Zeena Rivera ✨they/them✨ has a poster @ SfN & is defending soon👀
LightNews LightNews
banner
zeenarivera.bsky.social
Zeena Rivera ✨they/them✨ has a poster @ SfN & is defending soon👀
@zeenarivera.bsky.social
100 followers 140 following 27 posts
motivated scientist decides to study motivation & decisions


@UCLA Neuroscience #NSF GRFP #HHMI Gilliam
Posts Replies Media Videos
zeenarivera.bsky.social
come thru for my poster at HH2 from now-ish to 5 today thx @sfn.org #sfn #sfn2025
Zeena holding up their poster tube in front of their face and looking to the right
November 18, 2025 at 8:00 PM
zeenarivera.bsky.social
the prize for bingo is friendship 🥰 #sfn2025 #sfn

i'm making sure I say hi to people I don't get to see too often @sfn.org
a very blurry picture of a sheet with the words "SFN Friends Bingo" on it with a cute axolotol and frog and rat on it. Behind are some booths at society for neuroscience 2025
November 16, 2025 at 8:41 PM
zeenarivera.bsky.social
(3/4) A couple years back, Andrew and I were talking about how PR, given a consistent work rate, kinda looked like a depleting patch (re: foraging). Now, applying optimality modeling, we find that our rats "overharvest" similarly to (other) patch-leaving tasks 🤯.
Rats' strategies were correlated with, but systematically greater than, the optimal bout length. The model-determined optimal bout length is plotted against the median bout length observed in each session. Observed bout length was strongly correlated with the model-predicted optimal bout length. However, nearly all points fall above the dashed unity line, indicating that rats frequently performed longer bouts than predicted by the model. Histograms along the x- and y-axis show density estimates computed separately for 60 s and 10 s reset delay data.
November 4, 2025 at 12:32 PM
zeenarivera.bsky.social
(2/4) Bout (length of time pressing for reward between no-access delay periods) length & frequency are sensitive to delay length. ***Note, the differences in the y-axis.
Ratio resets segmented PRR task performance into bouts of work. Cumulative records of active lever presses are plotted for the first 800 s of three example sessions. Grey tick marks indicate reward delivery times. (A) In PR task sessions, rats earned reinforcers quickly at the beginning of sessions, but reward rate decreased as the ratio requirement progressed. Example record from session 2 of PR. In PRR sessions (B–C), lever pressing was segmented into bouts by ratio resets, which resulted in the reset delay (shaded regions). Example records of session 2 PRR-60 (B) and session 2 PRR-10 (C). Because reset presses returned the ratio requirement to one, cumulative records for PRR-10 and PRR-60 sessions were computed separately for each bout of work between successive ratio resets. Note the very different y-axes between the three example sessions.
November 4, 2025 at 12:32 PM
zeenarivera.bsky.social
(1/4) TL;(please still)R on #eNeuro

Rats can reset PR to its easiest difficulty by paying a delay cost on PRR task. They adaptively use the reset lever to go from receiving ~67 pellets (PR) ➡ ~210 pellets (PRR w/60s delay)➡ ~328 pellets (PRR w/10s delay; almost 15g 😳) w/in the same amount of time.
Rats were tested on the Progressive Ratio with Resets (PRR) task where 2 levers are present in an operant box. In this example, the left-side lever allows for the rat to do progressive ratio (PR) which starts at a requirement of 1 lever press & increases by 1 lever press. to earn reward (one 45mg sucrose pellet delivered in a hopper). The right-side lever resets the ratio requirement after a fixed reset delay where they cannot press either lever. Rats can press this lever at any point during PR. In PRR-10 sessions the reset delay was 10 seconds, while in PRR-60 sessions the reset delay was 60 seconds.
November 4, 2025 at 12:32 PM
zeenarivera.bsky.social
any other neuroscientists with narcolepsy out there?
November 2, 2025 at 9:40 AM
zeenarivera.bsky.social
learned how to fish. when does my lifetime supply of food get delivered
Zeena in a hat and a black tshirt holding up a 5 inch tilapia that they caught in a park.
June 30, 2025 at 11:50 PM
zeenarivera.bsky.social
Rats forage for play! 🛝⚽ 💕 🐀

Preprint from one of the labs I'm in just dropped! Props should be given to the hard working and talented summer student Raegan Logue & our PI Andrew for probably curating the weirdest purchasing history in our department.

www.biorxiv.org/content/10.1...
A screenshot of figure 1 from the linked paper in the tweet. Notably, there is a picture of the rat jungle gym that was used in the "toy patch" portion of the experiment. The other parts of the figure show a schematic and model of the task where rats have to choose which patch to forage in and how long to stay in it.
December 13, 2024 at 2:29 AM