Thread by @OryanZacks

So, are all vertebrates conscious? And how would we know?

I'm sure everyone is absolutely going to read the full paper, but here it is in 🧵form, just to give a taste and some back story.

@theASSC @ASSC26nyc

academic.oup.com/nc/article/202…

We started out by thinking about current theories of consciousness, which are largely focused on humans. We asked- Can they be applied to non-human animals?
And if so, what would that mean for the evolution of consciousness? What would it mean for the theories in question?

We decided to focus on the Global Neuronal Workspace Theory (GNWT) advanced by @StanDehaene and colleagues. We give an overview of our understanding of the theory as will be applied to non-human animals. While not perfect by any stretch, I hope it serves as a brief intro to GNWT.

The paper then takes a deep dive into fish neuroanatomy (Woohoo!). This was one of my favorite parts of the project and I learned so much.
We attempted to reconstruct the brain of a theoretical common ancestor of all living jawed vertebrates and there are a ton of juicy details!

Very briefly, most brain structures are conserved across all these vertebrates (except the cortex!), and we can inquire into their function and connectivity.
We were trying to figure out- is there something like a 'global neuronal workspace' in all vertebrates?!

And we think the answer is- Yes! All vertebrates have brain structures that functionally correspond to the architecture outlined by GNWT. These structures are connected in ways that resemble human connectivity, which is unsurprising since they are largely conserved.

But what about the GW itself? Doesn't it require a prefrontal cortex?
Importantly, we focus on *minimal* consciousness. We don't expect all vertebrates to have the same cognitive abilities or experiences that humans do. Some experiences may be possible w/o the prefrontal cortex.

Surprisingly, we found the highest level of integration in the basal fish brain is the hippocampal homolog! This area serves both memory functions and is the closest thing to a global workspace we could find. I admit this blew my mind 🤯🤯🤯
More about this in the paper 😉

We discuss the implications of a single brain network serving both memory and integration and how further developments in neuroanatomy influenced the evolution of consciousness.
We close by trying to cram in as many practical predictions as possible!

This paper was co-authored by myself and the amazing Eva Jablonka, and we drew a lot from her previous work. I highly recommend reading her books (with Simona Ginsburg) The Evolution of the Sensitive Soul and the more recently published Picturing the Mind.
mitpress.mit.edu/9780262046756/…

The figures were designed by the talented @DaphnePerlman. I highly recommend integrating visualizations into the writing process and reaching out to designers if, like me, you have absolutely zero ability in this area. Daphne was supportive and professional, check out her work!

Finally, I had a great experience publishing with @NeuroConsc! The review process was completely reasonable time-wise, the reviewers were thoughtful and caught (important!) details that we overlooked and everyone I interacted with, from the editor to the staff was great!