*Very* excited to see the last study of my PhD making the cover of
@ScienceMagazine
on the macaques of
@CayoSantiagoPR
.
We show that ecological disturbances can alter selective pressures on social ties leading to persistent societal changes.
🧵👇
So immensely proud to see my PhD work out today in
@Nature
!
Combining neuroscience and ethology to an unprecedented degree in primates, we uncover neural signatures of social support and grooming reciprocity—building blocks of relationships.
🧵👇
**NEW PREPRINT ALERT** co-authored w/
@seb_trem
(yes, 2nd in a week!!)
We show that inferring a brain area’s function from neural recordings alone can be misleading, with severe consequences to the field of neuroscience.
🧵👇 (1/10)
New paper out today in
@ScienceAdvances
!
We investigated how sociality relates to brain structure in a group of free-ranging rhesus macaques.
Co-authored w/
@MichaelLouisPl1
,
@jerome_sallet
, Cayo Biobank Research Unit et. al
(1/9) 🧵👇
*THRILLED* to share our latest work with
@seb_trem
& co in
@MichaelLouisPl1
’s lab!
Primates maintain long-term bonds through grooming and social support. How?
Here, we reveal neural signatures of natural social behavior in freely-moving macaques.
🧵👇
*Thrilled* to share our latest work with
@seb_trem
!
Pioneering work in rodents from
@anne_churchland
's group showed that spontaneous movements dominate neural dynamics across the whole brain. Is this also the case in macaque monkeys ?
🧵👇
Wonderful and incredibly talented comic artist right here!! Thanks so much for choosing to collaborate with me and make a dream come true 😍 Comic is such a powerful medium for science communication. I hope to see more of these!
How can social behavior affect survival after a natural disaster? HUGE congrats to
@CamilleTestard
and co-authors, whose study about Hurricane Maria's impact on
@CayoSantiagoPR
just came out in
@ScienceMagazine
! Check out the paper, the thread, and the COMIC. 🏝️🐒🐒🐒
Super excited to be at
#SfN2022
in SD! I’ll be talking about bridging behavioral ecology and neuroscience in primates, Sunday at 10:30am room SDCC 23. Incredible line-up for this nano symposium:
@neuroetho
@_janzimmermann_
@DMaisson
and more. Don’t miss it!
Ladies and gentlemen, the time has come… I am defending in just a few days!!! **Thursday June 29th at 2pm EST**. If you want to learn about how monkeys adjusted socially to a major hurricane or the neural basis of natural social interaction in macaques: zoom link 👇
These findings show the potential of social flexibility to provide resilience to rapid and unpredictable environmental disturbances and emphasize a dynamic link between the environment and fitness consequences of social behavior. Illustrative work by amazing
@HuWantsToKnow
below
*Excited* to share our latest review with
@LauraNewman33
& co about our team's multi-disciplinary efforts to characterize
#aging
and its modifiers in the
@CayoSantiagoPR
macaques: from immunity, to brain, microbiome, gene regulation and more.
🧵👇
*Very* excited to attend
@EFP_GfP2022
for the next few days as a symposium co-chair with the wonderful
@DeMoorDelphine
and
@erin_sira
on the Why’s and How’s of social relationships in primates!
Check out the stellar speaker list from behavioral ecologists to neuroscientists👇
I repeat: neural cognitive signals were *just as prevalent and strong* when the recorded brain area was *not* necessary for task performance compared to when it was. (6/10)
Surprisingly, monkeys did not reinforce existing relationships with their top partners, kin, or higher-ranking individuals, but rather extended their social network to include more partners. The less social monkeys before the storm sought out new connections the most. (7/16)
Using ERGMs, we found that monkeys formed new connections using a "path of least resistance approach", making friends with the friends of their friends and reciprocating grooming. (8/18)
In the post-disaster world, *heat* is now a critical threat. Macaques who were more tolerant of others are better able to access shade, lower their body temperature and, ultimately, 42% more likely to survive.
Excited to see my first first-author paper making it to the cover of
@CurrentBiology
! Picture by
@ljnbrent
illustrating the devastation of
@CayoSantiagoPR
after Hurricane Maria and the support monkeys found in each other in its aftermath 🐒🇵🇷
Delighted to have our paper featured on today’s cover of Current Biology! I took this shot 13mos after Hurricane Maria devasted Puerto Rico and
@CayoSantiagoPR
– it shows the sustained effects Maria had on the macaques who live there.
