The Download: DeepSeek’s latest AI breakthrough, and the race to build world models

This is today’s edition of The Download, our weekday newsletter that provides a daily dose of what’s going on in the world of technology.

Three reasons why DeepSeek’s new model matters

On Friday, Chinese AI firm DeepSeek released a preview of V4, its long-awaited new flagship model. Notably, the model can process much longer prompts than its last generation, thanks to a new design that handles large amounts of text more efficiently.

While the model remains open source, its performance matches leading closed-source rivals from Anthropic, OpenAI, and Google. It is also DeepSeek’s first release optimized Huawei’s Ascend chips—a key test of China’s dependence on Nvidia.

Here are three ways V4 could shake up AI.

—Caiwei Chen

The rise of world models

AI systems have already gained impressive mastery over the digital world, but the physical world remains humanity’s domain. As it turns out, building an AI that composes novels or code apps is far easier than developing one to fold laundry or navigate city streets. To bridge this gap, many researchers believe you need something called a world model.

Proponents like Stanford professor Fei-Fei Li and AMI Labs founder Yann LeCun argue these models can overcome the well-known limitations of LLMs—and realize AI’s promise for robotics. Find out why they’ve brought world models to the forefront of the field.

—Grace Huckins

World models are on our list of the 10 Things That Matter in AI Right Now, our essential guide to what’s really worth your attention in the field.

Subscribers can watch an exclusive roundtable unveiling the technologies and trends on the list, with analysis from MIT Technology Review’s AI reporter Grace Huckins and executive editors Amy Nordrum and Niall Firth.

The must-reads

I’ve combed the internet to find you today’s most fun/important/scary/fascinating stories about technology.

1 China has blocked Meta’s $2 billion acquisition of AI startup Manus
Regulators cited national security grounds. (WSJ $)
+ Beijing called the deal a “conspiratorial” attempt to hollow out its tech base. (FT $)
+ The country is tightening its grip on AI firms that try to leave. (TechCrunch)
+ The decision escalates China’s AI rivalry with the US. (Bloomberg $)
+ But there will be no winners in their competition. (MIT Technology Review)

2 Google is investing up to $40 billion in Anthropic
In a deal valuing the AI firm at $350 billion. (CNBC)
+ The funding will support the firm’s growing computing needs. (TechCrunch)
+ Anthropic and OpenAI are fighting for compute capacity. (Axios)

3 President Trump just fired the entire National Science Board
The NSF has played a crucial role in developing technology. (The Verge)
+ The move heightens fears over political interference in US science. (Nature)

4 Conspiracy theories about the Washington shooting are proliferating online
Over 300,000 posts appeared on X using the keyword “staged.” (NYT $)
+ The theories are also swirling on Bluesky and Instagram. (Wired)

5 The AI compute crunch is starting to hit the broader economy.
It’s affecting jobs, gadgets, and electricity prices. (404 Media)
+ The AI compute explosion is the tech story of our time. (MIT Technology Review)

6 Elon Musk says a new banking tool brings X close to a “super app”
He’s pledged to launch the tool this month. (Bloomberg)

7 AI optimism is surging across Asia while US sentiment cools
The divide could shape where adoption happens fastest. (Rest of World)

8 Apple is tying its new CEO’s ascent to its first foldable iPhone
It wants to build the buzz around John Ternus. (Gizmodo

9 Twelve firms are developing the Golden Dome’s space-based interceptors
They’ve won contracts worth up to $3.2 billion. (Ars Technica)

10 NASA has shared promising results from Artemis II
The spacecraft and rocket fared well. (Engadget)

Quote of the day

“Getting out the truth and establishing facts and reliable information takes time. But our audiences really don’t have that kind of patience.”

—Amanda Crawford, associate professor at the University of Connecticut, tells the NYT why conspiracy theories are gaining traction online.

