Barrow researchers unravel illusion

Barrow Neurological Institute researchers Jorge Otero-Millan, Stephen Macknik, and Susana Martinez-Conde share the recent cover of the Journal of Neuroscience in a compelling study into why illusions trick our brains. Barrow is part of St. Joseph's Hospital and Medical Center in Phoenix.

The study, led by Martinez-Conde's laboratory, explores the neural bases of illusory in Akiyoshi Kitaoka's striking , known as the "Rotating Snakes." Kitaoka is a Japanese psychology professor who specializes in visual illusions of geometric shapes and motion illusions.

The study shows that tiny eye movements and blinking can make a geometric drawing of "snakes" appear to dance. The results help explain the mystery of how the Rotating Snakes illusion tricks the .

"Visual illusions demonstrate the ways in which the brain creates a mental representation that differs from the physical world," says Martinez-Conde. "By studying illusions, we can learn the mechanisms by which the brain constructs our conscious experience of the world."

Earlier studies of the "Rotating Snakes" indicated the perception of motion was triggered by the eyes moving slowly across the illusion. But by tracking eye movements in eight volunteers, the vision neuroscientists found a different explanation: fast called "saccades," some of which are microscopic and undetectable by the viewer, drive the illusory motion.

Participants lifted a button when the snakes seemed to swirl and pressed down the button when the snakes appeared still. Right before the snakes appeared to move, participants tended to produce blinks, saccades and/or microsaccades, and right before the snakes stopped, participants' eyes tended to remain stable, Otero-Millan, Macknik, and Martinez-Conde report in the April 25th cover story.

"Studying the mismatch between perception and reality may lead to a deeper understanding of the mind," says Martinez-Conde. "The findings from our recent study may help us to understand the neural bases of motion perception, both in the normal brain, and in patients with brain lesions that affect the perception of motion. This research could aid in the design of neural prosthetics for patients with brain damage."

Related Stories

Medical research and magic come together

Nov 11, 2010

The unorthodox research collaboration between two Barrow Neurological Institute scientists and some of the world's greatest magicians is detailed in a new book called Sleights of Mind.

Tiny eye motions help us find where Waldo is

Feb 20, 2009

(PhysOrg.com) -- To recognize faces in a crowd, the brain employs tiny eye movements called saccades and microsaccades to help us search for objects of interest. While researchers know that these movements ...

Recommended for you

Neurons in human skin perform advanced calculations

15 hours ago

Neurons in human skin perform advanced calculations, previously believed that only the brain could perform. This is according to a study from Umeå University in Sweden published in the journal Nature Ne ...

Memory in silent neurons

Aug 31, 2014

When we learn, we associate a sensory experience either with other stimuli or with a certain type of behavior. The neurons in the cerebral cortex that transmit the information modify the synaptic connections ...

Why your favourite song takes you down memory lane

Aug 28, 2014

Music triggers different functions of the brain, which helps explain why listening to a song you like might be enjoyable but a favourite song may plunge you into nostalgia, scientists said on Thursday.

User comments