2017-04-13 16:36:31

Go with the flow: Babies, brains, behavior & open science

Rick O. Gilmore

Support: NSF BCS-1147440, NSF BCS-1238599, NICHD U01-HD-076595


  • A bit about me
  • A bit about my research
  • Sharing the goodness: Let's make science open

A bit about me


  • Associate Professor of Psychology
  • Founding Director of Human Imaging at Penn State's SLEIC
  • Co-founder and Co-Director of the Databrary.org digital library
  • A.B., Cognitive Science, Brown; M.S. & Ph.D., Psychology, Carnegie Mellon University
  • Folk music, theatre, poetry, cycling, hiking, paddling, hiking/backpacking, amateur radio (K3ROG)

A bit about my research


  • 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?


  • 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

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
  • Direction, speed of self-motion
    • Rotation, translation
    • Visual proprioception (eye vs. head vs. body)

Flow and self-motion

How Does Optic Flow Sensitivity Develop?

(R. Gilmore et al. 2007)

4-6 mo-old infants: Larger brain responses to linear patterns.

(Hou et al. 2009)

4-6 mo-old infants: Larger brain responses to faster speeds.

(Kiorpes and Movshon 2004)

Sensitivity to slow (linear) speeds develops slowly in monkeys.

Brain responses to flow


  • Time-varying optic flow patterns.
  • Steady-state visual evoked potentials (SSVEPs).
    • Event-related electro-encephalogram (EEG) technique.
    • Phase-locked responses at low-order harmonics.
  • n=29 4-8 year-olds.
  • (R. Gilmore, Thomas, and 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

1F1 Results Summary

  • Highly responsive channels over right lateral cortex
  • Radial & rotation >> translation
  • Amplitude and phase differences

3F1 Channel-Wise Results

3F1 Channels p < .0005

Complex Domain Plot of 3F1 Channels

3F1 Results Summary

  • Highly responsive channels over medial cortex
  • Speed, but not pattern tuned, 2 < 4 = 8 deg/s
  • Amplitude and phase differences

Results Summary

  • Anatomical separation of responses
    • speed (medial)
    • vs. pattern (lateral)
  • Radial & rotation != translation
  • Speed tuning

Children's 1F1

Adults' 1F1

Children's 3F1

Adults' 3F1

Behavioral responses to flow


  • 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)


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?

Measuring the statistics of visual experiences

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