Showing posts with label perception. Show all posts

2010-06-14

Computational Model Reveals How The Brain Recognizes Objects

How the brain recognizes objects

A new computational model sheds light on the workings of the human visual system and could help advance artificial-intelligence research, too.

Researchers at MIT’s McGovern Institute for Brain Research have developed a new mathematical model to describe how the human brain visually identifies objects. The model accurately predicts human performance on certain visual-perception tasks, which suggests that it’s a good indication of what actually happens in the brain, and it could also help improve computer object-recognition systems.

The model was designed to reflect neurological evidence that in the primate brain, object identification — deciding what an object is — and object location — deciding where it is — are handled separately. “Although what and where are processed in two separate parts of the brain, they are integrated during perception to analyze the image,” says Sharat Chikkerur, lead author on a paper appearing this week in the journal Vision Research, which describes the work. “The model that we have tries to explain how this information is integrated.”

Collected from: How the brain recognizes objects

The software's analysis of an image begins with the identification of interesting features -- rudimentary shapes common to a wide variety of images. It then creates a map that depicts which features are found in which parts of the image. But thereafter, shape information and location information are processed separately, as they are in the brain.

The software creates a list of all the interesting features in the feature map, and from that, it creates another list, of all the objects that contain those features. But it doesn't record any information about where or how frequently the features occur.

At the same time, it creates a spatial map of the image that indicates where interesting features are to be found, but not what sorts of features they are.

Collected from: Computational model sheds light on how the brain recognizes objects

What and where: A Bayesian inference theory of visual attention

In the theoretical framework described in this thesis, attention is part of the inference process that solves the visual recognition problem of what is where. The theory proposes a computational role for attention and leads to a model that predicts some of its main properties at the level of psychophysics and physiology. [...]

Attention and Object recognition in Videos

Collected from: Home (sharatsc)

A neuromoprhic approach to computer vision

View more presentations from tserre.

Collected from: A neuromoprhic approach to computer vision

Sources

How the brain recognizes objects
http://web.mit.edu/newsoffice/2010/people-images-0607.html
Computational model sheds light on how the brain recognizes objects
http://www.sciencedaily.com/releases/2010/06/100608101029.htm
Home (sharatsc)
http://www.sharat.org/
YouTube - Recognizing objects in video
http://www.youtube.com/watch?v=wXqwFDJJwII&feature=player_embedded#!
A neuromoprhic approach to computer vision
http://www.slideshare.net/tserre/a-neuromoprhic-approach-to-computer-vision

Related

New model reveals how the brain identifies objects
http://mcgovern.mit.edu/newsroom/press-release-archive/319-new-model-reveals-how-brain-identifies-objects
How the brain recognizes objects
http://www.physorg.com/news195112777.html
ScienceDirect - Vision Research : What and where: A Bayesian inference theory of attention
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T0W-5046M49-2&_user=10&_coverDate=05%2F20%2F2010&_alid=1366928793&_rdoc=1&_fmt=high&_orig=search&_cdi=4873&_sort=r&_docanchor=&view=c&_ct=1&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=68ec5e0a5f4bce2750ae0f70acb69884
Microsoft PowerPoint - Walther_NIPS07.ppt - Powered by Google Docs
http://docs.google.com/viewer?url=https%3A%2F%2Fnetfiles.uiuc.edu%2Fwalther%2Fwww%2FAttentionWorkshopNIPS07%2FWalther_NIPS2007.pdf&pli=1
Tomaso Poggio
http://mcgovern.mit.edu/principal-investigators/tomaso-poggio
Thomas Serre: Research
http://web.mit.edu/serre/www/Research.htm
Thesis Defense: Sharat Chikkerur
http://mcgovern.mit.edu/events/upcoming-events/321-thesis-defense-sharat-chikkerur

2009-04-10

How Touch Affects Vision

Clipped from: How You Feel The World Impacts How You See It

How You Feel The World Impacts How You See It

ScienceDaily (Apr. 10, 2009) — In the classic waterfall illusion, if you stare at the downward motion of a waterfall for some period of time, stationary objects — such as rocks — appear to drift upward. MIT neuroscientists have found that this phenomenon, called motion aftereffect, occurs not only in our visual perception but also in our tactile perception, and that these senses actually influence one another. Put another way, how you feel the world can actually change how you see it — and vice versa.

This stimulator was used in a study to show that how humans feel the world can actually change how they see it -- and vice versa.

Clipped from: MIT-led team creates touch-based illusion - MIT News Office

MIT news

MIT-led team creates touch-based illusion

Mind trick yields new insights on perception

In the visual illusion known as the apparent motion quartet, two dots are presented at diagonally opposite corners of an imaginary square. When the pattern alternates between the two diagonals--top left/bottom right followed by top right/bottom left--people perceive the dots as moving back and forth either horizontally or vertically. After a period of time, typically a minute or two, most observers report that the axis of motion appears to flip from vertical to horizontal or vice versa.
An example of the illusion can be seen at web.mit.edu/~tkonkle/www/AmbiguousQuartet.html.
To create a tactile version of this illusion, Olivia Carter, a postdoctoral researcher at Harvard University, and Talia Konkle, a graduate student in Moore's MIT lab, used a new piezoelectric stimulator device developed by Qi Wang and Vincent Hayward at McGill University. This device, originally designed as a computer Braille display, uses a centimeter-square array composed of 60 "tactors" to deliver precisely controlled touch stimuli to the finger tips of volunteer subjects.
When volunteer subjects were given the diagonally alternating stimuli, they perceived them as moving smoothly back and forth--and just as with the visual illusion, the direction of apparent motion flipped back and forth from vertical to horizontal, on average about twice per minute, even though there was no change in the stimulus itself.

