Does probe rt measure central processing demand?

Various authors have tried to assess the processing demands of a range of tasks by presenting a probe at different times during their performance. The assumption behind the technique is that the more processing capacity the main task requires the less will be left for processing the probe. Hence, it is claimed, the reaction time to the probe can be used to infer the capacity demands of the main task. An experiment is reported in which two groups of women combine manual responses to a visual Same/Different letter-match task with responding to an auditory probe. The only difference between the groups is that one responds manually to the probe and the other responds vocally. The two groups produce an entirely different pattern of interaction between the two tasks.

Were there an absolute central demand of the letter-match task which could be measured by the probe technique this should appear irrespective of the form of the probe task. Since the pattern of probe RTs does depend on the form of the response to the probe it is concluded that it is not possible to use a single form of probe task as a neutral measure of the central capacity demand of the main task.     

Impulsivity and speed-accuracy tradeoffs in information processing

Despite its theoretical importance for such areas of research as reflection-impulsivity (Kagan, 1966), there is little evidence to support the assumption that individual differences in the personality trait of impulsivity are associated with differences in the willingness to sacrifice accuracy for speed of information processing. The present studies explored this association further. In Experiment 1, high, medium, and low impulsives (identified by self-report) performed a visual-comparison task under conditions differing in the monetary payoff for speed relative to accuracy. High impulsives were consistently faster and less accurate than other subjects. However, an analysis based on Sternberg's (1969) additive-factor method indicated that high impulsives performed at least one stage of information processing as slowly and accurately as other subjects. In Experiment 2, it was found that high impulsives were actually more accurate than low impulsives when all subjects were required to process information extremely rapidly. Experiment 3 identified the response execution stage as one that high impulsives carry out just as slowly and accurately as other individuals. The data from these experiments pose problems for a simple speed-accuracy tradeoff model of impulsive cognitive functioning.     

Bidirectional associations of power and size in a priming task

Recent studies have shown that the size of a word's font affects people's judgements of its power. This result has been regarded as evidence for the association between power and size. It remains unclear, however, whether this association is bidirectional. The present study used a priming paradigm to determine whether processing power words was not only affected by processing size but also whether the reverse was true, consistent with metaphor representation being bidirectional. In Experiment 1, shapes in different sizes were used as priming materials, and power words were used as targets. In Experiment 2, to test the directionality of power and size, we tested two conditions using the exact same tasks but in reverse order: power words priming shapes and shapes priming power words. In Experiment 3, a significant priming effect was replicated when power words primed shapes in a lexical decision task rather than a powerful/powerless decision task. We found an interplay between power and size in all of the experiments. The bidirectional associations between power and size were in line with the strong version of Metaphoric Structuring, which claims that concrete concepts should influence abstract concepts and abstract domains should affect concrete domains. Thus, power is partially understood in terms of size, which demonstrates that abstract concepts are grounded in sensory motor processing.     

Spatial attention can be biased towards an expected dimension

A commonly held view in both exogenous and endogenous orienting is that spatial attention is associated with enhanced processing of all stimuli at the attended location. However, we often search for a specific target at a particular location, so an observer should be able to jointly specify the target identity and expected location. Whether attention can bias dimension-specific processes at a particular location is not yet clear. We used a dual task to examine the effects of endogenous spatial cues on the accuracy of perceptual judgments of different dimensions. Participants responded to a motion target and a colour target, presented at the same or different locations. We manipulated a central cue to predict the location of the motion or colour target. While overall performance in the two tasks was comparable, cueing effects were larger for the target whose location was predicted by the cue, implying that when attending a particular location, processing of the likely dimension was preferentially enhanced. Additionally, an asymmetry between the motion and colour tasks was seen; motion was modulated by attention, and colour was not. We conclude that attention has some ability to select a dimension at a particular location, indicating integration of spatial and feature-based attention.     

发展性阅读障碍者的快速命名缺陷

快速命名任务是一种需要命名多个高熟悉项目的认知任务,尤其适合用来对成因复杂的发展性阅读障碍进行研究。许多研究者使用不同类型的快速命名任务发现,发展性阅读障碍者的快速命名缺陷在眼动过程表现为中央凹和副中央凹的加工困难,在认知过程中表现为抑制能力较差等。未来的研究中应该注意到快速命名缺陷的复杂性,采用多种方法相结合的方式来探究快速命名缺陷的本质,从而建立系统性的假说。     

Is memory for spatial location automatically encoded?

