基于位置和基于语义交互作用的无意识启动

采用线索-靶子范式,同时操纵刺激的位置和语义属性,考察了基于位置和基于语义交互作用的无意识启动。实验1和实验2分别要求被试完成定位任务和辨别任务。结果发现,当刺激位置属性与实验任务需求相关时,无论刺激的语义属性是否一致都产生了基于位置的启动效应;当刺激的语义属性与实验任务相关时,出现了基于位置和基于语义交互的无意识启动,即启动项和目标项的位置不同时,语义辨别任务存在启动效应;而启动项与目标项位置相同时,语义辨别任务存在着抑制趋势。研究结果表明,基于位置和基于语义交互作用的无意识启动效应仅存在于辨别任务中,而不存在于定位任务中。     

The attentional blink is diminished for targets that form coherent semantic categories

Studies have shown that the attentional blink (AB) effect is diminished for intrinsically salient T2 stimuli, such as arousing, familiar, personally relevant words, or stimuli with salient low-level visual features. We examined whether the AB is diminished also for stimuli that do not have special inherent properties but are made salient by the context. One such contextual factor is the coherence of the T2 stimulus set. In three experiments, we found that the AB is diminished for stimuli that form a coherent semantic category within the T2 stimulus set. Both theoretical and practical implications are discussed.     

Enhanced perceptual processing of speech in autism

Theories of autism have proposed that a bias towards low-level perceptual information, or a featural/surface-biased information-processing style, may compromise higher-level language processing in such individuals. Two experiments, utilizing linguistic stimuli with competing low-level/perceptual and high-level/semantic information, tested processing biases in children with autism and matched controls. Whereas children with autism exhibited superior perceptual processing of speech relative to controls, and showed no evidence of either a perceptual or semantic processing bias, controls showed a tendency to process speech semantically. The data provide partial support to the perceptual theories of autism. It is additionally proposed that the pattern of results may reflect different patterns of attentional focusing towards single or multiple stimulus cues in speech between children with autism and controls.     

Stimulus factors and listening strategies in auditory memory: A theoretical analysis

A theory for the temporal course of perceptual coding during auditory short-term memory tasks is described. A low-level “sensor” and a high-level “identifier” process item and order information from stimulus word-strings. Both word durations and interword pauses are needed for this processing, and if adequate processing time is unavailable, perceptual delays will lead to degraded recall performance. Stimulus parameters and subject strategies interact to determine the quality and the order in which stimulus items are coded. These hypotheses are supported both by experiments using grammatical sentences and those using lists of unrelated words.     

A dynamic interactive theory of person construal

A dynamic interactive theory of person construal is proposed. It assumes that the perception of other people is accomplished by a dynamical system involving continuous interaction between social categories, stereotypes, high-level cognitive states, and the low-level processing of facial, vocal, and bodily cues. This system permits lower-level sensory perception and higher-order social cognition to dynamically coordinate across multiple interactive levels of processing to give rise to stable person construals. A recurrent connectionist model of this system is described, which accounts for major findings on (a) partial parallel activation and dynamic competition in categorization and stereotyping, (b) top-down influences of high-level cognitive states and stereotype activations on categorization, (c) bottom-up category interactions due to shared perceptual features, and (d) contextual and cross-modal effects on categorization. The system's probabilistic and continuously evolving activation states permit multiple construals to be flexibly active in parallel. These activation states are also able to be tightly yoked to ongoing changes in external perceptual cues and to ongoing changes in high-level cognitive states. The implications of a rapidly adaptive, dynamic, and interactive person construal system are discussed.     

The effects of negative relatedness upon word-picutre and word-word comparisons and subsequent recall.

In two experiments subjects were required to compare the meanings of either a word and a picture, or of two words. Different name levels, i.e. category versus superordinate names, had only a small effect on the time to compare a name with a picture. When incongruent stimulus pairs were semantically related, both positive and negative decision times were longer than when the incongruent pairs were unrelated; relatedness also affected subjects' recall of stimuli. Implications for models of semantic decision are discussed.     

