Mean orientation discrimination based on proximal stimuli.

Ensemble perception refers to the ability to accurately and rapidly perceive summary statistical representations of specific features from a group of similar objects. However, the specific type of representation involved in this perception within a three-dimensional (3-D) environment remains unclear. In the context of perspective viewing with stereopsis, distal stimuli can be projected onto the retina as different forms of proximal stimuli based on their distances, despite sharing similar properties, such as object size and spatial frequency. This study aimed to investigate the effects of distal and proximal stimuli on the perception of summary statistical information related to orientation. In our experiment, we presented multiple Gabor patches in a stereoscopic environment, allowing us to measure the discrimination threshold of the mean orientation. The object size and spatial frequency were fixed for all patches regardless of depth. However, the physical angular size and absolute spatial frequency covaried with the depth. The results revealed the threshold elevation with depth expansion, especially when the patches formed two clusters at near and far distances, leading to large variations in their retinotopic representations. This finding indicates a minor contribution of similarity of the distal stimuli. Subsequent experiments demonstrated that the variability in physical angular size of the patches significantly influenced the threshold elevation in contrast to that of binocular disparity and absolute spatial frequency. These findings highlight the critical role of physical angular size variability in perceiving mean orientations within the 3-D space.

Consciousness influences the enhancement of visual statistical learning in Zipfian distributions.

It has been reported that visual statistical learning (VSL) is facilitated in skewed distributions. However, it remains unclear whether enhancement of VSL in Zipfian distributions is due to consciousness of the regularities presented at high frequency. This study addressed this issue. We measured participants' subjective confidence in regularities and awareness of regularities during familiarization by combining a previously reported procedure for VSL with a postdecision wagering task and posttest questionnaire. The results demonstrated that Zipfian distribution enhanced not only VSL but also metacognitive sensitivity, particularly for high-frequency regularities, as the effects of consciousness on VSL were limited to high-frequency regularities. Moreover, the results indicated that awareness during familiarization mediated VSL enhancement in the Zipfian distribution. These results suggest that VSL for events with high-frequency regularities plays an important role in the cognition of events with low-frequency regularities via awareness. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Restriction of orientation variability and spatial frequency on the perception of average orientation.

During the observation of a single object, orientation and spatial frequency are jointly coded in an early stage of visual processing, as is evident from studies on the aftereffects of specific combinations of both these features. However, they become independent in the decision-making stage because observers can identify one feature while ignoring the other. Does this separability expand into the perception of ensemble representations? This study investigated the effect of the spatial frequencies of Gabor patches on orientation averaging. In the experiment, the average orientations of all eight patches composed of either homogeneous (i.e., eight 3 cycles/degree or 0.8 cycles/degree patches) or heterogeneous (i.e., four 3 cycles/degree and four 0.8 cycles/degree patches) spatial frequencies were stably estimated if the orientation varied within the range of ±7.7° around the true mean. However, when the range was extended to ±14°, we found that the averaging performance was better in the homogeneous lower spatial frequency than in the homogeneous higher spatial frequency and heterogeneous spatial frequency conditions. These results suggest that an ensemble perception of orientation is modulated by spatial frequency components.

The effect of visual distractors on visual working memory for surface roughness in the human brain.

Research has confirmed that the visual working memory representation of objects' roughness is robust against illumination changes in the human ventral visual cortex and intraparietal sulcus, but not yet against visual distractors during memory maintenance. Thus, this study investigated the effects of visual distractors on roughness-related brain regions during the maintenance phase using multi-voxel pattern analysis (MVPA). We conducted an fMRI experiment in which participants were asked to memorize a sphere's roughness against visual distractors, presented during the delay period in random trials. Region of interest-based MVPA showed no contribution of the ventral visual cortex and intraparietal sulcus to the roughness memory, regardless of behavioral performance. Post hoc searchlight MVPA revealed an above-chance decoding performance level in the brain regions presumably related to haptic processing when no visual distractors were shown. In contrast, when visual distractors appeared in the delay period, decoding performance exceeded the chance level in the ventral visual cortex. These results suggest that when visual distractors are presented during the memory phase, both visual and haptic processing are related to visual working memory for roughness, and the weighting of modality changes depending on the presence of visual distractors.

Diversity in Psychological Research Activities: Quantitative Approach With Topic Modeling.

