Implications for Computer Vision from Cognitive Science

1
Implications for Computer Vision from Cognitive
Science

• David Minnen
• Student CogSci Conference
• April 13, 2001

2
Overview

• Motivation
• Portents of Trouble in Categorization
• Insight from Infant Psychology
• Implications on Computer Vision
• Impact on Future Research

3
Motivation

• The human conceptual systems grows from
  generalizations of sensorimotor experience
• Infants have no knowledge base and thus must have
  a procedural means for image understanding and
  knowledge acquisition
• Artificial systems should be able to mimic these
  primitive abilities, but, so far, efforts have
  been largely unsuccessful

4
Background Objectivist Theory

• Categories in the world are defined by necessary
  and sufficient properties
• Humans can recognize these natural divisions
• Internal representations mirror the external world

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Adult Psychology Problem

• People dont demonstrate traditional categories
• Rather, experiments show prototype effects
• Analysis of problem solving reveals abstract,
  non-deductive processes such as analogy
• Evidence for use of imprecise reasoning

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Developmental Psych Problem

• Adults reason over accessible, propositional
  knowledge infants dont
• The transition from a procedural to a conceptual
  framework is not understood

7
Lakoffs Explanation

• Understanding is not purely logical and objective
• Rather, concepts are based on metaphors from
  embodied experience

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Support fromDevelopmental Psychology

• Classical theory
• Infants are purely sensorimotor organisms that
  follow preprogrammed stages
• Concepts arise from experience
• Current trend
• Humans are born with (primitive) accessible
  concepts which are then refined, not created

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Perceptual Analysis

• Local, spatio-temporal stimuli are analyzed
• Comparisons are encoded in image-schema
• Image-schema are used to understand new
  experiences

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Relationship to Computer Vision

• Machine Vision constrained environment
  characterized by Objectivist assumptions
• Move toward human perceptual abilities proved
  very challenging
• Possible explanation Bad background assumptions
  led to poor models

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Implications

• Fundamental Problem
• The Necessary and sufficient conditions
  definition of categories is easily represented in
  computer science terms
• Embodied cognition implies that an application
  Objectivist ideas will not be successful even in
  theory

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Possible Resolution

• Learn from our only example
• Mimic the process of moving from sensorimotor to
  conceptual reasoning
• Simulate the process of knowledge retrieval and
  application
• Problem
• These processes are exactly what is not
  understood in psychology or neuroscience

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Implications on Future Research

• Basis Automatic processes directed by innate
  principles jump start the human conceptual system
• Mandler posits that perceptual analysis is an
  innate ability
• Spelke suggests unlearned principles cohesion,
  boundedness, rigidity, no action at a distance
• Gelman introduces skeletal principles with
  similar intent

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Implications on Future Research

• Areas of Focus
• Motion Coherence Spatial separation
• Procedural encoding of base principles
• Transfer between (simple) experience and schema
  (i.e. abstraction reification)
• Of course, this is easy to say

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Current Efforts

• Current systems augment motion analysis with
  other techniques
• Static, intensity based segmentation - (Weiss 96)
  (Siskind 2000)
• Principle Component Analysis (Gibson, et al
  2000)
• This results in better performance relative to
  an adult human

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Improvements from aCognitive Perspective

• However, in a cognitive sense, these systems
  cheat
• The designer is imposing external constraints to
  achieve local performance
• A better method would be to allow the system to
  err but build processes that use later
  information to detect and correct the mistake

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Conclusion

• Current ideas in cogsci help explain the
  difficulties in human-level artificial perception
• Neuroscience and developmental psychology can
  help refocus efforts
• One plausible avenue for explanation is the
  artificial recreation of infant perception and
  development