One More Thing

MIRIAM MARTINCIC


Welcome to Kenya’s Great Carbon Valley: a bold new gamble to fight climate change

Kenya’s Great Rift Valley is home to five geothermal power stations, which harness clouds of steam to generate about a quarter of the country’s electricity. But some of the energy escapes into the atmosphere, while even more remains underground for lack of demand. That’s what brought Octavia Carbon here.

Last year, the startup began harnessing some of that excess energy to remove CO2 from the air. The company says the method is efficient, affordable, and—crucially—scalable. But the project also faces fierce opposition. 

Read the full story on the future of Kenya’s “Great Carbon Valley.”


—Diana Kruzman

We can still have nice things

A place for comfort, fun and distraction to brighten up your day. (Got any ideas? Drop me a line.)

+ Fred Again’s Tiny Desk Concert is a masterclass in intimate performance.
+ Here’s a delightful look at how we’re all linked through geography and shared heritage.
+ Take a short, peaceful break to watch Tokyo’s cherry blossoms from a bird’s eye view.
+ There’s something oddly satisfying about watching an industrial shredder turn everyday items into confetti.

How adolescent cannabis use reshapes the developing brain — a systematic review

Background and hypothesisCannabis use initiation during adolescence has increased globally, raising concerns about neurodevelopmental consequences during this critical period when the brain undergoes extensive remodeling in cannabinoid receptor-rich regions.Study designThis systematic review examines neurodevelopmental consequences of adolescent cannabis use, focusing on structural brain changes, cognitive impacts, addiction vulnerability, and long-term outcomes. We searched PubMed, EMBASE, PsycINFO, and Web of Science (2000-2025) for studies examining cannabis effects in adolescent populations. Following PRISMA guidelines, two reviewers screened 3,421 records and assessed 156 full-text articles, including studies with neuroimaging, cognitive assessments, or longitudinal follow-up.Study resultsThirty-six studies involving 8,432 participants met criteria: 23 longitudinal cohorts (62.2%), 8 cross-sectional (22.2%), 4 RCTs (11.1%), and 1 case-control study (2.8%). Neuroimaging revealed dose-dependent alterations including reduced prefrontal cortical and hippocampal/amygdala volumes, accelerated cortical thinning in longitudinal studies, and impaired white matter connectivity correlating with initiation age. Cognitive findings were mixed — some showed persistent deficits after prolonged abstinence in adolescent-onset users, others found no effects after controlling for confounders. Epidemiological studies consistently showed elevated addiction risk (ORs 3.9–7.2) in adolescents versus adults. Long-term associations included educational difficulties, mental health problems, and functional impairment, though causal relationships remained unclear.ConclusionsAdolescent cannabis use associates with structural brain changes, elevated addiction risk, and variable cognitive effects, suggesting greater vulnerability versus adult-onset use. However, methodological limitations including confounders, heterogeneous definitions, and observational designs limit causal inference. Findings support age-specific prevention and specialized interventions while highlighting needs for rigorous longitudinal research establishing causality.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifierCRD420251165329.

A longitudinal inquiry into the vicious cycle of social media addiction and self-injury: the moderating role of resilience

BackgroundThe reciprocal relationship between social networking addiction (SNA) and non-suicidal self-injury (NSSI) represents a critical, yet poorly understood, feedback loop in adolescent psychopathology. This study aimed to longitudinally test a “vicious cycle” model, examining the bidirectional effects between SNA and NSSI, and to investigate psychological resilience as a potential protective factor that could disrupt this harmful dynamic.MethodsA three-wave longitudinal study was conducted with a large cohort of 2,628 Chinese high school students (mean age = 16.1 years; 53.1% female) over a 12-month period. Participants completed measures of SNA, NSSI frequency, and psychological resilience at each wave. A cross-lagged panel model (CLPM) was used to examine the reciprocal, prospective relationships between SNA and NSSI. A multi-group CLPM was then employed to test the moderating role of resilience.ResultsThe CLPM revealed significant, positive, and reciprocal cross-lagged effects. SNA at T1 and T2 prospectively predicted increases in NSSI at T2 and T3, respectively (βs = .19 and.17). Conversely, NSSI at T1 and T2 prospectively predicted increases in SNA at T2 and T3 (βs = .14 and.12), providing robust evidence for a vicious cycle. Furthermore, resilience significantly moderated the pathway from SNA to NSSI. For adolescents with low resilience, the effect was strong and significant (β = .25), whereas for those with high resilience, the effect was rendered non-significant (β = .07).ConclusionsSocial networking addiction and non-suicidal self-injury are not merely comorbid but are locked in a mutually reinforcing developmental spiral over time. However, this dangerous cycle is not deterministic. Psychological resilience acts as a powerful protective buffer, effectively uncoupling the link from addictive social media use to self-harm. These findings underscore the urgent need for integrated, dual-focus interventions that address both online and offline maladaptive behaviors, while championing resilience-building as a primary strategy for prevention.