Recent cultural studies have discussed universality and diversity in human behavior using numerous samples investigated worldwide. We aimed to quantitatively extend this discussion to various research activities in psychology in terms of geographic regions and time trends. Most psychology departments have specialists in various fields of psychology. Further, research institutions in all regions typically aim to provide systematic and balanced research education. Nevertheless, most researchers recognize universal features and patterns of diversity in research activities in psychology in terms of regional differences and time trends. However, these arguments remain intuitive and vague, and no studies have conducted quantitative analyses. To this end, we conducted topic modeling for the abstracts of psychological articles with the regions of author affiliations and publication periods as covariates. The results showed that the topic proportions related to basic research were high in North-Central America, whereas those related to clinical research were high in Europe. Interestingly, the regional differences shown by topic modeling were not observed in the frequency analysis of keywords, indicating that topic modeling revealed implicit characteristics. Moreover, we observed an increasing trend of neuroscience topics across publication periods. However, this trend was not valid for the psychology journal Psychological Science. Taken together, our results suggest diversity of geographic regions and periods in research activities in psychology. More importantly, our findings indicate that universality holds neither for human behavior nor research activities on human mental processes.

Wisdom of crowds and collective decision-making in a survival situation with complex information integration.

BACKGROUND: The wisdom of crowds and collective decision-making are important tools for integrating information between individuals, which can exceed the capacity of individual judgments. They are based on different forms of information integration. The wisdom of crowds refers to the aggregation of many independent judgments without deliberation and consensus, while collective decision-making is aggregation with deliberation and consensus. Recent research has shown that collective decision-making outperforms the wisdom of crowds. Additionally, many studies have shown that metacognitive knowledge of subjective confidence is useful for improving aggregation performance. However, because most of these studies have employed relatively simple problems; for example, involving general knowledge and estimating values and quantities of objects, it remains unclear whether their findings can be generalized to real-life situations involving complex information integration. This study explores the performance and process of the wisdom of crowds and collective decision-making by applying the wisdom of crowds with weighted confidence to a survival situation task commonly used in studies of collective decision-making. RESULTS: The wisdom of crowds and collective decision-making outperformed individual judgment. However, collective decision-making did not outperform the wisdom of crowds. Contrary to previous studies, weighted confidence showed no advantage from comparison between confidence-weighted and non-weighted aggregations; a simulation analysis varying in group size and sensitivity of confidence weighting revealed interaction between group size and sensitivity of confidence weighting. This reveals that it is because of small group size and not the peculiarity of the survival task that results in no advantage of weighted confidence. CONCLUSIONS: The study's findings suggest that the wisdom of crowds could be applicable to complex problem-solving tasks, and interaction between group size and sensitivity of confidence weighting is important for confidence-weighted aggregation effects.

Material constancy in perception and working memory.

A key challenge for the visual system entails the extraction of constant properties of objects from sensory information that varies moment by moment due to changes in viewing conditions. Although successful performance in constancy tasks requires cooperation between perception and working memory, the function of the memory system has been under-represented in recent material perception literature. Here, we addressed the limits of material constancy by elucidating if and how working memory is involved in constancy tasks by using a variety of material stimuli, such as metals, glass, and translucent objects. We conducted experiments with a simultaneous and a successive matching-to-sample paradigm in which participants matched the perceived material properties of objects with or without a temporal delay under varying illumination contexts. The current study combined a detailed analysis of matching errors, data on the strategy use obtained via a self-report questionnaire, and the statistical image analysis of diagnostic image cues used for material discrimination. We found a comparable material constancy between simultaneous and successive matching conditions, and it was suggested that, in both matching conditions, participants used similar information processing strategies for the discrimination of materials. The study provides converging evidence on the critical role of working memory in material constancy, where working memory serves as a shared processing bottleneck that constrains both simultaneous and successive material constancy.

Functional difference between the ventral visual cortex and the intraparietal sulcus in visual working memory of material properties.

A recent study showed that objects' roughness (smooth or rough) was held in visual working memory (VWM) in the ventral visual cortex and the intraparietal sulcus (IPS). Here, we investigated the functional differences between these areas in the context of VWM of material properties. We focused on the process in which participants accurately extracted and maintained in their memories the glossiness and roughness of a sphere. Human participants performed two types of delayed material (glossiness or roughness) discrimination tasks in which they judged which task was to be performed based on the differences in the material properties of two sequentially presented sample spheres. This task allowed us to investigate how the visual system in the human brain could properly extract a material property and hold the information in VWM. By decoding the task information (glossiness or roughness) from the brain activity patterns in the delay period, we found that both the ventral visual cortex and the IPS contributed to maintenance in memory of material properties. We also showed different decoding patterns in the areas over the course of each trial; the ventral visual cortex performed at levels above chance performance in extracting a material property, and the IPS performed at levels above chance performance in maintaining the property in memory. These results suggest that, in VWM, material properties are visually processed in the ventral visual cortex, and the visual information is sent to the IPS to be robustly maintained.

