How the Brain Sees the World in 3-D


We live in a three-dimensional world, but everything we see is first recorded on our retinas in only two dimensions. So how does the brain represent 3-D information? In a new study, researchers for the first time have shown how different parts of the brain represent an object’s location in depth compared to its 2-D location.

Researchers at The Ohio State University had volunteers view simple images with 3-D glasses while they were in a functional magnetic resonance imaging (fMRI) scanner. The fMRI showed what was happening in the participants’ brains while they looked at the three-dimensional images.

The results showed that as an image first enters our visual cortex, the brain mostly codes the two dimensional location. But as the processing continues, the emphasis shifts to decoding the depth information as well.

“As we move to later and later visual areas, the representations care more and more about depth in addition to 2-D location. It’s as if the representations are being gradually inflated from flat to 3-D,” said Julie Golomb, senior author of the study and assistant professor of psychology at Ohio State.

“The results are surprising because a lot of people assumed we might find depth information in early visual areas. What we found is that even though there might be individual neurons that have some depth information, they don’t seem to be organised into any map or pattern for 3-D space perception.”

Golomb said many scientists have investigated where and how the brain decodes two-dimensional information. Others had looked at how the brain perceives depth. Researchers have found that depth information must be inferred in our brain by comparing the slightly different views from the two eyes (what is called binocular disparity) or from other visual cues.

But this is the first study to directly compare both 2-D and depth information at one time to see how 3-D representations (2-D plus depth) emerge and interact in the brain, she said.

The study was led by Nonie Finlayson, a former postdoctoral researcher at Ohio State, who is now at University College London. Golomb and Xiaoli Zhang, a graduate student at Ohio State, are the other co-authors. The study was published recently in the journal NeuroImage.

Participants in the study viewed a screen in the fMRI while wearing 3-D glasses. They were told to focus on a dot in the middle of the screen. While they were watching the dot, objects would appear in different peripheral locations: to the left, right, top, or bottom of the dot (horizontal and vertical dimensions). Each object would also appear to be at a different depth relative to the dot: behind or in front (visible to participants wearing the 3-D glasses).

The fMRI data allowed the researchers to see what was happening in the brains of the participants when the various objects appeared on the screen. In this way, the scientists could compare how activity patterns in the visual cortex differed when participants saw objects in different locations.

“The pattern of activity we saw in the early visual cortex allowed us to tell if someone was seeing an object that was to the left, right, above or below the fixation dot,” Golomb said. “But we couldn’t tell from the early visual cortex if they were seeing something in front of or behind the dot.

“In the later areas of visual cortex, there was a bit less information about the objects’ two dimensional locations. But the tradeoff was that we could also decode what position they were perceiving in depth.”

Golomb said future studies will look to more closely quantify and model the nature of three-dimensional visual representations in the brain.

“This is an important step in understanding how we perceive our rich three-dimensional environment,” she said.



Edublox Reading, Maths and Learning Clinic keeps you abreast of research on reading, learning, brain development and neuroplasticity.

Edublox is a system of cognitive exercises, aimed at developing and automatising the foundational skills of reading, spelling, writing, mathematics and the skills required in the learning of subjects such as History. Our programmes are adaptable for the gifted and less gifted, and applicable for all age groups. They can develop the learning skills of the high school learner to a very high degree, while they can also be used to prepare the Grade R child for reading and learning. Edublox is effective for a variety of learning difficulties: reading difficulties, maths difficulties, dyslexia and ADD/ADHD.

In this video four children, Kelsey, Tshepo, Liam and Joshua share how struggling to read affected them, as well as how it feels now that they can read. Contact Edublox for help if your child finds themselves in these children’s shoes.

Does your child hate school? Edublox can help:
.

“Sabrina started attending Edublox in the middle of 2015. At the time she was experiencing difficulty at school, as she simply could not read. Edublox examined her and gave us the news that she in fact had severe dyslexia and was three years behind in comprehension and reading.

“The challenge was to correct the dyslexia and to bring her up to grade level; I can validate that to catch up three years is no easy feat. Edublox and Sabrina worked very hard to improve her difficulties.

“The process began with Sabrina hating school and failing term 1/term 2 and hopelessly scraping through term 3. I had to make a conscious decision to keep her back in Grade 2 at the end of last year as I felt she has very difficult year, even though she was begging to cope I was worried that Grade 3 would be too much pressure and that she would be stuck in the same situation.

“When school year started 2016 Sabrina went back to Grade 2 and at first I was not sure I had made the right decision, however three days later I saw my daughter gleaming with joy — she was so happy because she was now the smarty pants in class. Edublox has helped Sabrina from failing hopelessly and hating school, to being one of the top students in her class and absolutely loving school and looking forward to every next day.

“In conclusion Edublox has helped my child immensely in every aspect of reading and comprehension. I am happy that I found Edublox and go as far as recommending them to anyone I know.

“This program is a process which helps with progress and is not an overnight miracle pill, but hard work between child and the educators and in a few short months you will be surprised with your child progress.”

Mrs. Peleias
November 2016

Click here for 590+ success stories




More information:

Edublox clinics specialise in cognitive training that makes learners smarter, and helps them learn and read faster, easier, and better. The classes address:

* Concentration: Focused and sustained attention.

* Perceptual skills: Visual and auditory foreground-background differentiation; visual and auditory discrimination, synthesis and analysis; form discrimination; spatial relations.

* Memory: Visual, auditory, sequential, iconic, short-term, long-term and working memory.

* Logical thinking: Deductive and inductive reasoning.

* Reading, spelling, vocabulary and comprehension.

Classes are offered in English and Afrikaans. Contact us

Share Button
March 25, 2017

Leave a Reply

avatar
  Subscribe  
Notify of
Skip to toolbar