Naveh-Benjamin (1987, 1988) has shown that memory for spatial location does not meet the criteria for automatic encoding as claimed by Hasher and Zacks (1979). Age, intention, concurrent processing demands, practice, strategies, and individual differences affected memory for location. These variables should have affected effortful but not automatic processing. The experiments reported in the present paper, in which a different task was used, showed that intention, practice, and concurrent processing demands did not affect memory for location. I concluded that (1) the location task used by Naveh-Benjamin included effortful subtasks and also incidental cover or concurrent processing tasks that interfered directly with performance, and (2) the variables that he manipulated may not have affected the encoding of location. The need to differentiate processes from task performance in analyzing the automaticity issue is discussed. The dominant mode for remembering location is automatic, but such information may also be remembered voluntarily.     

Predicting and manipulating the incidence of inattentional blindness

Inattentional blindness (IB) occurs when an observer, who is engaged in a resource-consuming task, fails to notice an unexpected although salient stimulus appearing in their visual field. The incidence of IB is affected by changes in stimulus-driven properties, but little research has examined individual differences in IB propensity. We examine working memory capacity (WMC), processing styles (flicker task), inhibition (Stroop task), and training in predicting IB. WMC is associated with IB (Experiments 1 and 2) but neither processing style (Experiment 1) nor inhibition (Experiment 2) was associated. In Experiment 2, prior training on a task reduced the incidence of IB compared to no prior training, and this effect was significantly larger when trained on the same tracking task as that used in the IB task rather than a different task. We conclude that IB is related to WMC and that training can influence the incidence of IB.     

数字空间联结的灵活性及其内在机制

数字空间联结一直是认知心理学领域研究的热点之一。探索数字空间联结的一个重要指标为空间-数字反应联合编码(spatial-numerical association of response codes, SNARC)效应(左/右手对小/大数反应更快更准确)。以往研究已验证SNARC效应的普遍性及其在方向上的灵活性, 并提出多种理论解释。此外, SNARC效应在加工阶段上也具有灵活性, 其原因可能有：(1)加因素法则的理解偏差; (2)观察的角度单一; (3)观察效标的差异; (4)使用任务的差异。结合以上因素, 提出双阶段(数量信息的空间表征、空间表征到反应选择)加工模型, 不同的操控因素分别作用于两个阶段可能是引起SNARC效应灵活变化的核心原因。未来研究可从对比任务差异、引入不同干扰因素等方面进一步验证双阶段加工模型, 并结合认知神经科学技术揭示数字空间联结灵活性的内在神经机制。     

Distinctiveness of processing,processing time and memory performance

The research reported here, explored the conditions where processing time can be used as a predictive measure for retention performance. The results showed that, in similar but quantitatively different tasks, both processing time and retention performance increased with increasing task difficulty. The strongly suggests that processing time can be used as an independent measure for extensiveness of processing, and as a predictor for later retention performance. This relationship, however, is restricted to the comparison of similar processing tasks that differ only in the amount of processing necessary to perform the task.It is hypothesized that longer processing times are indicative of more extensive processing, leading to the formation of more distinctive memory representations. These, in turn, cause higher retention performance because they allow better discrimination from other memory traces, and because they are retrieved more easily.Although distinctiveness of memory representations is an important variable in determining retention performance, it is not the only one. In a recall test, semantic relations between items had an effect on performance independent of distinctiveness.     

Processing Costs of Semantic and Episodic Retrieval in Younger and Older Adults

We examined the hypothesis that reduced processing resources may be responsible for declining memory with age. Younger and older adults performed semantic and episodic memory retrieval tasks both alone and while simultaneously performing a continuous reaction time (CRT) task. We sought to equate the memory performance of the two age groups. After controlling for baseline performance on the CRT task through a regression procedure, age did not affect either semantic or episodic retrieval processing costs. There is general slowing with age, but memory retrieval ability appears to remain intact. Studies that conclude otherwise have used an inappropriate method (difference scores) to adjust for general slowing.     

