Multidimensional signal detection analyses (MSDA) for testing separability and independence: A Pascal program

A Pascal (Turbo 6.0) program for testing perceptual separability, decisional separability, and perceptual independence—three types of independence defined in the context of general recognition theory (GRT)—is presented. GRT is essentially a multidimensional extension of signal detectability theory (Green & Swets, 1966) and has been employed in complete-identification experimental paradigms to examine whether information processing of stimulus dimensions is perceptually and/or decisionally separable and/or perceptually independent. The definitions of these different forms of “independence” are provided, the experimental design is described, and the program, MSDA, is described and demonstrated.     

Verbal Counting Moderates Perceptual Biases Found in Children's Cardinality Judgments

A crucial component of numerical understanding is one's ability to abstract numerical properties regardless of varying perceptual attributes. Evidence from numerical match-to-sample tasks suggests that children find it difficult to match sets based on number in the face of varying perceptual attributes, yet it is unclear whether these findings are indicative of incomplete numerical abstraction abilities early in development or instead are driven by specific demands of the matching task. In this study, we explored whether perceptual biases would be found in data from a numerical task invoking verbal representations of number and whether these biases are moderated by verbal counting behavior. Three- to 6-year-old children classified as proficient counters (cardinal principle knowers) participated in a number cardinality task in which they were asked to identify which of 2 arrays—either perceptually homogeneous or heterogeneous in appearance—contained a specific number of animals (e.g., “12 animals”). Results revealed an overall performance bias for homogeneous trials in this cardinality task, such that children were better able to exactly identify the target cardinality when items within the sets were perceptually identical. Further analyses revealed that these biases were found only for those children who did not explicitly verbally count during the task. In contrast, performance was unaffected by the perceptual attributes of the array when the child spontaneously counted. Together, results reveal that cardinality judgments are negatively impacted by perceptual variation, but this relationship is muted in those children who engage in verbal counting.     

Why does a red snake in the grass capture your attention?

It has been suggested that affective stimuli automatically capture attention; this preferential processing is thought to be related to the evolutionary significance of affective stimuli. However, recent evidence suggests that perceptual salience alone might explain why some affective stimuli are more likely to influence attentional processes in certain contexts. In this study, we manipulated affective and perceptual salience to better understand how affective information is processed and how it impacts attentional processes in different contexts. We used stimuli that are both affectively and perceptually salient, while varying the task requirement to encourage the processing of perceptually salient (Experiment 1) or affectively salient (Experiment 2) information. This design made it possible to observe independent and interdependent relationships between perceptual and affective salience. The results showed that when the task encouraged the processing of perceptually salient information, affective salience did not influence task performance. In contrast, when the task encouraged the processing of affectively salient information, affectively salient information impaired task performance. The findings suggest that the affective nature of the stimuli does not always influence attentional processes.     

Independence and separability in the perception of complex nonspeech sounds

All sounds are multidimensional, yet the relationships among auditory dimensions have been studied only infrequently. General recognition theory (GRT; Ashby & Townsend, 1986) is a multidimensional generalization of signal detection theory and, as such, provides powerful tools well suited to the study of the relationships among perceptual dimensions. However, previous uses of GRT have been limited in serious ways. We present methods designed to overcome these limitations, and we use these methods to apply GRT to investigations of the relationships among auditory perceptual dimensions that previous work suggests are independent (frequency, duration) or not (fundamental frequency [ f0], spectral shape). Results from Experiment 1 confirm that frequency and duration do not interact decisionally, and they extend this finding with evidence of perceptual independence. Results from Experiment 2 show that f0 and spectral shape tend to interact perceptually, decisionally, or both, and that perceptual interactions occur within, but not between, stimuli (i.e., the interactions suggest correlated noise across processing channels corresponding to perceptually separable dimensions). The results are discussed in relation to lower level sensory modeling and higher level cognitive and linguistic issues.     

Partial perceptual equivalence between vision and touch for texture information

The present study examined the extent to which vision and touch are perceptually equivalent for texture information in adults. Using Garbin's method, we selected two sets of textures having high versus low cross-modal dissimilarity values between vision and touch (Experiment 1). The two sets of textures were then used as material in a cross-modal matching task (Experiment 2). Results showed that asymmetries occurred in the performances when the stimuli had high cross-modal dissimilarity values, but not when the stimuli had low cross-modal dissimilarity values. These results extend Garbin's findings on shape information to the texture domain and support the idea that partial perceptual equivalence exists between vision and touch.     