If you’re still around this morning at
#ISBE2022
and wonder about the long-term effects of
#Hurricane
Maria on the
#CayoSantiago
rhesus macaques, come check out my talk this morning at 11:45 in the main auditorium!
Our heroic field assistants on the ground resumed research almost immediately after the disaster. They noticed monkeys seemed more tolerant of their past competitors. We sought out to investigate whether monkeys became friendlier after the storm. (4/16)
**STOKED** to see our work with
@seb_trem
& co out in
@NatureNeuro
today!
We investigate the effects of spontaneous movements on cognitive processing in the macaque cortex.
Detailed tweeprint below 👇
*Thrilled* to share our latest work with
@seb_trem
!
Pioneering work in rodents from
@anne_churchland
's group showed that spontaneous movements dominate neural dynamics across the whole brain. Is this also the case in macaque monkeys ?
🧵👇
If you're interested in how neuronal activity in the macaque brain relate to their intricate and flexible social behavior, check-out our recent study in
@Nature
with
@seb_trem
,
@MichaelLouisPl1
,
@KordingLab
and others! (Twitter thread available)
So non-necessary cognitive signals are prevalent in the cerebral cortex of primates, challenging one of the fundamental assumptions of cognitive neurophysiology and neuroscience more broadly. (7/10)
Monkey's increased tolerance for each other and propensity to make new friends is reminiscent of human responses observed in the aftermath of catastrophic events (12/16).
Shockingly, we found that the prevalence and strength of neural signals were **equivalent** across all four tasks using three standard metrics widely used in cognitive neurophysiology: tuning, persistent activity, and decoding accuracy. (5/10)
Finally, as a Junior Fellow
@Harvard
, I will investigate the molecular and circuit mechanisms in the brain regulating flexible sociality in mammals with
@DulacLab
. So stay tuned for some exciting science uncovering the neural control of sociality in changing ecosystems!
Without causal evidence building a framework within which correlations can be interpreted, investigators may capture neural signals that misrepresent the functional role of the brain area studied. This can fuel contradictions in the literature and slow progress in neuroscience.
We think these findings are consistent with a strategy to gain tolerance and support from the greatest number of individuals, and to benefit from broader social integration, rather than focusing on reinforcing relationships to “key” partners. (9/16)
One potential driver of this response is the formation of a large pool of partners that is mobilizable when needed, to reduce one’s vulnerability during times of instability or resource scarcity. (10/16)
To test this assumption, we recorded from the same neural implants in the PFC of monkeys as they performed 4 cognitive tasks. Crucially, only 1 of those tasks causally depended on the recorded area; there was no impairment on all other tasks after bilateral ablation of this area.
We found that social network size predicted mid-STS and insula volume--two brain areas implicated in social decision-making and empathy, respectively. These findings from monkeys living in naturalistic settings confirm prior lab studies on the neural correlates of sociality. 5/9
Excited to share our latest results on how rhesus macaques of
#CayoSantiago
adapt their social behavior in response to a devastating hurricane at
#abs2020
! Watch online now and join the Q&A session on Friday, July 31st at 4 pm ET.
@MichaelLouisPl1
@ljnbrent
There’s more!!
@DeMoorDelphine
from
@CrabExeter
with
@ljnbrent
will discuss what
#MacaqueNet
, a global collaboration of macaque researchers, can tell us about the evolution of social relationships. Check out the new website! . [Tinbergen: Evolution]
This logic is based on the assumption that neural activity during task performance is necessary for current task demands. But is this truly the case? If not, this seriously challenges the inferential power of recording and imaging techniques in neuroscience. (3/10)
Questions remain: What are the long-term fitness consequences of making new friends, or failing to do so, in this extreme context? What are the biological traits that underlie the variation in how much monkeys invested in new relationships? (13/16)
*COMIC ALERT*: you saw a sneak peak a couple tweets up. I paired up with a fantastic comic artist, scientist and educator
@HuWantsToKnow
to make a graphic novel version of this study accessible to a wide audience. Check it out!
Why is this the case? We don’t know. Perhaps neurons are representing inputs the area needs to perform its specialized computation (e.g. visual signals) even when the area is not necessary for current task demands. Other ideas? (8/10)
Future work in collaboration with
@jerome_sallet
,
@kchiou
,
@SMack_Lab
and others will investigate the impact of this devastating hurricane on the physiology of these macaques, from genomics to brain morphology. (14/16)
We used 4 years of data on two social groups, from 3 years before to 1 year after Hurricane Maria to make within-individual comparisons of grooming and proximity behavior. (5/16)
This work was done in collaboration with
@InchauspeJeanne
& Dr. Michael Petrides. We thank
@CIHR_IRSC
for funding this work and look forward to discussing further this controversial but critical topic. (10/10)
In a 1st study published in 2021
@CurrentBiology
, we showed that, in the immediate aftermath of the disaster, macaques built new social relationships. But why did they do so? and was this social response persistent and adaptive?
