Summary: A unique study tracked one person’s brain activity and behavior over five months, revealing how daily habits like sleep, exercise, and mood can impact the brain for days.
Researchers found that brain connectivity adjusts over time, influenced by heart rate, respiration, and physical activity, with even minor mood shifts leaving lasting effects. For instance, heart rate variability during rest strongly correlated with brain connectivity, highlighting how stress management and relaxation impact brain wiring.
This approach shows potential for improving mental health treatments, as personalized, real-time monitoring could help detect subtle neurological changes early.
Key Facts
- Brain activity is influenced by daily habits, with effects lasting up to 15 days.
- Heart rate variability was linked to brain connectivity, especially during rest.
- This study may inform future personalized approaches to mental health care.
Source: Aalto University
In a rare, longitudinal study, researchers from Aalto University and the University of Oulu tracked one person’s brain and behavioral activity for five months using brain scans and data from wearable devices and smartphones.
‘We wanted to go beyond isolated events,’ says research leader Ana Triana. ‘Our behaviour and mental states are constantly shaped by our environment and experiences. Yet, we know little about the response of brain functional connectivity to environmental, physiological, and behavioral changes on different timescales, from days to months.’
The study found that our brains do not respond to daily life in immediate, isolated bursts. Instead, brain activity evolves in response to sleep patterns, physical activity, mood, and respiration rate over many days. This suggests that even a workout or a restless night from last week could still affect your brain — and therefore your attention, cognition and memory — well into next week.
The research also revealed a strong link between heart rate variability — a measure of the heart’s adaptability — and brain connectivity, particularly during rest. This suggests that impacts on our body’s relaxation response, like stress management techniques, could shape our brain’s wiring even when we are not actively concentrating on a task.
Physical activity was also found to positively influence the way brain regions interact, potentially impacting memory and cognitive flexibility. Even subtle shifts in mood and heart rate left lasting imprints for up to fifteen days.
Study goes beyond a snapshot
The research is unusual in that few brain studies involve detailed monitoring over days and weeks. ‘The use of wearable technology was crucial’, says Triana. ‘Brain scans are useful tools, but a snapshot of someone lying still for half an hour can only show so much. Our brains do not work in isolation.’
Triana was herself the subject of the research, monitored as she went about her daily life. Her unique role as both lead author and study participant added complexity, but also brought firsthand insights into how best to maintain research integrity over several months of personalized data collection.
‘At the beginning, it was exciting and a bit stressful. Then, routine settles in and you forget,’ says Triana. Data from the devices and twice-weekly brain scans were complemented by qualitative data from mood surveys.
The researchers identified two distinct response patterns: a short-term wave lasting under seven days and a long-term wave up to fifteen days. The former reflects rapid adaptations, like how focus is impacted by poor sleep, but it recovers quickly. The long wave suggests more gradual, lasting effects, particularly in areas tied to attention and memory.
Single-subject studies offer opportunities for improving mental health care
The researchers hope their innovative approach will inspire future studies that combine brain data with everyday life to help personalise mental health treatment.
‘We must bring data from daily life into the lab to see the full picture of how our habits shape the brain, but surveys can be tiring and inaccurate,’ says study co-author, neuroscientist and physician Dr Nick Hayward.
‘Combining concurrent physiology with repeated brain scans in one person is crucial. Our approach gives context to neuroscience and delivers very fine detail to our understanding of the brain.’
The study is also a proof-of-concept for patient research. Tracking brain changes in real time could help detect neurological disorders early, especially mental health conditions where subtle signs might be missed.
“Linking brain activity with physiological and environmental data could revolutionize personalized healthcare, opening doors for earlier interventions and better outcomes,” says Triana.
About this neuroscience research news
Author: Sarah Hudson
Source: Aalto University
Contact: Sarah Hudson – Aalto University
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Longitudinal single-subject neuroimaging study reveals effects of daily environmental, physiological, and lifestyle factors on functional brain connectivity” by Ana Triana et al. PLoS Biology
Abstract
Longitudinal single-subject neuroimaging study reveals effects of daily environmental, physiological, and lifestyle factors on functional brain connectivity
Our behavior and mental states are constantly shaped by our environment and experiences.
However, little is known about the response of brain functional connectivity to environmental, physiological, and behavioral changes on different timescales, from days to months. This gives rise to an urgent need for longitudinal studies that collect high-frequency data.
To this end, for a single subject, we collected 133 days of behavioral data with smartphones and wearables and performed 30 functional magnetic resonance imaging (fMRI) scans measuring attention, memory, resting state, and the effects of naturalistic stimuli. We find traces of past behavior and physiology in brain connectivity that extend up as far as 15 days.
While sleep and physical activity relate to brain connectivity during cognitively demanding tasks, heart rate variability and respiration rate are more relevant for resting-state connectivity and movie-watching. This unique data set is openly accessible, offering an exceptional opportunity for further discoveries.
Our results demonstrate that we should not study brain connectivity in isolation, but rather acknowledge its interdependence with the dynamics of the environment, changes in lifestyle, and short-term fluctuations such as transient illnesses or restless sleep. These results reflect a prolonged and sustained relationship between external factors and neural processes.
Overall, precision mapping designs such as the one employed here can help to better understand intraindividual variability, which may explain some of the observed heterogeneity in fMRI findings.
The integration of brain connectivity, physiology data and environmental cues will propel future environmental neuroscience research and support precision healthcare.
