🔟 Together, this work reveals shared organising principles influencing cortical wave activity across species and provides a simple, scalable framework for analysing how regional heterogeneity shapes large-scale brain dynamics.

9️⃣ In the marmoset, we tested the effects of 3 different heterogeneity maps and found that the T1w/T2w model yielded the largest performance gains, thus emphasising the utility of our framework for analysing regional heterogeneity across brains with vastly different geometries.

8️⃣ In the macaque, we tested the effects of 19 different heterogeneity maps including 16 different neurotransmitter receptors. We found that receptors involved in inhibitory neurotransmission along with T1w/T2w had a strong role in shaping cortical activity.

7️⃣ Another advantage is that our model only requires a cortical surface mesh and a heterogeneity map, making it easy to apply across species. We thus applied our heterogeneous wave modelling approach to the macaque and marmoset to analyse the generality of our model.

6️⃣ An advantage of our approach is that it allows high resolution simulations along the cortical surface (>4000 points) avoiding the need for regional parcellations which can lead to variable results and obscure the true spatial pattern of cortical heterogeneity.

5️⃣ We found that performance gains of heterogeneous compared to homogeneous models were most pronounced in transmodal association cortices which is consistent with previous work showing that these areas exhibit greater variability in microstructural and molecular properties.

4️⃣ Our model consistently recapitulates known relationships between cortical heterogeneity and wave speed. In particular, models parameterised by excitation-inhibition balance and T1w/T2w yield the largest performance improvements relative to spatially homogeneous models.

3️⃣ We model activity on the continuous cortical surface and incorporate the influence of 8 spatially varying properties such as myelin (approximated by T1w/T2w MRI) and excitation-inhibition balance. We use 3 common evaluation metrics to compare our model against empirical data.

2️⃣ A growing body of work shows that large-scale cortical activity often takes the form of travelling waves but it remains unclear how regional differences in molecular, cellular, and physiological properties influence the propagation of these waves.

1️⃣ Pleased to announce our preprint where we introduce a high resolution model of large-scale cortical activity to study how regional heterogeneity shapes wave dynamics and whether these effects are conserved across species: https://t.co/A3pSxCUGk3 @AFornito @jchrispang