Tag: Psychology

New research reveals that activating the brain’s reward system through positive anticipation strengthens the immune response and increases antibody production

Can positive anticipation that activates the brain’s reward system strengthen the body’s immune defenses? A new study by Tel Aviv University, the Technion, and Tel Aviv Medical Center (Ichilov), published in the prestigious journal Nature Medicine, provides the first evidence in humans that brain activity associated with the expectation of reward has a measurable effect on the body’s response to a specific vaccine.

Training the Brain’s Reward SystemThe study was conducted through a collaboration between two research groups: the laboratory of Prof. Talma Hendler, from the School of Psychological Sciences and the Gray Faculty of Medical and Health Sciences, together with her former PhD student Dr. Nitzan Lubianiker, at Tel Aviv University and the Sagol Brain Institute at Tel Aviv Medical Center (Ichilov); and the laboratory of Prof. Asya Rolls from The George S. Wise Faculty of Life Sciences, together with her former student Dr. Tamar Koren of the Technion and the Department of Pathology at Tel Aviv Medical Center (Ichilov).

Eighty-five healthy volunteers participated in the experiment. Some underwent special brain training using fMRI neurofeedback technology — a method that enables individuals to learn, in real time, to regulate activity in specific brain regions through reinforcing learning. The aim of the brain training was to increase activity in a key region of the brain’s reward system including  the Ventral Tegmental Area (VTA), which is responsible for dopamine release in the context of mental activity related to the expectation of positive outcomes and motivation to obtain rewards. Participants were instructed to modulate their brain activity using various mental strategies (e.g. thoughts feelings memories) while monitoring positive feedback about the strategy that was saucerful in regulating their brain.

From Brain Activation to Antibodies

Immediately after completing the brain training, all participants received a hepatitis B vaccine. The researchers then tracked the immune response through a series of blood tests, measuring levels of specific antibodies produced following the vaccination.

The results showed that participants who succeeded in significantly increasing activity in the brain’s reward region also demonstrated a greater increase in antibody levels after vaccination. The association was specific to the VTA and was not observed in other brain regions used for control purposes (such as the hippocampus), nor in other reward-system areas linked to different reward-related experiences such as pleasure and satisfaction. In other words, the effect was both anatomically and mentally specific.

Dr. Nitzan Lubianiker, photo credit: Sameer Khan/Fotobuddy

The Role of Positive Anticipation

Furthermore, an in-depth analysis of the mental strategies participants used during training of the VTA (and not other regions) revealed that those who focused on positive anticipation — feelings of excitement, belief in a good outcome, or the expectation of something positive about to happen (such as a favorite food or a long-awaited meeting) — were able to maintain higher VTA brain activity over time, which was also associated with a better immune response. In other words, the researchers identified a link between reward-system brain activity, a mental state of positive anticipation, and the body’s response to an immune challenge.

According to the research team, this is not “positive thinking” in the popular sense or a New Age slogan, but a measurable neurobiological mechanism — related, among other things, to the well-known placebo effect in medicine (a therapeutic response beyond a specific medical intervention). “We show that mental states have a clear brain signature, and that this signature can influence physiological systems such as the immune system,” explain the researchers.

While the study does not propose a substitute for vaccines or medical treatment, it opens the door to new, noninvasive approaches that may one day strengthen immune responses, improve the effectiveness of medical treatments, and even contribute to fields such as immunotherapy and the treatment of chronic immune pathologies. The researchers note that the study’s findings underscore a broader message: the mind–body connection is not merely a theoretical concept, but a real biological process that can be measured, trained, and potentially harnessed to promote better health.

 Prof. Talma Hendler, Photo credit: Tel Aviv Medical Center (Ichilov).

Implications for Medicine and Health

The research team adds that the findings highlight the potential inherent in integrating neuroscience, psychology, and medicine. “Our study shows that the brain is not only a system that responds to the body’s state of health, but also an active player that influences it,” say Prof. Talma Hendler, Prof. Asya Rolls, Dr. Nitzan Lubianiker, and Dr. Tamar Koren. “The ability to consciously activate brain mechanisms associated with positive anticipation opens a new avenue for research and future treatments — as a complement to existing medicine, not as a replacement. In the future, it may be possible to develop simple, noninvasive tools to help strengthen immune responses and enhance the effectiveness of medical treatments by relying on the brain’s natural capacity to influence the body. However, it is important to emphasize that activation of the reward system and its effect on immune response vary between individuals. Therefore, this approach cannot replace existing medical treatments, but may well serve as an additional supportive component.”

New TAU study shows facial mimicry is part of how we make choices

Imagine sitting across from someone describing two movies to you. You listen attentively, trying to decide which one interests you more — but during that time, without noticing, your face already reveals what you prefer. You smile slightly when they smile, raise your eyebrows when they surprise you, and tense your muscles when they emphasize something. This phenomenon is called facial mimicry — and it turns out to be a better predictor of your choice than anything else.

This is the central finding of a new study from the School of Psychological Sciences at Tel Aviv University, led by doctoral student Liron Amihai in the lab of Prof. Yaara Yeshurun (together with Elinor Sharvit and Hila Man), in collaboration with Prof. Yael Hanein of TAU’s Fleischman Faculty of Engineering. The study was published in Communications Psychology.

