Featured Post from University of Florida

Study: What makes a smell bad?

Jan 29, 2026

3 min

You wouldn’t microwave fish around your worst enemy — the smell lingers both in kitchen and memory. It is one few of us like, let alone have positive associations with.

But what makes our brains decide a smell is stinky?

A new study from UF Health researchers reveals the mechanisms behind how your brain decides you dislike — even loathe — a smell.

Or as first author and graduate research fellow Sarah Sniffen puts it: How do odors come to acquire some sort of emotional charge?

In many ways, our world capitalizes upon the importance of smells to influence emotions, running the gamut from perfumes to cooking and even grocery store design.

“Odors are powerful at driving emotions, and it’s long been thought that the sense of smell is just as powerful, if not more powerful, at driving an emotional response as a picture, a song or any other sensory stimulus,” said senior author Dan Wesson, Ph.D., a professor of pharmacology and therapeutics in the UF College of Medicine and interim director of the Florida Chemical Senses Institute.

But until now, researchers have puzzled over what circuitry connects the parts of the brain vital to generating an emotional response with those responsible for smell perception.

The team started off with the amygdala, a brain region that curates your emotional responses to sensory stimuli. Although all our senses (sound, sight, taste, touch and smell) interact with this small part of your brain, the olfactory system takes a more direct route to it.

“This is, in part, what we mean when we say your sense of smell is your most emotional sense,” Sniffen said. “Yes, smells evoke strong, emotional memories, but the brain’s smell centers are more closely connected with emotional centers like the amygdala.”

In the study, researchers looked at mice, who share neurochemical similarities with people. They can learn about odors and categorize them as good or bad.

After observing their behavior and analyzing brain activity, the team found two genetically unique brain cell types that allow odors to be assigned into a bucket of good feelings or bad feelings.

Initially, the team expected that one cell type would generate a positive emotion to an odor, and another would generate a negative emotion. Instead, the brain’s cellular organization gives the cells the capability of doing either.

“It can make an odor positive or negative to you,” Wesson said. “And it all depends upon where that cell type projects in your brain and how it engages with structures in your brain.”

But why is knowing more about how we categorize smells important? Well, for starters, smells — and our reactions to them — are a part of life. Sometimes, however, our reactions to them can be outsized, or take on a negative association so strong it disrupts how we live.

“We’re constantly breathing in and out and that means that we’re constantly receiving olfactory input,” Sniffen said. “For some people that’s fine, and it doesn’t impact their day-to-day life. They might even think, ‘Oh, odors don’t matter that much.’ But for people who have a heightened response to sensory stimuli, like those with PTSD or anxiety or autism, it’s a really important factor for their day-to-day life.”

In the future, the research could help clinicians adjust for heightened sensory response that some people struggle with in their everyday lives, Wesson added. One example? A patient associating a clinic’s smell with transfusions that made them queasy.

Based upon the receptor systems in these specific brain pathways, the team members believe they might be able to change those associations.

Potentially, medications could suppress some of these pathways’ activity to allow you to overcome stressful and aversive emotional responses.

Conversely, these pathways could be activated to restore enjoyment to things that people might have grown indifferent to — like those who lose their appetite from illness.

“Emotions in part dictate our quality of life, and we’re learning more about how they arise in our brain,” Wesson said. “Understanding more about how our surroundings can impact our feelings can help us become happier, healthier humans.”

This research was supported by funding from the National Institute on Deafness and Other Communication Disorders and the National Institute on Drug Abuse. Sarah Sniffen was supported by a fellowship from the National Institute on Deafness and Other Communication Disorders.

Connect with:

Daniel Wesson

Associate Professor | Chair

Daniel Wesson is an expert in the sense of smell and how the brain processes sensory information.

