Latent inhibition and context change in psychometrically defined schizotypy

The disruption of latent inhibition within the schizophrenia spectrum has often been interpreted either as a result of increased attentional distractibility (attentional account) or as a result of deficient interference of past associations (associative account). The aim of the present investigation was to test competing predictions, as derived from the above theoretical accounts. In a visual search paradigm of latent inhibition, accuracy was examined as a function of prior experience with the target, and psychometrically defined schizotypy. In Experiment 1 (N=60), no context change was introduced. In accord with past evidence, latent inhibition was found to be intact in low-, but disrupted in high-schizotypy scorers, a result predicted both by attentional and associative accounts. In Experiment 2 (N=60), a context change was introduced. As predicted by past evidence, latent inhibition was disrupted in low-schizotypy scorers. However, latent inhibition was found to be intact in high-schizotypy scorers, a finding accommodated by attentional, but not associative accounts. Theoretical implications and alternative interpretations are also considered.     

Stopping rule use during information search in design problems

Information search is critical in most decision-making tasks. An important aspect of information search is the stopping rule used by the decision maker to terminate information acquisition. Decision-making problems may be usefully decomposed into design problems and choice problems. The distinction is critical because the goals of stopping behavior in the two types of problems are quite different. In design problems, the focus is on the sufficiency of information obtained for problem structuring and generating alternatives, while choice problems focus on convergence toward a solution. While previous research has studied stopping behavior in choice problems, the present research is concerned with stopping rule use during information search in design problems. To build theory in this area, we conducted two experiments. In the first, we presented professional systems analysts with an information search problem in a systems development context and asked them to gather information for a proposed system. Protocols of the search sessions were analyzed, and stopping rules used and information gathered by the analysts were identified. Results indicated that the use of certain stopping rules resulted in greater quantity and quality of information gathered. Additionally, stopping rule use, rather than analyst experience, accounted for the quantity and quality of information elicited. Finally, stopping rule use differed between more experienced and less experienced analysts. To apply our findings about stopping rules from the first experiment, we performed a second experiment in which we investigated stopping rule use in a consumer information search task on the world wide web. Results indicated the use of the same stopping rules as in the first experiment, although in different proportions. Implications for information search theory and practice are discussed.     

Testing the Adult Development Tower of Babel Hypothesis: Homogeneous by Perry Position Collaborative Learning Groups and Graduate Student Satisfaction

The purpose of this quasi-experimental study was to investigate what appears to be a grounding assumption in some adult developmental and educational research: persons of differing epistemologies who are grouped together will understand one another less well than persons who are grouped homogeneously. A robust effect is discussed within the context of adult development theory, research on collaborative learning groups, and Bruffee's social constructionist challenge (K. A. Bruffee, 1993) to Perry and to cognitive development theory. Collateral research questions relating to covariates of developmental position (according to the Perry scheme) are entertained; confirmatory qualitative data are presented.     

A general mechanism for linking personality traits to affect, motivation, and action

This article describes a general mechanism for linking personality traits to affect, motivation, and action. It is hypothesized that personality traits confer a propensity to perceive convergences and divergences between our belief that we can attain certain goals and the importance that we place on these goals (belief-importance or belimp theory). Belief and importance are conceptualized as two coordinates, together defining the belimp plane. Four distinct quadrants can be identified within the belimp plane (Hubris, Motivation, Depression, and Apathy), broadly corresponding to the personality dimensions of trait emotional intelligence, conscientiousness, neuroticism, and introversion. Strategies and requirements for testing belimp theory are presented as are a number of important theoretical and practical advantages that it can potentially offer.     

Low environmental calcium blocks long-term memory formation in a freshwater pulmonate snail

The freshwater snail Lymnaea stagnalis (L.) is considered a calciphile and exhibits reduced growth and survival in environments containing less than 20 mg/l environmental calcium. Although it has no apparent effect on survival at 20 mg/l, reducing environmental calcium increases metabolic demand, and as such we consider that this level of calcium acts as a stressor on the snail. We exposed snails to acute periods of low environmental calcium and tested their ability to form intermediate-term memory (ITM) and long-term memory (LTM) following one trial operant conditioning (1TT) to reduce aerial respiratory activity in hypoxic conditions. We also assessed whether there were changes in the electrophysiological properties of a single neuron, right pedal dorsal 1 (RPeD1), which has been demonstrated to be necessary for LTM formation. Following training in high (80 mg/l) environmental calcium, L. stagnalis formed ITM and LTM lasting 24 h and demonstrated a significant reduction in all activity measured from RPeD1; however when snails were exposed to low (20 mg/l) environmental calcium they were able to form ITM but not LTM. Although no behavioral LTM was formed, a partial reduction in RPeD1 activtiy measured 24 h after training was observed, indicating a residual effect of training. The strong effect that environmental calcium concentration had on physiology and behavior in response to training to reduce aerial respiration in L. stagnalis suggests that it is an element of gastropod husbandry that needs to be carefully considered when studying other traits. This study also indicates that L. stagnalis found naturally in low calcium environments may be less able to adapt to novel stressors than populations found in harder waters.     

