Tag: heart rate variability

Categories : Neurology PaediatricsTags :

Heart Rate Activity Influences When Infants Speak

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Photo by Johnny Cohen on Unsplash

The soft, gentle murmurs of a baby’s first expressions, like little whispers of joy and wonder to doting parents, are actually signs that the baby’s heart is working rhythmically in concert with developing speech.

Jeremy I. Borjon, University of Houston assistant professor of psychology, reports in Proceedings of the National Academy of Sciences that a baby’s first sweet sounds and early attempts at forming words are directly linked to the baby’s heart rate. The findings have implications for understanding language development and potential early indicators of speech and communication disorders.

For infants, producing recognisable speech is more than a cognitive process. It is a motor skill that requires them to learn to coordinate multiple muscles of varying function across their body. This coordination is directly linked to ongoing fluctuations in heart rate.

Borjon investigated whether these fluctuations in heart rate coincide with vocal production and word production in 24-month-old babies. He found that heart rate fluctuations align with the timing of vocalizations and are associated with their duration and the likelihood of producing recognisable speech.

“Heart rate naturally fluctuates in all mammals, steadily increasing then decreasing in a rhythmic pattern. It turns out infants were most likely to make a vocalisation when their heart rate fluctuation had reached a local peak (maximum) or local trough (minimum),” reports Borjon.

“Vocalisations produced at the peak were longer than expected by chance. Vocalisations produced just before the trough, while heart rate is decelerating, were more likely to be recognised as a word by naïve listener,” he said.

Borjon and team measured a total of 2708 vocalisations emitted by 34 infants between 18 and 27 months of age while the babies played with a caregiver. Infants in this age group typically don’t speak whole words yet, and only a small subset of the vocalisations could be reliably identified as words by naïve listeners (10.3%). For the study, the team considered the heart rate dynamics of all sounds made by the baby’s mouth, be it a laugh, a babble or a coo.

“Every sound an infant makes helps their brain and body learn how to coordinate with each other, eventually leading to speech,” Borjon said.

As infants grow, their autonomic nervous system grows and develops. The first few years of life are marked by significant changes in how the heart and lungs function, and these changes continue throughout a person’s life.

The relationship between recognisable vocalisations and decelerating heart rate may imply that the successful development of speech partially depends on infants experiencing predictable ranges of autonomic activity through development.

“Understanding how the autonomic nervous system relates to infant vocalisations over development is a critical avenue of future research for understanding how language emerges, as well as risk factors for atypical language development,” said Borjon

Source: University of Houston

Categories : Mental HealthTags :

Dogs and Owners Match Their Heart Rate Variability

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Photo by Pauline Loroy on Unsplash

A study at the University of Jyväskylä showed that the heart rate variability of a dog and its owner adapt to each other during interaction. High heart rate variability is associated with relaxation, while low heart rate variability indicates stimulation. The study, published in Scientific Reports, deepens our understanding of the emotional connection between a dog and its owner, including its underlying physiological mechanisms.

Emotional connection enhances interaction in human relationships. Emotional synchronisation in the interaction between a child and a parent is essential for affective attachment. The relationship between a dog and its owner is also based on attachment, but little is known about its physiological mechanisms.

The heart rate variability of a dog and its owner adapt to each other

In a study conducted at the University of Jyväskylä, at the Department of Psychology and Jyväskylä Centre for Interdisciplinary Brain Research, it was found that the heart rate variability of a dog and its owner are interconnected during interaction. Heart rate variability, in other words, the variation in the heartbeat intervals, indicates the state of the autonomic nervous system. High heart rate variability is associated with a state of relaxation and recovery, while low heart rate variability indicates stimulation or strain, such as stress during an exam or sport performance. In this study, the owner’s high heart rate variability was connected to the dog’s high heart rate variability, and vice versa. In addition, the physical activity levels of a dog and its owner mutually adapted to each other during the study. 

Different connections for activity and heart rate variability

The connections of heart rate variability and activity levels between a dog and its owner were monitored during specific interaction tasks. Both heart rate and activity level were interconnected between dogs and their owners, but at different times. During free-form resting periods, the owner’s high heart rate variability was connected to the dog’s high heart rate variability. In other words, when the owner was relaxed the dog was also relaxed. Moreover, the owner’s and dog’s activity levels were similar during the given tasks, such as playing. Although it is known that physical activity has an impact on heart rate, the strongest connections of these variables between dog and owner were found in different situations and do not fully explain each other. This suggests that the connection in heart rate variability reflects the synchrony of emotional state rather than of activity levels.

