工作记忆负载对特性干扰子激活和抑制加工的影响

在同一实验条件下采用干扰效应和负启动效应双指标考察了三种不同类型工作记忆(WM)负载对特性干扰子加工的影响,旨在求证胡耿丹等人从位置干扰子加工所提出的"双重作用机制"是否适用于特性干扰子加工,以及对Park等人的负载特异机制观点所做的拓展和完善在特性干扰子范畴内是否正确。结果显示:(1)WM负载对特性干扰子的加工亦存在双重作用机制,提示双重作用机制在单一WM负载范围内具有普适性;(2)当目标刺激与干扰子刺激的属性一致时,无论是在位置干扰子还是在特性干扰子视角下Park等人的负载特异机制观点均可一致地被拓展和完善。     

短时记忆定向遗忘的负荷效应:来自ERP的证据

采用事件相关电位(ERPs)技术,通过一个短时记忆测试,考察记忆/遗忘线索在不同的工作记忆负荷条件下诱发的脑电差异。实验以字母和数字为刺激,要求被试记忆或遗忘不同数量的视觉信息。ERP结果发现:在线索呈现230~430ms的时间窗口,高负荷条件的遗忘线索比低负荷条件的遗忘线索诱发了更正的ERPs。这一结果表明,抑制机制在定向遗忘中有重要作用,抑制不同数量的信息需要不同数量的认知资源。     

The types of stimuli loaded in memory can modulate its effects on visual search

The effects of memory load in visual search (VS) have shown a diversity of results from the absence through beneficial and detrimental effects of a concurrent memory load in VS performance. One of the hypotheses intended to explain the heterogeneity of results follows the idea proposed by certain models in the context of VS that the contents of working memory (WM) can modulate the attentional processes involved in VS (Desimone & Duncan, 1995; Duncan & Humphreys, 1989). In four experiments, we manipulated the similarity of information maintained in WM and those materials playing the role of target and distractors in the VS task. The results showed a beneficial effect in the first two experiments, where the materials in WM matched the target in VS. However, when they matched the distractors in the attentional task there is no effect in the slope of the search function. Present results strengthen those theories supporting that visual working memory is fractionated to allow for maintenance of items not essential to the attentional task (Downing & Dodds, 2004).     

Preoccupied minds feel less control: Sense of agency is modulated by cognitive load

People have little difficulty distinguishing effects they cause and those they do not. An important question is what underlies this sense of agency. A prevailing idea is that the sense of agency arises from a comparison between a predictive representation of the effect (of a given action) and the actual effect that occurs, with a clear match between the two producing a strong sense of agency. Although there is general agreement on this comparison process, one important theoretical issue that has yet to be fully determined is whether these computations are consciously performed. Here, we studied this issue by requiring participants to perform a simple judgment of agency task under conditions of different concurrent working memory load. Working memory operations are known to tax conscious cognitive resources. We found that agency judgments were moderated by working memory load, with lower agency ratings being observed in the high load condition, suggesting that the sense of agency is dependent on the availability of conscious cognitive resources. An examination of the time-course of this load effect suggests that it is the construction of the mental representation of the predicted effect which is particularly dependent on said resources.     

Early life adversity potentiates the effects of later life stress on cumulative physiological dysregulation

Background and Objectives: Previous research indicates that early life adversity may heighten stress reactivity and impair mechanisms for adaptive coping, suggesting that experience of stress in early life may also potentiate adults' physiological vulnerability to stress in later life. The study tested this hypothesis by investigating whether the experience of stressful events and circumstances (SEC) in childhood or adolescence amplified the effect of adulthood SEC on physiological dysregulation (allostatic load, AL) in later midlife. Design: Observational data were used in the present study. Physiological functioning was measured in later midlife (participants' age ranged from 49 to 63 years). Both childhood/adolescence and adulthood SEC were reported retrospectively on the same occasion. Methods: Participants were 5309 Danish men and women from Copenhagen Aging and Midlife Biobank (CAMB). SEC included socioeconomic and family factors. The AL index was based on nine cardiovascular, metabolic, and immune biomarkers. Results: Experience of SEC in both early life and adulthood independently predicted higher AL. In men, experience of SEC in early life also potentiated the effect of SEC in adulthood on AL. Conclusions: The results provide further insight into the mechanisms behind the “biological embedding” of childhood stress.     