Understanding the function of brain areas is one of the main goals of neuroscience. Based on correlations between a brain area’s activity and task variables, scientists often conclude that the brain area studied has a functional role in task performance. (2/10)
In 2017, Hurricane Maria hit an island off the coast of Puerto Rico home to a population of rhesus macaques. The event destroyed the island's vegetation leaving macaques exposed to excruciating heat (>40°C). Years later, the vegetation has *not* recovered
Hurricane Maria hit Puerto Rico in September 2017, causing massive destruction and 3000 deaths. Cayo Santiago Island, home to over 1500 macaques, was not spared. (3/16)
This tells us that proximity after the hurricane was not only a byproduct of individuals congregating in narrow shaded spaces during hot hours of the day but also reflects active social decisions in other contexts, which in turn predict access to valuable shade when most needed.
This was not the case before the ecological disruption, indicating a *shift* in the adaptive benefits of social ties. In other words, Hurricane Maria changed the "rules of the game" in this macaque society, leading to persistent changes in how individuals interact.
It’s always a pleasure to mix art and science. I really enjoy having these relaxed conversations about ideas, dreams and work. Fantastic write up by
@RebeccaHorne500
at
@_TheTransmitter
and a really fun shoot with Simon Simard! Come join the fun! Recruiting RA, PhD and Postdocs!!
5 years later, macaques continue to spend more time in proximity to one another, both in hot afternoon hours under the shade and in cool morning hours in exposed areas. Proximity between monkeys were highly correlated in these two contexts.
Last but not least I would like to thank Lovelace, Sallyride, Hooke and Amos, the monkeys who pariticipated in this study. Their lab life was vastly improved by the FDA approved tech we used here to record from their brains. Let's keep improving our ethics in animal research 💪
Overall, using more granular measures than group size, our results in a naturalistic macaque population endorse the hypothesis that the size of one's social network propels the expansion of *specific* brain circuits, both across and within species. (8/9)
Further supporting that macaques changed their sociality (and did not just develop a preference for shade), we found less aggression compared to before the storm. A surprising finding given the hierarchical nature of macaques and increased competition for shade after Maria
Rhesus macaques are excellent models for human
#aging
given the cross-species similarity in aging trajectories, physiology and sociality.
For an in-depth review on the topic, check out
@kchiou
's work!
This work would not have been possible without the Cayo Primate Research Center staff, and our field assistants Josue Negron and Daniel Philips! We also thank the Social Network Club at
@CrabExeter
for their feedback and insightful discussions. (15/16)
Finally, neural activity also reflected social support between partners during agonistic encounters: neural responses when a partner was threatened mirrored activity when the subject itself was threatened; and the presence of a partner led to dampened neural responses to threat.
Wondering how aging affects gene regulation across the primate brain? Check out our group’s latest work right here 👇Co-led by amazing
@kchiou
and
@AlexDeCasien
🤩! Oh.. Higher ranked individuals have younger brain transcriptomic profiles 🧐
🚨 New paper alert! 🚨
We generated a huge transcriptomic (i.e., mRNA, gene expression) 🧬 dataset from the 🧠 of rhesus macaques 🐒 & compared age-related patterns to those in humans 👶🏻🧒🏾🧑🏼🧑🏽🦳🧓🏻
(1/10)
Our macaque pairs exhibited near perfect reciprocity in their grooming interactions and neurons across both prefrontal and temporal crotex kept track of these social investments. We think this is biological evidence for a cognitively demanding form of reciprocity in this species.
Extreme weather, increasingly frequent with climate change, cause large and persistent ecological damage. As a result, selective pressures on individuals can change leading to phenotypic adjustments. Social relationships may be one way individuals adapt to ecosystem disturbance.
Group-living rhesus macaques have complex social lives, managing both competitive and cooperative relationships to survive. They also have a strict social hierarchy: every monkey has its place on the social ladder. (2/9)
Yet, whether such climatic events alter selection on sociality and whether animals, as a result, adaptively change their social relationships remain untested.
