Outline and Notes

This posting collects all the outline and notes postings in one place

Chapter	Outline	Notes
1: Big Brains, Bigger Brains	Outline	Notes
2: The Mind in the Machine	Outline	Notes
3: Genes Build Brains	Outline	Notes
4: Brains Arrive	Outline	Notes
5: The Brains of Mammals	Outline	Notes
6: From Olfaction to Cognition	Outline	Notes
7: The Thinking Brain	Outline	Notes
8: The Tools of Thought	Outline	Notes
9: From Brain Differences to Individual Differences	Outline	Notes
10: What's in a Species?	Outline	Notes
11: The Origins of Big Brains	Outline	Notes
12: Giant Brains	Outline	Notes
13: All But Human	Outline	Notes
14: More than Human	Outline	Notes

Notes on Chapter 14: More than Human

This chapter was largely about speculation: what cognitive abilities might Boskops have had?  Why did the Boskops die out?  What might the next steps in human intelligence be?

In the section "Brain and Superbrain" where the authors talk about why Boskops might have died out they raise the point again about how being super-intelligent is not that useful if you don't have a society to pass your insights on to.  While the average high school student may not be the equal of an Einstein in math, they do start out with knowledge gleaned from several thousand years of studying mathematics.

"The Final Path to Humans" points out that genetic control over brain structure is likely to be rather imprecise hence trying to engineer a human with superior cognitive abilities through genetics alone is liable to be very difficult.

The section, "Inconsistent Brain," talks about how Dmitry Belyaev domesticated foxes.  The reason I found this interesting it shows how simple breeding style genetics can result in behavioral changes.  Further investigation of exactly what produced a friendlier fox - was it a change in brain structure, hormones, something else - would be a fascinating study.

Chapter 14: More than Human

• Brain and Superbrain
• What abilities might a larger brain yield?
• Long paths: "Think it through"
• Being able to more fully explore the ramifications of a decision.
• Branching paths: "The continuity of self"
• Being able to recall the way that you were
• Example: when you were younger
• Stations at the ends of paths: "Phaedrus' knfie"
• Able to make very fine distinctions.
• (Why did the Boskops die out)
• Maybe they didn't want to spread like H. Sapiens
• Maybe they never reached a "critical population mass" where intelligence could have been more useful.
• New Paths, New Humans
• Speculation on how structural changes could have been triggered by minor gene changes.
• The Final Path to Humans
• Early mammals probably had brains that were focused on olfaction and audition.
• When mammals moved out of nocturnal niches, they had more brain development in the visual regions.
• Human beings are strongly auditory
• Human infants are more auditory than visual
• Audition would be useful to a language oriented species
• Neanderthals may have been more visual (larger anterior cortex)
• Genetic control of brain growth is very imprecise
• Stadium analogy
• Inconstant Brain
• Domestication of foxes
• Dmitry K. Belyaev's experiment in the 1950's
• Bred foxes for docility
• 30 to 35 generations
• Bred a group of foxes that were friendly to humans
• How were they different
• Physical
• Floppy ears
• Rolled up tail
• Coats of more than one color
• Mental/Chemical
• Higher levels of neurotransmitters such as serotonin
• Brain - uknown
• Rat breeding in the 1930's
• Bred for maze running.
• Could achieve the same results with normal rats by putting them in a maze for a few weeks.
• Next Steps
• Asperger's high functioning group
• If they moved to an island
• Transhumanists - directed evolution
• Using drugs that enhance learning abilities
• Resurrect the Boskops --- using their DNA
• Coda
• Boskops may have died out because of infant and mother mortality
• Perhaps they were wiped out by more warlike humans
• Perhaps they still exist and just blend in with the rest of humanity
• Anecdote about Boskop grave

Notes on Chapter 13: All But Human

The big thing I got from this chapter was that there is more to support the notion that most of the differences between human and animal cognitive abilities stem from the size of the human brain as opposed to its quality.

The evidence cited for differences in human vs. animal brains seemed fairly slim by comparison - from a structural standpoint it does not sound like there is a whole lot of differences between human brains and other primates.  The differences in proteins also seems rather small.

One area that is completely ignored is that glia cells - the non-neuronal cells in the brain that perform functions such as immunity, neurotransmitter re-uptake and myelination.  The book The Other Brain: From Dementia to Schizophrenia, How New Discoveries about the Brain Are Revolutionizing Medicine and Science describes how these other cells, that outnumber neurons in the brain by more than 3 to 1, appear to do much more than simply provide support to neurons.  It would be interesting to learn whether human brains differ significantly from other mammals with respect to glial cells instead of focusing exclusively on neurons.

The part at the end of the chapter about Boskops seemed out of place with respect to what the rest of the chapter talked about.  Furthermore, the discussion does not mention Neanderthals, Cro-Magnons or other possible sub-species that might have had a larger brain size than modern humans: the discussion left me thinking that the authors considered Boskops to be another sub-species rather than statistical outliers.

