2017-11-02 08:15:42

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Talk overview

  • Project status report
    • The development of optic flow processing
    • Play & Learning Across a Year (PLAY) project
    • The Proximal Emotional Environment Project (PEEP)
  • Toward an open, transparent, robust, and integrative developmental science

The development of optic flow processing

Questions about optic flow

  • What is optic flow?
  • Why is optic flow important?
  • How does optic flow sensitivity develop?
  • How do brain systems for processing optic flow develop?
  • What shapes these patterns of development?

Approach

  • EEG measures of brain responses to optic flow
  • Psychophysical (behavioral) measures of optic flow perception
  • Empirical measures of experienced optic flow across development from head-mounted video cameras and computer vision analyses

What is Optic Flow?

  • Structured pattern of visual motion generated by observer movement

Types of Optic Flow

Why is optic flow important?

  • Geometry of environment
    • Surface layout, orientation
    • Object motion
  • Visual proprioception
    • Rotation, translation

Flow types specify self-motion

How Does Optic Flow Sensitivity Develop?

How Does Optic Flow Sensitivity Develop?

How Does Optic Flow Sensitivity Develop?

What about older children?

  • Present: Time-varying optic flow patterns
  • Measure: Steady-state visual evoked potentials (SSVEPs)
    • Event-related electro-encephalograms (EEGs)
    • Phase-locked responses at low-order harmonics
  • \(n=29\) 4-8 year-olds
  • (R. Gilmore, Thomas, & Fesi, 2016)

2 deg/s translation

4 deg/s rotation

8 deg/s radial

1F1 Channel-Wise Results

1F1 Channels p < .0005

Complex Domain Plot of 1F1 Channels

3F1 Channel-Wise Results

3F1 Channels p < .0005

Complex Domain Plot of 3F1 Channels

Results Summary

  • Anatomical & frequency separation of responses
    • vs. pattern (lateral, 1F1)
    • speed (medial, 3F1)
  • Radial & rotation \(\neq\) translation
  • Speed tuning (slow < med & fast)
  • Similar to, but different from adults

Children's 1F1

Adults' 1F1

Children's 3F1

Adults' 3F1

What about behavior?

  • Time-varying optic flow
    • Radial, linear
    • {2 deg/s, 8 deg/s}
    • {5, 10, 15, 20%} coherence (adults)
    • {15, 30, 45, 60%} and {20, 40, 60, 80%} (children)

Methods

Children's responses p(correct)

Adults' responses p(correct)

Speed effects in children

Speed effects in adults

Pattern effects in children

Pattern effects in adults

Behavioral Summary

  • Children's behavior: more accurate to detect fast speeds, radial patterns
  • Adults more accurate to detect slow speeds, radial patterns
  • Response speeds in children and adults (not shown) show similar patterns
  • But, why?

Potential factors shaping development of flow sensitivity

  • External
    • Environment
  • Internal
    • Posture
    • Locomotion, head, eye movements

Head mounted eye tracker data from "coupled" infant/mom dyads

Adolph, K. (2015). Active vision in passive locomotion: real-world free viewing in infants and adults. Databrary. Retrieved February 18, 2017 from http://doi.org/10.17910/B7.123

Synchronized infant and mother cams

Findings