (noise dots). Using forced-choice procedures, detectability of weak signals within noise was measured for translation, rotation, and expansion/contraction. Sensitivity to all motion types was approximately equal, with practiced observers reliably detecting coherent motion at signal levels as low as 4%. Observers were able to identify the motion structure presented on a given trial at signal levels corresponding to the detection threshold, implying that the neural signals supporting detection are labeled for motion type. Results are discussed in the context of hierarchical analysis of optic flow in which all motion types are registered as patterns of activity among neurons comprising a single mechanism.     

Intertrial-interval effects on sensitivity (A') and response bias (B") in a temporal discrimination by rats.

Killeen and Fetterman's (1988) behavioral theory of animal timing predicts that decreases in the rate of reinforcement should produce decreases in the sensitivity (A') of temporal discriminations and a decrease in miss and correct rejection rates (decrease in bias toward "long" responses). Eight rats were trained on a 10- versus 0.1-s temporal discrimination with an intertrial interval of 5 s and were subsequently tested on probe days on the same discrimination with intertrial intervals of 1, 2.5, 5, 10, or 20 s. The rate of reinforcement declined for all animals as intertrial interval increased. Although sensitivity (A') decreased with increasing intertrial interval, all rats showed an increase in bias to make long responses.     

Stimulus control and response bias in an analogue prey-detection procedure

The present study compared the performance of 6 pigeons trained to detect luminance differences in two different signal-detection procedures. Exposed to a three-key array, the pigeons were trained to peck the left key when the brighter of two light intensities had been presented on the center key and to peck the right key when the dimmer of two light intensities had been presented on the center key. Procedure A was a standard signal-detection procedure in which left/bright and right/dim responses produced food reinforcement and left/dim and right/bright responses produced periods of timeout. Procedure B was designed to simulate some of the contingencies operating in a prey-detection situation. Left-key responses produced reinforcement following the brighter center-key stimulus and a period of timeout following the dimmer center-key stimulus. Right-key responses always produced a short period of timeout irrespective of the stimulus. Within each procedure, the duration of timeout arranged for false alarms (left/dim responses) was varied between 3 s and 120 s. Measures of accuracy and response bias were compared between the two procedures. The timeout manipulation produced systematic, but relatively small, changes in these measures when right/dim responses (i.e., correct rejections) produced reinforcement (Procedure A). Arranging timeout for right/dim responses in Procedure B produced greater variability in accuracy and response bias than did arranging reinforcement, but this variability was not related to timeout duration. Overall, discrimination accuracy was considerably higher when right/dim responses produced timeout than when they resulted in reinforcement, and accuracy was accompanied by a large bias toward the response associated with reinforcement. These results are consistent with a recently proposed model of signal detection.     

Stimulus Presentation Ratios And The Outcomes For Correct Responses In Signal-detection Procedures

Three pigeons were trained to discriminate between two line orientations (S₁ and S₂). A left-key peck was correct when S₁ was presented, and a right key-peck was correct when S₂ was presented. In all procedures, correct responses were occasionally reinforced with food paired with the presentation of the magazine light. Incorrect responses produced a blackout. Six detection procedures were used. In the first, the signal presentation ratio was varied across conditions and the reinforcer ratio was allowed to covary. In the second, the signal presentation ratio was held constant at 1:1 and the reinforcer ratio varied across conditions. In the third, the signal presentation ratio was varied across conditions and the reinforcer ratio was held constant at 1:1. In these three procedures, correct responses that were not scheduled for reinforcement were followed by blackout. The remaining three procedures repeated those described above with one procedural change: Nonreinforced but correct trials were followed by the presentation of the magazine light. Birds showed systematic preferences for the key associated with the stimulus presented or reinforced most often. There was no change in the birds' performance over changes in the feedback for nonreinforced but correct responses.     

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.     

自由回忆中元记忆监控的作用及其影响因素

采用“类信号检测论方法”,通过两个实验,研究了在记忆信息提取过程中元记忆的预见性监测判断（Feeling-of-knowing）和元控制的作用及其影响因素。实验一探讨了识记材料的难易、识记遍数对元监测判断以及输出控制中的反应标准是否有影响;实验二探讨了严格和宽松的奖惩条件对输出控制中反应标准的影响。用计算机随机呈现识记用的词表材料,识记之后让被试进行FOK等级判断和自由回忆,再用“类信号检测论”方法统计实验数据,分析各种条件下回忆成绩、FOK判断等级,计算出相应的符合率和反应标准。实验一结果表明,不同材料难度和识记遍数下的回忆成绩和FOK判断等级差异显著,但输出控制中的反应标准值没受这些因素的影响;实验二结果是严格和宽松奖惩条件下的反应标准值差异显著,严格条件下的反应标准显著高于宽松条件下的反应标准,表明奖惩条件对信息提取中的反应标准有显著影响     

错误信息特征对学科领域知识丰富性不同学生学习的错误监控之影响

采用Go/No-Go范式,26名中学生参与实验。考察在基于主体错误反应和基于客体错误信息两类错误监控条件下,学科领域知识教学实验组和对照组对不同类型错误信息监控的脑电成分。结果显示,(1) 错误反应监控条件下,实验组对要义特征的错误反应诱发的ERN较字面特征的更负,而对照组则相反。(2) 错误信息监控条件下,两组学生均表现出监控字面特征错误诱发的ERN波幅较监控要义特征错误的更大。(3) 两种监控条件均表现出实验组产生的ERN波形较对照组的更负。表明：虽然两类监控条件均能诱发明显的ERN,但其影响因素并不相同：基于主体错误反应的监控主要受个体对其错误加工深度的影响;基于客体错误信息的监控则受错误信息的清晰性影响。