Conceptual priming for realistic auditory scenes and for auditory words

Two experiments were conducted using both behavioral and Event-Related brain Potentials methods to examine conceptual priming effects for realistic auditory scenes and for auditory words. Prime and target sounds were presented in four stimulus combinations: Sound–Sound, Word–Sound, Sound–Word and Word–Word. Within each combination, targets were conceptually related to the prime, unrelated or ambiguous. In Experiment 1, participants were asked to judge whether the primes and targets fit together (explicit task) and in Experiment 2 they had to decide whether the target was typical or ambiguous (implicit task). In both experiments and in the four stimulus combinations, reaction times and/or error rates were longer/higher and the N400 component was larger to ambiguous targets than to conceptually related targets, thereby pointing to a common conceptual system for processing auditory scenes and linguistic stimuli in both explicit and implicit tasks. However, fine-grained analyses also revealed some differences between experiments and conditions in scalp topography and duration of the priming effects possibly reflecting differences in the integration of perceptual and cognitive attributes of linguistic and nonlinguistic sounds. These results have clear implications for the building-up of virtual environments that need to convey meaning without words.     

The importance of information localization in scene gist recognition

People can recognize the meaning or gist of a scene from a single glance, and a few recent studies have begun to examine the sorts of information that contribute to scene gist recognition. The authors of the present study used visual masking coupled with image manipulations (randomizing phase while maintaining the Fourier amplitude spectrum; random image structure evolution [RISE]; J. Sadr & P. Sinha, 2004) to explore whether and when unlocalized Fourier amplitude information contributes to gist perception. In 4 experiments, the authors found that differences between scene categories in the Fourier amplitude spectrum are insufficient for gist recognition or gist masking. Whereas the global 1/f spatial frequency amplitude spectra of scenes plays a role in gist masking, local phase information is necessary for gist recognition and for the strongest gist masking. Moreover, the ability to recognize the gist of a target image was influenced by mask recognizability, suggesting that conceptual masking occurs even at the earliest stages of scene processing.     

Hemispheric asymmetries in children's perception of nonlinguistic human affective sounds

In the present work, we developed a database of nonlinguistic sounds that mirror prosodic characteristics typical of language and thus carry affective information, but do not convey linguistic information. In a dichotic-listening task, we used these novel stimuli as a means of disambiguating the relative contributions of linguistic and affective processing across the hemispheres. This method was applied to both children and adults with the goal of investigating the role of developing cognitive resource capacity on affective processing. Results suggest that children's limited computational resources influence how they process affective information and rule out attentional biases as a factor in children's perceptual asymmetries for nonlinguistic affective sounds. These data further suggest that investigation of perception of nonlinguistic affective sounds is a valuable tool in assessing interhemispheric asymmetries in affective processing, especially in parceling out linguistic contributions to hemispheric differences.     

Cerebral Lateralization in Random Letter Task in the Visual Modality: A Transcranial Doppler Study

Seven right handed volunteers were studied to determine cerebral lateralization patterns for a visually presented random letter task. The subjects participated in three conditions, which included resting baseline, passive fixation (nonlinguistic), and random letter (linguistic) tasks. Mean blood flow velocity (MBFV) was recorded using bilateral simultaneous transcranial Doppler measurements in the posterior cerebral arteries in these conditions. The experimental conditions produced an increase in MBFV during both tasks but the linguistic task showed a greater change. There was a tendency toward right lateralization with the linguistic compared to the nonlinguistic tasks. There is a physiological correlate of right hemisphere participation in the processing of the random letter task.     

Diagnostic colours contribute to the early stages of scene categorization: Behavioural and neurophysiological evidence

We examined the effects of colour cues on the express categorization of natural scenes. Using a go/no-go paradigm sensitive to fast recognition processes, we measured early event-related potential (ERP) correlates of scene categorization to elucidate the processing stage at which colour contributes to scene recognition. Observers were presented with scenes belonging to four colour-diagnostic categories (desert, forest, canyon and coastline). Scenes were presented in one of three forms: Diagnostically coloured, nondiagnostically coloured, or greyscale images. In a verification task, observers were instructed to respond whenever the presented stimulus matched a previously presented category name. Reaction times and accuracy were optimal when the stimuli were presented as their original diagnostically coloured version, followed by their greyscale version, and lastly by their nondiagostically coloured version. These effects were mirrored in the early (i.e., 150 ms following stimulus onset) ERP frontal correlates. Their onset was delayed for greyscale scenes compared to diagnostically coloured scenes, and for nondiagnostically coloured scenes compared to the other two conditions. Frontal ERP amplitudes also decreased for greyscale and nondiagnostically coloured scenes. Together, the results suggest that diagnostic colours are part of the scene gist responsible for express scene categorization.     

