A psychophysiological study on the function of the response‐stop in the Eriksen task1,2

Abstract: In the Eriksen task, we examined the hypothesis ( Iwaki, 1998 ) that a negative event‐related potential, which was enlarged at the frontal site synchronized with the presentation of an erroneous response causing stimulus, is related to the response‐stop function. Fourteen subjects responded selectively with their hands to the stimuli that consisted of a central target letter and surrounding compatible noise letters (e.g., HHHHH) or incompatible noise (e.g., SHHHS for small‐conflict condition or SSHSS for large‐conflict). The results showed that the increased negativity for the incompatible stimuli was synchronized with the stimulus onset but not with the response. Based on the hypothesis above, it is predicted that greater enhancement of an erroneous response by a stimulus causes the response‐stop to work harder in order to avoid an error, and this results in the larger negativity. This was supported by the evidence showing that the negativity was largest for the large‐conflict incompatible stimulus, followed by the small‐conflict, and then the compatible. We also discuss the possibility that the negativity is the NO‐GO potential concerned with the response‐stop function.     

视时距知觉适应后效的空间选择性

时距知觉适应后效是指长时间适应于某一特定时距会导致个体对后续时距产生知觉偏差。其中对视时距知觉适应后效空间选择性的探讨存在争议,有研究支持位置不变性,也有研究支持位置特异性。这类研究能有效揭示时距编码的认知神经机制,位置不变性可能意味着时距编码位于较高级的脑区,而位置特异性则可能意味着时距编码位于初级视觉皮层。未来还可以探究时距知觉适应后效的视觉坐标表征方式,开展多通道研究以及相应的神经基础研究。     

SIMPLIFIED HABIT REVERSAL TREATMENT FOR CHRONIC HAIR PULLING IN THREE ADOLESCENTS: A CLINICAL REPLICATION WITH DIRECT OBSERVATION

Three developmentally normal adolescents with chronic hair pulling were treated with a simplified habit reversal procedure consisting of awareness training, competing response training, and social support. Treatment resulted in an immediate reduction to near-zero levels of hair pulling, with one to three booster sessions required to maintain these levels. The results were maintained from 18 to 27 weeks posttreatment, although 1 participant reported difficulty at follow-up. The effectiveness of simplified habit reversal and suggestions for future research are discussed.     

Fluctuations of answer and confidence rating in a general-knowledge problem task: Is confidence rating a result of direct memory-relevant output monitoring?

In order to examine whether confidence rating is a result of direct memory-relevant output monitoring, a general-knowledge test was used. A question set was answered in experimental session 1, and the same question set was employed in session 2. Subjects chose one answer from two alternatives. No significant difference in answer accuracy was found between sessions, which suggests that identical information processing was carried out, and that any difference between sessions was based on probabilistic fluctuation. The major results were as follows: (a) In both sessions, answer accuracy was an increasing function of confidence. (b) Answer-change rate (rate of different answers to the same question between sessions) decreased monotonically with confidence. (c) The distributions of confidence rating in session 2, conditional on the rating in session 1, were nearly identical in no-answer-change and answer-change cases. These results suggest that confidence rating is not a result of monitoring memory-relevant output itself but an estimation of possibility of answer fluctuation.     

Response persistence under ratio and interval reinforcement schedules

In Experiment 1, rats were exposed to progressive-ratio schedules of food reinforcement while other rats were exposed simultaneously to yoked-interval schedules that arranged equivalent interreinforcer intervals but required only a single response at the end of the interval for food delivery. In Experiment 2, a within-subject yoked-control procedure was employed in which pigeons were exposed to alternating sessions (one per day) of progressive-ratio schedules and yoked-interval schedules as described above. In both experiments, responding under the yoked-interval schedule persisted beyond the point at which responding under the progressive-ratio schedule had ceased. The progressive-ratio schedules controlled break-and-run distributions, and the yoked-interval schedules controlled more even distributions of responses in time. Response rates decreased and postreinforcement pauses increased over time within individual sessions under both schedules. The results suggest that responding maintained by interval schedules is more persistent than that maintained by ratio schedules. The limitations and implications of this conclusion are discussed in the context of other investigations of response strength and behavioral momentum.     

A test for conditional independence between response time and accuracy

An important distinction between different models for response time and accuracy is whether conditional independence (CI) between response time and accuracy is assumed. In the present study, a test for CI given an exponential family model for accuracy (for example, the Rasch model or the one‐parameter logistic model) is proposed and evaluated in a simulation study. The procedure is based on the non‐parametric Kolmogorov–Smirnov tests. As an illustrative example, the CI test was applied to data from an arithmetics test for secondary education.     

Individual and combined effects of noncontingent reinforcement and response blocking on automatically reinforced problem behavior

Noncontingent reinforcement (NCR) and response blocking are 2 common interventions for problem behavior maintained by automatic reinforcement. We implemented NCR and blocking with 1 boy and found this combined intervention to be effective at decreasing high rates of automatically reinforced pica. With another child, we compared the effects of blocking alone to the combined intervention. With the third child, we compared NCR alone and blocking alone to the combined intervention. Results showed that the combined intervention was effective at reducing automatically reinforced problem behavior while moderate to high levels of item engagement maintained. When evaluated individually, neither NCR nor blocking was sufficient to reduce problem behavior to clinically significant levels.     

Assessment and treatment of problem behavior maintained by mand compliance

We modified functional analysis procedures to include a condition in which we reinforced problem behavior by complying with a child's mands. After identifying compliance with mands as a reinforcer, we evaluated the efficacy of a token system with a response‐cost contingency and incorporated discriminative stimuli to signal when mands would be reinforced. The token system with response cost effectively reduced problem behavior. Similar procedures may be beneficial when continuous adult compliance is not possible, when adults want to control when they will comply with the child's mands, or to build a child's tolerance for adult‐directed situations.