Brain activity for visual judgment of lifted weight

It is well established that humans can recognize high-level aspects from point-light biological motion, such as gender and mood. If the task is to judge the manipulated weight we expected that sensorimotor regions should be recruited in the brain. Moreover, we have recently shown that chronic pain in a limb that is involved in the presented movement disturbs the weight judgment. We therefore hypothesized that some cortical regions usually activated during the processing of pain will also be activated while viewing point-light biological motion with the instruction to judge the manipulated weights. We investigated point-light biological motion of two types of movements performed with different weights in a blocked fMRI experiment in healthy subjects. In line with our a priori hypothesis, we found strong activity in the regions known as the neuromatrix of pain, such as the anterior cingulate (ACC), insula, as well as primary and secondary somatosensory regions. We also found activation in the occipital and temporal regions that are typical for biological motion, as well as regions in the cerebellum and prefrontal cortex. The activation of the somatosensory regions probably serves the judgment of the biological motion stimuli. Activation of the anterior cingulate and the insula might be explained by their role in the integration of behaviorally relevant information. Alternatively, these structures are known to be involved in the processing of nociceptive information and pain. So it seems possible that the interference between judgment of weights and perception of pain in chronic pain patients occurs in the somatosensory areas, anterior cingulate and/or insula. This finding provides important information as to the underlying mechanisms used for the weight judgment task, but also why chronic pain interferes with this task.     

A specific calculating ability

We report two experiments that investigate the calculating strategy used by a low IQ savant to identify prime numbers. Hermelin and O'Connor (1990) had suggested previously that this subject may use a procedure first described by Eratosthenes to detect a prime number, namely, dividing a target number by all primes up to the square root of the target number and testing for a remainder. In the first experiment, we compare the reaction times of the savant to decide whether a number is prime with those of a control subject proficient in mathematical calculation. In addition, we measured the savant's speed of information processing using an inspection time task. We found that the reaction times of the savant, although generally faster, followed the same pattern of the control subject who reported using the Eratosthenes procedure. The savant's inspection time indicated that his speed of processing was far superior to that expected from someone of his IQ. In the second experiment, we measured the time it takes mathematics students to divide by different prime numbers and we also tested them on the prime identification task. We used their division times to simulate their performance on the prime number identification task under the assumption that they used the Eratosthenes procedure. We also simulated the reaction times that would result from a simple memory-based procedure for identifying primes. We found that the Eratosthenes simulation, in contrast to the memory simulation, provided a good fit to both the students' and the savant's reaction times. We conclude that the savant is using a complex computational algorithm to identify primes and suggest two explanations of how the apparent contradiction between his low general intelligence and his superior numerical ability might be resolved.     

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。     

Is Semantic Processing During Sentence Reading Autonomous or Controlled? Evidence from the N400 Component in a Dual Task Paradigm

The present study contributes to the discussion on the automaticity of semantic processing. Whereas most previous research investigated semantic processing at word level, the present study addressed semantic processing during sentence reading. A dual task paradigm was combined with the recording of event-related brain potentials. Previous research at word level processing reported different patterns of interference with the N400 by additional tasks: attenuation of amplitude or delay of latency. In the present study, we presented Spanish sentences that were semantically correct or contained a semantic violation in a critical word. At different intervals preceding the critical word a tone was presented that required a high-priority choice response. At short intervals/high temporal overlap between the tasks mean amplitude of the N400 was reduced relative to long intervals/low temporal overlap, but there were no shifts of peak latency. We propose that processing at sentence level exerts a protective effect against the additional task. This is in accord with the attentional sensitization model (Kiefer & Martens, 2010), which suggests that semantic processing is an automatic process that can be enhanced by the currently activated task set. The present experimental sentences also induced a P600, which is taken as an index of integrative processing. Additional task effects are comparable to those in the N400 time window and are briefly discussed.     

Use of evidence in a categorization task: analytic and holistic processing modes

Category learning performance can be influenced by many contextual factors, but the effects of these factors are not the same for all learners. The present study suggests that these differences can be due to the different ways evidence is used, according to two main basic modalities of processing information, analytically or holistically. In order to test the impact of the information provided, an inductive rule-based task was designed, in which feature salience and comparison informativeness between examples of two categories were manipulated during the learning phases, by introducing and progressively reducing some perceptual biases. To gather data on processing modalities, we devised the Active Feature Composition task, a production task that does not require classifying new items but reproducing them by combining features. At the end, an explicit rating task was performed, which entailed assessing the accuracy of a set of possible categorization rules. A combined analysis of the data collected with these two different tests enabled profiling participants in regard to the kind of processing modality, the structure of representations and the quality of categorial judgments. Results showed that despite the fact that the information provided was the same for all participants, those who adopted analytic processing better exploited evidence and performed more accurately, whereas with holistic processing categorization is perfectly possible but inaccurate. Finally, the cognitive implications of the proposed procedure, with regard to involved processes and representations, are discussed.     