Interference with reelin signaling in the lateral entorhinal cortex impairs spatial memory

Entorhinal neurons receive extensive intracortical projections, and form the primary input to the hippocampus via the perforant pathway. The glutamatergic cells of origin for the perforant pathway are distinguished by their expression of reelin, a glycoprotein involved in learning and synaptic plasticity. The functional significance of reelin signaling within the entorhinal cortex, however, remains unexplored. To determine whether interrupting entorhinal reelin signaling might have consequences for learning and memory, we administered recombinant receptor-associated protein (RAP) into the lateral entorhinal cortex (LEC) of young Long-Evans rats. RAP prevents reelin from binding to its receptors, and we verified the knockdown of reelin signaling by quantifying the phosphorylation state of reelin’s intracellular signaling target, disabled-1 (DAB1). Effective knockdown of reelin signaling was associated with impaired performance in the hippocampus-dependent version of the water maze. Moreover, inhibition of reelin signaling induced a localized loss of synaptic marker expression in the LEC. These observations support a role for entorhinal reelin signaling in spatial learning, and suggest that an intact reelin signaling pathway is essential for synaptic integrity in the adult entorhinal cortex.     

学业优秀者和学业不良者的倒摄抑制比较 ——从结构化和非结构化角度

以汉字为实验材料,以学业优秀者和学业不良者为被试,探讨学习材料的结构化和非结构化性质对倒摄抑制产生的影响,以及两类学生学习两类材料时的倒摄抑制差异。并通过指导语,逐步揭示结构化材料中的规则,迫使被试采用有效的学习策略,来观察倒摄抑制的变化情况。结果表明:一、与非结构化材料相比,学习结构化材料表现出更好的记忆绩效,但未发现两者对倒摄抑制的不同影响;二、和学优者相比,学业不良者的记忆绩效较差,倒摄抑制值也较大;三、对材料规则的提示会促进学业不良学生的记忆绩效,降低倒摄抑制,但对学习优秀者的影响不大;四、一些汉字识别特征影响倒摄抑制,如当干扰项和目标项构形相同时,会降低倒摄抑制。     

The premotor theory of attention and the Simon effect

In the paper by Hommel (2011-this issue), the roles of the theory of event coding (TEC) and the premotor theory of attention (PMTA) for the Simon effect were considered. PMTA was treated by Hommel in terms of the proposal that attentional orienting can be viewed as the preparation of a saccade towards a certain location, and was dismissed as providing no useful contribution for an attentional explanation of the Simon effect. Here we considered a more recent and broader conception of the PMTA, compared this approach with TEC, and confronted both approaches with a few studies focusing on the role of spatial attention for the Simon effect. It was argued that PMTA may account more easily for various studies examining the influence of spatial attention on the Simon effect. We concluded our paper by listing some elements that an overall encompassing theory on the Simon effect should contain.     

The relationship between attentional capture and deviations in movement trajectories in a selective reaching task

According to action-centered models of attention, attention and action systems are tightly linked such that the capture of attention by an object automatically initiates response-producing processes. In support of this link, studies have shown that movements deviate towards or away from non-target stimuli. These deviations are thought to emerge because attentional capture by non-target stimuli generates responses that summate with target responses to develop a combined movement vector. The present study tested attention–action coupling by examining movement trajectories in the presence of non-target stimuli that do or do not capture attention. Previous research has revealed that non-target cue stimuli only capture attention when they share critical features with the target. Cues that do not share this feature do not capture attention. Following these studies and their findings, participants in the present study aimed to the location of a single white square (onset singleton target) or a single red square presented with two white squares (color singleton target). In separate blocks, targets were preceded by non-predictive cues that did or did not share the target feature (color or onset singleton cues). The critical finding of the present study was that trajectory effects mirrored the temporal interference effects in that deviations were only observed when cue and target properties matched. Deviations were not observed when the cue and target properties did not match. These data provide clear support for the link between attentional capture and the activation of response-producing processes.     

The forgiveness process in primary and secondary victims of violent and sexual offences

It is possible that the physical and mental health of crime victims might be improved by forgiving those who have offended against them. To date, no research has been undertaken to examine the processes that influence victims' forgiveness. The goal of this project was to examine the forgiveness process in primary and secondary victims of violent and sexual crimes. In Study 1, qualitative data were collected by interviewing 21 people who had been affected by sexual or other violent crime. Data analysis identified five themes that were common to both primary and secondary victims, namely benefit of forgiveness, self‐forgiveness, perspective taking, offender behaviour, and time. An empowerment theme was unique to primary victims, and a principal victim theme was unique to secondary victims. To further explore these qualitative findings, a quantitative survey of 60 primary and secondary victims was conducted. Results confirmed that primary victims are pragmatic forgivers who are internally focused and forgive because that will benefit their healing. Conversely, secondary victims did not think forgiveness benefited, or would impact on, their own or the primary victim's recovery process. Neither group saw forgiveness as a moral issue, nor thought that forgiveness should influence whether an offender should face court.