Brain complexity: baby brains under study (Introduction)

by David Turell , Wednesday, February 07, 2018, 00:16 (2482 days ago) @ David Turell

New born babies have very incomplete fiber pathways and only a small number of neurons as compared to adults. As a result they show no emotional reactions other than crying. This essay looks at it for answers:

https://blogs.scientificamerican.com/observations/why-dont-babies-smile-from-birth/?utm...

"When my son was born a few months ago, he quickly established himself as the tyrant of our household, one that ruled with a singular phonetic ultimatum (“Oooo—whaaah”), tiny iron fists clutched in fury, and a face that roiled like the churning sea. His placid silence instantly devolved to wrath, wrath (once appeased) acquiesced to staring, staring occasionally melted into surprise, an overabundance of which puddled into an outstretched, fearful startle. In his tough, all-work-no-play gig, he presided for weeks without smiling, cooing, giggling or any apparent sign of happiness.

"During these overtures, I often wondered why he never cracked a smile.

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"In the late 19th century Sigmund Freud observed that his patients were unable to recall events from early childhood, a phenomenon he called infantile amnesia.

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"The report, published in Science, suggested that memory formation requires a stable network of interconnected neurons, one that, for some types of memories, resides within the brain’s hippocampus. In infants, new neurons are born quite often in a process called neurogenesis. In adults, neurogenesis has slowed and so the overall network structure is more stable.

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"By slowing neurogenesis in infant mice, she showed that they were more able to remember. It appears that neurogenesis is sufficient to induce infantile amnesia, even in adults!

In order to remember, you need brain neurons to encode and then retrieve memories. In the throes of a neurogenic boom, maybe our little men weren’t happy because they simply couldn’t retrieve happy memories.

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“'Being happy requires a fair amount of self-referential thinking,

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"This concept of self-referential thinking, or the ability to reflect on how you’re feeling and your desires, is associated with a network of brain regions called the default mode network. Dustin told me about two studies, both published in Proceedings of the National Academy of Science, both of which suggest that the default mode network isn’t fully developed at birth.

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"that the brain’s default mode network, which is thought to coordinate self-referential thoughts, isn’t fully present at birth but comes more and more “online” with time.

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"they showed that the brain networks responsible for sight, touch, hearing and movement were well-formed at birth—which is corroborated by our observations that our sons could see, feel, hear and wiggle at birth (coordination is another story). They also showed that the default mode network was more-or-less present at birth, but that it was still coalescing, still “learning,” such that the activity within this network became more coordinated the older the infants got.

"It appeared that both studies showed that the brain’s full repertoire of functional networks were roughed-out at birth, but that they became more polished with age.

"Now four months old now, my son has begun to smile and giggle. So it’s more clear when things are going well and when we’re in DEFCON 1. As to the question of whether he’s happy, I remain unsure. Even though he looks contemplatively at his hands (when they’re not in his mouth), I’m unsure this counts as self-referential thought."

Comment: the point of this essay is that there is very little going on in the infant's brain at birth, but it does develop rather quickly. Another aspect of the infant starting as a blank slate.