Processing two tasks with varying task order: central stage duration influences central processing order

In a recent study, Sigman and Dehaene (2006, PLoS Biology, 4, 1227–1238) reported that perceptual processing duration influences processing order of two tasks in the psychological refractory period paradigm (PRP). The present study examines whether the duration of central processes also influences processing order. For this purpose, we employed letter tasks with different central processing durations and varied task order in the PRP. In one part of the experiment, a tone discrimination task was combined with a similar time-consuming letter discrimination task. In the other part, the tone task was combined with a more time-consuming letter task, which required a mental rotation of the letter thereby prolonging central processing. If the duration of central processes influences processing order, participants should perform the tone task first more often when it is presented with the more time-consuming mental rotation task, than when it is presented with the similar time-consuming letter task. The results clearly confirm this prediction and thus show that not only perceptual processing duration but also central processing duration affects processing order in a dual-task situation. We suggest that the reported effect mirrors a tendency of participants to minimize total reaction time to both tasks by reducing slack time.     

Electrophysiological evidence of central interference in the control of visuospatial attention

Visuospatial attention can be deployed to different locations in space without movement of the eyes. A large body of human electrophysiological studies reveals enhanced sensory-perceptual responses to stimuli that appear at an attended location. However, it is not clear that the mechanisms that underlie visuospatial attention are under the control of attention mechanisms that limit central processing in multiple-task situations. We investigated this question by incorporating a visual task that required the deployment of visuospatial attention as the second task of psychological refractory period (PRP) dual-task paradigms. The N2pc component of the event-related potential was used as an electrophysiological index of the moment-by-moment deployment of visuospatial attention to monitor when and where observers were attending while they performed concurrent central processing known to cause the PRP effect. Electrophysiological evidence shows that central processing interfered with the N2pc, suggesting that visuospatial attention is under the control of capacity-limited central mechanisms.     

Reactive effects of concurrent verbalization in person perception tasks

The reactive effects of concurrent verbalization (CV) on task performance in impression formation research have not been investigated, despite increasing use of this process tracing method. Since many person perception tasks involve multiple trials, assessment of reactivity should focus on carry-over and reactive-practice effects, as well as changes in task performance concurrent with thinking aloud. An experimental method for assessing these three forms of reactivity was demonstrated in an information-request impression formation task. Concurrent reactive effects were found for both continuous and intermittent CV. For the former, task processing was mildly slowed but altered in a manner suggestive of more efficient learning of, and memory for cues requested early in task performance. The substantial slowing of task processing during trial 1 intermittent CV largely disappeared by trial 2, indicating that subjects may require more practice for this method to be used effectively. The results for continuous CV are in line with recent findings which are inconsistent with certain predictions from the predominant theory of verbal protocol generation (Ericsson and Simon, 1984). Investigators using CV are urged to incorporate empirical checks for reactivity into their experimental designs.     

Crossmodal action selection: Evidence from dual-task compatibility

Response-related mechanisms of multitasking were studied by analyzing simultaneous processing of responses in different modalities (i.e., crossmodal action). Participants responded to a single auditory stimulus with a saccade, a manual response (single-task conditions), or both (dual-task condition). We used a spatially incompatible stimulus-response mapping for one task, but not for the other. Critically, inverting these mappings varied temporal task overlap in dual-task conditions while keeping spatial incompatibility across responses constant. Unlike previous paradigms, temporal task overlap was manipulated without utilizing sequential stimulus presentation, which might induce strategic serial processing. The results revealed dual-task costs, but these were not affected by an increase of temporal task overlap. This finding is evidence for parallel response selection in multitasking. We propose that crossmodal action is processed by a central mapping-selection mechanism in working memory and that the dual-task costs are mainly caused by mapping-related crosstalk.     

执行功能与数量加工：回顾与展望

回顾了执行功能与数量加工之间的复杂关系。其中,执行功能的4个子系统——抑制、转换、刷新和双任务协调对数量加工的影响各不相同：抑制可以在一定程度上改变数量加工时的自动激活程度;转换功能则主要依赖注意来进行调节;刷新与数量加工关系的研究成果比较少;而双任务协调与数量加工之间的联系存在争论。文章最后分3个方面进行了研究趋势的展望,认为未来执行功能与数量加工的研究将突破相关研究的局限,通过更精巧的设计和大量特殊被试的研究取得突破性进展。