A fast procedure for studying conditional accuracy functions

This paper describes a procedure for obtaining conditional accuracy functions(CAFs) from naive observers and a restricted number of trials. The method permits the experimenter to counter the subjects’ tendency to favor accuracy in tasks in which stimulus discrimination is easy. Each time a block of 12 trials contains less than three errors, observers are instructed, by means of a speed-up signal, to respond faster. The subject is continuously informed about her/his effective reaction time. The data show that the desired speed-accuracy tradeoff was obtained within each of the 7 observers. The mean percent error was around 25%.     

A procedure for studying strategy development in humans

An early version of the computer gameStar Trek was modified to conduct behavioral research. By appropriate use of the starship’s weapon and defense systems, the player can kill enemy ships and avoid destruction. The player’s moves, as well as the time and state of the game environment when each move occurs, are recorded. The procedure tracks performance changes over time very well, and allows the dissection of performance into sequences of commands that reflect the subject’s play strategy. Computer games such asStar Trek could be the basis for experiments that bridge the gap between operant and cognitive research.     

MouseTracker: Software for studying real-time mental processing using a computer mouse-tracking method

In the present article, we present a software package, MouseTracker, that allows researchers to use a computer mouse-tracking method for assessing real-time processing in psychological tasks. By recording the streaming x-, y-coordinates of the computer mouse while participants move the mouse into one of multiple response alternatives, motor dynamics of the hand can reveal the time course of mental processes. MouseTracker provides researchers with fine-grained information about the real-time evolution of participant responses by sampling 60–75 times/sec the online competition between multiple response alternatives. MouseTracker allows researchers to develop and run experiments and subsequently analyze mouse trajectories in a user-interactive, graphics-based environment. Experiments may incorporate images, letter strings, and sounds. Mouse trajectories can be processed, averaged, visualized, and explored, and measures of spatial attraction/curvature, complexity, velocity, and acceleration can be computed. We describe the software and the method, and we provide details on mouse trajectory analysis. We validate the software by demonstrating the accuracy and reliability of its trajectory and reaction time data. The latest version of MouseTracker is freely available at http://mousetracker.jbfreeman.net.     

A procedure for studying echoic control in verbal behavior

Male and female college students answered standard questions about the women's liberation movement on three occasions. A set of target words was embedded in the questions, with one set used in Sessions 1 and 3, and a synonymous, but different set used in Session 2. The relative frequencies of usage of a given target word were directly related to whether the questions for that session contained the word. The results supported the hypothesis of echoics as proposed in Skinner's theory of verbal behavior.     

Peer counseling in an online chat service: a content analysis of social support

In a recently launched one-on-one chat service for young people with psychosocial problems, young peer volunteers (ages 16-23) have a leading role in the conversations, comparable to the role of counselors in web-based and telephone-based child help-line services. A content analysis of the chat conversations showed that the contribution of the peer counselors in the confidential chat sessions satisfied the various quality criteria of the service. Moreover, the peer counselors offered the young people who visited the site varied types of social support. The variety of types of social support appeared a stronger predictor of the quality ratings than the length of the conversation or the quantity (instead of variety) of social support, which emphasizes the importance of multidimensional social support in online conversations.     

A procedure for studying the within-session onset of human drug discrimination.

The purpose of the present study was to develop a procedure for measuring the within-session onset of human drug discrimination. During daily sessions, under double-blind conditions, caffeine-abstinent adults ingested a letter-coded capsule containing 178 mg caffeine or placebo. Trials were presented at 30-s intervals, beginning immediately after drug ingestion and continuing for 60 min. On each trial, subjects could guess which of their two letter-coded drugs they had received by pressing a left button (for one drug) or right button (for the other drug); subjects could also press a center "no guess" button instead of guessing. Each trial ended after one button press. After each session, subjects were told which drug they had received. Subjects earned one point (worth $0.10 per point) for each correct guess. Subjects lost either 0, 1, or 10 points for each incorrect guess; the point-loss contingencies were varied in random order across sessions. Discrimination earnings accumulated across all sessions. The point-loss contingencies decreased random responding and delayed the discrimination time course. Overall, this procedure provided an orderly and relatively continuous measure of the within-session onset of drug discrimination and should have a range of applications in understanding the human behavioral pharmacology of drugs.     