The limited contribution of early visual cortex in visual working memory for surface roughness.

Are visual representations in the human early visual cortex necessary for visual working memory (VWM)? Previous studies suggest that VWM is underpinned by distributed representations across several brain regions, including the early visual cortex. Notably, in these studies, participants had to memorize images under consistent visual conditions. However, in our daily lives, we must retain the essential visual properties of objects despite changes in illumination or viewpoint. The role of brain regions-particularly the early visual cortices-in these situations remains unclear. The present study investigated whether the early visual cortex was essential for achieving stable VWM. Focusing on VWM for object surface properties, we conducted fMRI experiments, while male and female participants performed a delayed roughness discrimination task in which sample and probe spheres were presented under varying illumination. By applying multi-voxel pattern analysis to brain activity in regions of interest, we found that the ventral visual cortex and intraparietal sulcus were involved in roughness VWM under changing illumination conditions. In contrast, VWM was not supported as robustly by the early visual cortex. These findings show that visual representations in the early visual cortex alone are insufficient for the robust roughness VWM representation required during changes in illumination.

Association between synesthetic colors and sensitivity to physical colors changed by type of synesthetic experience in grapheme-color synesthesia.

Grapheme-color synesthesia is a condition in which visual perception of letters induces simultaneous perception of a specific color. Previous studies indicate that grapheme-color synesthetes are more sensitive to physical colors than non-synesthetes. Synesthetic colors are found to be concentrated in multiple regions of the color space, forming "synesthetic color clusters". The present study investigated whether color sensitivity corresponding to synesthetic color clusters (clustered colors) is higher than color sensitivity that does not correspond to synesthetic color clusters (non-clustered colors). However, we found no difference in the color sensitivity for clustered and non-clustered colors. We also investigated whether the color sensitivity is dependent on the synesthetic experience (associators and projectors). We found that the greater the tendency toward associator characteristics, the greater the sensitivity for clustered colors compared to that for non-clustered colors. Our findings suggest an association between synesthetic colors and physical color sensitivity that is modulated by synesthetic experience.

Neural Mechanisms of Memory Enhancement and Impairment Induced by Visual Statistical Learning.

Prior research has reported that the medial temporal, parietal, and frontal brain regions are associated with visual statistical learning (VSL). However, the neural mechanisms involved in both memory enhancement and impairment induced by VSL remain unknown. In this study, we examined this issue using event-related fMRI. fMRI data from the familiarization scan showed a difference in the activation level of the superior frontal gyrus (SFG) between structured triplets, where three objects appeared in the same order, and pseudorandom triplets. More importantly, the precentral gyrus and paracentral lobule responded more strongly to Old Turkic letters inserted into the structured triplets than to those inserted into the random triplets, at the end of the familiarization scan. Furthermore, fMRI data from the recognition memory test scan, where participants were asked to decide whether the objects or letters shown were old (presented during familiarization scan) or new, indicated that the middle frontal gyrus and SFG responded more strongly to objects from the structured triplets than to those from the random triplets, which overlapped with the brain regions associated with VSL. In contrast, the response of the lingual gyrus, superior temporal gyrus, and cuneus was weaker to letters inserted into the structured triplets than to those inserted into the random triplets, which did not overlap with the brain regions associated with observing the letters during the familiarization scan. These findings suggest that different brain regions are involved in memory enhancement and impairment induced by VSL.

Spatial variability induces generalization in contextual cueing.

We can incidentally learn regularities in a visual scene, and this kind of learning facilitates subsequent processing of similar scenes. One example of incidental learning is referred to as contextual cueing, a phenomenon in which repetitive exposure to a particular spatial configuration facilitates visual search performance in the configuration. Previous studies have demonstrated that effects of contextual cueing generalize to similar, but not entirely identical configurations. Although humans may be capable of extracting regularity from variable instances and applying it to a new instance, the mechanisms underlying generalization in contextual cueing are not fully understood. We hypothesized that contextual cueing results from extraction of variance in item locations, and the variance is used to calculate the similarity between the learned and new configuration. Based on this hypothesis, we predicted that contextual cueing would generalize more widely when the variability of item locations during learning is large compared with when it is small. The results supported our hypothesis, indicating that spatial variability induced generalization in contextual cueing. This finding suggests that, in incidental learning, the similarity between a learned and new representation is computed based on the variance of inputs. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Robust color-shape binding representations for multiple objects in visual working memory.

