Processes and Functions of The Structural Changes of the Brain
The brain is a complex system of highly interrelated elements, and its successful development requires that each component be formed in a timely, fully integrated manner with the others. This process happens throughout four stages, each being crucial for the functional and structural components of our brains. The processes are:
Neurogenesis
Migration
Differentiation
Pruning
A complex system of interrelated elements
Successful development requires timely, complete, and correct integration of components.
Involves the production of new nerve cells (neurons), which help transmit information throughout the nervous system.
Neurons play major roles in various cognitive functions, including but not limited to mood regulation, cognitive flexibility, and memory encoding.
Neurons contribute to various cognitive and functional aspects of human life, such as mood regulation, memory encoding, flexibility, and more.
Neurogenesis is a critical stage of structural change
It sets the foundation for brain function
While neurogenesis mostly occurs during early development, it can still happen during adulthood.
The neurons produced in neurogenesis migrate to their “designated” location around 9 weeks after conception
They travel along glial fibers which are supported by the central nervous system
These fibers go from the brain’s inward structure to the cortical layers
Glial Fibers: non-neuronal cells in the central nervous system that form early in the fetal brain
Function: provide support and protection for neurons
As the brain grows, the glial fibers stretch and curve, these fibers then form pathways that direct neurons to the “correct” position in the brain
Neurons “climb” along the fibers like a snake of a tree
At the cells' final position, dendritic growth starts
Dendritic growth: allows neurons to connect with other neurons
The process then begins building layer-by-layer, progressing outward from the brain cortex (outermost layer of the brain, located on the top of your cerebrum
Neuronal Growth
Neuronal growth occurs in the brain cortex
New neurons form below the previously layers
The new neurons then travel outside while passing existing layers of neurons
The growth of connections between neurons (synapses)
Synapse: a junction between two nerve cells, consisting of a minute ages across which impulses pass by diffusion of a neurotransmitter
Synapses start growing shortly after conception
Eventually becomes rapid, with 40,000 synapses per second
Rapidness continues until nearly 2 years of age
This is followed by a plateau and then a rapid reduction of the number of synapses
The elimination of the connections between neurons made in Differentiation
Elimination of neurons themselves
Elimination occurs at a rate of 100,000 synapses per second
Pruning is most active during childhood and adolescence, correlating with critical periods of learning and development.
The brain undergoes significant reorganization during these periods, allowing for the acquisition of complex skills and adaptive behaviors.
Pruning lasts until the end of puberty
At this point, around 50% of initially formed synapses are eliminated
This is followed by another plateau and then another drop in the number of synapses in old age
Synaptic pruning continues into old age
Contributes to changes in cognitive functions associated with aging
The balance between synapse formation and pruning shifts throughout life
Reflects the brain's ongoing adaptation to experiences and environmental demands
Efficient pruning is essential for healthy cognitive development.
Excessive or insufficient pruning can lead to neurological and psychiatric conditions.
Excessive pruning has been linked to disorders such as schizophrenia.
Insufficient pruning is associated with autism spectrum disorders.
Complexity and Maturation
Understanding human psychological development involves more than just changes in brain structure.
It requires integrating knowledge across several domains:
Structural Changes: While structural changes in the brain occur throughout development, they alone cannot fully explain psychological maturation.
Integration of Knowledge: To gain a comprehensive understanding, it's essential to combine insights from studies on structure-function relationships in the adult brain, behavioral changes observed in adults with brain lesions, and evidence from advanced neuroimaging techniques.
Infants vs. Adults
Infants have a higher synaptic density compared to adults.
This abundance of synaptic connections reflects the brain's plasticity early in life.
Misconceptions
Having more synaptic connections does not necessarily translate to superior cognitive abilities.
Synaptic pruning plays a critical role in cognitive development.
It refines and strengthens essential connections
Supporting Studies
Werker and Tees (1992)
Focus: Studied infants' ability to discriminate phonemes from English and Hindi.
Method: Used the High-Amplitude Sucking (HAS) technique to measure infants' responses to speech sounds
Findings:
Infants initially discriminated between speech sounds from both English and Hindi.
Infants primarily discriminate speech sounds from their parents' language by one-year-old.
Showed synaptic pruning refines cognitive abilities, focusing sensitivity on native language sounds.
Significance: Emphasized synaptic pruning's role in language development, illustrating how early experiences shape perceptual abilities.
Understanding brain development has evolved from early post-mortem studies to modern neuroimaging techniques. Initial studies focused on brain size, which increased until about 9-10 years old, but didn't directly determine cognitive ability. The advent of MRI and PET scans enabled real-time insights, emphasizing neuronal connectivity over brain size.
Post-Mortem Studies: Early understanding of brain development was primarily derived from post-mortem studies focusing on brain size and anatomical features.
Limitations: While these studies provided foundational insights, they were limited by their inability to observe dynamic changes in the living brain and their focus on anatomical rather than functional aspects.
Findings: They revealed that brain size increases steadily until around 9-10 years of age. However, the relationship between brain size and cognitive ability is not linear, underscoring the need for more nuanced approaches to studying brain development.
Advancements: The advent of modern brain imaging technologies, such as MRI (Magnetic Resonance Imaging) and PET (Positron Emission Tomography), has revolutionized our ability to study the brain in real time.
Significance: These technologies enable researchers to examine not only the structural aspects of the brain but also its functional organization and activity patterns. This shift has emphasized the importance of neuronal connectivity and networks over simple measures of brain size or density.
