The Nervous System: Thought, Memory, and Sleep

The Nervous System: Thought, Memory, and Sleep

The Higher Nervous System

The Parietal-Occipital-Temporal Junction:

• Spatial Awareness: This area integrates information from vision, hearing, and touch to create an awareness of the body’s position and movement within space.

• Wernicke’s Area: This is the brain’s most important language comprehension center. Most higher cognitive functions rely on language, making Wernicke’s area crucial for thought processes.

• Angular Gyrus: Responsible for the initial processing of visual language. This area helps create meaning from words received visually. Without the angular gyrus, a person can still understand language through listening, but not reading.

• Object Recognition Area: Identifies and recognizes objects.

Bilingualism:

• If both languages are learned concurrently, they are stored together in the same brain areas.

The Functions of the Prefrontal Cortex:

• Simultaneous Information Monitoring: This area plays a key role in storing and retrieving information from memory.

• Future Planning: Enables humans to anticipate, evaluate the consequences of actions before taking them, and choose the best course.

• Complex Problem Solving: Including mathematical and logical problems.

• Synthesizing Events and Knowledge: To make inferences and regulate behavior according to moral conventions.

Consequences of Damage to the Prefrontal Cortex:

• Difficulty solving complex problems.

• Lack of motivation and ambition in setting goals.

• Decreased enthusiasm for life.

• Impaired logical reasoning.

• Difficulty performing repetitive actions.

• Inappropriate communication responses, personality defects, and lack of control in sexual and excretory behavior.

Facial Recognition (Prosopagnosia):

• Prosopagnosia is the inability to recognize faces, significantly impacting other brain functions.

• The cortex dedicates a large area to facial recognition, highlighting its importance.

• The occipital portion of the facial recognition area connects to the visual cortex, and the temporal portion links to the limbic system, involved in emotions, brain activation, and controlling a person’s behavior when interacting with their environment.

Dyslexia:

• Dyslexia is a reading disorder caused by damage to the angular gyrus, affecting the translation of visual information.

Dominant Hemisphere:

• “Dominant” refers to the language processing ability.

• The non-dominant hemisphere is usually stronger in other intelligences, including body language, tone of voice, music, and non-verbal visual experiences.

Corpus Callosum and Anterior Commissure:

• The corpus callosum connects the two hemispheres, ensuring information exchange between them.

• The anterior commissure plays a supplementary role, connecting the emotional areas of both hemispheres.

• Corpus Callosum Severing: Causes the two hemispheres to operate independently, leading to disruptions in action control and sensation.

Mechanism of Desensitization at Sensory Nerve Endings:

• Desensitization occurs due to the gradual closing of calcium channels at sensory nerve endings, reducing the ability to receive stimulation.

Consolidation:

• Consolidation is the process of strengthening synapses, enhancing the ability to receive information and form memories.

• Mechanism: Increased neurotransmitter release from the synapse.

Formation of Long-Term Memory:

• Structural Synaptic Changes: Including increased neurotransmitter vesicle release, increased vesicle numbers, and changes in dendritic spine structure, resulting in stronger transmission.

Classification of Long-Term Memory:

• Declarative Memory: Conscious, clear, and transparent memory, often called explicit memory.

• Implicit Memory: Unconscious, taken-for-granted memory, including skills and habits.

Encoding New Memories during Consolidation:

• New memories are encoded into different groups of information.

• The brain compares and stores similarities and differences instead of storing unprocessed information.

• Memories are stored randomly but are always linked to similar memories.

Role of the Hippocampus:

• The hippocampus plays a crucial role in determining whether thoughts are important enough to store, based on reward and punishment.

• The hippocampus receives signals from reward and punishment areas of the limbic system.

Impact of Thalamic Damage on Memory:

• Thalamic damage can cause retrograde amnesia, preventing the patient from remembering past memories.

• The thalamus plays a role in searching and retrieving information from memory.

Impact of Hippocampal Damage on Reflex Learning:

• Hippocampal damage does not affect the learning of physical skills, such as sports, because this type of learning does not rely on verbal memory.

The Importance of Reward and Punishment Centers in Learning and Memory:

• Reward and punishment centers play a significant role in information selection.

• Stimulating the reward center strengthens information, creating a memory imprint.

• The punishment center helps eliminate unnecessary information.

Limbic System:

• The hypothalamus is the main control center of the limbic system, controlling the body’s survival and endocrine functions.

Mechanism of Memory Formation:

• Memory consolidation can be disrupted by a loss of consciousness.

Autonomic Nervous System (ANS):

• Sympathetic Nervous System: Controls “fight or flight” responses.

• Parasympathetic Nervous System: Controls “rest and digest” responses.

Functions of Brain Structures:

• Hypothalamus: Controls survival functions, including blood pressure, heart rate, body temperature, sleep, hunger, thirst, and sexual behavior.

• Amygdala: Responsible for processing emotions, especially fear.

• Hippocampus: Responsible for forming new memories, especially explicit memory.

• Thalamus: Acts as a relay center for transmitting information between the cortex and other brain areas.

• Cerebellum: Controls motor functions, including balance, coordination, and movement adjustments.

• Basal Ganglia: Responsible for motor control, learning, and behavior.

• Red Nucleus: Responsible for controlling muscle movement.

• Substantia Nigra: Produces dopamine, a neurotransmitter involved in motor control.

• Caudate Nucleus: Responsible for controlling conscious motor activities.

• Putamen: Responsible for controlling unconscious motor activities.

• Subthalamic Nucleus: Responsible for controlling muscle movements.

• Ventromedial Hypothalamus: Responsible for controlling eating behavior and emotions.

• Periventricular Hypothalamus and Midbrain Central Gray Area: Process punishment signals.

Sleep:

• REM Sleep: The stage of sleep with high brain activity, often accompanied by dreams.

• Slow-wave Sleep: Deep sleep stage, usually dreamless.

• EEG: Technique for measuring brain electrical activity.

• EOG: Technique for measuring eye movements.

• EMG: Technique for measuring muscle activity.

Mechanism of Sleep Induction:

• Sleep is produced by the inhibition of brain activity.

• Sleep-inducing centers: Raphe nuclei, nucleus of the tractus solitarius, and some areas in the thalamus.

• Acetylcholine: Neurotransmitter that increases the occurrence of REM sleep.

Role of Sleep:

• Restoring energy for the brain.

• Consolidating memories.

• Eliminating unnecessary information.

• Neural development.

• Regulating endocrine functions.

Circadian Rhythm:

• The suprachiasmatic nucleus (SCN) in the hypothalamus is the nervous system’s circadian rhythm clock.

• Circadian rhythms are controlled by clock genes.

Memory Research:

• Research on epilepsy has contributed to understanding memory mechanisms.

Types of Brain Waves:

• Alpha Waves: Occur during rest and relaxation.

• Beta Waves: Occur during wakefulness and focus.

• Theta Waves: Occur during sleep or drowsiness.

• Delta Waves: Occur during deep sleep.

• Delta waves are measured in children both awake and asleep.

Note:

• The information in this article is compiled from various sources. Consult specialized materials for more comprehensive and accurate knowledge.

• This article provides general information only and is not medical advice.

• If you have any health concerns, consult a doctor or healthcare professional.