Enhancing Inhibitory Control in Older Adults: A Biofeedback Study

The study by Tinello and colleagues (2023) draws on contemporary models of executive functioning that treat inhibitory control as multidimensional rather than a single, unitary ability.

What is the Science?

Inhibitory control refers to the capacity to suppress irrelevant information, resist distractions, and withhold inappropriate responses in the service of goal-directed behavior. Research on aging has shown that certain components of inhibition become particularly vulnerable in later life, with meaningful consequences for independence, emotional regulation, and everyday functioning.

At the same time, the field increasingly views neurocognitive aging as plastic rather than fixed, thereby opening the door to interventions targeting the physiological systems that support cognition.

Two physiological systems are central to this work. The first is autonomic regulation, indexed by heart rate variability (HRV), which reflects the dynamic balance between sympathetic and parasympathetic influences on the heart.

Higher resting HRV is associated with better executive functioning and emotion regulation, consistent with the neurovisceral integration model linking prefrontal networks to autonomic control. This relationship has direct clinical relevance, as HRV biofeedback is increasingly used in mental health practice to help clients improve self-regulation.

The second system involves cerebral hemodynamics in the prefrontal cortex. Through neurovascular coupling, increased neural activity is accompanied by increased local blood oxygenation, providing a physiological window into cortical engagement during cognitive effort.

By combining HRV biofeedback with near-infrared hemoencephalography (nirHEG) neurofeedback, the authors position their intervention at the intersection of central and peripheral regulation.

The theoretical premise is that training individuals to self-regulate both autonomic activity and prefrontal blood oxygenation may enhance specific components of inhibitory control that rely on prefrontal circuitry.

For clinicians working with older adults, this dual-target approach represents an innovative extension of single-modality biofeedback protocols.

What Did They Study?

The authors investigated whether a 10-week multimodal biofeedback intervention could improve inhibitory control in healthy older adults. Importantly, they did not treat inhibition as a single outcome. Instead, they distinguished between interference control, which involves resisting distracting or competing information, and response inhibition, which involves withholding a prepotent motor response. This distinction aligns with neurocognitive evidence showing partially dissociable neural substrates for these functions and has practical implications for intervention design.

Thirty-four adults aged 65 to 80 were randomly assigned to either an active biofeedback group or an active control group. All participants were cognitively healthy at baseline and free of major neurological or cardiovascular conditions. The intervention group received combined HRV biofeedback and nirHEG neurofeedback once per week for 10 weeks, along with recommendations for home practice of slow-paced breathing.

The control group followed the same schedule, wore the same sensors, and viewed the same visual material, but did not receive real-time physiological feedback. Instead of home breathing practice, they were asked to read articles at home.

In addition to behavioral measures of inhibitory control, the study assessed physiological outcomes, including resting HRV and prefrontal blood oxygenation, both at rest and during training. This design allowed the authors to examine not only whether cognition changed, but also whether the intervention meaningfully engaged the targeted physiological systems.

How Did They Do It?

Participants completed a comprehensive baseline assessment that included computerized and paper-based cognitive tasks, followed by physiological recordings. Interference control was measured using an Arrows task and a Stroop task, while response inhibition was assessed with a Go/No Go task. These tasks were chosen to tap different inhibitory demands and response modalities.

Physiological assessment involved 5-minute resting HRV recordings and near-infrared measurements of blood oxygenation over three prefrontal sites corresponding to standard EEG positions (Fp1, Fpz, Fp2). HRV was quantified using time-domain measures sensitive to parasympathetic activity and overall autonomic regulation, specifically the SDNN and RMSSD, metrics familiar to clinicians who use HRV in practice.

During the intervention phase, participants in the biofeedback group first completed HRV biofeedback sessions focused on slow-paced breathing at each individual's resonance frequency. Visual and auditory feedback signaled successful regulation of autonomic activity, and participants were encouraged to practice paced breathing at home between sessions.

