Limitations on animacy categorization in ensemble perception

Many studies have shown that people can rapidly and efficiently categorize the animacy of individual objects and scenes, even with few visual features available. Does this necessarily mean that the visual system has an unlimited capacity to process animacy across the entire visual field? We tested this in an ensemble task requiring observers to judge the relative numerosity of animate vs. inanimate items in briefly presented sets of multiple objects. We generated a set of morphed “animacy continua” between pairs of animal and inanimate object silhouettes and tested them in both individual object categorization and ensemble enumeration. For the ensemble task, we manipulated the ratio between animate and inanimate items present in the display and we also presented two types of animacy distributions: “segmentable” (including only definitely animate and definitely inanimate items) or “non-segmentable” (middle-value, ambiguous morphs pictures were shown along with the definite “extremes”). Our results showed that observers failed to integrate animacy information from multiple items, as they showed very poor performance in the ensemble task and were not sensitive to the distribution type despite their categorization rate for individual objects being near 100%. A control condition using the same design with color as a category-defining dimension elicited both good individual object and ensemble categorization performance and a strong effect of the segmentability type. We conclude that good individual categorization does not necessarily allow people to build ensemble animacy representations, thus showing the limited capacity of animacy perception.

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Reaction Time for Object Categorization Is Predicted by Representational Distance

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00476 ◽

2014 ◽

Vol 26 (1) ◽

pp. 132-142 ◽

Cited By ~ 43

Author(s):

Thomas A. Carlson ◽

J. Brendan Ritchie ◽

Nikolaus Kriegeskorte ◽

Samir Durvasula ◽

Junsheng Ma

Keyword(s):

Decision Making ◽

Temporal Cortex ◽

Internal Representation ◽

Inferior Temporal Cortex ◽

Object Categorization ◽

Object Representations ◽

Multivariate Pattern Analysis ◽

Individual Object ◽

Multivariate Pattern ◽

The Brain

How does the brain translate an internal representation of an object into a decision about the object's category? Recent studies have uncovered the structure of object representations in inferior temporal cortex (IT) using multivariate pattern analysis methods. These studies have shown that representations of individual object exemplars in IT occupy distinct locations in a high-dimensional activation space, with object exemplar representations clustering into distinguishable regions based on category (e.g., animate vs. inanimate objects). In this study, we hypothesized that a representational boundary between category representations in this activation space also constitutes a decision boundary for categorization. We show that behavioral RTs for categorizing objects are well described by our activation space hypothesis. Interpreted in terms of classical and contemporary models of decision-making, our results suggest that the process of settling on an internal representation of a stimulus is itself partially constitutive of decision-making for object categorization.

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Serial dependence tracks objects and scenes independently

10.1101/2021.07.12.452024 ◽

2021 ◽

Author(s):

Thérèse Collins

Keyword(s):

Visual Processing ◽

Scene Perception ◽

Temporal Integration ◽

Object Perception ◽

Serial Dependence ◽

Recent Past ◽

Individual Object ◽

Ensemble Perception ◽

Visual Attribute ◽

Feature Values

The visual world is made up of objects and scenes. Object perception requires both discriminating an individual object from others and binding together different perceptual samples of that object across time. Such binding manifests by serial dependence, the attraction of the current perception of a visual attribute towards values of that attribute seen in the recent past. Scene perception is subserved by global mechanisms like ensemble perception, the rapid extraction of the average feature value of a group of objects. The current study examined to what extent the perception of single objects in multi-object scenes depended on previous feature values of that object, or on the average previous attribute of all objects in the scene. Results show that serial dependence occurs independently on two simultaneously present objects, that ensemble perception depends on previous ensembles, and that serial dependence of an individual object occurs only on the features of that particular object. These results suggest that the temporal integration of successive perceptual samples operates simultaneously at independent levels of visual processing.

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Multiple object categorization and effect of spatial frequencies

10.7287/peerj.preprints.26666 ◽

2018 ◽

Author(s):

Alvydas Soliunas ◽

Aleksandras Pleskaciauskas ◽

Algis Daktariunas

Keyword(s):

Reaction Time ◽

Object Categorization ◽

Probe Word ◽

Psychophysical Experiment ◽

Multiple Objects ◽

Visual Objects ◽

Performance Accuracy ◽

Multiple Object ◽

Spatial Frequencies

A process of interaction between objects and scene is widely investigated but much less attention is paid to the interaction between objects in multiple objects stimuli. In psychophysical experiment, we presented one, two, or three visual objects simultaneously for 100 ms and then asked subjects to answer whether objects belong to the same category (Experiments 1 and 2), or whether afterwards presented probe-word signify an object that was presented (Experiments 3 and 4). Interestingly, performance accuracy and reaction time did not depend on the number of objects if they belonged to the same category, but performance deteriorated when more categories were presented. Filtering out high or low spatial frequencies did not affect performance peculiarities of the objects of the same or different categories. The findings support assumption that visual objects of the same category could be identified simultaneously but the different categories are identified successively.

