Monday, May 9, 2011

Sensory Illusions

Our brain tries to fill in the gaps in what we perceive and sometimes errors occur. Optical illusions, auditory illusions, and magic tricks take advantage of this.

Test your own senses and take the BBC's sense challenge:

Some sites that have specific illusions:
            Spanish Castle Illusion:
            Watercolour Illusion:
            Above is the Hermann Grid Illusion

The following are links that contain various optical illusions:

 This is the Rene Magritte Museum in Brussels, Belgium. He was a surrealist artist in the early 1900s and famously exploited human perceptual errors to make interesting, thought-provoking paintings. You can see more of his work here:

Many artists use a knowledge of perception to create art, but another famous and very clear example of this is M.C. Escher.

Thursday, May 5, 2011

Biology 30: Exploring Virtual Neurons

Use these online animations to help you study and understand how a nerve impulse travels down the axon, how resting membrane potential is maintained, and the mechanism of neurotransmitter release in the synapse.

Click on image above to read all labels.

Explore this website to see animations for all of these processes and mechanisms in the neuron:

A virtual neuron - see how it behaves here: l

See how resting membrane potential is maintained here:

An animation of an action potential here: 

Another animation for nerve impulse/action potential here:

This one shows the changes in the ion channels during an action potential. Make sure you know where sodium and potassium move during depolarization and repolarization. You can check it out here:

More animations from the same organization that did the last animation. Check out "Propagation of an action potential" and "Synaptic vesicle fusion and neurotransmitter release" here: