Strategic regulation of cognitive control by emotional salience: A neural network model

We present a neural network model of stimulus processing, which uses a mechanism of adaptive attentional control to regulate the moment to moment deployment of attention according to both the demands of the current task, and the demands of emotionally salient information. This mechanism allows negative emotional information to reduce cognitive control to aid in the detection of threats, which produces a momentary withdrawal from the current task set to allow unbiased processing of available information. The combination of cognitive and emotional regulation of task set allows this model to address inter-trial aspects of emotional interference in colour naming. In particular, we focus on the nature of the emotional interference in colour naming (McKenna & Sharma, 2004) as well as in word reading (Algom, Chajut, & Lev, 2004) and show how this form of interference is functionally distinct from the classic Stroop effect. Our model addresses a range of findings in colour naming and word reading tasks and is informed by recent neuroimaging data concerning the interaction between the anterior cingulate and prefrontal cortices. The model is used to explore the interface between cognition and emotion with a series of predictions, including a qualitative distinction between state and trait forms of anxiety.     

Perceptual interactions in two-word displays: familiarity and similarity effects

Previous studies have demonstrated the existence of perceptual interactions in the processing of two-word displays such as SAND LANE. When postcued to report one of the two words, subjects often make migration errors, in that the report of the specified word includes a letter of the other word (e.g., LAND or SANE instead of SAND). We find that migrations depend on the abstract, structural similarity of the strings, but not on the physical similarity; on whether the strings are words; and on whether the possible migration responses are words. We also rule out an interpretation of migration errors that attributes them to a guessing strategy. Our findings are interpreted in terms of models in which both strings simultaneously access high-level structural knowledge, that is, knowledge about what sequences of letters fit together to form familiar wholes.     

Lexical retrieval constrained by sound structure: the role of the left inferior frontal gyrus

Positron emission tomography was used to investigate two competing hypotheses about the role of the left inferior frontal gyrus (IFG) in word generation. One proposes a domain-specific organization, with neural activation dependent on the type of information being processed, i.e., surface sound structure or semantic. The other proposes a process-specific organization, with activation dependent on processing demands, such as the amount of selection needed to decide between competing lexical alternatives. In a novel word retrieval task, word reconstruction (WR), subjects generated real words from heard non-words by the substitution of either a vowel or consonant. Both types of lexical retrieval, informed by sound structure alone, produced activation within anterior and posterior left IFG regions. Within these regions there was greater activity for consonant WR, which is more difficult and imposes greater processing demands. These results support a process-specific organization of the anterior left IFG.     

A psychophysiological and driving performance evaluation of focal and ambient visual processing demands in simulated driving

Research has focused little on the ambient and focal visual channels within which driving and side-task information can be processed. In the current experiment, for the purpose of demonstrating differentiation of focal and ambient visual processing attentional demands on driving performance and physiological response, subjects participated in a dual-task driving simulation that contained focal and ambient components. We hypothesized that ambient demands would not have any effects on driving performance or physiological response, whereas the focal-side-task would cause a deterioration in driving performance and specific changes in physiological response. Support for these hypotheses would provide evidence that focal visual processing is attention demanding, whereas the processing of ambient visual information is not.Some results suggest that ambient visual information was processed pre-attentively, whereas focal visual information requires attentional resources to be processed. Driving performance deteriorated and changes in physiological response occurred when the focal side-task was added to driving, but not when the ambient side-task was added. However, we failed to see predicted changes in driving performance and physiological response as the demands of the focal and ambient components of the driving simulation varied. The results of the current study suggest that a differentiation in attention demands between focal and ambient vision does exist, but that further research is needed to better understand the nature and practical consequences of the differentiation.     

Examining the interactivity of lexical orthographic and phonological processing.