The cognitive specificity of learned helplessness and depression deficits: The role of self-focused cognitions

Abstract

Four experiments assessed similarities and differences in learned helplessness and depression-related deficits in cognitive performance and self-focused cognitions. Subjects answered the Beck Depression Inventory (Beck, Ward, Mendelson, Mock, & Erbaugh, 1961), were exposed to no-feedback or failure in unsolvable problems, and their response time in a digit comparison task (with or without a memory component, with different number of digits, and different number of mental transformations) and self-focused cognitions were assessed. Learned helplessness and depression deficits were found in a memory task, and the deficits increased with the number of digits. Depression deficits also increased with the number of transformations, and were also found in the no-memory/two transformation condition. Finally, task-related worries were related to learned helplessness deficits, and task-irrelevant thoughts were related to depression deficits. Findings were discussed in terms of the cognitive specificity of learned helplessness and depression deficits.     

Smile when you say that: Effects of willingness on dispositional inferences

A large body of research has investigated how perceivers integrate a target’s behavior with information about situational forces. However, little research has investigated how the willingness with which a behavior is performed affects inferences. Two experiments examined the effect of behavioral willingness on dispositional inferences. In experiment 1, a target’s willingness to help had a strong effect on inferences. In experiment 2, effects of willingness were even stronger under cognitive load. Implications are discussed.     

Elaboration and consequences of anchored estimates: An attitudinal perspective on numerical anchoring

In the standard numerical anchoring paradigm, the influence of externally provided anchors on judgment is typically explained as a result of elaborate thinking (i.e., confirmatory hypothesis testing that selectively activates anchor-consistent information in memory). In contrast, theories of attitude change suggest that the same judgments can result from relatively thoughtful or non-thoughtful processes, with more thoughtful processes resulting in judgments that last longer over time and better resist future attempts at change. Guided by an attitudinal approach to anchoring, four studies manipulated participants’ level of cognitive load to produce relatively high versus low levels of thinking. These studies show that, although anchoring can occur under both high and low thought conditions, anchoring based on a higher level of thinking involves greater use of judgment-relevant background knowledge, persists longer over time, is more resistant to subsequent attempts at social influence, and is less likely to result from direct numeric priming.     

Muscular contribution to low-back loading and stiffness during standard and suspended push-ups

Push-up exercises are normally performed to challenge muscles that span upper extremity joints. However, it is also recognized that push-ups provide an effective abdominal muscle challenge, especially when the hands are in contact with a labile support surface. The purpose of this study was to compare trunk muscle activation levels and resultant intervertebral joint (IVJ) loading when standard and suspended push-ups were performed, and to quantify and compare the contribution of trunk muscles to IVJ rotational stiffness in both exercises. Eleven recreationally trained male volunteers performed sets of standard and suspended push-ups. Upper body kinematic, kinetic, and EMG data were collected and input into a 3D biomechanical model of the lumbar torso to quantify lumbar IVJ loading and the contributions of trunk muscles to IVJ rotational stiffness. When performing suspended push-ups, muscles of the abdominal wall and the latissimus dorsi were activated to levels that were significantly greater than those elicited when performing standard push-ups (p<.05). As a direct result of these increased activation levels, model-predicted muscle forces increased and consequently led to significantly greater mean (p=.0008) and peak (p=.0012) lumbar IVJ compressive forces when performing suspended push-ups. Also directly resulting from the increased activation levels of the abdominal muscles and the latissimus dorsi during suspended push-ups was increased muscular contribution to lumbar IVJ rotational stiffness (p<.05). In comparison to the standard version of the exercise, suspended push-ups appear to provide a superior abdominal muscle challenge. However, for individuals unable to tolerate high lumbar IVJ compressive loads, potential benefits gained by incorporating suspended push-ups into their resistance training regimen may be outweighed by the risk of overloading low-back tissues.     

Evidence for conditional sex differences in emotional but not in sexual jealousy at the automatic level of cognitive processing

The two evolutionary psychological hypotheses that men react more jealous than women to sexual infidelity and women react more jealous than men to emotional infidelity are currently controversial because of apparently inconsistent results. We suggest that these inconsistencies can be resolved when the two hypotheses are evaluated separately and when the underlying cognitive processes are considered. We studied jealousy with forced‐choice decisions and emotion ratings in a general population sample of 284 adults aged 20–30 years using six infidelity dilemmas and recordings of reaction times. The sex difference for emotional jealousy existed for decisions under cognitive constraint, was also evident in the decision speed, increased for faster decisions, and was stronger for participants with lower education. No evidence for a sex difference in sexual jealousy was found. Our results support the view of a specific female sensitivity to emotional infidelity that canalizes the development of an adaptive sex difference in emotional jealousy conditional to the sociocultural environment. Copyright © 2007 John Wiley & Sons, Ltd.