Psychedelics get a boost from the White House

President Trump recently signed an executive order which aims to increase access to psychedelic drug treatments. He was joined at the signing by podcaster Joe Rogan, who said he’ ha’d messaged the president about research on the psychedelic ibogaine. 

In this week’s STATus Report, host Alex Hogan chats with STAT Washington correspondent Daniel Payne about what the executive order does and doesn’t do. Hogan also looks at why ibogaine, and psychedelic drugs more broadly, are increasingly being taken seriously for stubbornly hard-to-treat conditions like addiction, depression, and PTSD.

Rational causal induction from events in time.

Psychological Review, Vol 133(3), Apr 2026, 584-618; doi:10.1037/rev0000570

A longstanding focus in the causal learning literature has been on inferring causal relations from contingencies, where these abstract away from time by collating independent instances or by aggregating over regularly demarcated trials. In contrast, individual causal learners encounter events in their daily lives that occur in a continuous temporal flow with no such demarcation. Consequently, the process of learning causal relationships in naturalistic environments is comparatively less understood. In this article, we lay out a rational framework that foregrounds the role of time in causal learning. We work within the Bayesian rational analysis tradition, starting by considering how causal relations induce dependence between events in continuous time and how this can be modeled by stochastic processes from the Poisson–Gamma distribution family. We derive the qualitative signatures of causal influence and the general computations needed to infer structure from temporal patterns. We show that this rational account can parsimoniously explain the human preference for causal models that invoke shorter, more reliable, and more predictable causal influences. Furthermore, we show this provides a unifying explanation for human judgments across a wide variety of tasks in the reanalysis of seven experimental data sets. We anticipate the framework will help researchers better understand the many manifestations of continuous-time causal learning across human cognition and the tasks that probe it, from explicit causal structure induction settings to implicit associative or reinforcement learning settings. (PsycInfo Database Record (c) 2026 APA, all rights reserved)

STAT+: Trump’s boosting of psychedelics, cannabis signal a new era in GOP drug policy

The days of “Just Say No,” it seems, are long gone. 

Over the weekend, President Trump signed an executive order to increase the availability of certain psychedelics as treatments for mental health conditions, ordering that $50 million be spent, and that the Food and Drug Administration fast-track reviews to usher in their approval. At one point, the president joked to the motley assembly of administration officials, a former Navy SEAL, and the podcaster Joe Rogan:  “Can I have some, please?” 

On Wednesday, the Trump administration announced it had downgraded medical marijuana from the highest tier of controlled substances, and was pushing the Drug Enforcement Administration to do the same for recreational marijuana.

The president’s lenient tack on some mind-altering drugs ushers in a new world of right-wing drug policy. While the administration has emphasized hardline, militaristic tactics when it comes to fentanyl, its recent actions on “softer” drugs could represent a new era not just for Republican politics but also for American drug policy writ large. 

“With this imminent move, we are now confronted with the most pro-drug administration in our history,” Kevin Sabet, the CEO of the anti-legalization advocacy group Smart Approaches to Marijuana, said in a statement. “Policy is now being dictated by marijuana CEOs, psychedelics investors, and podcasters in active addiction — it is a travesty and injustice to the American people of unprecedented proportions. The marijuana industry is the new Big Tobacco, and President Trump is welcoming them to the homes of families across this country with open arms.”

