Free Mind Hacks™: Tips & Tools for Using Your Brain by Tom Stafford, Matt Webb Page B

becomes
     important when you consider that the evidence for each quality — in other words, the rate at
     which the neurons in that part of the map are firing — is noisy, and it isn’t the absolute
     value of neural firing that is used to calculate which is the correct value but the
     relative value. (See See Movement When All Is Still on the motion
     aftereffect for an example of this in action.)
    The more cells the brain dedicates to building the map representing a sense or motor
     skill, the more sensitive we are in discriminating differences in that type of input or in
     controlling output. With practice, changes in our representational maps can become
     permanent.
    Brain scanning of musicians has shown that they have larger cortical representations
     of the body parts they use to play their instruments in their sensory areas — more neurons
     devoted to finger movements among guitarists, more neurons devoted to lips among
     trombonists. Musicians’ auditory maps of “tone-space” are larger, with neurons more finely
     tuned to detecting differences in sounds, 1 and orchestra conductors are better at detecting where a sound among a
     stream of other sounds is coming from.
    It’s not surprising that musicians are good at these things, but the neuroimaging
     evidence shows that practice alters the very maps our brains use to understand the world.
     This explains why small differences are invisible to beginners, but stark to experts. It
     also offers a hopeful message to the rest of us: all abilities are skills, if you practice
     them, your brain will get the message and devote more resources to them.
    End Note
    Münte, T. F., Altenmüller, E., & Jäncke, L. (2002). The
     musician’s brain as a model for neuroplasticity. Nature Neuroscience
     Reviews, 3 , 473–478. (This is a review paper rather than an original
     research report.)
    See Also
    Pantev, C., Oostenveld, R., Engelien, A., Ross, B., Roberts, L. E., &
     Hoke, M. (1998). Increased auditory cortical representation in musicians. Nature, 392 , 811–814.
Pleger B., Dinse, H. R., Ragert, P., Schwenkreis, P., Malin, J. P., &
     Tegenthoff, M. (2001). Shifts in cortical representations predict human discrimination
     improvement. Proceedings of the National Academy of Sciences of the USA,
     98 , 12255–12260.

Chapter 2. Seeing: Hacks 13–33
    The puzzle that is vision lies in the chasm between the raw sensation gathered by
     the eye — light landing on our retinas — and our rich perception of color, objects, motion, shape,
     entire 3D scenes. In this chapter, we’ll fiddle about with some of the ways the brain makes
     this possible.
    We’ll start with an overview of the visual system [ Understand Visual Processing ] , the limits of your vision [ See the Limits of Your Vision ] , and the active
     nature of visual perception [ To See, Act ] .
    There are constraints in vision we usually don’t notice, like the blind spot [ Map Your Blind Spot ] and the 90 minutes of
     blindness we experience every day as vision deactivates while our pupils jump around [ Glimpse the Gaps in Your Vision ] . We’ll have a
     look at both these and also at some of the shortcuts and tricks visual processing uses to make
     our lives easier: assuming the sun is overhead [ Fool Yourself into Seeing 3D and Objects Move, Lighting Shouldn’t ] , jumping out of the way
     of rapidly expanding dark shapes [ Explore Your Defense Hardware ] (a handy shortcut for faster
     processing if you need to dodge quickly), and tricks like the use of noisy neurons [ Neural Noise Isn’t a Bug; It’s a Feature ] to
     extract signal out of visual noise.
    Along the way, we’ll take in how we perceive depth [ Depth Matters and Create Illusionary Depth with Sunglasses ] , and motion [ See Movement When All Is Still and Turn Gliding Blocks into Stepping Feet ] . (That’s both the correct
     and false perception of motion, by the way.) We’ll finish off with a little optical illusion
     called the