Periodic Reporting for period 1 - IN-MIND (Infant verbal Memory in Development: a window for understanding language constraints and brain plasticity from birth)
Berichtszeitraum: 2022-09-01 bis 2025-02-28
The development of language is one of the most fascinating and complex processes observed in humans. For children with typical development, spoken language emerges spontaneously around the first year of life. This allows them to reach important milestones in communication and social participation. The second year of life is marked by rapid vocabulary growth and the ability to form increasingly complex sentences. However, words and phrases are not the true starting point of language. From birth, infants have very sophisticated learning and perceptual abilities, some of these are present due to the humans’ biological endowment while others are shaped by early prenatal and postnatal experience with the native language.
Some children suffer from Specific Language Impairment (SLI), a delay or disorder in one or more areas of language development. SLI is likely the most common developmental disorder in childhood, with a prevalence generally cited around 7%. So far, no single cause has been identified for SLI. In most children, its expression seems to be determined by a complex, multi-causal disorder involving interacting environmental and genetic factors. Currently, SLI can be reliably diagnosed in children from around the age of 3. However, recent scientific studies highlight the importance of identifying behavioral and neurophysiological markers even earlier.
The Project – Objectives
IN-MIND aims at observing and measuring key auditory memory skills that support a child’s language development from birth up to 2 years of age. The primary objective is to understand the essential memory functions and processes that precede and accompany critical language milestones, as well as possible factors associated with typical and atypical developmental trajectories. The focus is on innate/biological predispositions, neurophysiological responses, and brain activity and connectivity related to learning and memory mechanisms. Additionally, the study examines the role that certain factors, such as sleep quality and interactions with parents or other adults, may play in forming and retrieving auditory memories during a child’s first 2 years of life.
The results of this research could lay the groundwork for identifying early vulnerabilities and sensitive periods in which primary prevention interventions may be most effective. The findings could thus contribute to the advancement of innovative screening and assessment tools, public health initiatives, and parenting education programs, to name a few potential long-term applications.
Some children suffer from Specific Language Impairment (SLI), a delay or disorder in one or more areas of language development. SLI is likely the most common developmental disorder in childhood, with a prevalence generally cited around 7%. So far, no single cause has been identified for SLI. In most children, its expression seems to be determined by a complex, multi-causal disorder involving interacting environmental and genetic factors. Currently, SLI can be reliably diagnosed in children from around the age of 3. However, recent scientific studies highlight the importance of identifying behavioral and neurophysiological markers even earlier.
The Project – Objectives
IN-MIND aims at observing and measuring key auditory memory skills that support a child’s language development from birth up to 2 years of age. The primary objective is to understand the essential memory functions and processes that precede and accompany critical language milestones, as well as possible factors associated with typical and atypical developmental trajectories. The focus is on innate/biological predispositions, neurophysiological responses, and brain activity and connectivity related to learning and memory mechanisms. Additionally, the study examines the role that certain factors, such as sleep quality and interactions with parents or other adults, may play in forming and retrieving auditory memories during a child’s first 2 years of life.
The results of this research could lay the groundwork for identifying early vulnerabilities and sensitive periods in which primary prevention interventions may be most effective. The findings could thus contribute to the advancement of innovative screening and assessment tools, public health initiatives, and parenting education programs, to name a few potential long-term applications.
Mapping verbal memory at birth
We have implemented a wireless setup that combines two brain imaging techniques, HD-DOT and EEG, along with a 3D registration method. HD-DOT is a cutting-edge technology that uses near-infrared light to create detailed maps of brain activity. By combining HD-DOT with EEG, we can gather both precise location information from HD-DOT and fast, real-time data from EEG. Additionally, we monitor heartbeat and breathing rates, along with video-based algorithms to assess infant behavior. This unique combination of methods helps us study brain activity related to speech, memory, brain plasticity, and sleep stages in newborns and infants.
So far, we tested and found evidence that only a few days after birth human infants can retain and recognize the sound of one word they have previously heard. The memory for the first words resists potential interference from other words pronounced by other speakers. However, we have also found that protracted consolidation periods are needed for the newborn brain to turn initial memory traces resistant to interference.
Phonological memory and the journey into its making in infancy
Because there was no existing test to measure phonological working memory in infants, we developed a new test called ADAM. This infant-controlled eye-tracking-based test allows us to see how well infants remember certain sound sequences and predict what will come next. The test adjusts its difficulty level based on how quickly each infant learns, making it personalized to each baby’s abilities.
