Brain and Behavior: The Biological Foundations of Psychology

Brain and Behavior

The Nervous System

The nervous system is the body's primary communication network, coordinating voluntary and involuntary actions and transmitting signals between different parts of the body. It is composed of specialized cells called neurons and supporting cells known as glia.

• Central Nervous System (CNS): Consists of the brain and spinal cord. The brain is the main processing center, while the spinal cord transmits information between the brain and the rest of the body.

• Peripheral Nervous System (PNS): All neural elements outside the CNS. It connects the CNS to limbs and organs.

Divisions of the Peripheral Nervous System

• Somatic Nervous System (SNS): Controls voluntary movements and transmits sensory information to the CNS.

• Autonomic Nervous System (ANS): Regulates involuntary bodily functions (e.g., heart rate, digestion). It is further divided into:

  • Sympathetic Nervous System: Activates the "fight or flight" response during stress or danger.

  • Parasympathetic Nervous System: Promotes "rest and digest" functions, conserving energy and calming the body.

Neurons and Glia

• Neuron: The basic unit of the nervous system, responsible for transmitting information via electrical and chemical signals.

• Glial Cells: Support neurons by providing nutrients, removing waste, and insulating axons (myelin sheath). Glia also participate in communication and outnumber neurons by about 9 to 1.

Structure of a Neuron

• Dendrites: Receive incoming signals from other neurons.

• Cell Body (Soma): Integrates incoming information and contains the nucleus.

• Axon: Transmits electrical impulses away from the cell body toward other neurons or muscles.

• Axon Terminals: Release neurotransmitters to communicate with other cells.

• Myelin Sheath: Insulating layer that speeds up neural transmission. Damage to myelin (e.g., in multiple sclerosis) impairs movement and sensation.

Neural Communication

• Resting Potential: The electrical charge difference across the neuron's membrane when inactive (inside is negative relative to outside).

• Action Potential: A rapid change in electrical charge that travels down the axon when the neuron is sufficiently stimulated (reaches threshold). This is an all-or-nothing event.

• Ion Channels: Open during action potentials, allowing sodium (Na+) to enter and potassium (K+) to exit, reversing the charge temporarily.

• Synapse: The gap between neurons where neurotransmitters are released to transmit signals chemically.

Neurotransmitters and Neuropeptides

• Neurotransmitters: Chemical messengers that cross synapses to excite or inhibit (để kích thích hoặc ức chế) the next neuron. Examples include acetylcholine, dopamine, GABA, glutamate, norepinephrine, and serotonin.

• Neuropeptides: Regulate the activity of neurons, influencing pain, emotion, pleasure, and other processes. Examples: endorphins and enkephalins (natural painkillers).

Neurotransmitter	Main Functions	Disorders/Effects
Acetylcholine	Muscle activation, learning, memory	Blocked by curare (paralysis)
Dopamine	Pleasure, reward, movement	Excess: schizophrenia; Deficit: Parkinson's disease
Serotonin	Mood, appetite, sleep	Deficit: depression
GABA	Main inhibitory neurotransmitter	Deficit: anxiety, seizures
Glutamate	Main excitatory neurotransmitter	Excess: migraines (chứng đau nửa đầu) seizures
Norepinephrine	Arousal, alertness (Kích thích, tỉnh táo)	Imbalance: mood disorders

Neuroplasticity and Neurogenesis (Tính dẻo dai thần kinh và sự hình thành thần kinh)

• Neuroplasticity: The nervous system's ability to change and adapt in response to experience, learning, or injury (e.g., London taxi drivers' enlarged brain areas for navigation).

• Neurogenesis: The formation of new neurons, especially in the adult brain, contributing to learning and memory.

Brain Research Methods

Understanding the brain's structure and function relies on a variety of research techniques.

Exploring Brain Structure

• Dissection: Studying autopsied brains to identify anatomical regions.

• CT (Computed Tomography) Scan: Uses X-rays to create detailed images of brain structure; useful for detecting tumors, injuries, and strokes.

• MRI (Magnetic Resonance Imaging): Uses magnetic fields and radio waves to produce high-resolution images of brain anatomy without radiation exposure.

Exploring Brain Function

• Case Studies: Observing behavioral changes following brain injury or disease (e.g., Phineas Gage).

• Electrical Stimulation of the Brain (ESB): Activating brain regions with mild electrical currents to observe effects on behavior.

