Metacognition of perceptual resolution across and around the visual field.

Do people have accurate metacognition of non-uniformities in perceptual resolution across (i.e., eccentricity) and around (i.

Ensemble memory of a scene interacts with current perception regardless of attentional requirements.

How do we maintain a rich and stable perceptual experience across the entire visual scene, even when we are focusing on a subset of visual inputs? The current study explored this question by investigating whether the visual system processes summary statistics of multiple features regardless of task relevance, and how they interact with subsequent perception. To test the processing of multifeature summary statistics under different attentional requirements, we presented multiple Gabor patches with heterogeneous orientations/colors and asked participants to attend to a single feature dimension (Experiments 1 and 3) or a single item (Experiment 2) for the memory task. During the memory maintenance period (before memory response), we asked the participants to perform a discrimination task (Experiments 1 and 2) or a boundary localization task (Experiment 3) to test how the memory of the ensemble representation alters the subsequent perceptual experience.

Outlier rejection in the process of pooling.

Ensemble perception allows our visual system to process large amounts of information efficiently by summarizing its statistical properties. A key aspect of ensemble perception is the devaluation of outlying elements, which leads to more informative summary statistics with reduced variance and a more representative mean. However, the mechanisms underlying this outlier rejection process are not well understood.

Partial blindness: Visual experience is not rich, but not sparse.

Is our perceptual experience constrained by an information bottleneck (i.e., the limited capacity for cognitive access), and if so, how? To answer these questions, we investigated observers' perceptual resolution for an individual face when they saw either a single face or multiple faces simultaneously.

Americans weigh an attended emotion more than Koreans in overall mood judgments.

Face ensemble coding is the perceptual ability to create a quick and overall impression of a group of faces, triggering social and behavioral motivations towards other people (approaching friendly people or avoiding an angry mob). Cultural differences in this ability have been reported, such that Easterners are better at face ensemble coding than Westerners are. The underlying mechanism has been attributed to differences in processing styles, with Easterners allocating attention globally, and Westerners focusing on local parts.

The effect of masks on the emotion perception of a facial crowd.

The present study investigated the effect of facial masks on people's ability to perceive emotions in crowds. We presented faces with the bottom halves occluded by masks or full faces without occlusion. In two sequentially presented crowds, we varied the number of faces, emotional valence, and intensity of facial expressions, examining the impact of masks on the perception of crowd emotion.

A population response model of ensemble perception.

Ensemble representations have been considered as one of the strategies that the visual system adopts to cope with its limited capacity. Thus, they include various statistical summaries such as mean, variance, and distributional properties and are formed over many stages of visual processing. The present study proposes a population-coding model of ensemble perception to provide a theoretical and computational framework for these various facets of ensemble perception.

Similarity-based clustering of multifeature objects in visual working memory.

This study investigated the similarity-based clustering mechanism of multifeature stimuli, wherein items are separated or grouped based on their similarity in visual working memory (VWM). In particular, we investigated whether clustering occurred at an individual feature level or at an integrated object level when participants encoded objects with multiple features for VWM. To test this, we conducted two experiments in which participants remembered and reconstructed a randomly chosen feature (either color or orientation) from one of five presented stimuli.

The relationship between ensemble representations of facial information.

People accurately evaluate various types of facial information (gaze direction, facial expression, facial identity, and gender) of multiple faces. Considering such varieties, summarizing abilities of facial information might vary depending on its type because it is either changeable (e.g.

Effects of attention on visual discrimination and awareness: Evidence from eye-specific attention.

The role of attention in visual awareness is a foundational issue for understanding consciousness, but remains highly controversial. Therefore, in two experiments, we investigated whether and how attention modulates visual awareness using a monocular cuing paradigm. Although observers are not aware of which eye received a cue, a monocular cue can attract eye-specific attention to a cued eye.

Neural representations of ensemble coding in the occipital and parietal cortices.

The human visual system is able to extract summary statistics from sets of similar items, but the underlying neural mechanism remains poorly understood. Using functional magnetic resonance imaging (fMRI) and an encoding model, we examined how the neural representation of ensemble coding is constructed by manipulating the task-relevance of ensemble features. We found a gradual increase in orientation-selective responses to the mean orientation of multiple stimuli along the visual hierarchy only when these orientations were task-relevant.

Multivariate summary of a complex scene.

The current study investigated how people summarize and represent objects with multiple features to cope with the complexity due to the number of objects and feature dimensions. We presented a set of circles whose color and size were either correlated perfectly (r = 1) or not correlated at all (r = 0). Using a membership identification task, we found that participants formed a statistical representation that included information about conjunctions as well as each color and size dimensions.