In the first studies using the ADAM test, we looked at how many sound pieces or ‘chunks’ infants can hold in their memory for a short time. Our findings show that infants can handle both small (fewer than 3) and larger (more than 3 sounds) groups of syllables without any difficulty switching between them. This is different from how they process visual information, where infants tend to display strong limits in processing small and large number of items simultaneously. We think that being able to remember and work with groups of different sizes at once may help infants naturally process transient speech streams, allowing them to go beyond typical memory limits.
Phonological memory development in relation to linguistic skills, daily interactions and sleep
IN-MIND also tests the idea that early memory development is connected to environmental factors and language milestones in infants. To study this, we measured the language input that infants receive, their ability to understand and produce words, as well as their environment and sleep patterns.
Our early results show that infants with a stronger memory span also show better language skills. For example, babies with a higher memory span produced more vocal sounds compared to those with lower memory spans. We also found that sleep patterns—both night and day—are linked to differences in language skills and predict how they will evolve a few months later. Additionally, it seems that cultural factors like the number of adults who care for the child, and the quality of interactions with adults influence language development. This shows how important it is for infants to receive different kinds of language exposure from an early age.
We have implemented a wireless setup that combines two brain imaging techniques, HD-DOT and EEG, along with a 3D registration method. HD-DOT is a cutting-edge technology that uses near-infrared light to create detailed maps of brain activity. By combining HD-DOT with EEG, we can gather both precise location information from HD-DOT and fast, real-time data from EEG. Additionally, we monitor heartbeat and breathing rates, along with video-based algorithms to assess infant behavior. This unique combination of methods helps us study brain activity related to speech, memory, brain plasticity, and sleep stages in newborns and infants.
So far, we tested and found evidence that only a few days after birth human infants can retain and recognize the sound of one word they have previously heard. The memory for the first words resists potential interference from other words pronounced by other speakers. However, we have also found that protracted consolidation periods are needed for the newborn brain to turn initial memory traces resistant to interference.
Phonological memory and the journey into its making in infancy
Because there was no existing test to measure phonological working memory in infants, we developed a new test called ADAM. This infant-controlled eye-tracking-based test allows us to see how well infants remember certain sound sequences and predict what will come next. The test adjusts its difficulty level based on how quickly each infant learns, making it personalized to each baby’s abilities.
In the first studies using the ADAM test, we looked at how many sound pieces or ‘chunks’ infants can hold in their memory for a short time. Our findings show that infants can handle both small (fewer than 3) and larger (more than 3 sounds) groups of syllables without any difficulty switching between them. This is different from how they process visual information, where infants tend to display strong limits in processing small and large number of items simultaneously. We think that being able to remember and work with groups of different sizes at once may help infants naturally process transient speech streams, allowing them to go beyond typical memory limits.
Phonological memory development in relation to linguistic skills, daily interactions and sleep
IN-MIND also tests the idea that early memory development is connected to environmental factors and language milestones in infants. To study this, we measured the language input that infants receive, their ability to understand and produce words, as well as their environment and sleep patterns.
Our early results show that infants with a stronger memory span also show better language skills. For example, babies with a higher memory span produced more vocal sounds compared to those with lower memory spans. We also found that sleep patterns—both night and day—are linked to differences in language skills and predict how they will evolve a few months later. Additionally, it seems that cultural factors like the number of adults who care for the child, and the quality of interactions with adults influence language development. This shows how important it is for infants to receive different kinds of language exposure from an early age.
Our latest findings contribute to understanding the neuroplastic changes underlying learning and memory capacities from birth. Our studies demonstrate that the reorganization of the neural circuitries that is crucial for long-term memory, begins earlier than previously thought. We also found that newborns can start forming lasting memories even though a key memory area in their brains, called the hippocampus, is not fully mature yet. This discovery challenges the traditional view that the hippocampus is essential for building long-term memories at all ages.
Other results of the project mark an important first step in understanding the limits in the number of sounds or ‘chunks’ infants can remember at different ages. Until now, this ability had only been studied for visual memory, but these new findings in verbal memory give us valuable insights into how children develop language skills. Practically, understanding the early stages of phonological memory can help us find early signs of language difficulties linked to memory problems. It could also help us identify the best times to offer support to children who might be at risk for language delays.
Other results of the project mark an important first step in understanding the limits in the number of sounds or ‘chunks’ infants can remember at different ages. Until now, this ability had only been studied for visual memory, but these new findings in verbal memory give us valuable insights into how children develop language skills. Practically, understanding the early stages of phonological memory can help us find early signs of language difficulties linked to memory problems. It could also help us identify the best times to offer support to children who might be at risk for language delays.