Dr. Greg Kitchener recommended that I read Conversations with Neil’s Brain – The Neural Nature of Thought and Language, by William H. Calvin and George A. Ojemann. The book had a key reference about the changes in reflectance of neural tissue in response to how active the neural tissue was. This gave me a better understanding of the changes in the brightness in the retinoscopic reflexes. The book itself was about Neil, an epileptic whose illness was secondary to a car accident. Doctors were not able to control his seizures with any medications and decided to surgically remove most of his temporal lobe on one side. The author takes you step by step through the testing and evaluations as well as the surgery. The writing is informative, yet easy to understand. It helped reinforce much of what I already understood about the neurology of the human brain. I can’t say that I agree with his opinions about the neurological underpinnings of learning disabilities, dyslexia, and attention deficit disorder, but I do highly recommend this book. It’s published by Addision-Wesley. The ISBN of the paperback edition is 0-201-48337-8.
Some Quotes for a Section on Laterality:
· “About 5 percent of all people have language in the right brain and another 5 to 6 percent have significant language function in both halves.” (Page 43)
· “Dichotomies make researchers happy, they ease the burden of overworked students, they sell books and shortcut study guides – but in reality, things are usually more complicated, and therefore harder to remember.” (Page 45)
· “Stimulation of Broca’s area or Wernicke’s area does not cause speech. If the patient is already speaking, the electricity merely causes errors. If not, nothing seems to happen. The anatomy doesn’t come with labels and, unless the brain happens to be speaking at the same time, the functions of the cortical language areas aren’t obvious” (Page 45)
· “Many patients with strongly lateralized language do not necessarily have strongly lateralized visual-spatial functions. Visual-spatial functions are more strongly lateralized in males than in females.” (Page 66)
· “Damage to the underside of the temporal lobe tends to interfere with object recognition, but damage to the parietal lobe tends to impair awareness that objects are even there – and, of course, making movement toward them.” (Page 67)
· “The parietal lobes are probably what keep our visual experiences from looking like an amateur videotape, jerking from here to there. Our eyes do indeed jerk from here to there, even faster than a camera, but we don’t perceive it that way. The seeming stability of our perceived world is probably because it is, in large part, actually a mental model of our visual world – that we update from all those jerky images we get.” (Page 68)
· “Nearly two-thirds of the neurons recorded from the human temporal lobe seemed to be interested in faces.” “We like to talk about areas of the brain having specialties, but the information is usually stored redundantly over a wide area.” (page 71)
· “Disturbance of musical abilities in professional musicians usually takes left-brain damage. It’s been suggested that as you gain proficiency in music, it is increasingly organized like a language, dependent on your left brain. But not on exactly the same areas as spoken language.” (Page 73)
All of this talk of laterality and change in brain as it is used triggered in me a number of discussions I have been involved in over the years:
- Humor in strabismics
- Space – time problems: lost in space = lost in time
- Spatial and temporal mismatches or disconnects in strabismics
- Lack of subtlety and nuance in the use of language in strabismics
All of this suggests that it MIGHT be interesting to have a series of fMRI or fPET scans done before and after VT with strabismics.
Next comes a section on paying attention:
Defective function of these circuits seems to be the basis for attention deficit syndrome and minimal learning disorders, situations in which a child has difficulty sustaining attention. These might well involve those selective-attention circuits passing through the left thalamus that focus attention on verbal information such as object names.
More severe malfunctions in these circuits are probably a part of autism, in which there is an overall limitation in attending to the external environment, especially in attending to the presence of other people and perhaps to verbal information.(Page 87)
I wrote in the margins: Maybe yoked prisms in autism works by altering blood flow to the thalamus?
There is a section later in the book where they are talking about the underlying neurology that may be involved in amblyopia.
Now you’ve got to know at what level in the visual pathway the neurons begin comparing the slightly different view from the two eyes. It’s not until the sixth-order neuron. The fifth-order neurons – the ones in cortical layer IVc which receive the lateral geniculate inputs – are still “monocular”. (Page 180)
There is a section where the authors are discussing deprivation amblyopia in monkeys. In response to the statement, “So the bad eye had been disconnected?” they state:
That’s probably too strong a way of expressing it, since drugs that block inhibitory synapses can temporarily reveal some underlying connections from both eyes. (Page 181)
In a section on sequencing and learning new skills, there is a quote about which I feel very positive. Indeed it should be the basis for changing how we approach training many activities in society. For example, many musicians when young are in groups that spend nearly all their time preparing for a concert. The spend most of their time working to perfect a single thing. I have always felt that it would be better to do lots and lots of different things and to be exposed to many different ways to do things. In my own musical practice I will work on a piece for performance but in small pieces over time. I prefer to read new material or to spend 10-15 minutes on one thing and to then switch to something else. Here is the quote:
The cortical-subcortical division between novel associations and skilled routine suggests, however, that it may be discovering the rules of the game which is more important to developing cortical sequencing abilities than accomplished performance. Learning many new songs might be better than learning to sing one song well, at least for exercising sequencing cortex. (Page 250)
In this section the authors end with an admonition that we should all keep in mind:
….giving names to things can be dangerous, even when the specialization seems as obvious as that for language. “Language cortex” is only cortex that appears to support language function, among other functions.Defining its function by what stops working in its absence confuses a correlation with a cause.(Page 251)