Language-guided visual processing affects reasoning: The role of referential and spatial anchoring

Language is more than a source of information for accessing higher-order conceptual knowledge. Indeed, language may determine how people perceive and interpret visual stimuli. Visual processing in linguistic contexts, for instance, mirrors language processing and happens incrementally, rather than through variously-oriented fixations over a particular scene. The consequences of this atypical visual processing are yet to be determined. Here, we investigated the integration of visual and linguistic input during a reasoning task. Participants listened to sentences containing conjunctions or disjunctions (Nancy examined an ant and/or a cloud) and looked at visual scenes containing two pictures that either matched or mismatched the nouns. Degree of match between nouns and pictures (referential anchoring) and between their expected and actual spatial positions (spatial anchoring) affected fixations as well as judgments. We conclude that language induces incremental processing of visual scenes, which in turn becomes susceptible to reasoning errors during the language-meaning verification process.     

上下文预期在快速场景识别中的作用

本研究首先考察上下文预期是否能够影响快速场景识别,进而通过比较不同空间频率的场景信息来探究上下文预期在快速场景识别不同阶段的作用。共包括3个实验:实验1采用双眼竞争范式,考察对快速呈现场景刺激的主观选择是否受到上下文预期的影响;实验2采用词汇分类与快速场景识别的双任务范式,比较预期与非预期条件下快速场景识别绩效的差异;实验3分别以低频信息(实验3a)和高频信息(实验3b)作为实验材料,探讨预期效应的作用阶段。结果发现:上下文预期可以影响快速场景识别过程中的主观选择与反应绩效;对不同空间频率的场景信息,场景刺激与预期相一致时均可以提高辨别力,但预期对反应偏好的影响只发生在对高空间频率场景信息的加工阶段。因此,上下文预期在快速场景识别不同加工阶段的作用不同,快速场景识别需要结合不同空间频率信息加工的结果。     

The effect of scene structure on time perception

The current experiments examined the hypothesis that scene structure affects time perception. In three experiments, participants judged the duration of realistic scenes that were presented in a normal or jumbled (i.e., incoherent) format. Experiment 1 demonstrated that the subjective duration of normal scenes was greater than subjective duration of jumbled scenes. In Experiment 2, gridlines were added to both normal and jumbled scenes to control for the number of line terminators, and scene structure had no effect. In Experiment 3, participants performed a secondary task that required paying attention to scene structure, and scene structure's effect on duration judgements reemerged. These findings are consistent with the idea that perceived duration can depend on visual–cognitive processing, which in turn depends on both the nature of the stimulus and the goals of the observer.     

How many pixels make a memory? Picture memory for small pictures

Torralba (Visual Neuroscience, 26, 123–131, 2009) showed that, if the resolution of images of scenes were reduced to the information present in very small “thumbnail images,” those scenes could still be recognized. The objects in those degraded scenes could be identified, even though it would be impossible to identify them if they were removed from the scene context. Can tiny and/or degraded scenes be remembered, or are they like brief presentations, identified but not remembered. We report that memory for tiny and degraded scenes parallels the recognizability of those scenes. You can remember a scene to approximately the degree to which you can classify it. Interestingly, there is a striking asymmetry in memory when scenes are not the same size on their initial appearance and subsequent test. Memory for a large, full-resolution stimulus can be tested with a small, degraded stimulus. However, memory for a small stimulus is not retrieved when it is tested with a large stimulus.     

Scene recognition following locomotion around a scene

Effects of locomotion on scene-recognition reaction time (RT) and accuracy were studied. In experiment 1, observers memorized an 11-object scene and made scene-recognition judgments on subsequently presented scenes from the encoded view or different views (ie scenes were rotated or observers moved around the scene, both from 40 degrees to 360 degrees). In experiment 2, observers viewed different 5-object scenes on each trial and made scene-recognition judgments from the encoded view or after moving around the scene, from 36 degrees to 180 degrees. Across experiments, scene-recognition RT increased (in experiment 2 accuracy decreased) with angular distance between encoded and judged views, regardless of how the viewpoint changes occurred. The findings raise questions about conditions in which locomotion produces spatially updated representations of scenes.     