Partial awareness can be induced by independent cognitive access to different spatial frequencies.

Partial awareness-an intermediate state between complete consciousness and unconsciousness-has been explained by independent cognitive access to different levels of representation in hierarchical visual processing. This account, however, cannot explain graded visual experiences in low levels. We aimed to explain partial awareness in low levels of visual processing by independent cognitive access to different spatial frequencies.

Perceived variability reflects the reliability of individual items.

When confronted with many visual items, people can compute their variability accurately and rapidly, which facilitates efficient information processing and optimal decision making. However, how the visual system computes variability is still unclear. To investigate this, we implemented situations whereby estimates of variability based on several possible variability measures (e.

Quality of average representation can be enhanced by refined individual items.

Ensemble perception is efficient because it summarizes redundant and complex information. However, it loses the fine details of individual items during the averaging process. Such characteristics of ensemble perception are similar to those of coarse processing.

Contextual cueing in target absent trials by distractor-distractor associations.

refers to finding a target more efficiently in repeated displays than in novel displays. However, conflicting results have been reported regarding whether target absent judgments can also be efficient in repeated displays. To resolve this controversy, we first tested 3 factors that might influence the strength of distractor-distractor associations and then investigated how such associations produced faster responses on repeated target absent trials by measuring the patterns of eye movements.

Effects of Selective Attention on Mean-Size Computation: Weighted Averaging and Perceptual Enlargement.

For efficient use of limited capacity, the visual system summarizes redundant information and prioritizes relevant information, strategies known respectively as and . Although previous studies showed a close relationship between these strategies, the specific mechanisms underlying the relationship have not been determined. We investigated how attention modulated mean-size computation.

The visual system does not compute a single mean but summarizes a distribution.

Ongoing discussions on perceptual averaging have the implicit assumption that individual representations are reduced into a single prototypical representation. However, some evidence suggests that the mean representation may be more complex. For example, studies that use a single item probe to estimate mean size often show biased estimations.

Ensemble perception and focused attention: Two different modes of visual processing to cope with limited capacity.

The visual system has a limited capacity for dealing with complex and redundant information in a scene. Here, we propose that a distributed attention mode of processing is necessary for coping with this limit, together with a focused attention mode of processing. The distributed attention mode provides a statistical summary of a scene, whereas the focused attention mode provides relevant information for object recognition.

Adaptation to mean and variance: Interrelationships between mean and variance representations in orientation perception.

When there are many visual items, the visual system could represent their summary statistics (e.g., mean, variance) to process them efficiently.

Novel procedure for generating continuous flash suppression: Seurat meets Mondrian.

Continuous flash suppression (CFS) entails presentation of a stationary target to one eye and an animated sequence of arrays of geometric figures, the mask, to the other eye. The prototypical CFS sequence comprises different sized rectangles of various colors, dubbed Mondrians. Presented as a rapid, changing sequence to one eye, Mondrians or other similarly constructed textured arrays can abolish awareness of the target viewed by the other eye for many seconds at a time, producing target suppression durations much longer than those associated with conventional binocular rivalry.

Power of averaging: Noise reduction by ensemble coding of multiple faces.

Face perception is an important ability in social interaction. Holistic processing of a face enables us to understand facial attributes easily despite similarity of faces. Ensemble coding of multiple faces enables us to judge the characteristics of a crowd easily despite the limited capacity of the visual system.

Search termination when the target is absent: The prevalence of coarse processing and its intertrial influence.

The visual system can flexibly distribute attentional resources to search areas, with this reflected in the spatial scale of information processing. Visual processing can be either coarse at a global level, or fine at a local level. Previous studies showed the transition between these 2 modes, from coarse to fine, but it has been unclear when and how this occurs.

Distributed attention model of perceptual averaging.

The visual system efficiently processes complex and redundant information in a scene despite its limited capacity. One strategy for coping with the complexity and redundancy of a scene is to summarize it by using average information. However, despite its importance, the mechanism of averaging is not well understood.

Similarity-based clusters are representational units of visual working memory.

We investigated whether clustering based on feature similarity improves the representational quality of visual working memory (VWM). We hypothesized that similar items are organized into clusters, and their recall precision increases with fewer clusters because of reduced memory load. In a series of 6 experiments, participants remembered orientations or colors of several stimuli and estimated the orientation (color) of cued item(s).