The Flanker Task: Measuring Focus Under Pressure
The flanker task is a
well-established neuroscience tool assessing attention and inhibitory control –
essentially, the brain's ability to focus on the central task and ignore
distractions. Participants must quickly identify the direction of a central arrow
while ignoring surrounding "flanker" arrows pointing either the same
way (easy) or the opposite way (hard). Success depends on processing speed and
accuracy under distraction.
Machine Learning Cuts Through Complexity
Led by Professor Naiman Khan and
PhD student Shreya Verma, the team fed data from 374 adults (ages 19-82) into
various machine learning algorithms. This data included:
- Age,
BMI, blood pressure (systolic & diastolic)
- Physical
activity levels
- Dietary
patterns (assessed via the Healthy Eating Index)
- Performance
metrics from the flanker task
"Standard
statistical approaches cannot embrace this level of complexity all at
once," explained Khan. "Machine learning offers a promising avenue
for analyzing large datasets with multiple variables and identifying patterns
that may not be apparent through conventional approaches."
The algorithms
were rigorously tested and validated to determine which factors most accurately
predicted how quickly participants could respond correctly on the flanker test.
The Hierarchy of Cognitive Influencers Emerges
The machine learning model revealed a clear hierarchy of
influence:
- Age: The
strongest predictor, confirming known declines in processing speed with
aging.
- Diastolic
Blood Pressure: Emerged as the second most influential factor.
- Body
Mass Index (BMI): Closely followed diastolic BP.
- Systolic
Blood Pressure: Also a major predictor.
- Diet
(Healthy Eating Index): Played a smaller, but still relevant and
statistically significant role.
- Physical
Activity: Emerged as a moderate predictor.
- Diet & Exercise as Compensators: While
diet ranked lower than blood pressure and BMI, the analysis suggested its
power might lie in interaction. Healthy eating and physical activity
appeared to sometimes offset the negative cognitive
effects associated with higher BMI or other detrimental factors.
"Physical activity emerged as a moderate predictor... with results
suggesting it may interact with other lifestyle factors, such as diet and
body weight, to influence cognitive performance," Khan noted.
- Blood Pressure's Crucial Role: The
prominence of both systolic and diastolic blood pressure highlights
cardiovascular health as a critical pillar of brain health, potentially
influencing blood flow and vessel integrity in the brain.
- BMI's Cognitive Cost: The strong link
between higher BMI and poorer flanker performance underscores the systemic
impact of body weight on neurological function.
The study
acknowledges that established brain-healthy diets like DASH, Mediterranean, and
MIND have shown protective effects against cognitive decline. However, this ML
approach suggests that in the complex interplay of factors influencing real-time
cognitive performance (like the flanker task), direct physiological
markers like blood pressure and body weight might have a more immediately
measurable impact than overall dietary patterns alone.
"Clearly,
cognitive health is driven by a host of factors, but which ones are most
important?" asked Verma. "We wanted to evaluate the relative strength
of each of these factors in combination with all the others."
The findings
point towards a future where machine learning helps tailor interventions.
"This study reveals how machine learning can bring precision and nuance to
the field of nutritional neuroscience," Khan stated. "By moving
beyond traditional approaches, machine learning could help tailor strategies
for aging populations, individuals with metabolic risks or those seeking to
enhance cognitive function through lifestyle changes."
While eating
well and staying active remain vital components of a brain-healthy lifestyle,
this cutting-edge machine learning study emphasizes that managing blood
pressure and maintaining a healthy weight may be even more critical for
preserving sharp focus and quick cognitive processing as we age. It
underscores the interconnectedness of cardiovascular health, metabolic health,
and brain function, providing a clearer roadmap for interventions aimed at
maintaining cognitive vitality.