The discussion about Boskops does give a very good reason for decreasing brain size, to whit that a larger brain at birth translates to a more difficult birthing process.  Given how dangerous childbirth is for modern women, a child with a 30% larger head would pose an even greater risk than existing babies.  The loss of a mother is especially bad because it means the loss of an established and valuable member of a society, making a community of large brained individuals even more difficult to support.

Chapter 13: All But Human

• Introduction
• Science is empirical: based on observation.
• It is difficult to "prove" that something is true, instead often times you eliminate alternatives.
• Well known facts can have exception: Newton vs. quantum physics.
• Are human beings intelligent because their brains are different from other animals or because the human brain is larger?
• Differences
• Most of the human brain is the same as other animals
• Cell Types
• Voon Economo neurons - only occur in humans gorillas chimps and bonobos.
• Occur in areas that are active during social interaction.
• Local Circuits
• Broca's and Wernicke's areas.
• "Double-wide" brain cells.
• Connectivity
• Our brains appear to form synapses more readily than other animals.
• Protein thrombospondin.
• Neurons have longer dendrites and have more synapses than apes.
• Human brain is 3 times the size of a chimp brain, but it does not have 3 times as many neurons.
• Recent Genes
• FOXP2
• 200,000 years old.  
• Appears to be language related.
• Microcephalin 
• 50,000 years old
• Regulates brain size
• ASPM
• 10,000 years old
• Involved with microcephaly - reduced brain size.
• Brain Shape
• Area 10
• Involved in higher brain functions.
• Could be larger than expected.
• Others claim it is the correct size for a 1350cc brain.
• From Quantity to Quality
• Where does language come from?
• Why do humans have it, but no other animal seems to?
• Some theorize that humans have a special language module in the brain.
• Others argue that it is size - human beings have much larger (400%) brains than chimps, etc.
• For the time being, neither argument can be conclusively proven as more likely.
• From Brain Advances to Cognitive Advances
• The gap
• Big brains arrive 100,000 years ago
• Real cultural changes start at roughly 20,000 years ago
• Why the gap?
• Critical mass theory
• A critical population is needed to create and pass on knowledge.
• From Cognition to Language
• Observation is that the cortex is already set up to reason in terms of grammars.
• Then the existing structures can be easily used to deal with languages.
• Rather than trying to create a new structure just to deal with language.
• Learning Curve
• There is a large gulf between human style communication (complex) 
• And animal style communication (relatively simple).
• Theory that as a cortical circuit is lengthened, the grammars it can recognize become more complex.
• From Speaking to Writing
• Written language skills are among the most difficult cognitive skills that humans display.
• Unlike spoken language, reading & writing cannot be expected to manifest spontaneously.
• Lack of evidence of reading & writing could have been because of a lack of population 
• 30,000 years ago Europe had a population of around 5,000.
• Why did the Boskops die out?
• Massive difficulty with childbirth (larger heads).
• Means a smaller population
• Smaller population means no critical mass.
  

Notes on Chapter 12: Giant Brains

Ideally, this chapter explains why the Boskop find was forgotten. In the first couple of sections, the authors talk about how the find was viewed by prominent scientists and how there were multiple finds that corroborated each other.

The section, "How Giant Brains were Forgotten," goes into the Piltdown fraud.  The authors argue that the fraud tainted subsequent finds by British paleontologists and that the Boskop discovery fell victim to this.  A secondary reason for the find being forgotten is the "irresistible fallacy" that human beings are the apex of evolution, that evolution leads inexorably towards intelligence and that therefore no prehistori

Preview

c species could have been more intelligent than humans.

The authors spend the rest of the chapter speculating about how Boskops could have been more intelligent and the nature of intelligence itself.

According to the authors, their intention was not to try and cast the Boskop find as an indication of a separate race.  To quote the above link:  It is not possible to read Big Brain and conclude that the authors believe in any way in this notional “Boskop race”, nor that we have in any way somehow mistakenly adopted decades-old, long-rejected interpretations of these skulls.

The problem I had with this was that I did get the impression  that the authors were trying to argue in favor of the notion that the South African find was indicative of a "Boskop Race."  Whether my impression is unique or not is something that you will have to figure out by reading the book on your own.

Chapter 12: Giant Brains

• Introduction
• Back to the Boskops
• The find was examined by others
• The Man of the Future
• Fitzsimons found 3 more skulls.
• The subsequent finds were more complete than the initial find.
• Boskops were the inspiration for aliens like the "grays"
• All this happend near the time of the Piltdown fraud
• How Giant Brains were Forgotten
• About Piltdown
• 1912
• Gravel pit in the Piltdown region of England.
• Charles Dawson was the "discoverer"
• Dawson took his find to Arthur Smith Woodard
• The Piltdown discovery became very popular in England though doubted in other parts of the world.
• Martin Hinton was apparently the perpetrator of the fraud
• "practice" bones were found in one of his closets
• The fraud created a lasting stain on the reputation of British anthropology
• Inside the Giant Brain
• Speculation on Boskop capabilities
• Boskops had approximately 25% larger brains than modern humans
• Argues for enhanced planning, memory and association abilities.
• Giant Brains and Intelligence
• Nobody knows what effects a larger brain would have on IQ.
• Guesses that 25% larger brain would result in 10-30 points.
• People who were "gifted" (130+) would become genius level (140 to 160).
• People who were genius level (150+) would become superhuman (160 to 180).

