内源性注意与外源性注意对数字加工的不同影响

分别采用内源性注意和外源性注意实验范式,材料为小数（1－4）和大数（6－9）的中文与阿拉伯数字,任务为判断数字是否大于5,考察在注意与非注意条件下不同大小数字加工的距离效应和符号效应。结果发现：⑴在内源性线索和外源性线索的注意条件下,大小数都出现了距离效应;但在非注意条件下,内源性线索时的大小数都出现了距离效应,而外源性线索时只有小数出现了距离效应,大数的距离效应明显减弱或消失。⑵在内源性线索和外源性线索的注意条件下,大小数都没有出现符号效应;但在非注意条件下,大数没有出现符号效应,而小数出现了符号效应（阿拉伯数字的绩效比中文数字差）,并且内源性线索时的符号效应强度小于外源性线索。     

内源性注意和外源性注意对中小学生SNARC效应的影响

采用内源性注意和外源性注意实验范式,以判断数字奇偶为任务,材料为1～9的阿拉伯数字,考察内源性和外源性线索不同注意条件下中小学生的数字加工SNARC效应。结果发现:(1)内源性线索和外源性线索条件下,中小学生在数字加工任务中所表现出来的SNARC效应随着年龄增长逐渐增大;(2)内源性线索和外源性线索注意条件下,各年级学生均表现出显著的SNARC效应;(3)内源性线索非注意条件下,中学生能够表现出显著的SNARC效应,但小学生的SNARC效应不明显;外源性线索非注意条件下,高中生能够表现出显著的SNARC效应,但小学生和初中生的SNARC效应不明显,说明外源性注意对中小学生数字加工SNARC效应的影响比内源性注意大,且对SNARC效应的影响主要表现在较大的数字8和9上。     

不同注意条件下的空间－数字反应编码联合效应

考察在无线索、内源性线索与外源性线索时不同符号数字在注意与非注意条件下的空间－数字的反应编码联合效应（Spatial Numerical Association of Response Codes,简称SNARC效应）。采用1到9的中文与阿拉伯数字为材料,以判断数字奇偶为任务。实验结果表明：⑴无线索时注意条件下阿拉伯和中文数字都出现了SNARC效应,而非注意条件下则都没有出现,并且受影响的主要是较大的数字（8、9）;⑵外源性线索和内源性线索时,我们得到一个逐渐递减的SNARC效应,受影响的也主要是较大的数字（8、9）。在内源性线索的注意条件阿拉伯和中文数都有SNARC效应,而在非注意条件只有阿拉伯数有SNARC效应;在外源性线索的注意条件只有阿拉伯数有SNARC效应,而在非注意条件阿拉伯和中文都没有SNARC效应,说明外源性注意的影响比内源性注意更大,中文数字所受的影响比阿拉伯数字更大。     

视觉选择性注意对注意缺损多动障碍儿童数字距离效应的影响

采用Posner的内源性和外源性线索实验范式,材料为1~9的阿拉伯数字(不包括5),以判断目标数字是否大于5为任务,考察视觉选择性注意中的内源性注意和外源性注意对注意缺陷型多动障碍儿童(ADHD)数字加工距离效应的影响。结果发现:(1)内源性和外源性注意条件下,正常儿童在数字判断加工任务中的反应时短于ADHD儿童;(2)内源性有效线索提示条件下,ADHD儿童和正常儿童均表现出显著的数字距离效应;而无效线索提示条件下,ADHD儿童的大小数字距离效应均不明显,正常儿童仍然表现出显著的数字距离效应;(3)外源性有效线索提示条件下,ADHD儿童的小数字距离效应显著,但大数字距离效应不明显,正常儿童则表现出显著的大小数字距离效应;而无效线索提示条件下,只有正常儿童表现出显著的数字距离效应,ADHD儿童的数字距离效应不显著。     

内源性注意和外源性注意条件下SOA变化对数字距离效应的影响

采用内源性注意和外源性注意实验范式,材料为小数(1～4)和大数(6～9)的阿拉伯数字,以判断数字是否大于5为任务,考察内源性和外源性线索不同注意条件下SOA对数字距离效应的影响。结果发现:(1)内源性线索条件下,随着SOAs增加,大小数的距离效应逐渐增大,当SOA为900ms时,大小数的距离效应最明显;(2)外源性线索条件下,当SOA为300ms时,大小数的距离效应最显著,随着SOAs增加,大小数的距离效应逐渐减小。     

感数——它能告诉我们什么?

