New vision of how we explore our world

April 5, 2013, St. Joseph's Hospital and Medical Center

Brain researchers at Barrow Neurological Institute have discovered that we explore the world with our eyes in a different way than previously thought. Their results advance our understanding of how healthy observers and neurological patients interact and glean critical information from the world around them.

The research team was led by Dr. Susana Martinez-Conde, Director of the Laboratory of Visual Neuroscience at Barrow, in collaboration with fellow Barrow Neurological Institute researchers Jorge Otero-Millan, Rachel Langston, and Dr. Stephen Macknik, Director of the Laboratory of Behavioral . The study, titled "An oculomotor continuum from exploration to fixation", was published in the Proceedings of the National Academy of Sciences.

Previously, scientists thought that we sample from the world in two main different modes: exploration and fixation. "We used to think that we make large to search for objects of interest, and then fix our gaze to see them with high detail," says Martinez-Conde. "But now we know that's not quite right."

The discovery shows that even during visual fixation, we are actually scanning visual details with small eye movements—just like we explore visual scenes with big eye movements, but on a smaller scale. This means that exploration and fixation are two ends of the same continuum of oculomotor scanning.

Subjects viewed natural images while the team measured their eye movements with high-speed eye tracking. The images could range in size from the massive, presented on a room-sized video monitor in the Barrow Neurological Institute's Eller Telepresence Room, normally used for Barrow's surgeons to collaborate in brain surgeries with colleagues around the world, to images that are just half the width of your thumb nail.

In all cases, the researchers found that subjects' eyes scanned the scenes with the same general strategy, along a smooth continuum of dynamical changes. "There was no in the characteristics of the eye movements, whether the visual scenes were huge or tiny, or even when the subjects were fixing their gaze. That means that the brain controls eye movements in the same way when we explore and when we fixate," said Dr. Martinez-Conde.

Scientists have studied how the brain controls eye movements for over 100 years, and the idea —challenged here—that fixation and exploration are fundamentally different behaviors has been central to the field. This new perspective will affect future research and bring focus to the study of neurological diseases that impact oculomotor behavior.

Explore further: Barrow researchers unravel illusion

Related Stories

Barrow researchers unravel illusion

May 1, 2012
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 ...

Barrow researchers use magic for discoveries

May 22, 2012
Researchers at Barrow Neurological Institute at St. Joseph's Hospital and Medical Center have unveiled how and why the public perceives some magic tricks in recent studies that could have real-world implications in military ...

Abnormal involuntary eye movements in amblyopia linked to changes in subcortical regions of brain

October 16, 2012
Little is known about oculomotor function in amblyopia, or "lazy eye," despite the special role of eye movements in vision. A group of scientists has discovered that abnormal visual processing and circuitry in the brain have ...

Recommended for you

Study suggests brainwave link between disparate disorders

May 24, 2018
A brainwave abnormality could be a common link between Parkinson's disease, neuropathic pain, tinnitus and depression—a link that authors of a new study suggest could lead to treatment for all four conditions.

In a break with dogma, myelin boosts neuron growth in spinal cord injuries

May 23, 2018
Recovery after severe spinal cord injury is notoriously fraught, with permanent paralysis often the result. In recent years, researchers have increasingly turned to stem cell-based therapies as a potential method for repairing ...

Memory molecule limits plasticity by calibrating calcium

May 23, 2018
The brain has an incredible capacity to support a lifetime of learning and memory. Each new experience fundamentally alters the connections between cells in the brain called synapses. To accommodate synaptic alterations, ...

New type of vertigo identified

May 23, 2018
Neurologists have identified a new type of vertigo with no known cause, according to a study published in the May 23, 2018, online issue of Neurology, the medical journal of the American Academy of Neurology.

Study confirms that men and women tend to adopt different navigation strategies

May 23, 2018
When navigating in a known environment, men prefer to take shortcuts to reach their destination more quickly, while women tend to use routes they know. This is according to Alexander Boone of UC Santa Barbara in the US who ...

Changes to specific MicroRNA involved in development of Lou Gehrig's disease

May 23, 2018
A new Tel Aviv University study identifies a previously unknown mechanism involved in the development of Lou Gehrig's disease, or amyotrophic lateral sclerosis (ALS). The research focuses on a specific microRNA whose levels ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.