Perceptual implicit memory requires attentional encoding

Perceptual implicit memory for previously attended and unattended words was measured either in a word-stem completion task or in a perceptual fluency (perceptual identification) task. Subjects (N = 144) first engaged in a focused attention task in which they were to identify one of two words presented for 100, 200, or 300 msec. Words were classified as attended if they were reported during the focused attention task and unattended if they were not. Results for both implicit memory tests indicated reliable perceptual implicit memory for attended words but not for unattended words, regardless of focused attention exposure duration. The results indicate that perceptual implicit memory tasks reflect attentional encoding processes; that is, words must undergo attentional encoding if they are to affect performance on a later perceptual implicit memory test.     

Perceptual encoding efficiency in visual search

The authors present 10 experiments that challenge some central assumptions of the dominant theories of visual search. Their results reveal that the complexity (or redundancy) of nontarget items is a crucial but overlooked determinant of search efficiency. The authors offer a new theoretical outline that emphasizes the importance of nontarget encoding efficiency, and they test this proposal using dot pattern stimuli adapted from W. R. Garner and D. E. Clement (1963). The results provide converging support for the importance of nontarget encoding efficiency in accounting for visual search performance.     

Perceptual encoding and decision strategies for integral dimensions

These three experiments employed rectangles in stimulus identification tasks. Consistent with the stimulus set used by Weintraub, the rectangles were generated by modifying a square. Across experiments, the number of stimulus/response alternatives was varied (two-, three-, and four-choice tasks). In the two-choice task, redundancy gain for the positively correlated set was just as large as for the negatively correlated set. In contrast, reaction time ws faster for the negatively correlated set than for the positively correlated set in the three-choice task (after extended practice) and in the four-choice task. Considered in the context of previous research, the data support two conclusions. First, the initial perceptual processing of rectangles is accomplished by separate dimensional analyzers operating in parallel. Second, observers adopt a different decision strategy for the negatively correlated set than for the positively correlated and the single dimension sets when the number of stimulus/response alternatives is increased.     

Perceptual identification and the cross-race effect

The current research examined whether the cross-race effect (CRE) was evident in perceptual identification tasks and the extent to which certain boundary conditions moderated the effect. Across two experiments, a significant CRE was observed in measures of accuracy and response latency. As predicted, Experiment 1 showed that the CRE was exacerbated when encoding time was brief and test set size was increased. Experiment 2 replicated the effect of set size, but also showed that the CRE was more pronounced when the retention interval was lengthened. The theoretical and practical implications of the results are discussed.     

Perceptual encoding in comparative judgments of race

Ss made comparative judgments along the black-white racial dimension using opposite response sets (“Which is blacker?” or “Which is whiter?”). Three classes of pictures were used: B (black),W (white), and M (racially mixed). I or the BM judgments. “Which is whiter?” took significantly longer. The MW and BW judgments showed no difference between response instructions. Analysis of the stimuli showed that skin tone was not the primary perceptual attribute used in racial encoding. The observation of a funnel effect in the judgment latencies is shown to be consistent with other research demonstrating the effect of response set in comparative judgments Further. the results support sociological observations about the cultural use of the linguistic labels “black” and “white”     

Perceptual and attentional factors in encoding irrelevant spatial information

Numerous studies found superior performance when the irrelevant location of a stimulus and response location were corresponding than when they were not corresponding (Simon effect), suggesting that stimulus location is processed in an obligatory manner. The present study compared Simon effects from the location of a relevant (i.e., to-be-attended) object to those from the location of an irrelevant (i.e., to-be-ignored) object. In four experiments, participants were presented with a rectangular frame and a square, with the relevant object in green or red color and the irrelevant object in gray or white color. Participants’ task was to respond with a lateral keypress to the color of the relevant object, and we varied spatial correspondence between the location of the relevant or the irrelevant object and the response, respectively. Results consistently showed larger Simon effects from the location of the relevant than from the irrelevant object, even when the irrelevant object was made very salient. These results suggest that location processing is largely confined to relevant (i.e., attended) objects, stressing the role of attention shifts for location encoding.     

Perceptual interference at encoding enhances item-specific encoding and disrupts relational encoding: Evidence from multiple recall tests

Interfering with perception during encoding can enhance later memory, a phenomenon known as the perceptual interference effect. This effect is investigated in the context of the item-specific-relational framework (e.g., Hunt & McDaniel, 1993), which suggests that the perceptual interference enhances item-specific encoding and impedes relational encoding. Two experiments performed with multiple recall tests support this view. Prior research indicates that item-specific processing increases item gains across tests, whereas relational processing protects against item losses (e.g., Burns, 1993; Klein, Loftus, Kihlstrom, & Aseron, 1989). Consistent with the item-specific-relational framework, perceptual interference produced significant increases in both item gains and losses relative to a control condition.     