AddictionBrain FunctionElectronic CigarettesSensory ProcessingSmell, Learning & Memory

Find Experts

Apr 12, 2026

3 min

Study finds most cancer patients exposed to misinformation; UF researchers pilot 'information prescription'

Ninety-three percent of patients with a new cancer diagnosis were exposed to at least one type of misinformation about cancer treatments, a UF Health Cancer Center study has found. Most patients encountered the misinformation — defined as unproven or disproven cancer treatments and myths or misconceptions — even when they weren’t looking for it. The findings have major implications for cancer treatment decision-making. Specifically, doctors should assume the patient has seen or heard misinformation. “Clinicians should assume when their patients are coming to them for a treatment discussion that they have been exposed to different types of information about cancer treatment, whether or not they went online and looked it up themselves,” said senior author Carma Bylund, Ph.D., a professor and associate chair of education in the UF Department of Health Outcomes and Biomedical Informatics. “One way or another, people are being exposed to a lot of misinformation.” Working with oncologists, Bylund and study first author Naomi Parker, Ph.D., an assistant scientist in the UF Department of Health Outcomes and Biomedical Informatics, are piloting an “information prescription” to steer patients to sources of evidence-based information like the American Cancer Society. The study paves the way for other similar strategies. Most notably, the study found the most common way patients were exposed to misinformation was second hand. “Your algorithms pick up on your diagnosis, your friends and family pick up on it, and then you’re on Facebook and you become exposed to this media,” Parker said. “You’re not necessarily seeking out if vitamin C may be a cure for cancer, but you start being fed that content.” And no, vitamin C does not cure cancer. Health misinformation can prevent people from getting treatment that has evidence behind it, negatively affect relationships between patients and physicians, and increase the risk of death, research has shown. People with cancer are particularly vulnerable to misinformation because of the anxiety and fear that comes with a serious diagnosis, not to mention the overwhelming amount of new information they have to suddenly absorb. While past research has studied misinformation by going directly to the source — for instance, studying what percentage of content on a platform like TikTok is nonsense — little research has looked at its prevalence or how it affects people. The team first developed a way to identify the percentage of cancer patients exposed to misinformation. UF researchers collaborated with Skyler Johnson, M.D., at Huntsman Cancer Institute, an internationally known researcher in the field. The survey questions were based on five categories of unproven or disproven cancer treatments — vitamins and minerals, herbs and supplements, special diets, mind-body interventions and miscellaneous treatments — and treatment misconceptions. The myths and misconceptions were adapted from National Cancer Institute materials and included statements like “Will eating sugar make my cancer worse?” The team surveyed 110 UF Health patients diagnosed with prostate, breast, colorectal or lung cancer within the past six months, a time when patients typically make initial treatment decisions. Most had heard of a potential cancer treatment beyond the standard of care, and most reported they had heard of at least one myth or misconception. The most common sources were close friends or family and websites, distant friends/associates or relatives, social media and news media. The findings mark a shift in misinformation research, with major implications for the doctor-patient relationship, said Bylund, a member of the Cancer Control and Population Sciences research program at the UF Health Cancer Center. “I still think media and the internet are the source and why misinformation can spread so rapidly, but it might come to a cancer patient interpersonally, from family or friends,” she said. Most patients rarely discussed the potential cancer treatments they had heard about with an oncologist, the study also found. Next, the researchers plan to survey a wider pool of patients, then study the outcomes of interventions designed to decrease misinformation exposure, like the information prescription.

