Blog Archives
Simple ‘eye’ grown from stem cells
A Japanese team of researchers have turned embryonic mouse stem cells into a very basic eye, or ‘optic cup’. This video shows a time-lapse of the cells self-organising into the structure:
As you watch the video and read the article, think about the following curriculum links:
- How do cells ‘organise’ and how do stem cells become differentiated?
- What might be the therapeutic uses of this in the future?
- What functionality does this ‘eye’ have compared to ours?
“Remarkably, the rudimentary eye and the different types of cells it contained took shape spontaneously from a floating cluster of embryonic stem cells the scientists had cultured.”
The Guardian has a good article on the story. The original paper was published in Nature (paywall), but their Scitable area has a very good focus on stem cells.
Perception of Stimuli
Close your left eye and stare at the +. Move your head closer to the screen and keep staring at the +, but pay attention to the dot. What happens? Explain why.
- Explain it yourself first, then check at Serendip’s great website.
You need to know the structure of the eye to succeed! This eye structure tutorial from Sumanas might help.
The solution and loads more perception demonstrations can be found at Serendip’s playground.
Your biggest challenge is this one: “Explain the processing on visual stimuli, including edge enhancement and contra-lateral processing“.
So here are our class notes:
There are many more resources on the main page for this topic:
E2 Perception of Stimuli (including some cool links to illusions)
Here is Pawan Sinha talking about how the brain learns to see, and how we can help the children who are born blind in India. Find out more about Sinha’s work and Project Prakash at his university website (MIT).
Pawan Sinha: How the Brain Learns to See (TED 2010)
Perfect timing for our Neurobiology unit, and a real showcase for the interdisciplinary nature of science and humanitarian work – here is Pawan Sinha talking about how the brain learns to see, and how we can help the children who are born blind in India. Find out more about Sinha’s work and Project Prakash at his university website (MIT).
E2 Perception of Stimuli
Class presentation:
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Essential Biology: E2 Perception of Stimuli
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- Hermann Grid Illusion
Sight:
Collection of animations from North Harris College
Eye structure tutorial from Sumanas
Simple how-the-eye-works from BiologyMad
The Sense of Sight from Wisconsin Online
How many megapixels is the human eye? from Brainiac.
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Hearing:
How the Ear Works, from NobelPrize.org
The Sense of Hearing from Wisconsin Online
Neat Ear Tutorial from University of Alaska Fairbanks
McGraw Hill Effect of Sound Waves on Cochlear Structures
Test your hearing range (carefully) from the University of New South Wales
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- Mantis Shrimp: Awesome Vision
Interesting reading:
The peer-iodic table of illusions, from NewScientist.com
The Mantis Shrimp’s amazing visual capabilities, from NotExactlyRocketScience
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The eye is not irreducably complex – it is the product of natural selection
Evolution of vertebrate eyes from Pharyngula
Owl monkey example of eye evolution, from NotExactlyRocketScience
Video, The Evolution of the Eye, from PBS:
i-Biology 