The nature of feature-bound object representations in visual working memory (VWM) remains unclear. Many studies claim that they are held by a resource-limited system and are fragile. Using a novel paradigm called the redundant feature reviewing task, the current study showed that color-shape binding representations for multiple objects are maintained and matched with perceptual representation in a robust fashion in VWM. A set of features was presented in a two-object memory display, followed by a linking display in which placeholders either moved or stayed. Then participants judged if a single object probe contained any features of the memory display, regardless of object correspondence. The advantage of color-shape conjunction relative to single features, as indexed by feature coactivation, was retained in the memory matching within the same object and between different objects, regardless of object motion. In contrast, the object-specific preview benefit (OSPB), an index of accessibility to memory representations, was reduced when objects moved, suggesting that motion disrupts the spatiotemporal continuity of memory representations. A meta-analysis of the magnitude of the OSPB in the moving condition across the experiments showed a significant OSPB, suggesting that object file representations bound to spatiotemporal locations are responsible for feature coactivation. Taken together, these findings suggest that the nonspatial features of multiple objects are bound and maintained in VWM, in a robust fashion, regardless of the objects' motion. The cost of object motion in the memory matching performance likely reflects the correspondence between identity and spatiotemporal location, rather than the binding of nonspatial features. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Neural correlates of visual short-term memory for objects with material categories.

Behavioral and neuroscience studies have shown that we can easily identify material categories, such as metal and fabric. Not only the early visual areas but also higher-order visual areas including the fusiform gyrus are known to be engaged in material perception. However, the brain mechanisms underlying visual short-term memory (VSTM) for material categories are unknown. To address this issue, we examined the neural correlates of VSTM for objects with material categories using a change detection task. In each trial, participants viewed a sample display containing two, four, or six objects having six material categories and were required to remember the locations and types of objects. After a brief delay, participants were asked to detect an object change based on the images or material categories in the test display (image-based and material-based conditions). Neuronal activity in the brain was assessed using functional magnetic resonance imaging (MRI). Behavioral results showed that the number of objects encoded did not increase as a function of set size in either image-based or material-based conditions. By contrast, MRI data showed a difference between the image-based and material-based conditions in percent signal change observed in a priori region of interest, the fusiform face area (FFA). Thus, we failed to achieve our research aim. However, the brain activation in the FFA correlated with the activation in the precentral/postcentral gyrus, which is related to haptic processing. Our findings indicate that the FFA may be involved in VSTM for objects with material categories in terms of the difference between images and material categories and that this memory may be mediated by the tactile properties of objects.

Gradual formation of visual working memory representations of motion directions.

Although it is well accepted that the formation of visual working memory (VWM) representations from simple static features is a rapid and effortless process that completes within several hundred milliseconds, the storage of motion information in VWM within that time scale can be challenging due to the limited processing capacity of the visual system. Memory formation can also be demanding especially when motion stimuli are visually complex. Here, we investigated whether the formation of VWM representations of motion direction is more gradual than that of static orientation and examined the effects of stimulus complexity on that process. To address these issues, we examined how the number and the precision of stored items in VWM develop over time by using a continuous report procedure. Results showed that while a viewing duration of several seconds was required for the successful storage of multiple motion directions in VWM regardless of motion complexity, the accumulation of memory precision was much slower when the motion stimulus was visually complex (Experiments 1 & 2). Additional experiments showed that the difference in memory performance for simple and complex motion stimuli cannot be explained by differences in signal-to-noise levels of the stimulus (Experiment 3). These results demonstrate remarkable temporal limitations in the formation of VWM representations for dynamic objects, and further show how this process is affected by stimulus properties such as visual complexity and signal-to-noise levels.

Constancy of visual working memory of glossiness under real-world illuminations.

Glossiness is a surface property of material that is useful for recognizing objects and spaces. For glossiness to be effective across situations, our visual system must be unaffected by viewing contexts, such as lighting conditions. Although glossiness perception has constancy across changes in illumination, whether visual working memory also realizes glossiness constancy is not known. To address this issue, participants were presented with photo-realistic computer-generated images of spherical objects and asked to match the appearance of reference and test stimuli in relation to two dimensions of glossiness (contrast and sharpness). By comparing performance in terms of the match between perception and memory, we found that both features were well recalled, even when illumination contexts differed between the study and test periods. In addition, no correlation was found between recall errors related to contrast and sharpness, suggesting that these features are independently represented, not only in perception, as previously reported, but also in working memory. Taken together, these findings demonstrate the constancy of glossiness in visual working memory under conditions of real-world illumination.

