Overall, our findings demonstrate that higher-order visual cortex remains plastic beyond early development, but the timing of experience fundamentally constrains how later-acquired neural representations are refined.
Finally, we asked how the lack of early face experience impacts core IT tuning properties. We found that IT neurons in these monkeys show reduced tuning for face expression, viewpoint and identity compared to control monkeys, despite years of normal face exposure.
Neurally, IT neurons did acquire face selectivity after later face exposure, but hand selectivity persisted - even after 4–8 years of normal face exposure! Face and hand selectivity were strongly correlated, revealing mixed selectivity rather than a full cortical reorganization.
Here, we find that after prolonged face exposure, these monkeys largely matched typically-raised control monkeys in how much they preferred looking at faces or different face expressions. However, they systematically differed on which face features they focus on (upper vs lower).
Previous work from our lab showed that monkeys that grew up without seeing faces for the first year of life preferentially looked at hands rather than faces and developed hand-selective responses in inferotemporal (IT) cortex (www.nature.com/articles/nn....).
We used a unique macaque model in which monkeys grew up without face experience (while preserving all other visual input), followed by years of normal face exposure, to causally test plasticity in higher-order visual cortex.
Can the adult brain acquire typical representations after missing an essential early-life experience? New work with Marge Livingstone: “Early face deprivation leads to long-lasting deficits in cortical face processing”.
www.biorxiv.org/content/10.6...
Curious how the face-processing system recovers when early face experience is missing? Come see me present new data on recovery and limits of plasticity at #SfN2025 @sfn.org on Tues, Nov 18 at 10:45 am (SDCC Rm 33)!
www.abstractsonline.com/pp8/#!/21171...
These findings suggest that the predictive power of LMss for human visual cortex responses is not due to the evolution or learning of language per se, but rather reflects the statistical structure of the visual world as captured by natural language
www.biorxiv.org/content/10.1...
6/6
New preprint “Monkey See, Model Knew: LLMs accurately predict visual responses in humans AND NHPs”
Led by Colin Conwell with @emaliemcmahon.bsky.social Akshay Jagadeesh, Kasper Vinken @amrahs-inolas.bsky.social @jacob-prince.bsky.social George Alvarez @taliakonkle.bsky.social & Marge Livingstone 1/n
Our new work is out in @NatureComms! rdcu.be/d0ea2. Face cells are pareidolia-selective, but this selectivity 1) is not explained by human ratings, 2) did not require a face-like configuration, but was 3) driven by local features 4) explained by features present in non-pareidolia nonface objects.