After a brief break, they engaged in nirHEG neurofeedback, during which changes in prefrontal blood oxygenation were translated into game-like visual feedback. The control group received the same setup and duration but without contingent feedback and was encouraged to read articles at home rather than practice breathing.

After 10 weeks, all participants repeated cognitive and physiological assessments. The authors then used repeated-measures statistical models to evaluate pre-to-post intervention changes, group differences, and interactions with baseline physiological status.

What Did They Find Regarding Inhibitory Control?

The results revealed a nuanced pattern rather than uniform improvement across all outcomes. In the domain of inhibitory control, the biofeedback group showed a significant reduction in interference effects on the Arrows task, indicating improved efficiency in resolving competing spatial information. This improvement was not observed in the control group.

In contrast, no training-related benefits were observed for response inhibition, as measured by the Go/No-Go task, where performance was already near ceiling in both groups.

Findings from the Stroop task showed that while the control group exhibited slower responses at post-test, suggesting possible fatigue or reduced self-regulation under pressure, the biofeedback group maintained stable performance. This pattern implies that the intervention may have supported resilience against performance decline rather than producing overt gains on this more demanding verbal task.

Physiologically, HRV increased after training in participants who had low baseline HRV, but only in the biofeedback group. Participants with higher baseline HRV showed no significant gains. This finding is clinically meaningful because it suggests that those with the greatest physiological vulnerability may derive the most benefit from biofeedback training.

Prefrontal blood oxygenation at rest did not show significant pre-post changes. However, during training sessions, participants in the biofeedback group demonstrated significantly greater increases in blood oxygenation, particularly at the midline prefrontal site (Fpz), indicating successful real-time engagement of the targeted neural system.

What Were the Strengths and Limitations?

A major strength of this study lies in its multimodal design and its theoretically informed separation of inhibitory subcomponents.

By randomizing subjects to an HRV plus nirHEG biofeedback condition and to a control group exposed to the same environment without feedback, the authors strengthened causal inferences about the role of biofeedback itself.

The integration of behavioral and physiological outcomes provides a richer account of how and for whom the intervention may be effective.

At the same time, several limitations temper the conclusions. The sample size was modest, in part due to pandemic-related constraints, limiting statistical power and generalizability. Some cognitive measures, particularly response inhibition, were affected by ceiling effects, reducing sensitivity to change. Although the intervention period was substantial, it may still have been too brief to induce lasting changes in resting cerebral oxygenation or to generalize to untrained tasks.

The authors conformed to many of the consensus statement's research recommendations for neurofeedback (Ros et al., 2020). Still, their control-group methods left several questions requiring further exploration through experimentation (Freedland et al., 2011), for example, whether groups differed in their levels of expectancy.

Finally, the sample consisted of healthy, well-educated older adults, leaving open the question of whether larger effects would emerge in more vulnerable or clinical populations.

What Was the Impact?

This study is the first to examine the combination of HRV and nirHEG biofeedback for healthy older adults.

It provides some evidence that combined HRV biofeedback and nirHEG neurofeedback can selectively enhance aspects of inhibitory control in later life. Rather than supporting a global cognitive enhancement narrative, the findings underscore the importance of targeting specific cognitive processes and matching them to appropriate physiological mechanisms.

The work also highlights individual differences as a critical factor.

Participants with lower baseline autonomic regulation appeared to benefit most from HRV gains, suggesting that biofeedback interventions may be particularly valuable for those with greater physiological vulnerability.

For clinicians, this finding reinforces the importance of baseline assessment in treatment planning. More broadly, the study advances the field of cognitive aging by demonstrating the feasibility of integrating central and peripheral biofeedback methods in older adults and by providing a template for future multidomain interventions.

Key Takeaways

This study offers several insights relevant to clinical practice. First, inhibitory control in aging is not unitary, and interventions may differentially affect interference control and response inhibition depending on the mechanisms they engage.