Sex differences in clerical speed: Perceptual encoding vs. verbal encoding

Most interpretations of sex differences on clerical speed tests have emphasized the role of rapid perception of details and shifts in attention. Some have emphasized comparison and decision processes. Sex differences in speeded, successive matching were studied in four experiments with college students. The experimental task involved the successive identification of stimulus items presented in lists by tapping matching items on response cards. Sex differences were found to be related to response-card content and not to stimulus-list content. When the identification response involved tapping words, colors, or directional symbols, females were significantly faster than males; however, when the identification response involved tapping shapes, no significant sex differences were found. Results indicated that sex differences in some aspect of short-term memory may also be involved. Earlier interpretations of sex differences on speeded matching tasks in terms of such global concepts as perceptual speed are believed to be inadequate. An alternative explanation is discussed emphasizing verbal encoding, memory, and evaluation processes.     

Perceptual identification of visually degraded stimuli

In this article, we describe procedures, materials, and some representative results of a microcomputer-based approach to the degradation of visual stimuli for the investigation of perceptual identification. We discuss application of the procedures for the production of visually degraded picture, letter, and word stimuli, and of visual stimuli common to neuropsychological investigations.     

Perceptual effects of scene context on object identification

Summary In a number of studies the context provided by a real-world scene has been claimed to have a mandatory, perceptual effect on the identification of individual objects in such a scene. This claim has provided a basis for challenging widely accepted data-driven models of visual perception in order to advocate alternative models with an outspoken top-down character. The present paper offers a review of the evidence to demonstrate that the observed scene-context effects may be the product of post-perceptual and task-dependent guessing strategies. A new research paradigm providing an on-line measure of genuine perceptual effects of context on object identification is proposed. First-fixation durations for objects incidentally fixated during the free exploration of real-world scenes are shown to increase when the objects are improbable in the scene or violate certain aspects of their typical spatial appearance in it. These effects of contextual violations are shown to emerge only at later stages of scene exploration, contrary to the notion of schema-driven scene perception effective from the very first scene fixation. In addition, evidence is reported in support of the existence of a facilitatory component in scene-context effects. This is taken to indicate that the context directly affects the ease of perceptual object processing and does not merely serve as a framework for checking the plausibility of the output of perceptual processes. Finally, our findings are situated against other contrasting results. Some future research questions are highlighted.     

Perceptual interactions of facial dimensions in speeded classification and identification

The representation underlying the identification and classification of semirealistic line drawings taken from a computer model of the face was investigated by using a speeded classification task and an identification task. These data were analyzed by using a multidimensional extension of signal detection theory, within which varieties of perceptual interactions between dimensions within and across stimuli can be characterized. The dimensions of interest here were eye separation, nose length, and mouth width. The response time and accuracy data from the speeded classification task suggest that processing of a given feature did depend on whether other features were present or absent, but given that other features were present, the results strongly support separability (a macrolevel, across-stimulus form of invariance) for all pairs of facial dimensions used. This separability was confirmed by the subsequent identification task. Owing to its greater resolution, the identification task can reveal interactions that might exist at more microlevels of processing. In fact, the identification data did indicate the presence of perceptual dependence between facial dimensionswithin a stimulus when the dimensions that were varied were close in spatial proximity (i.e., eye separation and nose length). Within the theoretical framework, perceptual dependence can be interpreted as correlated noise between otherwise separate channels (and hence, is logically distinct from separability). This dependence was greatly reduced for dimensions that were more distant (eyes and mouth). The relation between these results and the configural effects that have been observed with faces as stimuli in other studies is discussed.     

Perceptual implicit memory relies on intentional,load-sensitive processing at encoding

In two experiments, we examined whether the encoding processes leading to perceptual implicit memory satisfied the intentionality and load insensitivity criteria for automaticity. Whether participants intended to process words or digits, in displays containing both, was manipulated in Experiment 1. Results showed an effect of intention on a subsequent perceptual identification task and a recognition task. Load (one, two, and four words) and exposure duration (1,000, 600, and 200 msec) at encoding were manipulated in Experiment 2. Recognition was affected by both variables, but performance on the perceptual identification task was affected only by load. In both experiments, the results showed that controlled (intentional, load-sensitive) processing of words at encoding is essential for later perceptual implicit memory. That is, the encoding processes leading to perceptual implicit memory fail both criteria of automaticity.     