Integrality over different paradigms: Card sorting and two-stimulus matching

Orthogonal interference—indicating the cohesiveness between geometrical dimensions—was examined using two separate tasks: (1) card sorting and (2) two-stimulus matching requiring same/different responses. The card-sorting results of the present experiment were contrasted with the results of our previous research (1977, 1979) which used the two-stimulus matching task. Results were generally similar in that the orthogonal interference and, consequently, the degree of integrality/separability were the same for both tasks. Evidence was found for the emergence of a new nominal dimension. This and other results are only compatible with a weaker form of the global-to-local hypothesis of perceptual processing.     

Time course of perceptual grouping by color

Does perceptual grouping operate early or late in visual processing? One position is that the elements in perceptual layouts are grouped early in vision, by properties of the retinal image, before perceptual constancies have been determined. A second position is that perceptual grouping operates on a postconstancy representation, one that is available only after stereoscopic depth perception, lightness constancy, and amodal completion have occurred. The present experiments indicate that grouping can operate on both a preconstancy representation and a postconstancy representation. Perceptual grouping was based on retinal color similarity at short exposure durations and based on surface color similarity at long durations. These results permit an integration of the preconstancy and postconstancy positions with regard to grouping by color.     

Separability and integrality of global and local levels of hierarchical patterns

We used a constrained classification task to examine the perceptual relations between global and local levels in hierarchical patterns composed of many, relatively small elements and those composed of few, relatively large elements. In Experiments 1 and 3 subjects were asked to make classifications based on "form" or "texture." In Experiments 2 and 4 they were asked to classify according to the "shape" of the configuration or the elements. The results indicate that configural and elemental levels are perceptually separable for many-element patterns when processed as form and texture: Subjects could attend to either level without being affected by variation along the irrelevant dimension. However, when the same many-element patterns were processed for global and local shape, subjects could not selectively attend to either level. For few-element patterns, global configuration and local elements appeared to be perceptually integral dimensions. These results are relevant to two issues: the global precedence hypothesis and the explanations of integral and separable dimensions.     

Perceptual processing affects the reactivation of a sensory dimension during a categorization task

According to grounded theories of cognition, knowledge is grounded in its sensory-motor features. Therefore, perceptual and conceptual processing should be based on the same distributed system so that conceptual and perceptual processes should interact. The present study assesses whether gustatory stimulation (participants tasted a sweet or a nonsweet yoghurt) could influence performance on a categorization task that involves the reactivation of the same sensory dimension. The results indicate that participants were slower (Experiment 1) or faster (Experiment 2), respectively, at categorizing pictures as representing edible sweet stimuli when they either simultaneously or had previously tasted a sweet yoghurt as compared to a nonsweet yoghurt. These results confirm the significant overlap between perceptual and memory mechanisms and suggest the functional equivalence between perceptually present and perceptually absent (memory reactivated) dimensions.     

联想启动与知觉启动的比较研究

采用快速命名方法探讨不同加工水平对联想启动效应的影响。被试分别在深、浅加工条件下学习一系列颜色词,然后完成颜色命名和再认任务,并设立词命名任务,以比较联想启动和知觉启动的异同。结果表明,在颜色命名任务中,深、浅加工条件下均可形成对颜色词的启动效应,但浅加工条件下的再认成绩明显低于深加工,出现了联想启动和再认的分离现象。词命名表现出与颜色命名相似的结果,但它们在有意识回忆方面仍存在一定的差异,提示知觉表征系统单独并不能支持联想启动,联想启动可能是多个记忆系统共同作用的结果。     

Developmental trends in the use of perceptual and conceptual attributes in grouping,clustering, and retrieval

In Experiment I, two tasks were administered to children aged 4, 5, and 9 in order to investigate preference for perceptual versus conceptual attributes in grouping of common objects, and in various aspects of memory. The grouping task revealed a clear chronological progression: color and form determined the youngest children's grouping about equally; form dominated in the 5-year-olds; and most of the oldest children grouped primarily by conceptual attributes. In the memory task, three lists—one organized by color, one by form, one by superordinate category—were presented for free, followed by cued recall. Clustering showed the developmental shift from color to form to concept, while cued recall showed conceptual superiority at all ages. Experiment II replicated the memory task, yielding the same results. The results were discussed in terms of the relative abstractness and predictability of conceptual versus perceptual attributes and the difficulty of abstraction in encoding and the function of predictability in retrieval.     