Apr 9, 2026

2 min

New AI tool matches students with high-impact internships

Finding the right internship can be an important step for students, but it’s not always clear which opportunities will lead to the strongest growth. To help solve that problem, University of Florida researchers have developed an AI-powered tool that helps students identify internships most likely to accelerate their technical and professional development. Unlike traditional recommendation engines, Pro-CaRE not only predicts which opportunities will lead to stronger outcomes, it also explains why each suggestion is a good fit. In testing data collected from the students, Pro-CaRE’s predictions proved highly accurate, accounting for more than 72% of the differences in learning gains among participants. While the pilot is being tested in engineering, the tool could be adopted for other disciplines. “Internships are one of the most critical parts of an engineering education, but students often struggle to know which experiences will actually help them grow,” said Jinnie Shin, assistant professor of research and evaluation methodology in the UF College of Education. “What makes Pro-CaRE unique is that it doesn’t just offer a list of options. It provides personalized recommendations backed by data and it tells students clearly why an opportunity is a good match for them.” Pro-CaRE creates matches by analyzing each student’s coursework, major, background and self-reported interest, confidence and self-efficacy in engineering skills. It then compares that profile with a carefully chosen set of similar peers to refine suggestions. The result is more precise guidance that adapts to students at different stages of their degree programs. “Students shouldn’t have to guess or hope that an internship will be worthwhile,” Shin said. “With Pro-CaRE, they can approach opportunities knowing they’re backed by evidence, whether the role is onsite, hybrid or remote and whether it’s at a startup or a Fortune 500 company.” The system is designed to work across a wide range of companies and contexts, giving students flexibility while ensuring their choices align with their personal and professional goals. Each recommendation comes with a clear “why this?” explanation, so students can make confident decisions and discuss options more effectively with advisors. Pro-CaRE was developed by a cross-disciplinary UF team combining expertise in education and engineering. Alongside Shin, the project’s co-principal investigators include Kent Crippen in the College of Education and Bruce Carroll in the Herbert Wertheim College of Engineering. The team is exploring external funding opportunities to expand the usage and test the efficacy on a larger scale. “Ultimately, our goal is to empower students to invest their time in experiences that will have the greatest impact,” Shin said. “Pro-CaRE bridges the gap between what students hope to gain and what internships can truly deliver.”

Apr 7, 2026

2 min

Using AI tools empowers and burdens users in online Q&A communities

Whether you’ve searched for cooking tips on Reddit, troubleshooted tech problems on community forums or asked questions on platforms like Quora, you’ve benefited from online help communities. These digital spaces rely on people across the world to contribute their knowledge for free, and have become an essential tool for solving problems and learning new skills. New research reveals that generative artificial intelligence tools like ChatGPT are creating a double-edge effect on users in these communities, simultaneously making them more helpful while potentially overwhelming them to the point of decreasing their responses. “On the positive side, AI helps users learn to write more organized and readable answers, leading to a noticeable increase in the number of responses,” explained Liangfei Qiu, Ph.D., study coauthor and PricewaterhouseCoopers Professor at the University of Florida Warrington College of Business. “However, when users rely too heavily on AI, the mental effort required to process and refine AI outputs can actually reduce participation. In other words, AI both empowers and burdens contributors: it enables more engagement and better readability, but too much reliance can slow people down.” The study examined Stack Overflow, one of the world’s largest question-and-answer coding platforms for computer programmers, to investigate the impact of generative AI on both the quality and quantity of user contributions. Qiu and his coauthor Guohou Shan of Northeastern University’s D’Amore-McKim School of Business measured the impact of AI on users’ number of answers generated per day, answer length and readability. Specifically, they found that users who used AI tools to generate their responses contributed almost 17% more answers per day compared to those who didn’t use AI. The answers generated with AI were both shorter by about 23% and easier to read. However, when people relied too heavily on AI tools, their participation decreased. Qiu and Shan noted that the additional cognitive burden associated with heavier AI usage negatively affected the impact on a user’s answer quality. For online help communities grappling with AI policies, this research provides valuable insight into how these policies can be updated in the current AI environment. While some communities, like Stack Overflow, have banned AI tools, this research suggests that a more nuanced approach could be a better solution. Instead of banning AI entirely, the researchers suggest striking a balance between allowing AI usage while promoting responsible and moderated use. This approach, they argue, would enable users to benefit from efficiency and learning opportunities, while not compromising quality content and user cognition. “For platform leaders, the takeaway is clear: AI can boost participation if thoughtfully integrated, but its cognitive demands must be managed to sustain long-term user contributions,” Qiu said.