Assessment Centre Observation Procedures: An Experimental Comparison of Traditional,Checklist and Coding Methods

Concern about the construct validity of assessment centre judgements has led to calls for research into observers’ cognitive processes. In an experiment comparing the Traditional observation procedure against use of a Behavioural Checklist and of Behavioural Coding, six outcome variables were examined. The methods were found to yield similar outcomes in terms of accuracy of judgement, accuracy of written evidence, correlation between dimension ratings, and attitude toward the method employed. However, significant between-method differences were observed in variability between observers and in their willingness to recommend a procedure. It is argued that Behavioural Coding has special merit in assessment centres; the method reduces the cognitive demands placed on assessors, and valuably structures their information-processing. Traditional objections to simultaneous observation and classification are shown to be inappropriate.     

Complex learning and information processing by pigeons: a critical analysis

Three models of conditional discrimination learning by pigeons are described: stimulus configuration learning, the multiple-rule model, and concept learning. A review of the literature reveals that true concept learning is not characteristic of the behavior of pigeons in matching-to-sample, oddity-from-sample, or symbolic matching studies. Instead, pigeons learn a set of sample-specific S^D rules. Transfer of the discrimination to novel stimuli, at least along the hue dimension, is predicted by a “coding hypothesis”, which holds that pigeons make a unique, but usually unobserved response, R₁, to each sample, and that the comparison stimulus chosen depends on which R₁ was emitted in the presence of the sample. Convincing evidence is found that pigeons do code sample hues, but there is little evidence that allows one to infer that the “coding event” must have behavioral properties. Parameters of the conditional discrimination paradigm are identified, and it is shown that by appropriate parametric manipulation, a variety of analogous tasks may be generated for both human and animal subjects. The tasks make possible the comparative study of complex learning, attention, memory, and information processing, with the added advantage that behavior processes may be compared systematically across tasks.     

群体面孔情绪的整体编码及其影响因素

当面孔以群体形式出现,认知神经系统会自动整合情绪信息提取平均情绪,此过程被称为群体面孔情绪的整体编码。探讨其与低水平整体表征的分离,与个体表征的关系及神经活动特点是揭示其加工机制的关键,但目前尚未形成系统性模型。未来应综合利用眼动、神经电生理和脑成像技术,结合注意、记忆及社会线索进一步拓展对其认知神经机制和影响因素的研究,同时关注具有认知情感障碍的特殊人群,并从毕生发展的角度探索其发展轨迹。     

Generative models, brain function and neuroimaging

The representational capacity and inherent function of any neuron, neuronal population or cortical area in the brain is dynamic and context-sensitive. Functional integration, or interactions among brain systems, that employ driving (bottom up) and backward (top-down) connections, mediate this adaptive and contextual specialisation. A critical consequence is that neuronal responses, in any given cortical area, can represent different things at different times. This can have fundamental implications for the design of brain imaging experiments and the interpretation of their results. Our arguments are developed under generative models of brain function, where higher-level systems provide a prediction of the inputs to lower-level regions. Conflict between the two is resolved by changes in the higher-level representations, which are driven by the ensuing error in lower regions, until the mismatch is "cancelled". From this perspective the specialisation of any region is determined both by bottom-up driving inputs and by top-down predictions. Specialisation is therefore not an intrinsic property of any region but depends on both forward and backward connections with other areas. Because the latter have access to the context in which the inputs are generated they are in a position to modulate the selectivity or specialisation of lower areas. The implications for classical models (e.g., classical receptive fields in electrophysiology, classical specialisation in neuroimaging and connectionism in cognitive models) are severe and suggest these models may provide incomplete accounts of real brain architectures. Here we focus on the implications for cognitive neuroscience in the context of neuroimaging.     

Functional integration and the mind

Different cognitive functions recruit a number of different, often overlapping, areas of the brain. Theories in cognitive and computational neuroscience are beginning to take this kind of functional integration into account. The contributions to this special issue consider what functional integration tells us about various aspects of the mind such as perception, language, volition, agency, and reward. Here, I consider how and why functional integration may matter for the mind; I discuss a general theoretical framework, based on generative models, that may unify many of the debates surrounding functional integration and the mind; and I briefly introduce each of the contributions.     