The number and type of connections involving different levels of orthographic and phonological representations differentiate between several models of spoken and visual word recognition. At the sublexical level of processing, Borowsky, Owen, and Fonos (1999) demonstrated evidence for direct processing connections from grapheme representations to phoneme representations (i.e., a sensitivity effect) over and above any bias effects, but not in the reverse direction. Neural network models of visual word recognition implement an orthography to phonology processing route that involves the same connections for processing sublexical and lexical information, and thus a similar pattern of cross-modal effects for lexical stimuli are expected by models that implement this single type of connection (i.e., orthographic lexical processing should directly affect phonological lexical processing, but not in the reverse direction). Furthermore, several models of spoken word perception predict that there should be no direct connections between orthographic representations and phonological representations, regardless of whether the connections are sublexical or lexical. The present experiments examined these predictions by measuring the influence of a cross-modal word context on word target discrimination. The results provide constraints on the types of connections that can exist between orthographic lexical representations and phonological lexical representations.     

How to say "no" to a nonword: a leaky competing accumulator model of lexical decision

We describe a leaky competing accumulator (LCA) model of the lexical decision task that can be used as a response/decision module for any computational model of word recognition. The LCA model uses evidence for a word, operationalized as some measure of lexical activity, as input to the YES decision node. Input to the NO decision node is simply a constant value minus evidence for a word. In this way, evidence for a nonword is a function of time from stimulus onset (as in standard deadline models) modulated by lexical activity via the competitive dynamics of the LCA. We propose a simple mechanism for determining the value of this constant online during the first trials of a lexical decision experiment, such that the model can rapidly optimize speed and accuracy in discriminating words from nonwords. Further optimization is achieved via trial-by-trial adjustments in response criteria as a function of task demands and list context. We show that the LCA model can simulate mean response times and response distributions for correct and incorrect YES and NO decisions for a number of benchmark experiments that have been shown to be fatal for deadline models of lexical decision. Finally, using lexical activity calculated by a computational model of word recognition as input to the LCA decision module, we provide the first item-level simulation of both word and nonword responses in a large-scale database.     

The influence of speech rate and accent on access and use of semantic information

Circumstances in which the speech input is presented in sub-optimal conditions generally lead to processing costs affecting spoken word recognition. The current study indicates that some processing demands imposed by listening to difficult speech can be mitigated by feedback from semantic knowledge. A set of lexical decision experiments examined how foreign accented speech and word duration impact access to semantic knowledge in spoken word recognition. Results indicate that when listeners process accented speech, the reliance on semantic information increases. Speech rate was not observed to influence semantic access, except in the setting in which unusually slow accented speech was presented. These findings support interactive activation models of spoken word recognition in which attention is modulated based on speech demands.     

Priming in a free association task as a function of association directionality

Two experiments investigated priming in free association, a conceptual implicit memory task. The stimuli consisted of bidirectionally associated word pairs (e.g., BEACH-SAND) and unidirectionally associated word pairs that have no association from the target response back to the stimulus cue (e.g., BONE-DOG). In the study phase, target words (e.g., SAND, DOG) were presented in an incidental learning task. In the test phase, participants generated an associate to the stimulus cues (e.g., BEACH, BONE). In both experiments, priming was obtained for targets (e.g., SAND) that had an association back to the cue, but not for targets (e.g., DOG) for which such a backward association was absent. These results are problematic for theoretical accounts that attribute priming in free association to the strengthening of target responses. It is argued that priming in free association depends on the strengthening of cue-target associations.     

汉字位置加工和词边界效应的认知机制

在中文阅读中, 为了进行词汇识别, 需要对汉字在词中的相对顺序进行加工, 即汉字位置加工。汉字位置加工是词汇识别和阅读理解的重要环节。如果汉字位置未得到加工, 可转置词将很难被区分。可转置词由相同汉字构成, 但每个汉字所处位置不同。以往研究发现, 词内汉字位置加工是比较灵活的; 而且词边界信息会影响汉字位置的加工, 即汉字位置加工存在词边界效应。该效应产生的原因及影响因素有哪些?本项目采用眼动追踪技术, 在自然阅读中系统探讨如下三个问题:(1)词的首/尾汉字如何调节汉字位置加工过程; (2)嵌套词和歧义词边界如何影响汉字位置加工; (3)语境合理性和预测性如何影响汉字位置加工的词边界效应。本项目将为首个中文汉字位置加工模型的建立提供数据支持和科学基础, 推进现有的中文词汇识别和词切分模型的进一步完善, 并为词汇的高效率教授与学习提供科学指导。     