Controlling low-level image properties: The SHINE toolbox

Visual perception can be influenced by top-down processes related to the observer’s goals and expectations, as well as by bottom-up processes related to low-level stimulus attributes, such as luminance, contrast, and spatial frequency. When using different physical stimuli across psychological conditions, one faces the problem of disentangling the contributions of low- and high-level factors. Here, we make available the SHINE (spectrum, histogram, and intensity normalization and equalization) toolbox for MATLAB, which we have found useful for controlling a number of image properties separately or simultaneously. The toolbox features functions for specifying the (rotational average of the) Fourier amplitude spectra, for normalizing and scaling mean luminance and contrast, and for exact histogram specification optimized for perceptual visual quality. SHINE can thus be employed for parametrically modifying a number of image properties or for equating them across stimuli to minimize potential low-level confounds in studies on higher level processes.     

Cognitive control outside of conscious awareness

To test whether cognitive control can operate fully unconsciously on conflicts arising between two interfering subliminal stimuli, we designed a priming paradigm in which a subliminal reverse Color-Word Stroop item (a color word written on a congruent/incongruent color rectangle) preceded a supraliminal one in each trial. We found (a) a conflict adaptation effect, with a smaller reverse Stroop effect on the visible probe items after incongruent than after congruent subliminal prime items and (b) a negative priming effect, with longer reaction-times on incongruent visible probe items when the color word corresponded to the color of the rectangle in the preceding subliminal prime item than when it was not. These effects replicate the ones classically reported in studies using visible items and suggest that cognitive control was transferred from the subliminal prime to the visible probe items. Taken together, our results demonstrate that cognitive control can operate on conflicting subliminal information.     

Dissociating prelexical and postlexical processing of affective information in the two hemispheres: effects of the stimulus presentation format

Using a lexical decision task, the authors investigated whether brain asymmetries in the detection of emotionally negative semantic associations arise only at a perceptually discriminative stage at which lexical analysis is accurate or can already be found at crude and incomplete levels of perceptual representation at which word-nonword discrimination is based solely on guessing. Emotionally negative and neutral items were presented near perceptual threshold in the left and right visual hemifields. Word-nonword discrimination performance as well as the bias to classify a stimulus as a "word" (whether or not it actually is a word) were assessed for a normal, horizontal stimulus presentation format (Experiment 1) and for an unusual, vertical presentation format (Experiment 2). Results show that while the two hemispheres are equally able to detect affective semantic associations at a prelexical processing stage (both experiments), the right hemisphere is superior at a postlexical, perceptually discriminative stage (Experiment 2). Moreover, the findings suggest that only an unusual, nonoverlearned stimulus presentation format allows adequate assessment of the right hemisphere's lexical-semantic skills.     

Congruency effects in conceptualizing for speech

In naming a picture at the basic level, a semantically related distractor word induces interference in comparison to an unrelated word. When the task is changed from basic-level naming to categorization, however, this effect reverses to semantic facilitation. In previous studies, this semantic facilitation effect was attributed to “message congruency” at the conceptual level. The present study examines the nature of this message congruency effect: Is it due to competition between two activated category concepts in the incongruent condition or is it due to convergence of activity on a single category concept in the congruent condition? Two experiments show that neither the strength with which the context stimulus activates an incongruent category concept nor the semantic distance between the category concepts activated by target and distractor affect target categorization speed. We conclude that the message congruency effect is most likely due to convergence on a single category concept in the category-congruent condition.     

汉语句子阅读理解中的语境效应

采用计算机快速系列视觉呈现技术,以反应时为指标,利用命名法,考察了汉语句子阅读中的语境效应。该研究表明：语境的作用机制是灵活的,它会随语境条件的变化而变化。在启动词与目标词语义联结弱的情况下,如果语境对目标词是一种低干扰,那么各模块之间彼此独立,一个模块不受另一个模块的影响;如果句法关系改变后的语境对目标词形成高干扰,各模块相互作用,不同语境对词汇通达有不同的作用。当启动词与目标词间有较强的语义联结时,语境效应主要来源于词与词之间的联结启动,这时的语境作用机制符合模块化理论;而当启动词与目标词间有较弱的语义联结时,随语境干扰强度的增加,目标词的词汇通达也随之增加,这时的语境作用机制则符合相互作用理论。     