Tracking the Smallest Facial Movements

The study was conducted with dozens of pairs in which one person described two different films to their partner, after which the participants had to choose which film they preferred to watch. Using unique technology, the research team was able to track micro-movements of the face that are not visible to the naked eye.

Research team – Left to right – Prof. Yaara Yeshurun & Liron Amihai

The findings showed that participants consistently preferred the option during which they showed more mimicry of the speaker’s positive expressions . They did so even when they were explicitly instructed to choose according to their personal taste and not according to the speaker.

This finding is particularly interesting given that the listeners’ own facial expressions (for example, how much they smiled in general) did not predict their choice, but rather the degree to which they mimicked the speaker.

Even Without Seeing a Face

In another phase of the experiment, participants listened to an actress reading the movie summaries using audio only, without any video. Even though they could not see her face, the researchers found that the participants mimicked her “smile in the voice” and this mimicry again predicted their choice.

The research team: “The study indicates that facial mimicry is not only a social mechanism that helps us connect with other people. It likely also serves as an ‘internal signal’ to the brain that is indexing agreement.”

Illustration of a participant in the study with an EMG electrode measuring her facial expressions activation

More Than Politeness

Liron Amihai explains: “The study showed that we are not just listening to a story — we are actually being ‘swept’ toward the speaker with our facial expressions’ mimicry, and this muscular feedback might influence our decisions. This mimicry often happens automatically, and it can predict which option we will prefer long before we think about it in words. Facial mimicry, therefore, is not merely a polite gesture, but also a part of the decision-making system.”

Liron concludes: “With the help of this technology and these findings, we may be able in the future to build systems that identify emotional preferences naturally — without asking a single question.
In conclusion, the study illustrates that decision-making is not only a matter of thought — but also of feeling, bodily response, and unconscious communication. Facial mimicry emerged as a significant predictor of our preferences. This is a meaningful step toward understanding how we choose, feel, and empathize with others, and it has many implications for the worlds of advertising, marketing, and decision-making processes.”

A new TAU–Ichilov study shows that tracking eye movements can assess memory more accurately than verbal reports, with potential use for infants, Alzheimer’s patients, and brain injury victims.

Researchers from Tel Aviv University and Tel Aviv Sourasky Medical Center (“Ichilov”) have measured subjects’ memory without asking whether they remembered something or not – -simply by tracking their eye movements as they watched animation videos. The study demonstrated that people actually remember more than they report. Moreover, this method can be used to measure memory in subjects who cannot speak— including infants, patients with brain injuries, and even animals.

The groundbreaking study was led by Dr. Flavio Jean Schmidig, Daniel Yamin, Dr. Omer Sharon, and Prof. Yuval Nir from the Sagol School of Neuroscience, the Gray Faculty of Medical and Health Sciences, and the Fleischman Faculty of Engineering at Tel Aviv University, as well as the Sagol Brain Institute at the Tel Aviv Sourasky Medical Center (“Ichilov”). The paper was published in Communications Psychology.

Beyond Traditional Memory Tests

“Memory is usually tested through direct questioning, with subjects verbally reporting whether they remember a certain event,” explains Dr. Flavio Schmidig, currently completing his postdoctoral research in Prof. Yuval Nir’s lab at TAU. “For example, a subject might be shown a picture and asked if they remember having seen it before. However, this type of testing cannot be performed on animals, infants, patients with advanced Alzheimer’s, or people with head injuries who cannot speak. In this study we wanted to test memory in a more natural way, without asking people to remember.”

“Gaze Memory” Illustration by Ana Yael

Inside the Experiment

In the study, 145 healthy subjects watched specially created animation videos that included a surprising event –  for example, a mouse suddenly jumping out of the corner of the frame. Tracking the subjects’ eye movements  across two separate viewings of the same films, the researchers found that during the second viewing, subjects shifted their gaze toward the area where the surprising event was about to occur. A comparison of eye movement data with verbal memory reports indicated that gaze direction was in fact a more accurate measure.  In some cases, subjects said they did not remember the mouse, yet their gaze indicated that they did.

“The study proves that tracking eye movements can be an excellent alternative to verbal questions such as ‘Do you remember this?’,” says Daniel Yamin. “In a series of experiments, we demonstrated that gaze direction is a very sensitive gage of memory. Even when subjects said they didn’t remember, their gaze direction showed they did. This means that sometimes people remember, but can’t say that they remember. By using AI machine learning techniques, it is possible to infer automatically, from just a few seconds of eye tracking, whether someone has seen a video before and formed a memory of it.”

“When I ask you if you remember,” adds Dr. Sharon, “you might give any of several answers: yes, no, not sure, etc. But when you look to the left of the frame due to a vague memory that something is about to happen there, finer nuances can be discerned. Now we have a tool for testing to what extent memory is present. Our new method is also more natural than traditional memory tests.”

Looking Ahead

“The results of this study are especially relevant when verbal reports on memory cannot be obtained,” adds Prof. Yuval Nir, the study’s supervisor. “We believe that in the future this new method may be used for measuring memory functions in infants, Alzheimer’s patients, and people with brain injury whose speech ability has been impaired. Gaze direction can be simply detected by the camera of a laptop or smartphone as the subject views a video – with no need for large, sophisticated equipment. The method has the potential for identifying memories even in situations that have so far been out of reach for us as scientists and clinicians.”