Clipped from: Laterotactile.com - Projects - Tactile Graphics

Haptic Memory Game

The video below describes the memory game and provides a good introduction to laterotactile skin stimulation.

Sources:
How You Feel The World Impacts How You See It
MIT-led team creates touch-based illusion - MIT News Office
Laterotactile.com - Projects - Tactile Graphics
A Haptic Memory Game using the STReSS2 Tactile Display on Vimeo

Related:
What You See Is What You Feel -- Telis 2009 (409): 1 -- ScienceNOW
In a Sensory Hack, What You Touch Affects What You See | 80beats | Discover Magazine
Scientists create touch-based illusion
Laterotactile.com - Devices - STReSS
MIT : Brain and Cognitive Sciences : People : Faculty : Christopher Moore
T.Konkle.Demos
The Moore Lab
Current Biology - Motion Aftereffects Transfer between Touch and Vision

2008-09-01

Sensory Substitution with the Eye Candy

The EYE CANDY

Clipped from: Faux-Drugs: Hallucinogenic Eye Candy USB Lollies Take Your Brain to That Special Place, For Real

Hallucinogenic Eye Candy USB Lollies Take Your Brain to That Special Place, For Real

Clipped from: EYE CANDY

The candy that provides you with a sensational new way to see.

This delicious new confectionary uses cutting edge Sensory Substitution Technology to transmit vivid emotive images into your mind's eye.

Available in six unique flavours, each helping you achieve the right state of mind by projecting specially created evocative imagary into your field of vision.

Eye Candy is the natural way to become the person you want to be.

How it works

Clipped from: EYE CANDY

Each of your senses (touch, smell, sight, taste, hearing) sends information to the brain at a different frequency. The brain determines where the sensorial information it receives comes from by the frequency at which it resonates, it can then process it in the appropriate way (e.g. turn sight information from the eyes into pictures in the mind). An array of resonators positioned on the surface of an Eye Candy transmit information from the tongue to the brain at the frequency that the eyes usually send visual information to the brain. A pleasant sensation of soda bubbles can be felt on the tongue as the mind decodes this sensorial information as vivid pictures.

This process is called sensory substitution and can be used to supplement peoples senses, enabling them to see the evocative images contained within Eye Candy.

Sensory Substitution

Clipped from: Sensory substitution - Wikipedia, the free encyclopedia

Sensory substitution means to transform the characteristics of one sensory modality into stimuli of another sensory modality. It is hoped that sensory substitution systems can help handicapped people by restoring their ability to perceive a certain defective sensory modality by using sensory information from a functioning sensory modality. A sensory substitution system consists of three parts: a sensor, a coupling system, and a stimulator. The sensor records stimuli and gives them to a coupling system which interprets these signals and transmits them to a stimulator. Sensory substitution concerns human perception and the plasticity of the human brain; and therefore, allows us to study these aspects of neuroscience more through neuroimaging.

Clipped from: Wired Science . Mixed Feelings | PBS
Mixed Feelings
Scientists Rewire the Brain through the Tongue

Clipped from: Vision Device
Vision Device

The BrainPort vision device is a non-surgical assistive visual prosthetic device that translates information from a digital video camera to your tongue, through gentle electrical stimulation.

[...]
The current prototype works best for individuals who are blind and have no better than light perception.

Clipped from: HowStuffWorks "How BrainPort Works"

The BrainPort technology maniuplates the brain's sensory input and can allow the blind to see. See more BrainPort images.

Clipped from: TCNL
Tactile Communication & Neurorehabilitation Laboratory
at UW-Madison (TCNL)

Welcome to TCNL, founded January, 2008. Our mission is
to develop solutions for sensory and neurological disorders by applying
principles of neuroplasticity, enabling the brain to process information
in new ways.

2008-07-14

Optical Illusion Videos

A collection of videos about optical illusions with in addition to many examples of static and dynamic illusions also the use in advertising, a lecture about scientific aspects, the use in combination with music and an animated journey in a world of paradox and illusion.

clipped from en.wikipedia.org

Optical illusion

From Wikipedia, the free encyclopedia

An optical illusion (also called a visual illusion) is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed by the brain to give a percept that does not tally with a physical measurement of the stimulus source. There are three main types of illusion - literal optical illusions that create images that are different from the objects that make them, physiological illusions that are the effects on the eyes and brain of excessive stimulation of a specific type - brightness, tilt, color, movement, and cognitive illusions where the eye and brain make unconscious inferences.