Perceptual interactions of facial dimensions in speeded classification and identification.

The representation underlying the identification and classification of semirealistic line drawings taken from a computer model of the face was investigated by using a speeded classification task and an identification task. These data were analyzed by using a multidimensional extension of signal detection theory, within which varieties of perceptual interactions between dimensions within and across stimuli can be characterized. The dimensions of interest here were eye separation, nose length, and mouth width. The response time and accuracy data from the speeded classification task suggest that processing of a given feature did depend on whether other features were present or absent, but given that other features were present, the results strongly support separability (a macrolevel, across-stimulus form of invariance) for all pairs of facial dimensions used. This separability was confirmed by the subsequent identification task. Owing to its greater resolution, the identification task can reveal interactions that might exist at more microlevels of processing. In fact, the identification data did indicate the presence of perceptual dependence between facial dimensions within a stimulus when the dimensions that were varied were close in spatial proximity (i.e., eye separation and nose length). Within the theoretical framework, perceptual dependence can be interpreted as correlated noise between otherwise separate channels (and hence, is logically distinct from separability). This dependence was greatly reduced for dimensions that were more distant (eyes and mouth). The relation between these results and the configural effects that have been observed with faces as stimuli in other studies is discussed.     

Perceptual automaticity in expert chess players: Parallel encoding of chess relations

A check detection task in a 5 × 5 section of the chessboard, containing a King and one or two potential checking pieces was employed. The checking status (i.e., the presence or absence of a check) and the number of attackers (one or two) were manipulated. It was found that the reaction time cost for adding a distractor was differentially greater inno trials thanyes trials for novice, but not for expert, chess players. In addition, we contrasted standard check detection trials with trials in which one of two attackers was cued (colored red) and the task was to determine the checking status of the cued attacker while ignoring the other attacker. We documented a Stroop-like interference effect on trials in which a cued nonchecking attacker appeared together with an attacker that was checking (i.e., incongruent). These findings suggest automatic and parallel encoding procedures for chess relations in experts.     

Perceptual interference at encoding enhances recall for high- but not low-imageability words

Interfering with stimulus perception during encoding can improve later explicit memory (the perceptual-interference effect). The compensatory-processing hypothesis attributes the perceptualinterference effect to enhanced processing of higher level (nonvisual) information during perception. Recent research indicates that the semantic dimension of imageability is one type of higher level information that plays a role in word perception. To the extent that semantic representations play a more important role in the perception of high- than for low-imageability words, the compensatoryprocessing hypothesis predicts a larger perceptual-interference effect for high- than for lowimageability words. Two experiments confirm this prediction. A robust effect of perceptual interference was found for high- but not for low-imageability words.     

知觉经验与知觉内容

知觉(perception)是指我们通过视觉、听觉、触觉、嗅觉、味觉等感觉器官而获得的对事物以及外部世界的意识感知.知觉经验(perceptual experience)的一个显著的特点是它具有某种现象特征,即知觉者会体验到一种"那究竟像什么(what it is like)"的感觉.例如,一个人会从红色视觉经验中体验到"红色究竟像什么"的意识感受性(qualia).知觉内容(perceptual content)粗略地讲是指通过知觉经验向知觉者所传递的信息.关于知觉问题在哲学上的重要性,我们可以从以下几点来看:在形而上学方面,知觉是我们了解外部物理世界究竟存在什么的主要手段;在认识论方面,研究知觉是研究我们如何达到关于外部物理世界的知识的主要手段;在语言哲学方面,知觉内容是我们的心灵与外部物理世界的关联及互动在语言实践上的体现;在心灵哲学方面,知觉经验中的现象特征与意识及意向性之间存在着深层的内在联系.     

Perceptual closure and object identification: electrophysiological responses to incomplete pictures.

Event-related potentials were recorded during the naming of pictures of concrete objects. The pictures were presented at three levels of completeness: 10, 30, and 60%. The ERP waveforms were evaluated according to the level of picture completeness and the correctness of naming. A negative wave in the latency range of 250-550 ms was significantly more negative when the pictures were more incomplete, regardless of the correctness of response. This N400 wave is proposed as being related to hypotheses about the identity of the object. A late positive wave in the latency range of 550-650 ms followed the negativity, but only when the response was correct. This may reflect the subject's certainty about the perceptual analysis, a verification of the identity of the object. A slow parietal negativity lasting up to 2 sec was largest for the least complete picture. This therefore varied with the perceptual difficulty.