研究者在列举任务中发现,被试对3个以内项目的报告既快又准确（一般称之为“感数”）,而对3个以上项目的报告既慢又容易出错误（“计数”）,由此他们提出感数和计数属于两种不同性质的加工过程,一系列行为数据的反应时和正确率指标支持了这一假设。此外,最近的脑成像、电生理研究还发现,感数和计数在对注意的需求上同样存在着分离——感数无需注意,只有计数过程才需注意的参与。在此基础上,研究者从不同角度提出了一些解释感数现象的理论     

内外源性空间注意对多感觉整合的影响

本文采用内-外源性空间线索靶子范式, 操控内源性线索有效性(有效线索、无效线索)、外源性线索有效性(有效线索、无效线索)、目标刺激类型(视觉刺激、听觉刺激、视听觉刺激)三个自变量。通过两个不同任务难度的实验(实验1: 简单定位任务; 实验2: 复杂辨别任务)来考察内外源性空间注意对多感觉整合的影响。两个实验结果均发现外源性空间注意显著减弱了多感觉整合效应, 内源性空间注意没有显著增强多感觉整合效应; 实验2中还发现了内源性空间注意会对外源性空间注意减弱多感觉整合效应产生影响。结果表明, 与内源性空间注意不同, 外源性空间注意对多感觉整合的影响不易受任务难度的调控; 当任务较难时内源性空间注意会影响外源性空间注意减弱多感觉整合效应的过程。由此推测, 内外源性空间注意对多感觉整合的调节并非彼此独立、而是相互影响的。     

受助者结果类型对亲社会表现的影响:成人与儿童的对比研究

亲社会表现是指人们在社会交往中表现出来的谦让、帮助、合作、分享等行为,其影响机制受到广泛关注。本文通过两个研究（分别以大学生和二、四、六年级小学生为研究对象）探讨了受助者结果类型（受助者获得积极结果vs.受助者避免消极结果）对亲社会表现的影响。结果显示：（1）受助者避免消极结果条件比受助者获得积极结果条件诱发成人更高的亲社会意愿和行为;（2）六年级儿童帮助他人避免消极结果的亲社会意愿更强、情绪更积极;（3）相对于帮助他人避免消极结果,二年级儿童更倾向于帮助他人获得积极结果。这些结果说明受助者结果类型影响个体的亲社会表现（包括亲社会行为、亲社会意愿、亲社会情绪）,并且这种影响因成人和儿童有所不同：成人和年长儿童表现出亲社会损失规避现象,年幼儿童则表现出相反效应。     

内外源提示下学障儿童注意定向的眼动研究

对三、六年级22名学障儿童和22名按年龄、性别和受教育水平匹配的正常儿童在内外源提示下的注意表现进行了眼动研究。结果表明:当内源性提示有效性比例较低时,学障和正常儿童的提示效度效应均不明显;当提示目标间隔时间较长时,外源性提示有效性对各组被试的反应时无显著影响;在内外源性提示下,六年级儿童的绩效好于三年级;学障儿童在反应时间、加工速度上和正常儿童没有显著差异,但在加工广度和策略上不如正常儿童。这些结果表明学障儿童的注意定向和相关的认知加工能力与正常儿童有所差异。     