用PDP模型模拟Stroop任务的实验研究

本实验用基于ＰＤＰ原理构造的Ｓｔｒｏｏｐ任务模型模拟了Ｓｔｒｏｏｐ颜色－词的干扰现象。模型采用ＢＰ学习算法。经过训练,模型学会字词阅读和颜色命名。由于对模型采用６种不同的学习次数（这里为：５００,１０００,２０００,３０００,５０００,１００００）以及４种不同比例（这里为：４：１,６：１,８：１,１０：１）字词模式和颜色模式的训练,其结果字词通道的信息加工比颜色通道的加工更快更强,并产生不同的干扰模式,其字词加工的次数越多,干扰越大,次数越少,干扰也越小。这很可能说明语言的熟练程度对干扰模式有着更大的影响。模型还体现了加工过程的连续性质。但这个模型难以区分不同的加工任务。     

Walking through doorways causes forgetting: environmental integration

Memory for objects declines when people move from one location to another (the location updating effect). However, it is unclear whether this is attributable to event model updating or to task demands. The focus here was on the degree of integration for probed-for information with the experienced environment. In prior research, the probes were verbal labels of visual objects. Experiment 1 assessed whether this was a consequence of an item-probe mismatch, as with transfer-appropriate processing. Visual probes were used to better coordinate what was seen with the nature of the memory probe. In Experiment 2, people received additional word pairs to remember, which were less well integrated with the environment, to assess whether the probed-for information needed to be well integrated. The results showed location updating effects in both cases. These data are consistent with an event cognition view that mental updating of a dynamic event disrupts memory.     

Pupil-BLAH-metry: Cognitive effort in speech planning reflected by pupil dilation

In reading research, a longstanding question is whether any stages of lexical processing require central attention, and whether such potential demands are frequency-sensitive. In the present study, we examined the allocation of cognitive effort in lexical processing by examining pupil dilations and naming latencies in a modified delayed naming procedure. In this dual-task/change procedure, participants read words and waited for various delays before being signaled to issue a response. On most trials (80%), participants issued a standard naming response. On the remaining trials, they were cued to abandon the original speech plan, saying "blah" instead, thereby equating production across different words. Using feature-matched low- and high-frequency words, we observed the differences in pupil dilations as a function of word frequency. Indeed, frequency-sensitive cognitive demands were seen in word processing, even after naming responses were issued. The results suggest that word perception and/or speech planning requires the frequency-sensitive allocation of cognitive resources.     

Modeling individual differences in working memory performance: a source activation account

Working memory resources are needed for processing and maintenance of information during cognitive tasks. Many models have been developed to capture the effects of limited working memory resources on performance. However, most of these models do not account for the finding that different individuals show different sensitivities to working memory demands, and none of the models predicts individual subjects' patterns of performance. We propose a computational model that accounts for differences in working memory capacity in terms of a quantity called source activation , which is used to maintain goal-relevant information in an available state. We apply this model to capture the working memory effects of individual subjects at a fine level of detail across two experiments. This, we argue, strengthens the interpretation of source activation as working memory capacity.     

The role of saccades in multitasking: towards an output-related view of eye movements

The present paper presents an overview of research on the role of saccades in multitasking. Multitasking is known to cause performance costs in terms of increased response times and/or error rates. However, most of the previous research on multitasking was focused on manual and vocal action demands, and the role of eye movements has been largely neglected. As a consequence, saccade execution was mainly considered with respect to its functional role in gathering new visual information (input side of information processing). However, several more recent experiments confirmed that saccades both exhibit and cause dual-task costs in the context of other actions and should thus also be regarded as a response modality (output side of information processing). Theoretical implications as well as several open issues for future research will be outlined.     

