In this (incredibly late) podcast Ryan and Joel discuss some of the spookier bits of neuroscience. Prior to the start of the main cast, Joel introduces their new plans for upcoming casts which include a focus on interviews and guest hosts.
There are so many myths about neuroscience, from the obviously ridiculous to those that challenge our self-conceptions. Joel and Ryan take on their top ten.
Hello readers and listeners,
We have a few links based on our Episode 3 podcast: Top 10 NeuroMyths!
First off, thank you for tuning in again for another week. We hope to hear from you in the comments here, on our facebook page, or at firstname.lastname@example.org.
One change you might have noticed is the introduction of the amazing theme music. This is free for personal use at https://www.jamendo.com/en/track/327389/alexkay-up-and-out. The track felt perfect for our purposes with its thumping sci-fi beat.
Now, as the last podcast was in a ‘Top 10’ format, I think it makes sense to go through those 10 in order.
This wikipedia article gives such a good summary with links that I can just leave it here. The brain is highly specialized and energetically expensive, so if it’s there, we probably use it! If we only needed 10%, we could suffer serious brain damage and be fine! This myth is one of the older ones and also one of the most ridiculous. Would we buy this line about any of our other organs? ‘Oh yeah, your heart is great and all, but you only really NEED 10%. Just sell the rest on the black market. You’d be stupid not to!’
9) Vaccination Causes Autism
All three of these sources give decent outlines of the full story. Long story short, there is no solid, statistically grounded evidence to demonstrate a link between vaccines and increasing rates of autism. Once of the common claims of so-called ‘anti-vaxxers’ is that there is a government conspiracy surrounding vaccination. Either the government is using vaccines to control people (although causing economic strife by randomly producing diseases in its citizens is probably not a good method) or Big Pharma is protecting its profits (although vaccines are not exactly one of the top sellers – check this blog post for an analysis, as well as more discussion in the comments). Goodness knows the researchers are not rolling in money, and it would make someone’s career if they did find a connection between the two (Wakefield tried to do just this in the paper that started the theory).
These sources (the top papers is fairly academic, the lower more aimed at a lay audience) both suggest that while brain size is important, the crucial aspect of increased intelligence seems to be enhanced neuronal organization in the cortex. Bigger brains give us more space to wire neurons together in a cool way, but the top paper from Hofman suggests there is indeed an upper limit, at which the wiring arrangement becomes highly inefficient,
We also might wonder whether just because animals don’t show ‘our kind’ of intelligence we should discount the kinds that they show. Rats are able to distinguish thousands of scents at even very small amounts, but that isn’t important for our notions of intelligence. In any case, animals have brains that generally suit their needs quite well!
7) Our left brain and right brain have vastly different functions and operate independently
In one 2013 study (link to original study in story), fMRI showed no preference in terms of ‘hemisphericity’ in over 1000 participants.
Both creative and analytical tasks require cooperation in regions in both sides of the brain. While in some cases the sides of the brain operate rather independently (as in motor control), there is no reason to think that they handle these functions remarkably differently.
There are some small specializations, one of the most famous being the concentration of language processing in the left hemisphere. We mentioned a few specialized cases of brain damage to these centers:
I found a woman on YouTube who had a stroke at 18. Here is a video of her one year after and 5 years after. You can see a remarkable progression within that time in terms of how she copes, whether through behavioral changes or honest-to-goodness new learning. NEUROPLASTICITY!
6) ‘Neuro-training’ leads to wide-spead cognitive improvement
The scientific community seems to have come to a consensus that brain-training companies’ claims are overblown. Nobody disputes that through playing these training games people can improve on the narrow task of playing that game better, but generalizing to other contexts seems to be extremely limited. You would probably be better off exercising, or playing an instrument, or writing an essay, or creating a podcast!
5) Memory is limited and you can ‘fill up’ your memory
While sometimes we may have difficulty recalling the memories we have stored, in theory they are still there; they just need to be activated appropriately. Any limits to human long-term memory have not been discovered within human lifetimes outside of cases of brain damage.
4) Memory is a perfect reconstruction of an event based on the input from a single experience
Memories are imperfect and inaccurate. Rehearsing memories can change them, so even after the first encoding, they are not ‘locked-in.’ Interestingly enough, memories of traumatic or emotionally charged events are also subject to change, although they feel particularly vivid and accurate. These memories are often rehearsed, in the sense of ‘I remember where I was during the assassination of JFK.’ Repeated tellings of these stories activate the memories, making them actually more susceptible to change over time.
All of these are super fun. One of the ways in which we can make sense of these perceptual foibles is to realize that every part of us is evolutionarily produced; that is, all of our perceptual apparati are evolved to let us live long enough to reproduce, not necessarily to represent the world accurately. ‘Filling in’ represents an evolutionary bias where it is better to imagine something that is not there than to miss something that is. Better to flee from an imaginary tiger than miss the patterned stripes in the tall grass. More on this human tendency in future podcasts!
2) We are a unity
This is a somewhat esoteric concept, so it is tricky to provide good links.
But basically, the notion is that in the same way that we have fragmented, semi-overlapping systems underlying perception, similarly fragmented, semi-overlapping systems undergird consciousness. In some ways, our conscious experience is the narrative crafted from our ‘inner’ and ‘outer’ perceptions–those that are entering through our sense organs, those bubbling up from our memory, those arising from our complex network of internal monitoring (Am I thirsty/hungry/at an uncomfortable temperature?).
The best evidence for this is the selective destruction of neural functions through specific brain damage. We identified two forms of aphasia earlier in these show notes; the writings of Oliver Sacks and V.S. Ramachandran provide illuminating and fascinating examples of persons who have specific deficits in object recognition, attention to half of the perceptual world, color vision, motion vision–a host of highly specific changes which suggest that the neural tissue damaged underlies these functions.
Wikipedia has a surprisingly thorough treatment of the neuroscience of free will, including the Libet experiment we referenced in the podcast. A key question to frame the debate: if our brains ‘decide’ things outside of our conscious input, is that us executing control? Joel and I seem to disagree on this point, though we might just be stuck in semantics! The basic argument is that unconscious forces in your brain often come to decisions before you are consciously aware of it.
Indeed, some of these forces can be harnessed by shapers of public policy, for better or for worse. These ‘nudges’ seem promising to behavioral engineers as ways of creating a more efficient society, but some thinkers see this as a campaign to undercut free decision-making. One question to frame the debate: if innocuous changes to the environment in which you make a decision encourages you to make the decision which is in your best interest, should those environments be encouraged? On the other hand: if the ability to shape environments in a society lies with a centralized bureaucracy which can set universal standards to maximize compliance with rules through this ‘soft’ exertion of power, does this asymmetry of power diminish the free agency of citizens?
We probably need to put together a Free Will-cast at some point in the future. And maybe one on ‘Nudgeonomics.’
Those are a few podcasts to look forward to in the future!
We hope to see you next week,
Ryan of High Proof