不同位置的情绪面孔加工对返回抑制的影响

分别将情绪面孔图片作为线索（实验一）或靶子（实验二）呈现,利用线索-靶子范式考察了定位任务中情绪面孔加工对返回抑制的影响。结果发现：以不同情绪面孔作为线索时,返回抑制稳定出现,表现出与情绪加工的分离;而当情绪面孔作为靶子时,与中性面孔相比,情绪面孔引发的返回抑制量显著较小。该研究表明,在定位任务中,返回抑制不受线索生物性的影响,但是会受到靶子性质的影响,反映出机体在不同条件下对空间注意和情绪加工的灵活性。     

感数的认知机制：从注意到工作记忆

感数(subitizing)是对小数精确而迅速的知觉, 它反映了有机体的一种基本数量表征能力。研究者曾一度认为感数是一个前注意的并行加工过程, 近年来的一些研究发现感数是需要注意资源的, 但是注意资源假设不能有效解释感数与计数的分离。为解决这一困惑, 本文综述了感数和视空间工作记忆的相似性, 在此基础上提出一种新的观点来解释感数的认知机制：视空间工作记忆容量决定了个体一次能精确知觉到的客体的数量, 而注意决定了哪些信息进入视空间工作记忆。     

More than superstition: differential effects of featural heterogeneity and change on subitizing and counting

This study investigates the effects of item heterogeneity (differences in color and shape) and moment-to-moment feature change as it relates to the issue of whether subitizing and counting involve different processes. Participants enumerated displays of up to eight items that were either homogeneous or heterogeneous. In situations where the heterogeneous displays always had approximately half of the items of one type and half of the other, heterogeneity significantly sped enumeration in the counting range (6-8 items) and significantly slowed enumeration in the subitizing range (1-3 items), a dissociation that suggests that subitizing and counting involve different operations. Moment-to-moment feature change had no effect on subitizing. However, feature change slowed counting, but only when participants were enumerating heterogeneous items that were half of one type and half of the other, as might be expected if participants were using differences in features to select items by type.     

The role of pattern recognition in children's exact enumeration of small numbers

Enumeration can be accomplished by subitizing, counting, estimation, and combinations of these processes. We investigated whether the dissociation between subitizing and counting can be observed in 4‐ to 6‐year‐olds and studied whether the maximum number of elements that can be subitized changes with age. To detect a dissociation between subitizing and counting, it is tested whether task manipulations have different effects in the subitizing than in the counting range. Task manipulations concerned duration of presentation of elements (limited, unlimited) and configuration of elements (random, line, dice). In Study 1, forty‐nine 4‐ and 5‐year‐olds were tested with a computerized enumeration task. Study 2 concerned data from 4‐, 5‐, and 6‐year‐olds, collected with Math Garden, a computer‐adaptive application to practice math. Both task manipulations affected performance in the counting, but not the subitizing range, supporting the conclusion that children use two distinct enumeration processes in the two ranges. In all age groups, the maximum number of elements that could be subitized was three. The strong effect of configuration of elements suggests that subitizing might be based on a general ability of pattern recognition.     

Small subitizing range in people with Williams syndrome

Recent evidence suggests that the rapid apprehension of small numbers of objects—often called subitizing—engages a system which allows representation of up to 4 objects but is distinct from other aspects of numerical processing. We examined subitizing by studying people with Williams syndrome (WS), a genetic deficit characterized by severe visuospatial impairments, and normally developing children (4–6.5 years old). In Experiment 1, participants first explicitly counted displays of 1 to 8 squares that appeared for 5 s and reported “how many”. They then reported “how many” for the same displays shown for 250 ms, a duration too brief to allow explicit counting, but sufficient for subitizing. All groups were highly accurate up to 8 objects when they explicitly counted. With the brief duration, people with WS showed almost perfect accuracy up to a limit of 3 objects, comparable to 4-year-olds but fewer than either 5- or 6.5-year-old children. In Experiment 2, participants were asked to report “how many” for displays that were presented for an unlimited duration, as rapidly as possible while remaining accurate. Individuals with WS responded as rapidly as 6.5-year-olds, and more rapidly than 4-year-olds. However, their accuracy was as in Experiment 1, comparable to 4-year-olds and lower than older children. These results are consistent with previous findings, indicating that people with WS can simultaneously represent multiple objects, but that they have a smaller capacity than older children, on par with 4-year-olds. This pattern is discussed in the context of normal and abnormal development of visuospatial skills, in particular those linked to the representation of numerosity.     

