Methodological and empirical developments for the Ratcliff diffusion model of response times and accuracy

Summerfield, Egner, Mangels, and Hirsch (2006) suggested that visual misperception may be triggered by strong yet wrong expectation when sensory data are insufficient. Bar (2003) posits that immediately after stimulus presentation, low frequency spatial information (LFSI) convey the global form of the image which is matched to stored representations in the orbitofrontal cortex to generate predictions of the input. We used signal detection to test whether a strong prediction induced by informative global form, hence reducing the number of possible input matches, would facilitate recognition, but at the price of increasing the rate of misperceptions. Twenty-five participants were presented with target and foil images that shared global form, but differed in details. Pictures with informative global form resulted in higher confidence in recognition and shorter reaction times, but increased false alarms. Predictions of sensory input based on low frequency spatial information allow quick, facilitated recognition. However, the price for speed is the increased rate of misperceptions.     

Working memory and access to numerical information in children with disability in mathematics

The relationship among working memory, mathematic ability, and the cognitive impairment of children with difficulties in mathematics was examined. A group of children with difficulties in mathematics (MD) was compared with a group of children with a normal level of achievement matched for vocabulary, age, and gender (N = 49). The children were required to perform a variety of working memory and short-term memory tasks that had been administered 1 year previously. Moreover, the children were asked to perform tasks designed to provide information about speed of articulation. The results suggest a general working memory deficit in children with MD, specifically in the central executive component of Baddeley's model and primarily in the ability to inhibit irrelevant information. However, the MD children were not impaired in speech rate and counting speed tasks, which mainly involve the role of the articulatory loop.     

Sources of individual differences in fraction skills

The purpose of this investigation was to evaluate a conceptual model of relations between two kinds of mathematical knowledge (simple arithmetic and conceptual knowledge), two kinds of child characteristics (working memory and on-task related classroom behavior), and individual differences in three kinds of fraction outcomes (fraction computation, estimation, and word problems) in 105 fifth grade students. Structural equation modeling provided consistent evidence that conceptual knowledge independently contributes to individual differences in the three fraction outcomes. Simple arithmetic knowledge was uniquely related only to variability in fraction computation skills. Mathematical knowledge was found to mediate some of the contributions of both working memory and classroom behavior on variability in fraction outcomes. These supported mediating processes extend the current literature by explication of the pathways via which characteristics of children may affect individual differences in fraction outcomes.     

类比迁移发生机制的研究

本研究包含两个实验,探讨类比迁移发生的机制。实验一主要探索类比迁移中的图式归纳是一种自动加工还是控制加工。实验二主要探索类比迁移中的图式归纳是保留性的还是排除性的。本实验结果表明,类比迁移中的图式归纳主要是控制加工,是一种保留性的归纳。     

Behavioral contrast and the automaintained key peck

In two experiments behavioral contrast was demonstrated during discrimination training in a positive automaintenance procedure. During the baseline condition in each experiment, a key was transilluminated for eight seconds by one of two colors (CS) following a variable intertrial interval signaled by a dark key. Keylight transillumination terminated with a response-independent food presentation. In the first experiment, food was eliminated during one CS for up to fifty sessions. After reinstatement of food following each CS, the discrimination was reversed. Six of the eight subjects showed positive behavioral contrast, i.e., response rates increased during the CS associated with food as they decreased during the CS associated with no food. The effect was replicated in Experiment II, but it did not occur when both the food and its associated CS were eliminated. These results were comparable to those obtained with operant discrimination training procedures (behavioral contrast) and with Pavlovian discrimination training. The results suggest that additivity theories of behavioral contrast may be insufficient to account for these data.     

主题与类属关系的距离对分类和属性推理过程的影响：来自ERP的证据

不同关系类型对归纳推理具有重要的影响,然而主题关系（如,熊猫vs.竹子）与类属关系（如,熊猫vs.羚羊）在归纳推理中的神经机制仍然不清楚。本研究采用事件相关电位（ERP）技术,通过分开呈现属性归纳推理任务中的结论类别和结论属性,探讨两种关系类型及其距离在分类过程和属性推理过程中的ERP特征。结果发现：（1）结论类别呈现阶段,N400（370～500 ms）与LNC（the late negative component）（570～700 ms）时间窗口上,无论是主题关系还是类属关系,远距离比近距离均诱发了更大的负波;前者表明N400与语义整合密切相关,后者说明LNC与语义类别信息违背和假设形成有关。（2）结论属性呈现阶段,主题关系比类属关系诱发了更大的N1;同时,近距离比远距离诱发了更大的N1,反映了类别属性特征的知觉和自动化加工。结果表明：语义类别属性归纳存在距离效应,并且语义关系在属性推理过程中具有不同的加工方式。     

A translational evaluation of potential iatrogenic effects of single and combined contingencies during functional analysis

Recent research suggests that combining putative reinforcers for problem behavior into a single, synthesized contingency may increase efficiency in identifying behavioral function relative to traditional functional analysis (FA). Other research suggests potential shortcomings of synthesized contingency analysis (SCA), such as the potential for false-positive outcomes. In prior comparisons of traditional FAs and SCAs, investigators could not ascertain with certainty the true function(s) of the participants' problem behavior for use as the criterion variable. We conducted a translational study to circumvent this limitation by training a specific function for a surrogate destructive behavior prior to conducting a traditional FA and SCA. The traditional FA correctly identified the previously established function of the target response in all six cases and produced no iatrogenic effects. The SCA produced differentiated results in all cases and iatrogenic effects (i.e., an additional function) in three of six cases. We discuss these findings in terms of the mechanisms that may promote iatrogenic effects.     

Reduced specificity of autobiographical memories following a negative mood induction

Reduced autobiographical memory specificity (AMS) to emotional and neutral cue words appears to be a stable cognitive marker of clinical depression. For example, reduced AMS is present in remitted/recovered depressed patients and shows no reliable relationship with current levels of depressed mood in correlational studies. The present study examined whether reduced AMS could be induced in healthy volunteers with no history of depression, using a negative mood manipulation and whether levels of AMS and induced mood were positively correlated. Results showed a reduction in AMS following negative mood induction, compared to a neutral induction, whereas positive mood induction had no effects on AMS. Furthermore, lower happiness following the induction phase correlated positively with reduced AMS, and the extent of happiness reduction from pre- to post-induction correlated positively with reduction in AMS. These results suggest that AMS is, at least in part, a function of current emotion state. The implications for the literature on AMS as a stable marker of clinical depression are discussed.