[Feature Integration in Visual Working Memory].

This article reviews studies on feature integration in visual working memory, which is critical for various cognitive activities using visual information. Studies involving change detection and multiple object tracking tasks reported that feature-integrated object representations are successfully maintained, and that the parietal cortex plays a major role. Subsequent studies that involved explicit tasks on feature combination, such as feature swap detection and multiple object permanence tracking, revealed the role of the prefrontal cortex, but it remains equivocal whether visual working memory holds feature-integrated object representations. In addition, recent studies using an implicit-association test measure, the redundant feature reviewing task, combining object reviewing and redundancy gain paradigms, provided evidence on feature-integrated object representations in visual working memory. Electroencephalography data analysis showed prefrontal activities reflecting the integration of the color and shape of an object, which is consistent with the result of studies measuring explicit tasks. Altogether, these findings are consistent with a recently proposed "feature confirmation" model, claiming that object features can be integrated in bottom-up visual processing and the limitation in feature binding occurs in the top-down mechanism which confirms the presence of features and their combination.

Open monitoring meditation reduces the involvement of brain regions related to memory function.

Mindfulness meditation consists of focused attention meditation (FAM) and open monitoring meditation (OMM), both of which reduce activation of the default mode network (DMN) and mind-wandering. Although it is known that FAM requires intentional focused attention, the mechanisms of OMM remain largely unknown. To investigate this, we examined striatal functional connectivity in 17 experienced meditators (mean total practice hours = 920.6) during pre-resting, meditation, and post-resting states comparing OMM with FAM, using functional magnetic resonance imaging. Both FAM and OMM reduced functional connectivity between the striatum and posterior cingulate cortex, which is a core hub region of the DMN. Furthermore, OMM reduced functional connectivity of the ventral striatum with both the visual cortex related to intentional focused attention in the attentional network and retrosplenial cortex related to memory function in the DMN. In contrast, FAM increased functional connectivity in these regions. Our findings suggest that OMM reduces intentional focused attention and increases detachment from autobiographical memory. This detachment may play an important role in non-judgmental and non-reactive attitude during OMM. These findings provide new insights into the mechanisms underlying the contribution of OMM to well-being and happiness.

Pavlovian reward learning elicits attentional capture by reward-associated stimuli.

Feature-reward association elicits value-driven attentional capture (VDAC) regardless of the task relevance of associated features. What are the necessary conditions for feature-reward associations in VDAC? Recent studies claim that VDAC is based on Pavlovian conditioning. In this study, we manipulated the temporal relationships among feature, response, and reward in reward learning to elucidate the necessary components of VDAC. We presented reward-associated features in a variety of locations in a flanker task to form a color-reward association (training phase) and then tested VDAC in a subsequent visual search task (test phase). In Experiment 1, we showed reward-associated features in a task display requiring response selection and observed VDAC, consistent with most previous studies. In Experiment 2, features presented at a fixation display before a task display also induced VDAC. Moreover, in Experiment 3, we reduced the time interval between features and rewards so that features appeared after a task display and we obtained marginally significant VDAC. However, no VDAC was observed when features and rewards were simultaneously presented in a feedback display in Experiments 4 and 5, suggesting that a direct association between feature and reward is not sufficient for VDAC. These results are in favor of the idea that response selection does not mediate feature-reward association in VDAC. Moreover, the evidence suggests that the time interval of feature and reward is flexible with some restriction in the learning of feature-reward association. The present study supports the hypothesis that theories of Pavlovian conditioning can account for feature-reward association in VDAC.

Cultural Differences in Visual Search for Geometric Figures.

While some studies suggest cultural differences in visual processing, others do not, possibly because the complexity of their tasks draws upon high-level factors that could obscure such effects. To control for this, we examined cultural differences in visual search for geometric figures, a relatively simple task for which the underlying mechanisms are reasonably well known. We replicated earlier results showing that North Americans had a reliable search asymmetry for line length: Search for long among short lines was faster than vice versa. In contrast, Japanese participants showed no asymmetry. This difference did not appear to be affected by stimulus density. Other kinds of stimuli resulted in other patterns of asymmetry differences, suggesting that these are not due to factors such as analytic/holistic processing but are based instead on the target-detection process. In particular, our results indicate that at least some cultural differences reflect different ways of processing early-level features, possibly in response to environmental factors.