Brain works

How human brain memorize?

The human brain's ability to memorize is a complex process involving several key areas and stages. Here's a breakdown of how it works:

Key Brain Areas Involved:

• Hippocampus: This is crucial for forming new memories. It acts like a temporary storage site, connecting different aspects of an experience (sights, sounds, emotions) to create a cohesive memory.
• Neocortex: This is where long-term memories are stored. Over time, memories are transferred from the hippocampus to the neocortex for more permanent storage.
• Amygdala: This area is involved in emotional processing. Memories associated with strong emotions tend to be more vivid and easily recalled.

Stages of Memory Formation:

1. Encoding: This is the initial stage where information is perceived and processed. The brain takes in sensory information and associates it with existing knowledge and concepts.
2. Storage: This involves consolidating the encoded information into the brain's neural network. This process strengthens the connections between neurons, making the memory more stable.
3. Retrieval: This is the ability to access stored information later. When you try to remember something, your brain reactivates the neural pathways associated with that memory.

How Memories are Strengthened:

• Synaptic Plasticity: This refers to the brain's ability to strengthen or weaken connections between neurons (synapses) over time, in response to experience. Repetition and practice strengthen these connections, making it easier to retrieve memories.
• Emotional Significance: Events that evoke strong emotions are more likely to be remembered due to the amygdala's involvement.
• Context and Associations: Connecting new information to existing knowledge or creating associations can enhance memory.

Types of Memory:

• Short-term Memory (Working Memory): This holds information temporarily for immediate use. It has a limited capacity and duration.
• Long-term Memory: This is the relatively permanent storage of information. It can be further divided into:
  • Explicit Memory (Declarative Memory): Memories that can be consciously recalled, such as facts and events.
  • Implicit Memory (Nondeclarative Memory): Memories that are expressed through actions and skills, such as riding a bike or playing a musical instrument.

In summary, memorization involves a complex interplay of brain regions and processes. By encoding information, storing it through strengthened neural connections, and retrieving it when needed, the brain allows us to learn and remember our experiences.

Are human brain neurons connected in layered fashion? or it is random, like a mesh or graph? are new neurons automatically grown or added to the network during the perception phase, meaning that the network is not pre architecture but grow on-demand?

The connections between neurons in the human brain are neither strictly layered nor completely random. It's more accurate to describe them as a complex network with both structured and seemingly random elements.

Here's a breakdown:

• Not strictly layered: While some brain regions, like the cerebral cortex, have a layered structure (with distinct layers of neurons), the overall connectivity isn't simply a layer-by-layer arrangement. Neurons connect across different layers and regions in intricate ways.
• Not completely random: The connections aren't entirely haphazard either. There are patterns and rules that govern how neurons connect. For instance, neurons with similar functions tend to connect more frequently with each other.
• More like a complex network or graph: The brain's connectivity is best described as a complex network or graph, where neurons are nodes and connections between them are edges. This network exhibits properties of both order and randomness, allowing for both specialized processing and flexible adaptation.

Regarding new neuron growth:

• Neurogenesis: The process of generating new neurons, called neurogenesis, does occur in certain brain regions, primarily the hippocampus (involved in learning and memory) and the olfactory bulb (involved in smell).
• Limited in adults: While neurogenesis continues throughout life, it's much more limited in adults compared to during development. Most brain regions do not generate new neurons after early childhood.
• Not solely "on-demand": New neurons are not simply grown and added to the network during every perception phase. The brain's basic architecture is largely established during development. However, the existing network is constantly being modified through synaptic plasticity, where the strength of connections between neurons changes in response to experience.

In essence:

• The brain's neural network is a complex, dynamic structure with both organized and seemingly random connections.
• New neurons are generated in specific regions throughout life, but the majority of the network is established during development.
• The brain's ability to learn and adapt relies heavily on synaptic plasticity, which modifies existing connections rather than constantly adding new neurons to the network during every perception.

This complex interplay of structure and plasticity allows the brain to be both efficient and adaptable, enabling us to learn, remember, and navigate the world around us.

When a stimulant signal transmits across the network/graph, is it always feedforward or bi-directional?

When a stimulant signal transmits across the brain's neural network, it's not always strictly feedforward. While feedforward transmission is a fundamental aspect of neural communication, the brain also utilizes extensive feedback and recurrent connections, making the signal transmission often bi-directional or even more complex.

Here's a breakdown:

• Feedforward transmission: This refers to the unidirectional flow of information from one neuron or group of neurons to the next in a sequential manner. This is crucial for processing sensory information and executing motor commands.
• Feedback and recurrent connections: These connections allow neurons to send signals back to previous stages in the processing pathway or to other neurons within the same network. This creates loops and feedback mechanisms that are essential for:
  • Regulation and control: Feedback loops can regulate the activity of neural circuits, preventing overexcitation or maintaining stability.
  • Integration and processing: Recurrent connections allow for iterative processing and integration of information, enabling more complex computations.
  • Memory and learning: Recurrent networks are crucial for storing and retrieving memories, as well as for learning new patterns and associations.

Examples of bi-directional signal transmission:

• Sensory processing: When you see an object, information flows from the retina to the visual cortex in a feedforward manner. However, there are also feedback connections from higher visual areas back to earlier stages, allowing for top-down influences on perception.
• Motor control: When you perform a movement, signals flow from the motor cortex to the muscles. However, there is also sensory feedback from the muscles and joints back to the brain, allowing for adjustments and corrections during the movement.
• Cognitive functions: Higher-level cognitive functions like attention, decision-making, and working memory rely heavily on recurrent networks and feedback loops.

In summary:

• While feedforward transmission is a fundamental aspect of neural communication, the brain's neural network is characterized by extensive feedback and recurrent connections.
• This creates a complex interplay of feedforward and feedback signals, making the signal transmission often bi-directional or even more complex.
• These feedback mechanisms are crucial for regulation, integration, processing, memory, learning, and higher-level cognitive functions.

Therefore, it's more accurate to say that signal transmission in the brain is a dynamic process involving both feedforward and feedback mechanisms, allowing for complex and flexible information processing.