An innovative model for the study of vision

April 11, 2017, International School of Advanced Studies (SISSA)

A new study shows for the first time that the progressive processing of the visual signal underlying human object recognition is similarly implemented in the rat brain, thus extending the range of experimental techniques, from genetics to molecular biology and electrophysiology, that can be applied to the study of vision.

"Humans can recognise a face or an in a few tens of milliseconds, despite the fact that they may appear on our retina in an infinite number of ways, due to variations in brightness, size, orientation and position within the visual field. This capacity, known as invariant visual object recognition, is one of the fundamental properties of high-level vision and is due to the progressive processing of the through a specific sequence of cortical visual areas," says Davide Zoccolan, director of the SISSA visual neuroscience laboratory and head of the research project. "In our study, we have demonstrated the existence of a similar processing mechanism in rodents that opens up the possibility of studying the underlying neural circuits using a wide range of experimental techniques—molecular, genetic, electrophysiological, and so on, already applied in animal experiments."

Zoccolan's laboratory had already shown in a series of behavioural studies that rodents are able to carry out high-level visual object recognition tasks. "In this new study, we recorded the activity of hundreds of neurons belonging to four different visual cortical areas, from the primary visual cortex to the deepest visual area in temporal cortex, during a precise sequence of visual stimuli," he says. "These stimuli consisted of a sequence of 380 images obtained by presenting 10 different objects in 38 different ways, with variations in brightness, orientation or size. The objects were chosen in order to span a broad spectrum of visual properties. Some of them were digital reproductions of real objects, such as a face or a telephone, while others were abstract objects used in previous behavioural studies. Each image was presented for 250 milliseconds, more than enough for visual object recognition."

The recorded signals are complex and difficult to analyse, which is why it was essential the collaboration with Stefano Panzeri, director of the ITT neural computation laboratory in Rovereto and one of the leading experts in the development of algorithms for understanding the neural code using information theory and machine learning.

"We have observed that as we move from the to the deepest area in , information regarding light and contrast is lost, while the signal becomes increasingly invariant for transformations of single objects and increasingly discriminant of the identity of the objects, in the same way as occurs in primates," Zoccolan says. "It is a significant finding that opens up new pathways for the study of high-level vision and its development, as it does for the evolution of artificial vision systems."

Explore further: Why is an object's size perceived the same regardless of changes in distance?

Related Stories

Why is an object's size perceived the same regardless of changes in distance?

September 28, 2015
A group of researchers at Osaka University found that neurons in the monkey visual cortical area V4, one of the areas in the visual cortex, calculate the size of an object based on information on its retinal image size and ...

How rats see things

April 4, 2013
The image of an object, when projected into the eyes, may take on the most diverse shapes depending on the chosen point of view, as this can change its distance, perspective and so on, yet generally we have no difficulty ...

Deviations from expectations: detecting moving objects

November 11, 2016
Pawel Zmarz and Georg Keller at the FMI have identified neurons in the visual cortex that enable the detection of moving objects as we move along. These neurons integrate visual and motor-related input and signal a mismatch ...

Shape and meaning: A study explores how the brain encodes visual objects

August 9, 2013
Opening our eyes and seeing the world before us, full of objects, is a simple action we may take for granted. Yet our brain is constantly carrying out a huge analysis only to let us see a flower, a pen, the face of our children. ...

Study validates monkey model of visual perception

August 25, 2015
A new study from The Journal of Neuroscience shows that humans and rhesus monkeys have very similar abilities in recognizing objects "at a glance," validating the use of this animal model in the study of human visual perception. ...

Neuroscientists find evidence that the brain's inferotemporal cortex can identify objects

October 5, 2015
When the eyes are open, visual information flows from the retina through the optic nerve and into the brain, which assembles this raw information into objects and scenes.

Recommended for you

New neurons in the adult brain are involved in sensory learning

February 23, 2018
Although we have known for several years that the adult brain can produce new neurons, many questions about the properties conferred by these adult-born neurons were left unanswered. What advantages could they offer that ...

Study in mice suggests personalized stem cell treatment may offer relief for multiple sclerosis

February 22, 2018
Scientists have shown in mice that skin cells re-programmed into brain stem cells, transplanted into the central nervous system, help reduce inflammation and may be able to help repair damage caused by multiple sclerosis ...

Nolan film 'Memento' reveals how the brain remembers and interprets events from clues

February 22, 2018
Key repeating moments in the film give viewers the information they need to understand the storyline. The scenes cause identical reactions in the viewer's brain. The results deepen our understanding of how the brain functions, ...

Biomarker, clues to possible therapy found in novel childhood neurogenetic disease

February 22, 2018
Researchers studying a rare genetic disorder that causes severe, progressive neurological problems in childhood have discovered insights into biological mechanisms that drive the disease, along with early clues that an amino ...

A look at the space between mouse brain cells

February 22, 2018
Between the brain's neurons and glial cells is a critical but understudied structure that's been called neuroscience's final frontier: the extracellular space. With a new imaging paradigm, scientists can now see into and ...

Schizophrenia a side effect of human development

February 21, 2018
Schizophrenia may have evolved as an "unwanted side effect" of the development of the complex human brain, a new study has found.

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.