observer
e3a0db7c0a191854c176af1d20cdec80-Supplemental-Datasets_and_Benchmarks_Track.pdf
The descriptions of each task are as follows:799 Single-view tasks Single-view tasks test a model's ability to infer spatial properties from a single800 image. These tasks include:801 Depth estimation (OC, OO, NA): Predicting absolute or relative depth values for objects802 Distance prediction (OC, OO, NA): Estimating the Euclidean distance between objects or803 from an object to the camera.804 Object center distance inference (OO, MCA): Given objects A, B and C, determine which805 of B and C is farther or closer to A.806 Object spatial relation (OO, MCA): Determining relative positioning (e.g., left, right, in807 Spatial imagination (OC, OO, MCA): Predicting unseen spatial relationships based on809 limited visual information.810 Multi-view tasks Multi-view tasks require reasoning across multiple images to infer spatial rela-811 tionships. These tasks include:812 Viewpoint change inference (NA): Given two perspectives, output how the camera should813 be moved to see the second perspective.814 Multi-view distance prediction (OC, OO, NA): Estimating object distances across different816 views.817 Multi-view object matching (MCA): Identifying the same object across multiple views.818
Quantifying task-relevant representational similarity using decision variable correlation
Previous studies have compared neural activities in the visual cortex to representations in deep neural networks trained on image classification. Interestingly, while some suggest that their representations are highly similar, others argued the opposite. Here, we propose a new approach to characterize the similarity of the decision strategies of two observers (models or brains) using decision variable correlation (DVC). DVC quantifies the image-by-image correlation between the decoded decisions based on the internal neural representations in a classification task. Thus, it can capture task-relevant information rather than general representational alignment. We evaluate DVC using monkey V4/IT recordings and network models trained on image classification tasks. We find that model-model similarity is comparable to monkey-monkey similarity, whereas model-monkey similarity is consistently lower.
Situat3DChange: Situated 3DChange Understanding Dataset for Multimodal Large Language Model (Supplementary Materials)
The data generation process includes situation sampling, long-form text generation, query generation for the long-form text, and QA generation. It is based on human observations of changes, object attributes, and allocentric object relationships in 3DSSG [9], as well as egocentric relationships between the human and the objects. A.1 Situation Sampling We follow the situation categories of MSQA [4], namely sitting, interacting, and standing, but with more detailed geometric analysis: Sitting. The 28seat categories in 3RScan [8] are grouped into four types: 3large seats with backrests (e.g., sofa), 16 small seats with backrests (e.g., armchair), 1 large seat without a backrest (bed), and 8small seats without backrests (e.g., beanbag). Seatable and backrest areas are classified by surface normals, or by nearby walls within 0.5 m if no backrest exists. For small seats, the seating point is the bounding box center, oriented away from the backrest. For large seats, we select a point with a backrest behind and open space (0.5-1 m) in front.
Constructing efficient channels for ideal observers using the conjugate gradient method
Purpose: Task-based assessment of image quality (IQ) is critically important for the design and optimization of medical imaging systems. Ideal observers, including the Bayesian Ideal Observer (IO) and the ideal linear observer, i.e., the Hotelling observer (HO), provide objective figures of merit (FOMs) that quantify system performance on signal detection tasks. However, the application of ideal observers to high-dimensional image data is often computationally intractable. Channel mechanisms provide an effective framework for dimensionality reduction that can facilitate the computation of ideal observers. This work presents a conjugate gradient (CG)-based method to construct efficient channels for approximating the IO and HO performance.
Hierarchical VAEs provide a normative account of motion processing in the primate brain
The relationship between perception and inference, as postulated by Helmholtz in the 19th century, is paralleled in modern machine learning by generative models like Variational Autoencoders (VAEs) and their hierarchical variants. Here, we evaluate the role of hierarchical inference and its alignment with brain function in the domain of motion perception. We first introduce a novel synthetic data framework, Retinal Optic Flow Learning (ROFL), which enables control over motion statistics and their causes. We then present a new hierarchical VAE and test it against alternative models on two downstream tasks: (i) predicting ground truth causes of retinal optic flow (e.g., self-motion); and (ii) predicting the responses of neurons in the motion processing pathway of primates. We manipulate the model architectures (hierarchical versus non-hierarchical), loss functions, and the causal structure of the motion stimuli.
Modality-Agnostic Topology Aware Localization
This work presents a data-driven approach for the indoor localization of an observer on a 2D topological map of the environment. State-of-the-art techniques may yield accurate estimates only when they are tailor-made for a specific data modality like camera-based system that prevents their applicability to broader domains. Here, we establish a modality-agnostic framework (called OT-Isomap) and formulate the localization problem in the context of parametric manifold learning while leveraging optimal transportation. This framework allows jointly learning a lowdimensional embedding as well as correspondences with a topological map. We examine the generalizability of the proposed algorithm by applying it to data from diverse modalities such as image sequences and radio frequency signals. The experimental results demonstrate decimeter-level accuracy for localization using different sensory inputs.
Spatial-frequency channels, shape bias, and adversarial robustness
What spatial frequency information do humans and neural networks use to recognize objects? In neuroscience, critical band masking is an established tool that can reveal the frequency-selective filters used for object recognition. Critical band masking measures the sensitivity of recognition performance to noise added at each spatial frequency. Existing critical band masking studies show that humans recognize periodic patterns (gratings) and letters by means of a spatial-frequency filter (or "channel") that has a frequency bandwidth of one octave (doubling of frequency). Here, we introduce critical band masking as a task for network-human comparison and test 14 humans and 76 neural networks on 16-way ImageNet categorization in the presence of narrowband noise.
A simple model of recognition and recall memory
Nisheeth Srivastava, Edward Vul
We show that several striking differences in memory performance between recognition and recall tasks are explained by an ecological bias endemic in classic memory experiments - that such experiments universally involve more stimuli than retrieval cues. We show that while it is sensible to think of recall as simply retrieving items when probed with a cue - typically the item list itself - it is better to think of recognition as retrieving cues when probed with items. To test this theory, by manipulating the number of items and cues in a memory experiment, we show a crossover effect in memory performance within subjects such that recognition performance is superior to recall performance when the number of items is greater than the number of cues and recall performance is better than recognition when the converse holds. We build a simple computational model around this theory, using sampling to approximate an ideal Bayesian observer encoding and retrieving situational co-occurrence frequencies of stimuli and retrieval cues. This model robustly reproduces a number of dissociations in recognition and recall previously used to argue for dual-process accounts of declarative memory.
Showing versus doing: Teaching by demonstration
Mark K. Ho, Michael Littman, James MacGlashan, Fiery Cushman, Joe Austerweil, Joseph L. Austerweil
People often learn from others' demonstrations, and inverse reinforcement learning (IRL) techniques have realized this capacity in machines. In contrast, teaching by demonstration has been less well studied computationally. Here, we develop a Bayesian model for teaching by demonstration. Stark differences arise when demonstrators are intentionally teaching (i.e.