Selective attention during scene perception: Evidence from negative priming

In two experiments, we examined the role of semantic scene content in guiding attention during scene viewing. In each experiment, performance on a lexical decision task was measured following the brief presentation of a scene. The lexical decision stimulus named an object that was either present or not present in the scene. The results of Experiment 1 revealed no priming from inconsistent objects (whose identities conflicted with the scene in which they appeared), but negative priming from consistent objects. The results of Experiment 2 indicated that negative priming from consistent objects occurs only when inconsistent objects are present in the scenes. Together, the results suggest that observers are likely to attend to inconsistent objects, and that representations of consistent objects are suppressed in the presence of an inconsistent object. Furthermore, the data suggest that inconsistent objects draw attention because they are relatively difficult to identify in an inappropriate context.     

注意促进效应依赖于项目-背景的质心间距

近期研究者发现, 在某些条件下增加对第一任务的注意能够提高伴随发生的第二任务的成绩, 并将其命名为注意促进效应。研究者提出双任务交互模型对之进行解释, 认为该效应产生的必要条件是时间上的重叠, 而不受空间距离的影响。基于对这一观点的质疑, 本研究探究了检测项目与背景图片的质心间距对注意促进效应的影响。结果发现, 当目标项位于背景图片中央时(质心间距为0), 表现出注意促进效应; 而当二者分开一定的空间距离时, 出现了注意干扰/抑制效应。由此可见, 项目和背景的质心间距会对注意促进效应产生影响。     

A tachistoscopic study of hemispheric processing in stuttering and nonstuttering children

Hemispheric processing, expressed as mean reaction time to various visual stimuli presented to the left and right visual fields, was investigated in eighteen stuttering and nonstuttering children. Tachistoscopic procedures were used to present linguistic stimuli (words and nonwords) as well as nonlinguistic stimuli (familiar and unfamiliar geometric figures) to the visual fields. Subjects responded by pressing a telegraph key when they perceived a real word or a familiar geometric figure. They were to make no response when they perceived nonwords or unfamiliar geometric figures. Faster reaction times were taken as an index of the most efficient or dominant hemisphere for a given task. No significant differences were found in mean reaction times for groups, visual fields, type of task, nor any of their interactions. Likewise, the data on accuracy also did not suggest that a larger proportion of stutters responded more accurately when linguistic stimuli were presented to the right hemisphere. Based on mean reaction times and on accuracy data, the stuttering and nonstuttering children performed with similar efficiencies and processing patterns.     

The effects of distributed and focused attention on rapid scene categorization

It has been argued that distributed attention facilitates the rapid extraction of summary statistics that underpins rapid scene categorization. We directly examined this hypothesis by investigating whether distributed or focused attention is more compatible with the extraction of both summary statistics (Experiment 1) and semantic scene information (Experiments 2–4). Experiment 1 replicated Chong and Treisman’s (2005a) result that mean circle size judgments are more compatible with a distributed attention task than a focused attention task. Experiment 2 investigated whether this finding extends to simple scene categorization by replacing the averaging task with an animal detection task. Consistent with Experiment 1, the ability to detect the presence of an animal was more compatible with a distributed attention task than a focused attention task. Experiments 3 and 4 addressed whether distributed attention influences scene categorization tasks. When observers were asked to classify scenes based on their basic level (e.g., beach or forest; Experiment 3), there was no statistically significant difference between focused and distributed attention task conditions; however, superordinate level categorization (e.g., natural or manmade; Experiment 4) was faster when combined with a task requiring distributed attention compared to a task requiring focused attention.     

Eye movements serialize memory for objects in scenes

A gaze-contingent short-term memory paradigm was used to obtain forgetting functions for realistic objects in scenes. Experiment 1 had observers freely view nine-item scenes. After observers' gaze left a predetermined target, they could fixate from 1-7 intervening nontargets before the scene was replaced by a spatial probe at the target location. The task was then to select the target from four alternatives. A steep recency benefit was found over the 1-2 intervening object range that declined into an above-chance prerecency asymptote over the remainder of the forgetting function. In Experiment 2, we used sequential presentation and variable delays to explore the contributions of decay and extrafoveal processes to these behaviors. We conclude that memory for objects in scenes, when serialized by fixation sequence, shows recency and prerecency effects that are similar to isolated objects presented sequentially over time. We discuss these patterns in the context of the serial order memory literature and object file theory.     