Is emotional content obtained from parafoveal words during reading? An eye movement analysis

An eye-movement-contingent display change technique was employed to study whether adult readers extract semantic information from parafoveal words during reading. Three types of parafoveal preview conditions were contrasted: an emotional word, a neutral word, and an identical word condition. To have a maximally effective parafoveal manipulation, high-arousal emotional words (sex- and threat-related and curse words) were used as parafoveal previews. Readers' eye fixation patterns around the target word revealed no evidence for parafoveal semantic processing. Furthermore, the pupil size showed no signs for an emotional response triggered by an emotional word previewed parafoveally. These results are consistent with the view that, as a rule, only the fixated word is processed to a semantic level during reading.     

先前语境与随后副中央凹预视在词跳读中的相对作用

词跳读促使了阅读高效地进行。被跳读的词主要根据前文语境和副中央凹预视提前得到加工。分析跳读的影响因素可知,相比于语境因素（特别是预测性）和副中央凹词汇因素（如词频）,副中央凹词的视觉词长信息对跳读的影响最大。跳读密切联系当前眼动控制的两大内容,理想的阅读眼动控制模型需区别语境不同信息（即预测性、语义合理性和句法合理性）对跳读的作用。未来可扩展中文跳读的研究,解决中文跳读单元问题及相关争论。     

阅读中的眼跳目标选择问题

读者在阅读中面临如何选择眼跳落点位置的问题。研究者在有词间空格的字母文字中(如英语和德语)发现人们倾向于将眼跳落在词中心偏左的位置,这个位置被称为偏好注视位置(preferred viewing location,PVL)。中文文本并没有空格来标记词边界信息,这使得中文阅读的眼跳目标选择机制更加复杂。近年来,研究者从中央凹—副中央凹动态调节的角度研究了阅读中眼跳目标选择的机制。结果发现在中文阅读中眼跳目标选择受到中央凹和副中央凹信息加工的共同影响,而副中央凹的加工直接决定了眼跳落点位置。     

中性抽象词和具体词情绪信息获得的差异

采用词汇迫选学习范式考察不同类型词汇获得情绪信息的认知机制。结果发现：（1）在迫选过程中与积极图片匹配的具体词汇喜好度显著高于与消极图片匹配的喜好度,而抽象词学习并未表现出这样的效应。（2）积极图片下被选择词汇的喜好度显著高于未被选择词汇的喜好度,而消极图片下被选择词汇与未被选择词汇的喜好度差异不显著。该结果表明具体词相较于抽象词更易获得相应情绪信息,积极情绪比消极情绪信息更易被习得。     

三成分心理系统：诠释传递性推理的新理论

Wright在传递性推理的研究中提出三成分心理系统模型以来,该模型理论成为了传递性推理领域研究的热点。三成分心理模型是在经典皮亚杰理论和传统信息加工理论基础上提出来的,代表了人们进行传递性推理时所进行的传递性转换、顺序抽取和协调反应等三个主要的加工机制,在不同的加工机制中运用了不同的加工策略。在此基础上,文章讨论了三成分心理模型理论未来的研究方向。     

Attentional demands of visual word recognition

Becker's (1976, 1979, 1980, 1985; Becker & Killion, 1977; Eisenberg & Becker, 1982) verification model was used as a framework to investigate the attentional demands of word recognition. In two experiments, a lexical decision task and an auditory probe task were performed in single- and dual-task conditions. Responses to probes were divided into detection and movement measures that indexed the demands of recognition and response output, respectively. In Experiment 1, single- to dual-task decrements in probe detection performance were larger during low-frequency as compared with high-frequency trials. This finding indicates that the attentional demands of word recognition vary with word frequency. These findings were replicated in Experiment 2, which was designed to separate a response compatibility and a capacity interpretation of the results. The findings are interpreted within Becker's verification model.