The mere exposure effect is sensitive to color information: evidence for color effects in a perceptual implicit memory test

Priming effects in perceptual tests of implicit memory are assumed to be perceptually specific. Surprisingly, changing object colors from study to test did not diminish priming in most previous studies. However, these studies used implicit tests that are based on object identification, which mainly depends on the analysis of the object shape and therefore operates color-independently. The present study shows that color effects can be found in perceptual implicit tests when the test task requires the processing of color information. In Experiment 1, reliable color priming was found in a mere exposure design (preference test). In Experiment 2, the preference test was contrasted with a conceptually driven color-choice test. Altering the shape of object from study to test resulted in significant priming in the color-choice test but eliminated priming in the preference test. Preference judgments thus largely depend on perceptual processes. In Experiment 3, the preference and the color-choice test were studied under explicit test instructions. Differences in reaction times between the implicit and the explicit test suggest that the implicit test results were not an artifact of explicit retrieval attempts. In contrast with previous assumptions, it is therefore concluded that color is part of the representation that mediates perceptual priming.     

Visual search proceeds concurrently during the attentional blink and response selection bottleneck

It is well known that human information processing comprises several distinct subprocesses—namely, the perceptual, central, and motor stage. In each stage, attention plays an important role. Specifically, a type of attention—perceptual attention—operates to detect and identify a sensory input. Following this, another class of attention—central attention—is involved in working memory encoding and response selection at the central stage. While perceptual attention and central attention are known to be separate, distinct processes, some researchers reported findings that loading central attention postponed the deployment of perceptual attention needed to perform a spatial configuration search. We tested whether a similar pattern of results would emerge when a different kind of search task is used. To do so, we had participants perform a visual-search task of searching for a feature conjunction target, taxing perceptual attention while they are engaged in central processes, such as working memory encoding and response selection. The results showed that perceptual processing of conjunction search stimuli could be carried out concurrently with central processes. These results suggest that the nature of the concurrent visual search process is a determinant responsible for the dynamic relationship between perceptual attention deployed for visual search and central attention needed for working memory encoding and response selection.

     

Visually directed walking to briefly glimpsed targets is not biased toward fixation location

When observers indicate the magnitude of a previously viewed spatial extent by walking without vision to each endpoint, there is little evidence of the perceptual collapse in depth associated with some other methods (e.g. visual matching). One explanation is that both walking and matching are perceptually mediated, but that the perceived layout is task-dependent. In this view, perceived depth beyond 2-3 m is typically distorted by an equidistance effect, whereby the egocentric distances of nonfixated portions of the depth interval are perceptually pulled toward the fixated point. Action-based responses, however, recruit processes that enhance perceptual accuracy as the stimulus configuration is inspected. This predicts that walked indications of egocentric distance performed without vision should exhibit equidistance effects at short exposure durations, but become more accurate at longer exposures. In this paper, two experiments demonstrate that in a well-lit environment there is substantial perceptual anisotropy at near distances (3-5 m), but that walked indications of egocentric distance are quite accurate after brief glimpses (150 ms), even when the walking target is not directly fixated. Longer exposures do not increase accuracy. The results are clearly inconsistent with the task-dependent information processing explanation, but do not rule out others in which perception mediates both walking and visual matches.     

注意控制与短时记忆的知觉组织

、考察了短时记忆中的知觉组织是否受双作业时指导语引导的注意策略控制。各有24名北京大学本科生参加了自由回忆和顺序回亿实验。实验任务有2种：记忆和声音监控。声音监控或者安排在记忆编码阶段,或者安排在记忆提取阶段。双作业时的指导语类型有3种,分别强调记忆、声音监控或两种作业同样重要。记忆项目表分2种：不分组和知觉分组。研究发现：自由回忆中的知觉组织仅受编码阶段的指导语影响;顺序回忆中的知觉组织仅受提取阶段的指导语影响。作者设想,短时记忆中的知觉组织在编码和提取阶段都受注意控制,但记忆类型不同,注意控制的作用地点和表现形式也有所不同。     

Conjunction of color and form without attention: evidence from an orientation-contingent color aftereffect