序列语义的类别一致性关系能否进行无意识整合？

阈下语义之间能否进行整合,最近的研究给出了不同的结果。当多个阈下语义词语同时呈现时显示出无意识语义整合效应,但是当序列呈现时没有观察到无意识整合效应。本研究在保留同时呈现方法优点（不同空间呈现位置）的情况下研究了序列呈现的不同汉字词语之间能否产生无意识语义类别关系整合。在实验1中,两个相同或不同类别的词语作为阈下启动刺激先后在两侧呈现,且第一个词语消失后第二词语马上出现,结果显示出无意识语义类别整合效应。实验2延长了两个阈下启动词语之间的时间间隔,结果未发现无意识语义类别整合效应。另外,实验3进一步排除了实验1中第一个启动词语的视觉残留,结果也未观察到显著的无意识语义类别整合效应,说明实验1中观察到的无意识整合效应是视觉残留所致。综合三个实验结果表明,两个阈下词语之间的语义类别一致性关系只有在同时呈现这种特殊条件下才能进行无意识整合加工,说明了短时间维度对于无意识语义关系整合的重要性。     

Perceptual mechanism underlying gaze guidance in chimpanzees and humans

Previous studies comparing eye movements between humans and their closest relatives, chimpanzees, have revealed similarities and differences between the species in terms of where individuals fixate their gaze during free viewing of a naturalistic scene, including social stimuli (e.g. body and face). However, those results were somewhat confounded by the fact that gaze behavior is influenced by low-level stimulus properties (e.g., color and form) and by high-level processes such as social sensitivity and knowledge about the scene. Given the known perceptual and cognitive similarities between chimpanzees and humans, it is expected that such low-level effects do not play a critical role in explaining the high-level similarities and differences between the species. However, there is no quantitative evidence to support this assumption. To estimate the effect of local stimulus saliency on such eye-movement patterns, this study used a well-established bottom-up saliency model. In addition, to elucidate the cues that the viewers use to guide their gaze, we presented scenes in which we had manipulated various stimulus properties. As expected, the saliency model did not fully predict the fixation patterns actually observed in chimpanzees and humans. In addition, both species used multiple cues to fixate socially significant areas such as the face. There was no evidence suggesting any differences between chimpanzees and humans in their responses to low-level saliency. Therefore, this study found a substantial amount of similarity in the perceptual mechanisms underlying gaze guidance in chimpanzees and humans and thereby offers a foundation for direct comparisons between them.     

The effect of spatial attention on invisible stimuli

The influence of selective attention on visual processing is widespread. Recent studies have demonstrated that spatial attention can affect processing of invisible stimuli. However, it has been suggested that this effect is limited to low-level features, such as line orientations. The present experiments investigated whether spatial attention can influence both low-level (contrast threshold) and high-level (gender discrimination) adaptation, using the same method of attentional modulation for both types of stimuli. We found that spatial attention was able to increase the amount of adaptation to low- as well as to high-level invisible stimuli. These results suggest that attention can influence perceptual processes independent of visual awareness.     

Conflict-induced perceptual filtering

In a variety of conflict paradigms, target and distractor stimuli are defined in terms of perceptual features. Interference evoked by distractor stimuli tends to be reduced when the ratio of congruent to incongruent trials is decreased, suggesting conflict-induced perceptual filtering (i.e., adjusting the processing weights assigned to stimuli associated with the target and with the distractor features). In search of evidence for such a mechanism, we administered a flanker task, in which targets and distractors were defined in terms of stimulus location (Experiment 1) or color (Experiment 2). The efficiency of processing stimuli associated with target and distractor features was assessed in intermixed trials of a visual search task, in which a target had to be detected irrespective of these features. In both experiments search times were shorter for stimuli associated with the target feature than with the distractor feature of the flanker task. This effect was increased under conditions of a reduced congruent/incongruent ratio, thereby providing evidence for conflict-dependent perceptual filtering.     

