3️⃣ In a supplementary analysis, we also showed that inductive reasoning and matrix reasoning recruit the Multiple Demand (MD) system (Duncan, 2010), but deductive reasoning engages distinct brain areas (stay tuned for more on this!) 8/8

Thus, linguistic representations do not undergird abstract logical reasoning, 🚫adding to the body of evidence that we don’t use language to think. 🧩 7/8

Finding 2️⃣: Patients with aphasia, following severe damage to left Perisylvian cortex, reason logically ✅🧩 (in both an inductive and deductive reasoning task) despite their profound language loss 🚫🗣 6/8

Finding 1️⃣: fMRI data from neurotypical participants 🧠 as they performed inductive and deductive reasoning tasks suggests that the human language system is not engaged during abstract logical reasoning 🔍 5/8

We used a two-pronged approach: fMRI in healthy adults and behavioral investigation in patients with severe aphasia (teaming up with Rosemary Varley and Paris Jaggers + Yael Benn). In both approaches, we examined both inductive and deductive reasoning (thought to occur via the symbolic LOT). 4/8

Fedorenko et al. (2011) identified a fronto-temporal language network in the brain, responsible for human language processing, allowing us to probe whether the human language system is responsible for abstract symbolic reasoning. ⅜

Fodor (1975) hypothesized that human reasoning occurs via a symbolic Language of Thought (LOT) allowing us to reason abstractly, compositionally, and systematically. Some theorists (e.g. Chomsky, 1965) further speculated that this LOT was our natural language. 2/8

A special thanks to Alex Fung, the awesome RA who made this a lot of fun even when we were working at odd hours! 10/10

🌟To conclude: neither linguistic nor domain-general abstract representations (in the MD system) underlie intuitive physical reasoning! The physical-reasoning system therefore appears to be another specialized reasoning system, akin to the Theory of Mind system (@rebeccasaxe.bsky.social)! 9/10

4️⃣In a supplementary analysis, we also showed that another high-level reasoning system, the Theory of Mind (ToM) System, does not overlap with the physical-reasoning system, in spite of close spatial proximity in some parts of the brain 👥 8/10

3️⃣The language system does not respond during physical reasoning. And conversely, the physical-reasoning regions do not respond to language. Thus, linguistic representations do not undergird intuitive physical reasoning, 🚫 adding to the body of evidence that we don’t use language to think. 🧩 7/10

2️⃣In line with Fischer et al, (2016), the MD System partially overlaps with the Physics System, but shows distinct fine-grained activation patterns (more evidence for this dissociation is coming from @RTPramod soon, stay tuned!) 6/10

1️⃣We replicate Fischer’s and @RTPramod’s finding of a set of frontal and parietal areas and also find a new region in the left anterior frontal lobe! 🔍 5/10

a localizer for the Multiple Demand system (given that the topography of the physical reasoning system looks similar) and the language system (given some proposals that we use linguistic representations to represent and model physical world states 💭🌍) 4/10

What representations underlie our physical reasoning ability 🏗️? To answer this question, we collected fMRI data of participants (n=40) as they performed the block-tower localizer, as well as two other localizers:

@RTPramod and others have also shown that these areas also encode stability 🏛️, mass ⚖️, cohesion 🪨, contact 🤝, and forward simulation 🔄 (see our intro 🙂) 3/10

Fischer et al. (2016) identified a set of 🧠 areas that seem to be engaged when we reason about the physical world. He used a localizer task like this; and found a set of bilateral frontal and parietal areas: 2/10