Measures of response bias at minimum-detectable luminance levels in the pigeon

Using an operant analogue of the yes-no detection task, six pigeons were trained to detect luminance changes under two different reinforcement-scheduling procedures. In the first, an uncontrolled reinforcement-ratio procedure, the relative frequency of food reinforcers obtained for correct detections was free to vary with the birds' behavior as luminance levels were changed. In the second, a controlled reinforcement-ratio procedure, changes in preference could not alter the relative distribution of food reinforcers between the two response alternatives. Extreme response biases developed as luminance was decreased to threshold in the uncontrolled procedure. No progressive changes in response bias as a function of decreasing luminance were seen in the controlled procedure. Absolute thresholds for light intensity were lower in the controlled than in the uncontrolled procedure.     

A note on ALSCAL: The estimation of the additive constant

A method is given for the least squares regression of a squared variabled ² on the squared variable 0², where the relation between 0 andd is linear. The problem arises in MDS-algorithms where the loss function is defined in terms of squared distances (e.g., ALSCAL). It is pointed out that the Lagrangian multiplier is a root of fourth degree polynomial.     

On the exponent in the "generalized" matching equation

A power function equation between ratios of behavior and ratios of reinforcement rates has been called a generalized form of Herrnstein's (1961) matching law, even without a formal relationship having been shown between the two equations. The present work uses a functional relationship to prove that when ratios of reinforcement are not equivalent to ratios of behavior, and the transform leading to this inequality is consistent for every pair of reinforcement rates, the result is a power function relationship between response and reinforcement ratios. The label “generalized matching equation” for the power function equation is thus validated formally.     

Teaching communicative alternatives to socially withdrawn behavior: An investigation in maintaining treatment effects

This study examined the effectiveness of a contextual intervention strategy paired with an existing packaged intervention on the ability to produce increased and durable social involvement among children who displayed socially withdrawn behavior and their peers. Using a multiple baseline design across three socially withdrawn subjects, results indicated that the combination intervention effectively increased social interactions. Results also indicated that the effects of the intervention maintained two months after intervention termination. General implications for the use of the contextual intervention strategy to produce durable treatment outcomes are discussed.     

The nonconvergence of factals: A nonmetric common factor analysis

FACTALS is a nonmetric common factor analysis model for multivariate data whose variables may be nominal, ordinal or interval. In FACTALS an Alternating Least Squares algorithm is utilized which is claimed to be monotonically convergent.In this paper it is shown that this algorithm is based upon an erroneous assumption, namely that the least squares loss function (which is in this case a nonscale free loss function) can be transformed into a scalefree loss function. A consequence of this is that monotonical convergence of the algorithm can not be guaranteed.     

Feedback functions for variable-interval reinforcement

On a given variable-interval schedule, the average obtained rate of reinforcement depends on the average rate of responding. An expression for this feedback effect is derived from the assumptions that free-operant responding occurs in bursts with a constant tempo, alternating with periods of engagement in other activities; that the durations of bursts and other activities are exponentially distributed; and that the rates of initiating and terminating bursts are inversely related. The expression provides a satisfactory account of the data of three experiments.     

Psychometric and information processing properties of selected response time models

This paper discusses the compatibility of some response time (RT) models with psychometric and with information processing approaches to response times. First, three psychometrically desirable properties of probabilistic models for binary data, related to the principle of specific objectivity, are adapted to the domain of RT models. One of these is the separability of item and subject parameters, and another is double monotonicity. Next, the compatibility of these psychometric properties with one very popular information processing approach, the serial-additive model, is discussed. Finally, five RT models are analyzed with respect to their compatibility with the psychometric properties, with serial-additive processing and with some alternative types of processing. It is concluded that (a) current psychometric models each satisfy one or more of the psychometric properties, but are not (easily) compatible with serial-additive processing, (b) at least one serial-additive processing model satisfies separability of item and subject parameters, and (c) RT models will more easily satisfy double monotonicity than the other two psychometric properties.     

Anterior Temporal Lobectomy,Hippocampal Sclerosis,and Memory: Recent Neuropsychological Findings

Anterior temporal lobectomy (ATL) is an effective and increasingly utilized treatment for nonlesional, intractable mesial temporal lobe epilepsy. However, this surgery results in domain-specific neuropsychological morbidity for a subset of patients. Within the past decade, multidisciplinary studies have revealed that left ATL patients without significant sclerosis in the resected hippocampus are most at risk for a substantial postacute decline in the ability to encode new verbal information. These patients are also at risk for a significant decrement in confrontation naming and other retrieval-based language abilities. The memory deficit is not attributable to this disruption of language. A relationship between hippocampal sclerosis (HS) status and memory performance has not been identified consistently in right ATL patients, but investigation of new visuospatial measures continues. The influence of variables other than HS on neuropsychological outcome is also discussed.     

项目难度与被试能力分布最优匹配的模拟研究

该文运用蒙特卡罗方法对被测试能力分布与测验项目难度分布的匹配问题进行模拟分析,分析表明当能力分布为正态分布正偏态分布和负偏态分布时分别与测验项目难度分布与为正态分布,正偏态分布和负偏态分布匹配,比别的匹配有更高测验期望信息值,测验最大信息测验 系数,并且测验信息曲线最大值的能力点与能力分布的众数愈相一致,测验项目参数估计值性真实值的相关也更高。     

A transfer of self-discrimination response functions through equivalence relations

The present study tested the idea that human self-discrimination response functions may transfer through equivalence relations. Four subjects were trained in six symbolic matching-to-sample tasks (if see A1, choose B1; A1-C1, A2-B2, A2-C2, A3-B3, A3-C3) and were then tested for the formation of three equivalence relations (B1-C1, B2-C2, B3-C3). Two of the B stimuli (B1 and B2) were then used to train two different self-discrimination responses using either detailed instructions (Subjects 1 to 3) or minimal instructions (Subject 4) on two complex schedules of reinforcement (i.e., subjects were trained to pick the B1 stimulus if they had not emitted a response, and to pick the B2 stimulus if they had emitted one or more responses on the previous schedule). All 4 subjects showed the predicted transfer of self-discrimination response functions through equivalence relations (i.e., no response on the schedule, pick C1; one or more responses on the schedule, pick C2). Subjects also demonstrated this transfer when they were required to discriminate their schedule performance before exposure to the schedule (i.e., “what I intend to do”). Four control subjects were also used in the study. Two of these (Subjects 5 and 6) were not exposed to any form of matching-to-sample training and testing (nonequivalence controls). The 2 remaining subjects (7 and 8) were exposed to matching-to-sample training and testing that incorporated stimuli not used during the transfer test; C1 and C2 were replaced by N1 and N2 during the matching-to-sample training and testing, but C1 and C2 were used for the transfer tests (equivalence controls). All 4 subjects failed to produce the self-discrimination transfer performances observed with the experimental subjects.