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Ensemble Statistics Can Be Available before Individual Item Properties: Electroencephalogram Evidence Using the Oddball Paradigm

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01704 ◽

2021 ◽

pp. 1-13

Author(s):

Michael L. Epstein ◽

Tatiana A. Emmanoui

Keyword(s):

Oddball Paradigm ◽

Multivariate Pattern Analysis ◽

Object Processing ◽

Individual Object ◽

Object Properties ◽

Stimulus Evaluation ◽

Ensemble Perception ◽

Behavioral Studies ◽

Item Properties ◽

Multivariate Pattern

Abstract Behavioral studies have shown that statistical properties of object groups are perceived accurately with brief exposure durations. This finding motivated the hypothesis that ensemble perception occurs rapidly in vision. However, the precise timing of ensemble perception remains unclear. Here, we used the superior temporal resolution of electroencephalography to directly compare the timing of ensemble processing to that of individual object processing. The P3b was chosen as a particular component of interest, as it is thought to measure the latency of stimulus evaluation. Participants performed a simple “oddball” task in which sets of 51 lines with varied orientations sequentially flashed briefly on the display. In these sequences, there was a 20% chance of an individual oddball, wherein one marked object tilted clockwise, and a 20% chance of an ensemble oddball, wherein the average orientation of the set tilted 20% clockwise. In counterbalanced blocks, participants were instructed to respond to either individual or ensemble oddballs. ERP analysis was performed to test the timing of this processing. At parietal electrodes, P3b components were found for both individual and ensemble oddballs. Ensemble P3b components were found to occur significantly earlier than individual P3b components, as measured with both 50% area latency and 50% onset latency. Using multivariate pattern analysis, ensemble oddball trials were classifiable from standard trials significantly earlier in their timecourse than individual oddball trials. Altogether, these results provide compelling evidence that ensemble perception occurs rapidly and that ensemble properties can be available earlier than individual object properties.

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Ensemble perception in depth: Correct size-distance rescaling of multiple objects before averaging.

Journal of Experimental Psychology General ◽

10.1037/xge0000485 ◽

2019 ◽

Vol 148 (4) ◽

pp. 728-738 ◽

Cited By ~ 4

Author(s):

Natalia A. Tiurina ◽

Igor S. Utochkin

Keyword(s):

Multiple Objects ◽

Ensemble Perception ◽

Correct Size

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Using of deep convolutional neural networks for visual features extraction in multiple objects tracking task

2020 International Conference on Information Technology and Nanotechnology (ITNT) ◽

10.1109/itnt49337.2020.9253259 ◽

2020 ◽

Author(s):

Andrei Meshcheriakov ◽

Sergey Popov

Keyword(s):

Neural Networks ◽

Convolutional Neural Networks ◽

Features Extraction ◽

Tracking Task ◽

Visual Features ◽

Multiple Objects ◽

Deep Convolutional Neural Networks ◽

Objects Tracking

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Bottom-up processing of intermediate visual features is sufficient for animate/inanimate object categorization.

Journal of Vision ◽

10.1167/18.10.388 ◽

2018 ◽

Vol 18 (10) ◽

pp. 388

Author(s):

Amanda Del Giacco ◽

Valentinos Zachariou ◽

Leslie Ungerleider ◽

Xiaomin Yue

Keyword(s):

Object Categorization ◽

Visual Features ◽

Inanimate Object ◽

Bottom Up

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Supplemental Material for Ensemble Perception in Depth: Correct Size-Distance Rescaling of Multiple Objects Before Averaging

Journal of Experimental Psychology General ◽

10.1037/xge0000485.supp ◽

2018 ◽

Keyword(s):

Multiple Objects ◽

Ensemble Perception ◽

Correct Size

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From perceptual to language-mediated categorization

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2012.0391 ◽

2014 ◽

Vol 369 (1634) ◽

pp. 20120391 ◽

Cited By ~ 29

Author(s):

Gert Westermann ◽

Denis Mareschal

Keyword(s):

Conceptual Knowledge ◽

Object Categorization ◽

Current Debate ◽

First Year ◽

Perceptual Categorization ◽

Object Knowledge ◽

Individual Object ◽

First Year Of Life ◽

Object Features

From at least two months onwards, infants can form perceptual categories. During the first year of life, object knowledge develops from the ability to represent individual object features to representing correlations between attributes and to integrate information from different sources. At the end of the first year, these representations are shaped by labels, opening the way to conceptual knowledge. Here, we review the development of object knowledge and object categorization over the first year of life. We then present an artificial neural network model that models the transition from early perceptual categorization to categories mediated by labels. The model informs a current debate on the role of labels in object categorization by suggesting that although labels do not act as object features they nevertheless affect perceived similarity of perceptually distinct objects sharing the same label. The model presents the first step of an integrated account from early perceptual categorization to language-based concept learning.

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