基于伪装原理研究无意识视觉运动加工的方法

研究提出一种新的连续闪烁抑制(CFS)范式, 利用透明度混合(alpha blending)原理, 使目标刺激的颜色与相应位置的掩蔽刺激的颜色时刻保持一致。研究随机招募了8名被试, 向其优势眼呈现Mondrian图像序列, 非优势眼呈现固定速率运动的多个正方形。结果表明目标为多运动点动态刺激时, 该范式依然具备掩蔽作用, 且当目标刺激与相应位置的掩蔽刺激的颜色完全一致时, 掩蔽效果最好, 证明这种新范式比传统CFS范式对动态刺激的掩蔽作用更好。相比以往修改CFS掩蔽刺激的思路, 该范式为研究无意识视觉运动加工提供了新方法, 且适用性更广。     

Episodic feeling-of-knowing relies on noncriterial recollection and familiarity: Evidence using an online remember-know procedure

We examined the hypothesis that feeling-of-knowing judgments rely on recollection as well as on familiarity prompted by the cue presentation. A remember-know-no memory procedure was combined with the episodic FOK procedure employing a cue–target pair memory task. The magnitude of FOK judgments and FOK accuracy were examined as a function of recollection, familiarity, or the “no memory” option. Results showed that the proportion of R and K responses was similar. FOK accuracy and magnitude of FOK judgments were higher for R and K responses than for N responses. FOK accuracy related to R and K responses were above chance level, but FOK was not accurate in the “no memory” condition. Finally, both FOK magnitude and FOK accuracy were related more to recollection than to familiarity. These results support the hypothesis that both recollection and familiarity are determinants of the FOK process, although they suggest that recollection has a stronger influence.     

A method for studying stimulus class dynamics using budgerigars and vocal responding

We describe a methodology for examining stimulus class dynamics in budgerigars. Three budgerigars served as subjects. Four call types were trained as operant responses to four discriminative stimuli. The birds were over‐trained in this discrimination, and then run through two conditions. In Condition 1 the birds were trained to peck two of the four stimuli when these two stimuli appeared in two novel locations, while continuing to vocalize to all four stimuli when they occurred in the original training location. An analysis of vocal errors showed that the two stimuli assigned to the peck response were more likely to become confused with one another. In Condition 2 the birds experienced symbolic matching‐to‐sample training. Vocal discrimination trials were run concurrently with this training. The observed vocal‐response errors suggest that during a matching‐to‐sample task, sample stimuli became temporarily confused with one another. The results, although primarily intended to illustrate the utility of our method, support the hypothesis that stimuli assigned a common response become more similar, or equivalent, to one another.     

Process dissociation using a guided procedure

A method for achieving process dissociation is described that places less emphasis on participants' understanding and remembering interpretations of test cues than does the standard procedure. The proposed method, called the guided procedure, tests memory with a sequence of two prompts, one requesting word-stem recognition, followed by another for word-stem completion. Inclusion and exclusion conditions are produced by requesting completion of recognized stems to form previously presented or new words, respectively. Estimates of automatic and conscious memory produced by the standard and the guided procedures are compared in studies modeled after Toth, Reingold, and Jacoby (1994). Although not significantly different in many aspects, the outcomes differ in ways that may reflect less reliance on a generate-recognize strategy of participants tested with the guided procedure. Additional measures of memory available only with the guided procedure are presented.     

Decreasing rumination using a starchy food satiation procedure

A starchy food satiation procedure was evaluated in an ABAB withdrawal design on the post‐meal rumination of a nine‐year‐old girl with autism. During treatment unlimited quantities of starchy foods were provided following each meal. High rates of rumination occurred during baseline conditions, followed by an immediate decrease in rumination during treatment. Rumination decreased to 82 and 97% of baseline during the first and second treatment conditions, respectively. In addition, follow‐up probes were conducted at irregular intervals for 4 years following treatment, during which zero or near‐zero rates of rumination were sustained. This study extends the literature on the functional relation between increased starchy food quantity and rumination in adults to rumination with a young child, and demonstrates maintenance of the treatment effect for 4 years. Copyright © 2002 John Wiley & Sons, Ltd.