The brain is a complex system of highly interrelated elements, and its successful development requires that each component be formed in a timely, fully integrated manner with the others. This process happens throughout four stages, each being crucial for the functional and structural components of our brains. The processes are:
Neurogenesis
Migration
Differentiation
Pruning
A complex system of interrelated elements
Successful development requires timely, complete, and correct integration of components.
Involves the production of new nerve cells (neurons), which help transmit information throughout the nervous system.
Neurons play major roles in various cognitive functions, including but not limited to mood regulation, cognitive flexibility, and memory encoding.
Neurons contribute to various cognitive and functional aspects of human life, such as mood regulation, memory encoding, flexibility, and more.
Neurogenesis is a critical stage of structural change
It sets the foundation for brain function
While neurogenesis mostly occurs during early development, it can still happen during adulthood.
The neurons produced in neurogenesis migrate to their “designated” location around 9 weeks after conception
They travel along glial fibers which are supported by the central nervous system
These fibers go from the brain’s inward structure to the cortical layers
Glial Fibers: non-neuronal cells in the central nervous system that form early in the fetal brain
Function: provide support and protection for neurons
As the brain grows, the glial fibers stretch and curve, these fibers then form pathways that direct neurons to the “correct” position in the brain
Neurons “climb” along the fibers like a snake of a tree
At the cells' final position, dendritic growth starts
Dendritic growth: allows neurons to connect with other neurons
The process then begins building layer-by-layer, progressing outward from the brain cortex (outermost layer of the brain, located on the top of your cerebrum
Neuronal Growth
Neuronal growth occurs in the brain cortex
New neurons form below the previously layers
The new neurons then travel outside while passing existing layers of neurons
The growth of connections between neurons (synapses)
Synapse: a junction between two nerve cells, consisting of a minute ages across which impulses pass by diffusion of a neurotransmitter
Synapses start growing shortly after conception
Eventually becomes rapid, with 40,000 synapses per second
Rapidness continues until nearly 2 years of age
This is followed by a plateau and then a rapid reduction of the number of synapses
The elimination of the connections between neurons made in Differentiation
Elimination of neurons themselves
Elimination occurs at a rate of 100,000 synapses per second
Pruning is most active during childhood and adolescence, correlating with critical periods of learning and development.
The brain undergoes significant reorganization during these periods, allowing for the acquisition of complex skills and adaptive behaviors.
Pruning lasts until the end of puberty
At this point, around 50% of initially formed synapses are eliminated
This is followed by another plateau and then another drop in the number of synapses in old age
Synaptic pruning continues into old age
Contributes to changes in cognitive functions associated with aging
The balance between synapse formation and pruning shifts throughout life
Reflects the brain's ongoing adaptation to experiences and environmental demands
Efficient pruning is essential for healthy cognitive development.
Excessive or insufficient pruning can lead to neurological and psychiatric conditions.
Excessive pruning has been linked to disorders such as schizophrenia.
Insufficient pruning is associated with autism spectrum disorders.
Complexity and Maturation
Understanding human psychological development involves more than just changes in brain structure.
It requires integrating knowledge across several domains:
Structural Changes: While structural changes in the brain occur throughout development, they alone cannot fully explain psychological maturation.
Integration of Knowledge: To gain a comprehensive understanding, it's essential to combine insights from studies on structure-function relationships in the adult brain, behavioral changes observed in adults with brain lesions, and evidence from advanced neuroimaging techniques.
Infants vs. Adults
Infants have a higher synaptic density compared to adults.
This abundance of synaptic connections reflects the brain's plasticity early in life.
Misconceptions
Having more synaptic connections does not necessarily translate to superior cognitive abilities.
Synaptic pruning plays a critical role in cognitive development.
It refines and strengthens essential connections
Supporting Studies
Werker and Tees (1992)
Focus: Studied infants' ability to discriminate phonemes from English and Hindi.
Method: Used the High-Amplitude Sucking (HAS) technique to measure infants' responses to speech sounds
Findings:
Infants initially discriminated between speech sounds from both English and Hindi.
Infants primarily discriminate speech sounds from their parents' language by one-year-old.
Showed synaptic pruning refines cognitive abilities, focusing sensitivity on native language sounds.
Significance: Emphasized synaptic pruning's role in language development, illustrating how early experiences shape perceptual abilities.
Understanding brain development has evolved from early post-mortem studies to modern neuroimaging techniques. Initial studies focused on brain size, which increased until about 9-10 years old, but didn't directly determine cognitive ability. The advent of MRI and PET scans enabled real-time insights, emphasizing neuronal connectivity over brain size.
Post-Mortem Studies: Early understanding of brain development was primarily derived from post-mortem studies focusing on brain size and anatomical features.
Limitations: While these studies provided foundational insights, they were limited by their inability to observe dynamic changes in the living brain and their focus on anatomical rather than functional aspects.
Findings: They revealed that brain size increases steadily until around 9-10 years of age. However, the relationship between brain size and cognitive ability is not linear, underscoring the need for more nuanced approaches to studying brain development.
Advancements: The advent of modern brain imaging technologies, such as MRI (Magnetic Resonance Imaging) and PET (Positron Emission Tomography), has revolutionized our ability to study the brain in real time.
Significance: These technologies enable researchers to examine not only the structural aspects of the brain but also its functional organization and activity patterns. This shift has emphasized the importance of neuronal connectivity and networks over simple measures of brain size or density.