Notes on Chapter 11:The Origins of Big Brains

The message I took away from this chapter was that, for an animal to have a big brain in adulthood, it must have a large brain at birth.  During our evolution, human beings have evolved in such a way so as allow for offspring to have a huge brain at birth - even though an adult mountain gorilla may ultimately weigh in at 200kg, a human baby is almost twice the size of that same gorilla at birth!

One question that I had was "why is birth brain size so important?"  That is, why can't the brain of an animal grow massively after birth thereby allowing for a safer and easier birthing process?  I did not see an answer to this in the chapter.

Another point from this chapter was that, according to the authors, the mosaic theory of brain development does not find support in studies that compare the sizes of brains amongst primates.  Specifically, mosaic predicts that brain areas that are more useful should be larger than others.  But instead the brain regions appear to be the same relative sizes in all primates.  Useful brain regions are larger in humans, from an absolute standpoint, because the human brain is larger.

In an interview with Dr. Ginger Campbell on the Brain Science Podcast, Dr. Lynch mentions that a nice aspect to this theory is that it does not require special explanations regarding how evolution selected for intelligence, it just requires that evolution select for large brains.  While part of this can be explained by simply increasing the size of a human being (chimps and gorillas need larger brains than monkeys because their bodies are larger), this does not entirely explain human beings, because we have large brains even when compared to other primates.

Chapter 11: The Origins of our Big Brains

• The History around fossils
• Happened in and around the time of Darwin
• 1887 Discovery of Neanderthals 
• Virchow said the remains where a modern man with rickets
• Haeckel thought they were legit
• Dubois predicted that the "missing link" was in the Dutch East Indies
• Brain size in primates
• Body weight vs. brain weight seems to follow a logarithmic scale
• Except for humans - brain is larger than expected.
• Increase body by a factor of 10 and you get a 10 fold increase in brain size.
• 10^(x * g) where g is a constant
• Very good model for predicting brain or body weight given the other.
• Brain region sizes correlate very closely with other primates
• Gorillas and chimps are smarter than monkeys (communication, tool use).
• Humans have large brains even for a primate
• Brain size in the family of man
• 6 million years ago - start of split towards bipedalism
• 5 million - bipedal vs. non-bipedal are distinct species
• 4 million - Australiopithicus
• 450cc brain
• 2 million - Homo Habilis
• 600cc brain
• First evidence of tool use
• 1.5 to 1.8 million - Homo Erectus
• 800cc brain
• 500,000 - Homo Erectus+
• 1000cc brain
• 100,000 - Neanderthals
• 1500cc brain
• 10% larger than H. Sapiens (~1350cc)
• Mosaic theory vs. concerted
• How intelligence occurred
• Mosaic theory - evolutionary pressure for different brain regions at different times.
• Concerted - no pressure for any one region, just scale up the existing brain.
• Concerted predicts the size of various brain regions, mosaic does not.
• Big Babies
• Discussion is predicated on one accepting the concerted theory.
• Bipedalism
• required for walking erect
• Wider hip size
• Larger babies
• Birth weight determines brain size
• If you have a large brain then you must have larger babies at birth.
• Human - 1350cc brain - 3.3kg
• Gorilla - 500cc brain - 1.6kg
• Chimp - 400cc brain - 1.5kg
• Hip size
• Humans: 20% difference between men and women
• Chimps: 5% difference
• On Intelligence
• Where does all the brain power go?
• Memory
• Anecdote about memory experiment
• 10,000 picutres
• 90% accuracy (have you seen this before).

Notes on Chapter 10: What's in a Species?

The chapter talks about the fact that there are no other species in the same genus (homo) as human beings is rather unusual.  The authors go on to note that during most of the past million years, there were usually only 1 or two species in the genus at any one time.

The authors implicitly ask the question: is this because of how humanity evolved, or because of how human beings have been classified: are we really that different or have some scientists wanted to show that our species is different from the rest of the animal kingdom?

A bit of evidence is given for both cases.  For the notion of adding other species to the same genus there is the observation that the Neanderthal and human genomes indicate more interbreeding than was thought to have occurred before.  What's more, the authors note that the fossil record is relatively scant to base classification on.

On the side of differentiation of species, the observation of large brains, certain teeth and some behavior (notably speech) is mentioned.

Then the authors digress into a discussion of eugenics and some observations about why it is wrong and who supported it in the past (surprisingly, this includes Winston Churchill).  The authors note that even modern humans do not completely understand how the genome works or what all the pieces do, and what's more cannot define what "better" is.

I found the chapter's points to be rather obtuse: writing up this discussion was as useful in trying to understand the message as reading the material.