Categories
Healthcare Medicine Policy

What should society do about safe and effective application of AI to healthcare?

In a world awash with the rapid tide of generative AI technologies, governments are waking up to the need for a guiding hand. President Biden’s Executive Order is an exemplar of the call to action, not just within the halls of government but also for the sprawling campuses of tech enterprises. It’s a call to gather the thinkers and doers and set a course that navigates through the potential perils and benefits these technologies wield. This is more than just a precaution; it’s a preemptive measure. Yet these legislative forays are more like sketches than blueprints, in a landscape that’s shifting, and the reticence of legislators is understandable and considered. After all, they’re charting a world where the very essence of our existence — our life, our freedom, our joy — could be reshaped by the tools we create.

On a brisk autumn day, the quiet serenity of Maine became the backdrop for a gathering: The RAISE Symposium, held on October 30th, which drew some 60 souls from across five continents. Their mission? To venture beyond the national conversations and the burgeoning frameworks of regulation that are just beginning to take shape. We convened to ponder the questions of generative AI — not in the abstract, but as they apply to the intimate dance between patient and physician. The participants aimed to cast a light on the issues that need to be part of the global dialogue, the ones that matter when care is given and received. We did not an attempt to map the entirety of this complex terrain, but to mark the trails that seemed most urgent.

The RAISE Symposium’s attendees raised (sorry) a handful of issues and some potential next steps that appeared today in the pages of NEJM AI and Nature Medicine. Here I’ll focus on a singular quandary that seems to hover in the consultation rooms of the future: For whom does the AI’s medical counsel truly toll? We walk into a doctor’s office with a trust, almost sacred, that the guidance we receive is crafted for our benefit — the patient, not the myriad of other players in the healthcare drama. It’s a trust born from a deeply-rooted social contract on healthcare’s purpose. Yet, when this trust is breached, disillusionment follows. Now, as we stand on the precipice of an era where language models offer health advice, we must ask: Who stands to gain from the advice? Is it the patient, or is it the orchestra of interests behind the AI — the marketers, the designers, the stakeholders whose fingers might so subtly weigh on the scale? The symposium buzzed with talk of aligning AI, but the compass point of its benefit — who does it truly point to? How do we ensure that the needle stays true to the north of patient welfare? Read the article for some suggestions from RAISE participants.

As the RAISE Symposium’s discussions wove through the thicket of medical ethics in the age of AI, other questions were explored. What is the role of AI agents in the patient-clinician relationship—do they join the privileged circle of doctor and patient as new, independent arbiters? Who oversees the guardianship of patient data, the lifeblood of these models: Who decides which fragments of a patient’s narrative feed the data-hungry algorithms?

The debate ventured into the autonomy of patients wielding AI tools, probing whether these digital oracles could be entrusted to patients without the watchful eye of a human professional. And finally, we contemplated the economics of AI in healthcare: Who writes the checks that sustain the beating heart of these models, and how might the flow of capital sculpt the very anatomy of care? The paths chosen now may well define the contours of healthcare’s landscape for generations to come.

After you have read the jointly written article, I and the other RAISE attendees hope that it will spark discourse between you and your colleagues. There is an urgency in this call to dialogue. If we linger in complacency, if we cede the floor to those with the most to gain at the expense of the patient, we risk finding ourselves in a future where the rules are set, the die is cast, and the patient’s voice is but an echo in a chamber already sealed. It is a future we can—and must—shape with our voices now, before the silence falls.

I could have kicked off this blog post with a pivotal query: Should we open the doors to AI in the realm of healthcare decisions, both for practitioners and the people they serve? However considering “no” as an answer seemed disingenuous. Why should we not then question the very foundations of our digital queries—why, after all, do we permit the likes of Google and Bing to guide us through the medical maze? Today’s search engines, with their less sophisticated algorithms, sit squarely under the sway of ad revenues, often blind to the user’s literacy. Yet, they remain unchallenged gateways to medical insights that sway critical health choices. Given that outright denial of search engines’ role in health decision-making seems off the table and acknowledging that generative AI is already a tool in the medical kit for both doctors and their patients, the original question shifts from a hypothetical to a pragmatic sphere. The RAISE Symposium stands not alone but as one voice among many, calling for open discussions on how generative AI can be safely and effectively incorporated into healthcare.