序列语义的类别一致性关系能否进行无意识整合？

阈下语义之间能否进行整合,最近的研究给出了不同的结果。当多个阈下语义词语同时呈现时显示出无意识语义整合效应,但是当序列呈现时没有观察到无意识整合效应。本研究在保留同时呈现方法优点（不同空间呈现位置）的情况下研究了序列呈现的不同汉字词语之间能否产生无意识语义类别关系整合。在实验1中,两个相同或不同类别的词语作为阈下启动刺激先后在两侧呈现,且第一个词语消失后第二词语马上出现,结果显示出无意识语义类别整合效应。实验2延长了两个阈下启动词语之间的时间间隔,结果未发现无意识语义类别整合效应。另外,实验3进一步排除了实验1中第一个启动词语的视觉残留,结果也未观察到显著的无意识语义类别整合效应,说明实验1中观察到的无意识整合效应是视觉残留所致。综合三个实验结果表明,两个阈下词语之间的语义类别一致性关系只有在同时呈现这种特殊条件下才能进行无意识整合加工,说明了短时间维度对于无意识语义关系整合的重要性。     

Principles of feature integration in visual perception

Several recent theories of visual information processing have postulated that errors in recognition may result not only from a failure in feature extraction, but also from a failure to correctly join features after they have been correctly extracted. Errors that result from incorrectly integrating features are called conjunction errors. The present study uses conjunction errors to investigate the principles used by the visual system to integrate features. The research tests whether the visual system is more likely to integrate features located close together in visual space (the location principle) or whether the visual system is more likely to integrate features from stimulus items that come from the same perceptual group or object (the perceptual group principle). In four target-detection experiments, stimuli were created so that feature integration by the location principle and feature integration by the perceptual group principle made different predictions for performance. In all of the experiments, the perceptual group principle predicted feature integration even though the distance between stimulus items and retinal eccentricity were strictly controlled.     

Towards a cognitive model of distraction by auditory novelty: The role of involuntary attention capture and semantic processing

Unexpected auditory stimuli are potent distractors, able to break through selective attention and disrupt performance in an unrelated visual task. This study examined the processing fate of novel sounds by examining the extent to which their semantic content is analyzed and whether the outcome of this processing can impact on subsequent behavior. This issue was investigated across five laboratory experiments in which participants categorized visual left and right arrows while instructed to ignore irrelevant sounds. The results showed that auditory novels that were incongruent with the visual target (e.g., word “left” presented before a right arrow) disrupted performance over and above congruent novels (semantic effect) while both types of novels delayed responses in the visual task compared to a standard sound (novelty effect). No semantic effect was observed for congruent and incongruent standards, suggesting that novelty detection is necessary for involuntary semantic processing to unravel. While the novelty effect augmented as the difference between novels and the standard increased, the semantic effect was immune to this variation. Furthermore, the novelty effect decreased across the task while the semantic effect did not. A general cognitive framework is proposed encompassing these new findings and previous work in an attempt to account for the behavioral impact of irrelevant auditory novels on primary task performance.     

Partial awareness creates the "illusion" of subliminal semantic priming

We argue that the lack of consensus regarding the existence of subliminal semantic processing arises from not taking into account the fact that linguistic stimuli are represented across several processing levels (features, letters, word form) that can independently reach or not reach awareness. Using masked words, we constructed conditions in which participants were aware of some letters or fragments of a word, while remaining unaware of the whole word. Three experiments using the Stroop priming paradigm show that when the stimulus set is reduced and participants are encouraged to guess the identity of the prime, such partially perceived stimuli can nonetheless give rise to "semantic" processing. We provide evidence that this effect is due to illusory reconstruction of the incompletely perceived stimulus, followed by usual semantic processing of the result. We conclude that previously reported unconscious Stroop priming is in fact a conscious effect, but applied to a perceptual illusion.     

Stimulus categorization by brain-damaged patients

Patients with localized insult to the right hemisphere, or to either the anterior or the posterior portion of the left hemisphere, as well as neurologically intact controls, evaluated stimuli on a seven-point rating scale for their degree of category membership. The stimuli were taken from one of two continua, one composed of fruit and vegetable items, and the other of items differing in hue and shape. Different subsets of stimuli provided different contexts for the judgments of category membership. The two left-hemisphere groups showed anomalies in categorizing the fruit and vegetable items but not the perceptual items, while the reverse was true for the right-hemisphere patients. Moreover, both left-hemisphere groups demonstrated context effects in their judgments of the representativeness of the fruit and vegetable items, but differed in the way in which they responded to changing contexts. Left posterior patients demonstrated weak category boundaries and even reclassified items. In contrast, patients with left anterior damage showed highly categorical responses and less differentiation of items within a category. All groups showed striking context effects in judgments of perceptual items in terms of changes in representativeness ratings and the location of a category boundary. Alternative interpretations of the results are offered.