Varieties of Sensory Processing
June 5, 2007 by Kristina Chew, PhD
Filed under Health
As a sort of postscript to the earlier post on sensory processing, some references to the varieties of sensory processing:
One of the reasons that learning to read has been a challenge for Charlie is that he seems to have difficulties taking in all the letters on a page of a book, or even to know that all the letters in a word go together. Simultagnosia is when a person can only perceive one object at a time, as noted on Mind Hacks; it is one type of Visual Agnosia, which discusses “disorders of visual recognition” (here is a website for a book on visual agnosia). There are two types of simultagnosia, depending on how the brain has been affected:
Damage to the dorsal stream can cause dorsal simultanagnosia, where the patient cannot see two or more objects at the same time.
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Damage to the ventral stream can cause ventral simultanagnosia, where the patient can see multiple objects, but can only identify one at a time.
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I have noted that Charlie is very sensitive to high-pitched sounds. Today’s Science Daily describes a study on What did dinosaurs hear. Prof. Robert Dooling of the University of Maryland suggests that, while dinosaurs could probably not hear the high-pitched sounds of birds, they could probably hear “the very low frequency infrasound generated by the footsteps” of large animals, such as elephants today (and dinosaurs themselves). Go here for the full text of Prof Dooling’s paper.
Take this online test to find out whether or not you are tone deaf: The test takes some time as you have to listen to 36 pairs music samples, which may be the same or different. (I have to take it again because I stumbled through the first few examples, and was distracted by the honking of some Canadian geese outside.)
In his book Born on a Blue Day, “autistic savant” Daniel Tammet describes how he experiences numbers in terms of shape, color, and texture. Tammet has synesthesia in which “the senses appear to be cross-wired” (this post on Plus magazine discusses synesthesia and memory. Madam Fathom has a thorough and engaging overview on the history of synesthesia and of current research, Thanks to the Phineas Gage Fan Club which is hosting the 24th Encephalon, a neuroscience blog carnival.
