Question: Why is human cognition superior?

Scene 1: Heath Ledger in An Equation

What makes this scene so great?

It’s a tempo that’s thickening. Inevitable confrontations drowning everyone. What starts as shadowy thieving, finally overflows into open combat. This is the art of a film editor: assembling the footage (F), combing the soundtrack (S), adding the foley sounds (Fs) and adjusting colour grades ( C) . It’s stitching these sensations together that makes a film what it is.

We could describe a momentary sensation (Ms) as the collective weighting of each aforementioned component. Expanding each component into more rudimentary constituents would highlight the role time plays on each. Further, a momentary sensation is how our sensation from the film (Sf) changes with respect to time (t).

Morphologically we can see how the equation for Ms is a multivariable one. The sensation from a film is clearly not singularly-constructed.

Sensations from stimuli other than films are obviously multivariable too. And yet, within neuroscience — the way the brain is believed to function is exactly the opposite. Connections are excitatory or inhibitory. They are or aren’t. This isn’t to say complexity can’t develop out of a system such as this — in fact it’s the principle foundation of computing.

But consider what computers can’t do: they’re not conscious, for them to demonstrate 90%+ accuracy in natural language processing of one-speaker requires >500,000 separate data-points for training, subtle misinterpretations during image-processing makes them susceptible to catastrophic errors and they certainly require far more electrical energy, thermal maintenance and hardware-upgrading for long term-sustainability than any human brain.

Conversely, binary systems have brought ridiculously fast mathematical frameworks for computers to manipulate to process their instructions. Matrix transformations with dimensions in the thousands can be computed in relatively fast-speeds, moving image rendering in high-quality within immersive environments can be achieved in real-time and errorless-computation in real-time has enabled digital marketplaces, pacemakers and the successful deployment of ballistic missiles carrying nuclear warheads.

It should be clear that what computers can achieve to date are functions that humans have never been able to do. Even rudimentary computers used to orientate naval gun batteries in World War Two, such as the Rangekeepers, could mathematically outperform even the likes of Alan Turing.

But that was about it. Alan Turing outperformed the Rangekeepers in everything else. The connections and processes in a computer are fundamentally binary. The human brain may use binary connections, but I don’t believe that’s it, just like how the sensation from a film is far more than just the footage.

Scene 2: ???

I need to write a research paper on any neuroscience-based topic then format it like a PhD poster.

Scene 3: How does hemispherical morphology contribute to human’s superior cognitive abilities?

Hemispherical morphology is how the brain is divided into two as seen below.

But why? Why does the brain have to be divided into two to function? If you Google “why is the brain hemispherical” you’ll find a recurring answer: evolution. Which is the least informative answer you could receive.

Why does a plane crash? Because of gravity. That “clearly” explains why MH370 and MH17 crashed.

Why can’t the brain be a sphere of neural tissue? What does dividing the brain give to cognition?

I’ve begun answering this question for my report. My answer so far is preliminary and experimentally unproven but I’m excited as to what it already suggests. These are my thoughts:

  1. Abiogenesis (origination of life) is theorised to have evolved from deep sea thermal vents around 3.5 billion years ago. Abillion years ago, multi-cellular life evolved in growing complexity, utilising the newfound energy production powerhouses found in mitochondria. Radial symmetry originated prior to bilateral symmetry given the type of species present such as cnidarians (like jellyfish). Primitive nerve nets within these species were primarily reflex-systems comprising of mechanoreceptors.
  2. As the engine of evolution brought more complex organisms, those that were at the top of the food chain in aqueous environments benefited from their more developed physical features. Just like how a plane utilises a rudder, vertical stabilisers, ailerons, spoilers and flaps to manipulate airflow to direct movement, organisms with fins and bilateral symmetry could outmanoeuvre their prey. Bilateral symmetry consequently became a hallmark of predators and hence such animals were able to successfully breed.
  3. Early amniote (reptiles, birds and mammals) ancestors emerged from amphibians about 340 million years ago and divided into synapsids that lead to the first mammals. The closest comparison for mammals is with modern reptiles which when comparing their relative brains, highlight significant morphological discrepancies between brain structures but are unified in hemispherical orientations. Specifically, while mammals showcased a neocortex unlike reptiles/birds, they too shared brains that were divided into hemispheres.
  4. Nerve networks simultaneously developed in complexity as peripheral systems became more enhanced due to greater sensitivity: mechanoreceptors, chemoreceptors, photoreceptors, proprioceptors and so on.
  5. Evolution’s mutagenesis isn’t constant across all features of species. For instance, the brains of platypus and echidnas are highly specialised for somatosensation and electrorecpetion. Yet modern opossums and possums have changed little in overall morphology and brain size over the last 100 million years. That is to say, that brains can stop morphologically evolving.
  6. What benefit comes from halting evolution? Our early hominin ancestors (30 million years ago) had brains the size of our ancestors, ranging from 275–752 cm³. Over the last 2 million years, the brains of our ancestors increased greatly in size from 400–600 cm³ range to the 1200–1600cm³ range of modern humans.
  7. Morphological mutation produces larger brains in general ability partly because of more neurons and hence a richer connectome. Loosely, the value of a brain can be modelled like a telephone network using Metcalfe’s Law which describes how the usefulness of a telephone network is proportional to the square of the number of connected users (or neurons in this case). Clearly the brain has benefited from more cortical areas, as early mammals had roughly 20 cortical areas, while modern humans today demonstrate roughly 200 areas due in part to a neocortex that constitutes about 80% of the brain.
  8. Greater neuron count does not constitute greater cognitive ability. An African elephant has nearly 250 billion neurons compared to a human’s 100 billion.
  9. Hemispherical specialisations emerged more than 6 million years ago. In conjunction with growing brains, this meant more connections needed to be made as modularisation subdivided the brain. Optimised pathways between nuclei reduce the need for large amounts of thick, conducting axons (greater oligodendroglial cells coating the axial membranes accelerates action potentials). Hence, the eventual development of the corpus callosum enabled intra-hemispherical communication.
  10. It seems that intra-hemispherical communication would further enhance parallel processing but the corpus callosum is found only in placental mammals and not the remaining two classes of mammals: marsupials and monotremes. Additionally, while humans split from chimpanzees 7 million years ago, there is no increase in axon thickness in the corpus callosums of humans and chimpanzees.
  11. Given nerve nets at the time of bilaterisation’s pronouncement onto the animal kingdom were primitive and akin to peripheral nervous systems found in humans today, bilateral symmetry and consequently the hemispherical morphology of the brain seem to have little correlation with human’s superior cognition. Secondly, the brain has had ample opportunity to further enhance itself by maximising axonal connections in the corpus callosum — connections that seem unchanged from their state 7 million years ago. It seems to me, that not only does bi-hemispherical morphology and the derivative, hemispherical specialisation, have little correlation with superior human cognition. While the neocortex clearly powers superior cognitive abilities amongst mammals against other species, what makes human minds unique can’t be the structure of connections, but instead what the connections are exactly.

Scene 4: Echo Chamber

Consider the following coronal scan of the brain:

You can see the longitudinal fissure vertically separate the left and right hemispheres of the brain. From this visible split, we see two halves. But what does this split look like — it’s a deep groove in the brain. Are there any other grooves in the brain?

I see another groove — the lateral fissure (or Sylvian fissure). A further division?

The theory for the folded brain design is that the surface area of the brain naturally increases but could there be any other reasons?

I’ve got a few ideas but I need to think about them a bit more before I write them down. But for now, think about what this feels like:

The Joker: [Batman slams The Joker’s head on a table in the interrogation room] Never start with the head, the victim gets all fuzzy. He can’t feel the next…

[Batman slams a fist down on the Joker’s head; beat]

The Joker: See?

Written by

Electrical engineering/Neuroscience at University of Sydney. Aspiring neuro-trauma surgeon with a few software/hardware goals. www.streamplate.com

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