What dot clusters and bar graphs reveal: subitizing is fast counting and subtraction

In two studies, we found that dot enumeration tasks resulted in shallow-sloped response time (RT) functions for displays of 1-4 dots and steep-sloped functions for displays of 5-8 dots, replicating results implicating subitizing and counting processes for low and high ranges of dots, respectively. Extracting number from a specific type of bar graph within the same numerical range produced a shallow-sloped but scallop-shaped RT function. Factor analysis confirmed two independent subranges for dots, but all bar graph values defined a unitary factor. Significantly, factor scores and asymmetries both showed correlations of bar graph recognition to dot subitizing but not to dot counting, strongly suggesting that subitizing was used in both enumeration of low numbers of dots and bar graph recognition. According to these results, subitizing appears to be a nonverbal process operating flexibly in either additive or subtractive fashion on analog quantities having spatial extent, a conclusion consistent with a fast-counting model of subitizing but not with other models of the subitizing process.     

Subitizing and counting in typical and atypical development

Enumeration performance in standard dot counting paradigms was investigated for different age groups with typical and atypically poor development of arithmetic skills. Experiment 1 showed a high correspondence between response times and saccadic frequencies for four age groups with typical development. Age differences were more marked for the counting than the subitizing range. In Experiment 2 we found a discontinuity between subitizing and counting for dyscalculic children; however, their subitizing slopes were steeper than those of typically developing control groups, indicating a dysfunctional subitizing mechanism. Across both experiments a number of factors could be identified that affect enumeration in the subitizing and the counting range differentially. These differential patterns further support the assumption of two qualitatively different enumeration processes.     

Subitizing requires attention

While counting objects is typically a slow, serial process, enumerating about four or fewer objects has been considered to be a relatively effortless, parallel, and even preattentive process often referred to as subitizing. However, by combining a subitizing task with an attentional blink task, we show that subitizing is systematically affected by a closely preceding letter identification task. Vice versa, letter identification is also affected by a closely preceding subitizing task. Importantly, performance not only depended on the time between the two tasks, but also on the number of to-be-enumerated dots, even though this number fell within the subitizing range. The results imply that the processes underlying subitizing require attentional resources, suggesting that they are either serial in nature, or parallel, with capacity limited by the overall resources available.     

Hemispheric specialization in quantification processes

Three experiments were carried out to study hemispheric specialization for subitizing (the rapid enumeration of small patterns) and counting (the serial quantification process based on some formal principles). The experiments consist of numerosity identification of dot patterns presented in one visual field, with a tachistoscopic technique, or eye movements monitored through glasses, and comparison between centrally presented dot patterns and lateralized tachistoscopically presented digits. Our experiments show left visual field advantage in the identification and comparison tasks in the subitizing range, whereas right visual field advantage has been found in the comparison task for the counting range. Received: 11 January 1999 / Accepted: 17 March 2000     

Spatial working memory load affects counting but not subitizing in enumeration

The present study investigated whether subitizing reflects capacity limitations associated with two types of working memory tasks. Under a dual-task situation, participants performed an enumeration task in conjunction with either a spatial (Experiment 1) or a nonspatial visual (Experiment 2) working memory task. Experiment 1 showed that spatial working memory load affected the slope of a counting function but did not affect subitizing performance or subitizing range. Experiment 2 showed that nonspatial visual working memory load affected neither enumeration efficiency nor subitizing range. Furthermore, in both spatial and nonspatial memory tasks, neither subitizing efficiency nor subitizing range was affected by amount of imposed memory load. In all the experiments, working memory load failed to influence slope, subitizing range, or overall reaction time. These findings suggest that subitizing is performed without either spatial or nonspatial working memory. A possible mechanism of subitizing with independent capacity of working memory is discussed.