According to feature-integration theory (Treisman & Gelade, 1980), separable features such as color and shape exist in separate maps in preattentive vision and can be integrated only through the use of spatial attention. Many perceptual aftereffects, however, which are also assumed to reflect the features available in preattentive vision, are sensitive to conjunctions of features. One possible resolution of these views holds that adaptation to conjunctions depends on spatial attention. We tested this proposition by presenting observers with gratings varying in color and orientation. The resulting McCollough aftereffects were independent of whether the adaptation stimuli were presented inside or outside of the focus of spatial attention. Therefore, color and shape appear to be conjoined preattentively, when perceptual aftereffects are used as the measure. These same stimuli, however, appeared to be separable in two additional experiments that required observers to search for gratings of a specified color and orientation. These results show that different experimental procedures may be tapping into different stages of preattentive vision.     

Covert operations: orthographic recoding as a basis for repetition priming in word identification

When a word is generated from a semantic cue, coincident orthographic visualization of that word may cause priming on a subsequent perceptual identification test. A task was introduced that required subjects to visualize the orthographic pattern of auditorily presented words. When used at study, this task produced a pattern of priming similar to that produced by a generate study task. When used at test, equal priming on the orthographic task was produced by read and generate study tasks but not by a generate study task that failed to invite orthographic visualization. Priming on perceptually based word identification tests that results from a generate study episode may be largely due to orthographic recoding of the target rather than to conceptual processing.     

Selective weighting of action-related feature dimensions in visual working memory

Planning an action primes feature dimensions that are relevant for that particular action, increasing the impact of these dimensions on perceptual processing. Here, we investigated whether action planning also affects the short-term maintenance of visual information. In a combined memory and movement task, participants were to memorize items defined by size or color while preparing either a grasping or a pointing movement. Whereas size is a relevant feature dimension for grasping, color can be used to localize the goal object and guide a pointing movement. The results showed that memory for items defined by size was better during the preparation of a grasping movement than during the preparation of a pointing movement. Conversely, memory for color tended to be better when a pointing movement rather than a grasping movement was being planned. This pattern was not only observed when the memory task was embedded within the preparation period of the movement, but also when the movement to be performed was only indicated during the retention interval of the memory task. These findings reveal that a weighting of information in visual working memory according to action relevance can even be implemented at the representational level during maintenance, demonstrating that our actions continue to influence visual processing beyond the perceptual stage.     

色觉疲劳、语义饱和对颜色范畴知觉的即时影响

颜色范畴知觉究竟是语言的还是知觉的, 或两者交互引起的认知冲突所致仍在探究与争议之中。本研究采用色觉疲劳和语义饱和操作分别独立地改变知觉或语义加工, 观察二者对颜色范畴知觉效应的即时影响, 以期探究语言和知觉对颜色范畴的作用。结果显示, 色觉疲劳操作导致范畴间颜色辨别反应时减少, 颜色范畴效应增强。语义饱和操作导致被饱和颜色词所属的范畴内颜色辨别反应时增加, 颜色范畴效应增强。说明单独改变知觉或语义加工能力均能影响CCP效应, 支持了语言标签对比模型, 即语言与知觉的交互作用引起颜色范畴知觉的观点。     

Word recognition reflects dimension-based statistical learning

Speech processing requires sensitivity to long-term regularities of the native language yet demands listeners to flexibly adapt to perturbations that arise from talker idiosyncrasies such as nonnative accent. The present experiments investigate whether listeners exhibit dimension-based statistical learning of correlations between acoustic dimensions defining perceptual space for a given speech segment. While engaged in a word recognition task guided by a perceptually unambiguous voice-onset time (VOT) acoustics to signal beer, pier, deer, or tear, listeners were exposed incidentally to an artificial "accent" deviating from English norms in its correlation of the pitch onset of the following vowel (F0) to VOT. Results across four experiments are indicative of rapid, dimension-based statistical learning; reliance on the F0 dimension in word recognition was rapidly down-weighted in response to the perturbation of the correlation between F0 and VOT dimensions. However, listeners did not simply mirror the short-term input statistics. Instead, response patterns were consistent with a lingering influence of sensitivity to the long-term regularities of English. This suggests that the very acoustic dimensions defining perceptual space are not fixed and, rather, are dynamically and rapidly adjusted to the idiosyncrasies of local experience, such as might arise from nonnative-accent, dialect, or dysarthria. The current findings extend demonstrations of "object-based" statistical learning across speech segments to include incidental, online statistical learning of regularities residing within a speech segment.