This work was possible thanks to the herculean efforts of the Cayo Biobank Research Unit team (coordinated by
@monkeymullet
) collecting behavioral data and biological samples (including brains, blood, bones and much more), as well as the
@CayoSantiagoPR
team and co-authors! 9/9
Incredible opportunity to work in a cross-disciplinary and international team at the intersection of behavioral ecology, genomics and neuroscience!
@ljnbrent
and
@SMack_Lab
are outstanding mentors, highly recommend checking this out!
Finally, maternal social landscape and status did not predict variation in infants' brain structure. This suggest macaques' sociality-related differences in brain architecture arise later in development, as infants directly interact with other partners than their mother. (7/9)
Next, behavioral ecologist Dr. Oliver Schülke from
@uniGoettingen
@DPZ_eu
@PrimBehavEcol
will tell us about the role of mating strategies in the evolution of affiliative relationships from work in Thai Assamese macaques. [Tinbergen: Function]
#EFP_GfP2022
I’m super excited to say that I will be starting my lab as Asst. Prof. at the University of Pennsylvania
@PennSAS
in the beautiful, vibrant, and sunny city of Philadelphia. My lab will lead an integrative approach to animal cognition in the lab and in the field!!
#recruiting
The session starts with professor Erica van de Waal from
@unil
, director of the Inkawu Vervet Project
@InkawuP
, telling us about social learning in wild vervets ! [Tinbergen: Development]
#EFP_GfP2022
Overall, this work in primates truly integrates ethology and neuroscience. We uncovered neural signatures of behaviors never studied before, and made surprising discoveries which perhaps question the state of knowledge in neuroscience.
In this study, we recorded the affiliative and agonistic interactions of a naturalistic population of macaques for 3 months prior to scanning their brains. From these observations, we derived monkeys' number of friends, position in their social network, and social status. (4/9)
As in humans, everything macaques do is in the context of other macaques. Accordingly, neural population activity in both brain areas (again!) was strongly structured by the animal’s current behavior and the presence/identity of neighboring monkeys when those behaviors occurred.
(More in the initial twitter thread cited in my previous comment). Overall, I hope this work will be relevant to both neuroscience and ethology communities of which I am a part of! The joys of interdisciplinarity 💎
Great blog post by
@anne_churchland
on our work with
@seb_trem
looking at the effect of movement on cognitive signaling in the macaque brain. We may somewhat differ in the interpretation of the cross-species comparison but glad to start this discussion!
I wrote a first thread when we preprinted this article, which you can find here:
TLDR: we reveal neural signals across the most diverse array of natural behavior ever before in primates, including fundamental social behaviors critical for survival.
*THRILLED* to share our latest work with
@seb_trem
& co in
@MichaelLouisPl1
’s lab!
Primates maintain long-term bonds through grooming and social support. How?
Here, we reveal neural signatures of natural social behavior in freely-moving macaques.
🧵👇
Our understanding of the neurobiology of primate behavior largely derives from artificial tasks in highly contrived laboratory settings, overlooking most natural behaviors primate brains evolved to produce and the social contexts they navigate on a daily basis.
Surprisingly, we found no neuroanatomical correlates of social status or indirect connectedness. Perhaps the cognitive processes required to navigate direct relationships exert the strongest computational demands and therefore predict variation in specific brain structures. 6/9
@jcbyts
@NicoleCRust
@KordingLab
@seb_trem
@nienborglab
This is perhaps very much known but also very much ignored in the field when interpreting results. This study adds to the evidence that you,
@realAlexHuk
and others have provided on the non-necessity of neuro-behavioral correlations brain-wide.
Reciprocity is a critical building block of social relationships in both macaques and humans. “You scratch my back, I’ll scratch yours”. Macaques in the lab showed remarkable grooming reciprocity, and activity in both areas reflected mental accounting of these social investments.
The unique breadth and depth of data collected both longitudinally and cross-sectionally from the Cayo Santiago rhesus macaques has allowed detailed exploration of age-related variation across multiple biological domains (e.g., immunological, molecular, musculoskeletal).
The computational demands of living in large complex social groups is hypothesized to be one of the drivers of primate brain evolution. Yet, whether and how the diverse components of primates' natural social lives relate to brain structure remains largely unknown. (3/9)
During hours-long sessions, we manipulated the social context in which animals behaved. We paired our subjects or isolated them, manipulated the identity of neighboring monkeys & introduced social stressors.
Given the importance of movements in modulating cortical activity in both mice and monkeys, we used state-of-the-art computer vision methods to track full body movements and field of view during natural behavior.