Second, combining HRV biofeedback with near-infrared neurofeedback can improve interference control without necessarily enhancing response inhibition, pointing to the selective nature of physiological training effects.

Third, the physiological benefits of biofeedback are most pronounced in individuals with lower baseline autonomic regulation, suggesting that baseline assessment can help identify clients most likely to benefit.

Fourth, training-related increases in prefrontal blood oxygenation occur during feedback sessions even when resting levels remain unchanged, indicating that real-time neurophysiological engagement may be a more sensitive marker of change than resting measurements.

Finally, multimodal biofeedback represents a promising, targeted approach to supporting cognitive self-regulation in healthy older adults, with potential applications for clinical populations experiencing age-related cognitive concerns.

Glossary

Arrow tasks: a response-conflict paradigm in which individuals must respond based on a rule (e.g., arrow direction) while inhibiting a prepotent or conflicting cue (e.g., spatial location), indexing interference control and response inhibition.

autonomic nervous system: a division of the nervous system that regulates involuntary physiological processes, including heart rate and respiration.

Fpz (midline prefrontal site): the frontal pole electrode location at the midline of the scalp in the international 10–20 EEG system. Functionally, Fpz overlies regions of the medial prefrontal cortex implicated in top-down inhibitory control, including monitoring conflict, suppressing prepotent responses, and regulating attention and behavior through executive control networks.

heart rate variability: a measure of the variation in time between consecutive heartbeats, reflecting autonomic flexibility and self-regulatory capacity.

hemoencephalography: a neurofeedback technique that uses near-infrared light to measure changes in cortical blood oxygenation.

inhibitory control: a core executive function involving the suppression of irrelevant information or inappropriate responses.

interference control: a component of inhibitory control that enables resistance to distracting or competing stimuli.

neurovascular coupling: a physiological process linking neural activity to localized changes in cerebral blood flow and oxygenation.

near-infrared hemoencephalography (nirHEG) neurofeedback: a biofeedback method that trains individuals to modulate regional cortical activation by providing real-time feedback derived from near-infrared measures of relative cerebral blood oxygenation, typically over the prefrontal cortex.

response inhibition: a component of inhibitory control involving the suppression of a prepotent or ongoing motor response.

Stroop task: a cognitive interference paradigm in which individuals must name a stimulus attribute (e.g., ink color) while inhibiting an automatic, competing response (e.g., reading the word), thereby assessing selective attention, cognitive control, and response inhibition.

References

Freedland, K. E., Mohr, D. C., Davidson, K. W., & Schwartz, J. E. (2011). Usual and unusual care: existing practice control groups in randomized controlled trials of behavioral interventions. Psychosomatic Medicine, 73(4), 323–335. https://doi.org/10.1097/PSY.0b013e318218e1fb

Ros, T., Enriquez-Geppert, S., Zotev, V., Young, K. D., Wood, G., Whitfield-Gabrieli, S., Wan, F., Vuilleumier, P., Vialatte, F., Van De Ville, D., Todder, D., Surmeli, T., Sulzer, J. S., Strehl, U., Sterman, M. B., Steiner, N. J., Sorger, B., Soekadar, S. R., Sitaram, R., Sherlin, L. H., … Thibault, R. T. (2020). Consensus on the reporting and experimental design of clinical and cognitive-behavioural neurofeedback studies (CRED-nf checklist). Brain: A Journal of Neurology, 143(6), 1674–1685. https://doi.org/10.1093/brain/awaa009

Tinello, D., Tarvainen, M., Zuber, S., & Kliegel, M. (2023). Enhancing inhibitory control in older adults: A biofeedback study. Brain Sciences, 13(2), 335. https://doi.org/10.3390/brainsci13020335

About the Author

Dr. John Raymond Davis is an adjunct lecturer in the Department of Psychiatry and Behavioural Neurosciences at McMaster University's Faculty of Health Sciences. His scholarly contributions include research on EEG changes in major depression and case studies on neurological conditions. ​

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