Binding actions and scenes in visual long-term memory

How does visual long-term memory store representations of different entities (e.g., objects, actions, and scenes) that are present in the same visual event? Are the different entities stored as an integrated representation in memory, or are they stored separately? To address this question, we asked observers to view a large number of events; in each event, an action was performed within a scene. Afterward, the participants were shown pairs of action–scene sets and indicated which of the two they had seen. When the task required recognizing the individual actions and scenes, performance was high (80 %). Conversely, when the task required remembering which actions had occurred within which scenes, performance was significantly lower (59 %). We observed this dissociation between memory for individual entities and memory for entity bindings across multiple testing conditions and presentation durations. These experiments indicate that visual long-term memory stores information about actions and information about scenes separately from one another, even when an action and scene were observed together in the same visual event. These findings also highlight an important limitation of human memory: Situations that require remembering actions and scenes as integrated events (e.g., eyewitness testimony) may be particularly vulnerable to memory errors.     

Statistical learning using real-world scenes: extracting categorical regularities without conscious intent

ABSTRACT— Recent work has shown that observers can parse streams of syllables, tones, or visual shapes and learn statistical regularities in them without conscious intent (e.g., learn that A is always followed by B). Here, we demonstrate that these statistical-learning mechanisms can operate at an abstract, conceptual level. In Experiments 1 and 2, observers incidentally learned which semantic categories of natural scenes covaried (e.g., kitchen scenes were always followed by forest scenes). In Experiments 3 and 4, category learning with images of scenes transferred to words that represented the categories. In each experiment, the category of the scenes was irrelevant to the task. Together, these results suggest that statistical-learning mechanisms can operate at a categorical level, enabling generalization of learned regularities using existing conceptual knowledge. Such mechanisms may guide learning in domains as disparate as the acquisition of causal knowledge and the development of cognitive maps from environmental exploration.     

Object detection in natural scenes: Independent effects of spatial and category-based attention

Humans are remarkably efficient in detecting highly familiar object categories in natural scenes, with evidence suggesting that such object detection can be performed in the (near) absence of attention. Here we systematically explored the influences of both spatial attention and category-based attention on the accuracy of object detection in natural scenes. Manipulating both types of attention additionally allowed for addressing how these factors interact: whether the requirement for spatial attention depends on the extent to which observers are prepared to detect a specific object category—that is, on category-based attention. The results showed that the detection of targets from one category (animals or vehicles) was better than the detection of targets from two categories (animals and vehicles), demonstrating the beneficial effect of category-based attention. This effect did not depend on the semantic congruency of the target object and the background scene, indicating that observers attended to visual features diagnostic of the foreground target objects from the cued category. Importantly, in three experiments the detection of objects in scenes presented in the periphery was significantly impaired when observers simultaneously performed an attentionally demanding task at fixation, showing that spatial attention affects natural scene perception. In all experiments, the effects of category-based attention and spatial attention on object detection performance were additive rather than interactive. Finally, neither spatial nor category-based attention influenced metacognitive ability for object detection performance. These findings demonstrate that efficient object detection in natural scenes is independently facilitated by spatial and category-based attention.     

Recognition of natural scenes from global properties: seeing the forest without representing the trees

Human observers are able to rapidly and accurately categorize natural scenes, but the representation mediating this feat is still unknown. Here we propose a framework of rapid scene categorization that does not segment a scene into objects and instead uses a vocabulary of global, ecological properties that describe spatial and functional aspects of scene space (such as navigability or mean depth). In Experiment 1, we obtained ground truth rankings on global properties for use in Experiments 2-4. To what extent do human observers use global property information when rapidly categorizing natural scenes? In Experiment 2, we found that global property resemblance was a strong predictor of both false alarm rates and reaction times in a rapid scene categorization experiment. To what extent is global property information alone a sufficient predictor of rapid natural scene categorization? In Experiment 3, we found that the performance of a classifier representing only these properties is indistinguishable from human performance in a rapid scene categorization task in terms of both accuracy and false alarms. To what extent is this high predictability unique to a global property representation? In Experiment 4, we compared two models that represent scene object information to human categorization performance and found that these models had lower fidelity at representing the patterns of performance than the global property model. These results provide support for the hypothesis that rapid categorization of natural scenes may not be mediated primarily though objects and parts, but also through global properties of structure and affordance.