February 22nd, 2024

Categories
Healthcare Machine Learning Medicine Policy

When is the ‘steering’ of AI worth the squeezing?

Diagram of how RLHF is built atop the pretrained model to steer that pre-trained model to more useful behavoopr.

In population genetics, it’s canon that selecting for a trait other than fitness will increase the likelihood of disease, or at least characteristics that would decrease survival in the “wild”. This is evident in agriculture, where delicious fat corn kernels are embedded in husks so that human assistance is required for reproduction or where breast-heavy chickens have been bred that can barely walk . I’ve been wondering about the nature of the analogous tradeoff in AI. In my experience with large language models (LLM)—specifically GPT-4—in the last 8 months, the behavior of the LLM has changed over the short interval of my experience. Compared to logged prompt/responses I have from November 2022 (some of which appear in a book) the LLM is less argumentative, more obsequious but also less insightful and less creative. This publication now provides plausible, quantified evidence that there has indeed been a loss of performance in only a few months in GPT-3.5 and GPT-4. This in tasks ranging from mathematical reasoning to sociopolitically enmeshed assessments.

This study by Zou and colleagues at Berkeley and Stanford merits its own post for all its implications for how we assess, regulate, and monitor AI applications. But here, I want to briefly pose just one question that I suspect will be at the center of a hyper-fertile domain for AI research in the coming few years: Why did the performance of these LLMs change so much? There may be some relatively pedestrian reasons: The pre-trained models were simplified/downscaled to reduce response time and electricity consumption or other corner-cutting optimizations. Even if that is the case, at the same time, we know because they’ve said so (see quote below), that they’ve continued to “steer” (“alignment” seems to be falling into disfavor) the models using a variety of techniques and they are getting considerable leverage from doing so.

[23:45 Fridman-Altman podcast] “Our degree of alignment increases faster than our rate of capability progress, and I think that will become more and more important over time.”

Much of this steering is driven by human-sourced generation and rating of prompts/responses to generate a model that is then interposed between human users and the pre-trained model (see this post by Chip Huyen from which I copied the first figure above which outlines how RLHF—Reinforcement Learning from Human Feedback—is implemented to steer LLMs). Without this steering, GPT would often generate syntactically correct sentences that would be of little interest to human beings. So job #1 of RLHF has been to generate human relevant discourse. The success of ChatGPT suggests that RLHF was narrowly effective in that sense. Early unexpected antisocial behavior of GPT gave further impetus to additional steering imposed through RLHF and other mechanisms.

The connections between the pre-trained model and the RLHF models are extensive. It is therefore possible that modifying the output of the LLM through RLHF can have consequences beyond the narrow set of cases considered during the ongoing steering phase of development. That possibility raises exciting research questions, a few of which I have listed below.

QuestionElaboration and downstream experiments
Does RLHF degrade LLM performance?What kind of RLHF under what conditions? When does it improve performance?
How does the size and quality of the pre-trained model affect the impact of RLHF?Zou and his colleagues note that for some tasks GPT-3.5 improved whereas GPT-4 deteriorated.
How do we systematically monitor all these models for longitudinal drift?What kinds of tasks should be monitored? Is there an information theoretic basis for picking a robust subset of tasks to monitor?
Can the RLHF impact on LLM performance be predicted by computational inspection of the reward model?Can that inspection be performed without understanding the details of the pre-trained model?
Will we require artificial neurodevelopmental psychologists to avoid crippling the LLMs?Can Susan Calvin (of Asimov robot story fame) determine the impact of RLHF through linguistic interactions?
Can prompting the developers of RLHF prompts mitigate performance hits?Is there an engineered path to developing prompts to make RLHF effective without loss of performance?
Should RLHF go through a separate regulatory process than the pre-trained model?Can RLHF pipelines and content be vetted to be applied to different pre-trained models?

Steering (e.g. through RLHF) can be a much more explicit way of inserting a set of societal or personal values into LLM’s than choosing the data that is used to trained the pre-trained model. For this reason alone, research on the properties of this process is not only of interest to policy makers and ethicists but also to all of us who are working towards the safe deployment of these computational extenders of human competence.


I wrote this post right after reading the paper by Chen, Zaharia and Zou so I know that it’s going to take a little while longer for me to think through what are its broadest implications. I am therefore very interested in hearing your take on what might be good research questions in this space. Also if you have suggestions or corrections to make about this post, please feel free to email me. – July 19th, 2023