人类工作记忆的事件相关电位研究

20世纪90年代以来,采用ERP技术对人类工作记忆脑机制的研究已取得大量的成果。主要探讨了特定类型的工作记忆（词语、空间、客体工作记忆）是否存在与其贮存、复述以及中央执行功能相关的特异性ERP成分,并从它们的时间进程及头皮分布来考察工作记忆的心理过程和神经机制。研究结果对于Baddeley的认知结构模型提供了有益的修正和补充。     

Contextual learning induces an increase in the number of hippocampal CA1 neurons expressing high levels of BDNF

We examined behaviorally induced expression of brain-derived neurotrophic factor (BDNF) in area CA1 of the hippocampus. Sprague-Dawley rats were trained in a contextual fear conditioning (CFC) task, sacrificed 4h later, and their brains were processed for immunohistochemistry. We found distinctively high levels of BDNF immunoreactivity in a small number ( approximately 1%) of CA1 neurons in untrained animals. The number of these exceptional neurons, which are identified as BDNF(++) in this study, was increased by up to approximately 3% after CFC. This increase was blocked in the presence of a memory-impairing dose of a NMDA receptor antagonist (MK801 0.3 mg/kg, i.p.) given 30 min prior to training. The BDNF signal intensity in BDNF(++) neurons correlated with that of surrounding glutamic acid decarboxylase (GAD) 65. This correlation between GAD65 and BDNF signal intensities suggests that BDNF upregulation was associated with increased signaling via inhibitory GABAergic synapses that would lessen further intervening neuronal activity. Our observation that neurons which upregulate BDNF expression following a learning experience are rich in GAD65-enriched afferent synapses suggests that these neurons may have distinct roles in memory consolidation.     

工作记忆在数学运算过程中的作用

Baddeley和Hitch(1974)提出的工作记忆模型被广泛地应用数学运算领域,但是已有研究还缺乏系统性。首先,当前的研究主要集中在加法和乘法两种运算上,较少涉及减法、除法和更为抽象的代数运算;第二,研究者对语音环路和中央执行系统的作用进行了较深入的研究,但常常忽略视空间模板的作用;第三,工作记忆在数学运算过程中的作用具有动态性,它受到一些外部因素、数学任务内在因素和个体认知因素（如认知策略）的影响;第四,几乎有关研究都肯定中央执行系统在数学运算过程中的重要作用,然而负荷于中央执行系统的次级任务所含成分或功能的复杂性,导致我们很难确定中央执行系统如何作用于数学运算。对这些问题的研究将是未来可能的研究方向     

Response-repetition effects depend on motor set: Evidence for anatomical coding in response selection

Successful motor performance requires a process of response selection that chooses the correct response out of a set of possible ones. Most theories of response selection assume that this selection process operates on spatial codes, which define the location of stimuli and responses in environmental coordinates, with little or no role for the anatomical codes of the effectors involved. In this study, we tested this assumption by investigating response-repetition effects in a response-cuing paradigm using two motor sets (fingers on one hand vs. fingers on two hands). Reaction time results demonstrated a robust response-repetition benefit that was greater for the one-hand set than for the two-hands set. Furthermore, with the one-hand set the repetition benefit was independent of cue type and cue-stimulus interval on the previous trial, whereas with the two-hands set it was strongly modulated by these two factors. These differential response-repetition effects for one- and two-hands motor sets demonstrate the important role of the neuro-anatomical hand distinction in response selection, thereby supporting multiple coding notions.     

Implicit need for achievement predicts attenuated cortisol responses to difficult tasks

The present research tested the hypothesis that the implicit need for achievement (n Achievement) predicts attenuated cortisol (C) responses to difficult tasks, because it represents a propensity to view difficulty as a cue to mastery reward. In two studies, n Achievement was assessed through content-coding of imaginative stories and salivary C was assessed both at baseline and post-task. In Study 1 (N = 108 US students), n Achievement predicted an attenuated C response to a one-on-one competition in the laboratory, regardless of whether participants won or lost. In Study 2 (N = 62 German students), n Achievement predicted an attenuated C response to the Trier Social Stress Test (Kirschbaum, Pirke, & Hellhammer, 1993), but not to a non-stressful control task. In Study 2 only, the attenuating effect of n Achievement was moderated by gender, with only men showing the effect. Across both studies, the average effect size of the association between n Achievement and C responses to difficult tasks was r = −.28. These findings point to a role of n Achievement in emotion regulation.