Lavanya Sharan
March 28th, 2011

EtienneJules Marey (1884) developed ‘chronophotography’
Image sources: Wikimedia Commons, science-television.com
Slide content: Blake & Shiffrar (2007)

Markers attached to head and joints.
Videos of walking, running etc.
Can use animation and motion captures techniques for the same purpose.
Point light (PL) animations are now the mainstay of biological motion research.
Image source: Johansson (1973)
Slide content: Blake & Shiffrar (2007)

QuickTime™ and a
Sorenson Video decompress or are needed t o s ee this pic ture.
QuickTime™ and a
Sorenson Video decompress or are needed t o s ee this pic ture.
Phase-scrambled motion
Normal motion
Video source: Randolf Blake Lab
Slide content: Blake & Shiffrar (2007)

Hodgins et al. (1998) Knoblich & Flach (2001) McDonnell et al. (2009)
Very few studies that use ‘embodied’ forms.
Slide content: Blake & Shiffrar (2007)

Human motion perception is quite robust.
QuickTime™ and a
Sorenson Video decompressor are needed to s ee this pic ture.
Video source: Randolf Blake Lab
Slide content: Blake & Shiffrar (2007)

Human motion perception is quite robust.
Brief exposures (<100 ms)
Johannson 1973
Blurry dots, randomized contrast polarity over time
Mather et al., 1992, Ahlstrom et al. 1997
Stereoscopic depths are scrambled
Ahlstrom et al. 1997, Bulthoff et al. 1998, Lu et al. 2006
Dynamic noise dots
Bertenthal & Pinto 1994, Cutting et al. 1998, Ikeda et al. 2005
Markers not on joints
Bertenthal & Pinto 1994
Slide content: Blake & Shiffrar (2007)

How much can we tell about a figure?
Identity of figure
Cutting & Kozlowski 1977, Fani et al. 2005, Troje et al. 2005
Sex of figure
Kozlowski & Cutting 1977, 1978, Mather & Murdoch 1994,
Sumi 2000, Troje 2002, Pollick et al. 2005
Activities of two or more individuals
Mass et al. 1971
Emotional content
Clarke et al. 2005, Dittrich et al. 1996, Walk & Homan 1984
Facial expressions
Bassili 1978, Hill et al. 2003
Interactions with objects
Bingham 1993, Stoffregen & Flynn 1994
Slide content: Blake & Shiffrar (2007)

Inversion effects for body motions (Sumi
1984)
QuickTime™ and a
Sorenson Video decompressor are needed to s ee this pic ture.
Video source: Randolf Blake Lab
Slide content: Blake & Shiffrar (2007)

Sensitive to certain factors.
Number of markers and exposure duration
Neri et al. 1998, Poom & Olsson 2002, Thornton et al. 1998
Impaired recognition in periphery
Ikeda et al. 2005
Dim lighting
Grossman & Blake 1999
Phase scrambling
Grossman & Blake 1999, Hiris et al. 2005
Temporal duration
Beintema et al. 2003
Relative position of markers (form)
Beintema & Lappe 2002, Beintema et al. 2006, Hiris et al.
2005
Slide content: Blake & Shiffrar (2007)

Not limited to humans.
QuickTime™ and a
Sorenson Video decompressor are needed to see this picture.
Video source: Randolf Blake Lab
Slide content: Blake & Shiffrar (2007)

Biological recognition develops early.
4 and 8 month olds respond to human motion vs. scrambled dots.
Bertenthal 1993, Fox & McDaniel 1982, Hirai & Hiraki 2005,
Reid et al. 2006
Reach adult level performance by age 5
Pavlova et al. 2001
Older adults can perceive human motion inspite of age-related deficits in visual processing
Norman et al. 2004
Slide content: Blake & Shiffrar (2007)

Inversion effects
Good performance at temporal display rates higher than needed for lowlevel processing
Requires focused visual attention
Binocular rivalry
Perceived background flow
Image source: cs.bham.ac.uk
Slide content: Blake & Shiffrar (2007)
Low-level models of motion processing
Longer ISIs impair performance

Action recognition and action planning share representations
Prinz 1997, Hommel et al. 2001
Carrying out the same action as the PL figure improves performance
Reed & Farah 1995, Jacobs & Shiffrar 2005, Hamilton et al.
2004
Better at recognizing one’s own actions
Knoblich & Flach 2001, Loula et al. 2005, Jacobs et al. 2004
Individual with motor deficit perform differently on motion perception tasks
Bosbach et al. 2005, Funk et al. 2005, Shiffrar 2006, Pavlova et al. 2003
Chameleon effect
Chartrand & Bargh 1999
Slide content: Blake & Shiffrar (2007)

Can tell a lot about identity, sex, sexual orientation, dancing ability etc.
Loula et al. 2005, Barclay et al. 1978, Brownlow et al. 1997,
Montepare & Zebrowitz-McArthur 1988, Gunns et al. 2002,
Runeson & Frykholm 1983
Can identify emotion from PL figures
Atkinson et al. 2004, Pollick et al. 2001
Angry walker easier to detect than other emotions
Chouchourelou et al. 2006
Chameleon effect or social mimicry important for social interactions
Chartrand & Bargh 1999
Slide content: Blake & Shiffrar (2007)

Neurons in macaque STS
Perrett et al. 1982, 1985, Oram & Perrett 1996, Shiffrar
1994
Mirror neurons
Rizzolatti et al. 2001, Rizzolatti & Craighero 2004
Many case studies of individuals with deficits including autism
Schenk & Zihl 1997, Vaina et al. 1990, Cowey & Vaina
2000, Battelli et al. 2003, Jokisch et al. 2005, Blake et al. 2003, Kim et al. 2005, Virji-Babul et al. 2003,
Pavolova et al. 2006
TMS studies in STS
Grossman et al. 2005
Unlike MT, STSp selective for biological motion
Grossman et al. 2000, Grossman & Blake 2001,
Grossman et al. 2004
Image source & slide content: Blake & Shiffrar (2007)

More activation in right hemisphere
Beauchamp et al. 2003, Grossman et al. 2000, Peusken et al. 2005, Santi et al. 2003
Crude retinotopy
Grossman et al. 2000
Whole body motion, motion of body parts
Pelphrey et al. 2003, Calvert et al. 1997, Grezes et al.
1998, Puce et al. 1998
Statics figures do not produce activation
Pelphrey et al. 2003, Peuskens et al. 2005
Sounds of footsteps
Bidet-Caulet et al. 2005
Intentionality of actions and social judgments
Saxe et al. 2004, Frith & Frith 1999, Morris et al. 2005,
Winston et al. 2002, Allison et al. 2000, Iacoboni et al.
2004
Image source & slide content: Blake & Shiffrar (2007)

McDonnell et al. (2009)
Connection between faces & bodies?
Interactions with motor and social learning?
What about more real-world stimuli?
Slide content: Blake & Shiffrar (2007)