“The interconnection in heart rate variability between the dog and its owner during resting periods may be explained by the fact that in those instances there were no external tasks, but the counterparts could react more to each other’s state in a natural way,” says Doctoral Researcher Aija Koskela. 

Owner’s temperament is connected to the dog’s heart rate variability

The study also investigated various background factors for the interconnection of the heart rate variability of the dog and its owner. Bigger dogs had higher heart rate variability. In addition, the dog’s high heart rate variability was also explained by the owner’s negative affectivity, a temperament trait that reflects the person’s tendency to become easily concerned about negative things. This type of owner tends to develop a strong emotional bond with the dog, and therefore the shepherd dogs of this study possibly had a higher sense of safety with these owners. 

The dog also influences the owner

A surprising finding in the study was that the owner’s heart rate variability was best explained by the dog’s heart rate variability, even though also the owner’s activity level and body mass index, which are known to impact heart rate, were taken into account in the analysis.

“We exceptionally investigated both a dog’s and its owner’s heart rate and activity level simultaneously, whereas previous studies have commonly focused either on the human’s or the dog’s perspective,” says the leader of the study, Academy Research Fellow Miiamaaria Kujala. “The challenging research setting gives a better opportunity to investigate interactive aspects.”

This study indicates that the emotional states of dogs and their owners as well as the reactions of their nervous system become partially adapted to each other during interaction. The same mechanisms that strengthen human affective attachment also seem to support the relationship between a dog and its owner. This study deepens our understanding about interaction between species and about the meaning of emotional connection between dogs and humans. 

Interaction research involved dogs bred for cooperation

The study was funded mainly by the Research Council of Finland and the Agria & Svenska Kennelklubben Research Fund. It involved altogether 30 voluntary dog owners with their dogs. The dogs represented breeds refined for cooperating with humans, such as sheep dogs and retrievers. The research findings are in line with previous studies, which have suggested that breeds selected for cooperation are particularly sensitive to react to their owners’ behaviour and personality traits. Next, the project will seek to shed light more specifically on the influential mechanisms involved in this phenomenon.

Source: University of Jyväskylä

Categories : Cardiovascular Disease Mental HealthTags :

Mental Health Conditions Disrupt Blood Pressure and Heart Rate

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Photo by Alex Green on Pexels

A new study published in BioMedical Engineering has revealed that mental health is closely aligned to blood pressure and heart rate variations. The researchers found that mental illness could cause widely fluctuating blood pressure, which can lead to cardiovascular disease and organ damage.

University of South Australia researcher Dr Renly Lim and colleagues said there is clear evidence that mental illness interferes with the body’s autonomic functions, including blood pressure, heart rate, temperature and breathing.

“We reviewed 12 studies on people with anxiety, depression and panic disorders and found that, regardless of age, mental said is significantly associated with greater blood pressure variations during the day,” Dr Lim says.

“We also found that for people who are mentally ill, their heart rate does not adapt to external stressors as it should.

“Contrary to what many people think, a healthy heart is not one that beats like a metronome. Instead, it should adjust to withstand environmental and psychological challenges. A constantly changing heart rate is actually a sign of good health.”

Reduced heart rate variation (HRV) is common in people with mental illness and indicates that the body’s stress response is poor, exacerbating the negative effects of chronic stress.

Unlike normally consistent heart rates, HRV is more complex and is the time between two heartbeats, which should change according to external stressors.

“What we aim for is not a constantly changing heart rate but a high heart rate variation. This is achieved through a healthy diet, exercise, low stress and good mental health.”

Low HRV occurs during ‘fight-or-flight’ mode, or in those who are easily stressed and is common in people with chronic diseases, including cardiovascular and mental health problems.

While large blood pressure variations (BPV) during the day are not ideal, at night the systolic pressure should dip by between 10–20% to allow the heart to rest. People with mental health issues were found to have an insufficient BP drop at night, dropping less than 10%.

The reduced dipping can be caused by many factors, including autonomic dysfunction, poor quality of sleep and disrupted circadian rhythms that regulate the sleep-wake cycle.

“The takeout from this study is that we need to pay more attention to the physical impacts of mental illness,” Dr Lim said.

“It is a major global burden, affecting between 11–18 per cent (one billion) of people worldwide. Since mental illness can contribute to the deterioration of heart and blood pressure regulation, early therapeutic intervention is essential.”

Source: University of South Australia