Continue to STAT+ to read the full story…

The temporal stability of core symptoms of social media addiction and their comorbidity with anxiety and depression in adolescents: a longitudinal network analysis

IntroductionSocial media addiction (SMA) is often comorbid with anxiety and depression. This study examined the temporal stability of core SMA symptoms and the bridging symptoms with anxiety and depression.MethodsA total of 1,240 adolescents (179 males, 1,061 females; mean age = 15.46 ± 0.63 years, age range: 14 – 18) completed the Bergen Social Media Addiction Scale (BSMAS), the Patient Health Questionnaire–9 (PHQ–9), and the Generalized Anxiety Disorder–7 (GAD–7) on two separate occasions in 2023 (T1) and 2024 (T2). The four symptom networks, including the BSMAS networks, two comorbidity networks (the BSMAS–GAD and the BSMAS–PHQ), and the integrated BSMAS–GAD–PHQ network, were estimated using Gaussian graphical models. Core symptom centrality was assessed using Expected Influence (EI), whereas bridge symptoms were identified using Bridge Expected Influence (BEI).Results1) Although SMA, anxiety, and depression levels of respondents rose significantly over the year, all four networks showed strong temporal stability, with the edge weights (r = .892 –.973, p < .001), the EI (r = .806 – .961, p ≤ .002), and the BEI (r = .699 – .804, p ≤ .008) highly correlated between T1 and T2; network comparison tests showed no significant changes in overall structures of all four networks, with most edges showing stable weights. 2) Within the BSMAS network, BSMAS2 (tolerance) and BSMAS6 (conflict) exhibited the highest EI at both time points. 3) In the comorbidity networks, BSMAS3 (mood modification), BSMAS5 (withdrawal), and BSMAS6 (conflict) consistently served as bridge symptoms on the SMA side at both T1 and T2. 4) Across both time points, PHQ1 (anhedonia) and PHQ7 (concentration problems) exhibited the highest BEI on the depression side, whereas GAD1 (nervousness) and GAD5 (restlessness) did so on the anxiety side. 5) These bridge symptoms were also confirmed in the integrated network.DiscussionThese findings illuminate the temporal persistence and development of symptom relationships, offering a more dynamic understanding of SMA–depression–anxiety comorbidity in adolescents.

Internet addiction among nursing students: application of latent profile analysis and network analysis

BackgroundInternet addiction is widely reported and heterogeneous among nursing students. However, variable-centered approaches may not fully capture profile differences and core symptom patterns, potentially limiting precise interventions. Therefore, identifying distinct profiles and key symptoms is important for informing effective prevention.ObjectiveThis study aims to identify distinct internet addiction profiles among nursing students, explore the characteristics and core symptoms of these profiles, and investigate the factors associated with their variation.MethodsA cross-sectional survey was conducted among undergraduate nursing students from September to November 2025. Latent profile analysis (LPA) and network analysis were performed to characterize the patterns of problematic internet use across identified profiles.ResultLatent Profile Analysis revealed four distinct problematic internet use profiles: No-Problematic Internet Use Profile (17.895%), Low-Problematic Internet Use Profile (41.957%), Moderate-Problematic Internet Use Profile (26.676%), and High-Problematic Internet Use Profile (13.472%). Multinomial logistic regression identified gender, monthly household income, and physical activity as significant factors associated with profile membership. Network analysis highlighted central symptoms specific to each profile: Health-related problems (RP-IH) and compulsive internet use and withdrawal symptoms (Sym-C & Sym-W) exhibited the highest centrality within the Moderate- and High-Problematic Internet Use Profiles.ConclusionInternet addiction among undergraduate nursing students is a heterogeneous phenomenon that can be categorized into four distinct profiles. Our findings clarify key associated factors and identify central symptoms specific to each profile, potentially providing an empirical basis for nursing educators to develop targeted psychological interventions.
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