• Ablation and Deep Lesioning: Surgically removing or destroying brain tissue to study resulting behavioral changes.

• EEG (Electroencephalography): Measures electrical activity (brain waves) via electrodes on the scalp; useful for studying sleep, epilepsy, and mental states.

• PET (Positron Emission Tomography) Scan: Tracks radioactive glucose to visualize active brain regions during tasks.

• fMRI (Functional MRI): Measures changes in blood flow to indicate active brain areas during specific tasks (e.g., lying vs. telling the truth).

The Cerebral Cortex

The cerebral cortex is the brain's outer layer, responsible for higher-order functions such as perception (nhận thức,), thought, language, and voluntary movement. It is divided into two hemispheres (hai bán cầu) and four main lobes.

Hemispheric Lateralization (Bán cầu bên)

• Left Hemisphere: Controls the right side of the body; specialized for language, math, and sequential processing.

• Right Hemisphere: Controls the left side of the body; specialized for spatial abilities, pattern recognition, and holistic processing.(chuyên về khả năng không gian, nhận dạng mẫu và xử lý toàn diện)

• Corpus Callosum: Thick band of axons connecting the two hemispheres, allowing communication between them.

• Split-Brain Research: Cutting the corpus callosum (e.g., to treat epilepsy) reveals independent functioning of each hemisphere.

Sex Differences and Dominance

• Women's brains tend to have more interhemispheric connections, possibly supporting greater integration of rational and intuitive processing.

• Handedness is related to hemispheric dominance, but language is usually left-lateralized even in most left-handers.

Lobes of the Cerebral Cortex

	Main Functions	Key Areas
Lobe
Frontal		Movement, planning, reasoning, self-regulation, language production	Prefrontal cortex, Broca's area, primary motor cortex
Parietal	Sensory processing (touch, temperature, pain), spatial orientation	Primary somatosensory cortex
Temporal	Hearing, language comprehension, memory, Thính giác, hiểu ngôn ngữ, trí nhớ	Primary auditory cortex, Wernicke's area
Occipital	Vision	Primary visual cortex

• Association Areas: Integrate information from multiple sensory and motor areas, supporting complex functions like recognition and language.

• Mirror Neurons: Found in the motor cortex; active during both action and observation, possibly underlying imitation and empathy. ( bắt chước và đồng cảm.)

The Subcortex and Endocrine System (Hệ thống dưới vỏ não và nội tiết)

Beneath the cerebral cortex lies the subcortex, which includes structures essential for basic survival and emotional regulation. The endocrine system works alongside the nervous system to regulate bodily functions via hormones.

Major Regions of the Subcortex

• Hindbrain (Não sau:): Includes the medulla (controls vital functions), pons (sleep/arousal) )(Ngủ / Kích thích), reticular formation (attention, arousal), and cerebellum (coordination, skill memory). (và tiểu não (phối hợp, trí nhớ kỹ năng).)

• Midbrain (Não giữa): Connects hindbrain and forebrain; part of the brainstem, relaying information between the body and cortex. (một phần của thân não, chuyển tiếp thông tin giữa cơ thể và vỏ não.)

• Forebrain (Não trước): Includes the thalamus (sensory relay), hypothalamus (regulates drives and hormones), and limbic system (emotion and memory). (Bao gồm đồi thị (chuyển tiếp cảm giác), vùng dưới đồi (điều chỉnh ổ đĩa và hormone) và hệ thống limbic (cảm xúc và trí nhớ).)

Limbic System

• Amygdala: Processes emotions, especially fear and aggression.

• Hippocampus: Essential for forming new memories and spatial navigation.

• Pleasure and aversion centers (Trung tâm khoái cảm và ác cảm:): Involved in reward and punishment, influencing motivation and addiction.

The Endocrine System

• Pituitary Gland (Hệ thống nội tiết tuyến yên): The "master gland"; regulates other endocrine glands and releases growth hormone and oxytocin (social bonding).

• Pineal Gland: Releases melatonin, regulating sleep-wake cycles.

• Thyroid Gland: Controls metabolism; imbalances affect energy and mood.

• Adrenal Glands: Release epinephrine (adrenaline) and norepinephrine during stress; produce corticoids for salt balance and stress adaptation; secrete sex hormones.

Anabolic Steroids Steroid đồng hóa

• Synthetic versions of testosterone used to increase muscle mass; associated with serious side effects (e.g., aggression, organ damage).

Self-Regulation and Executive Function (Chức năng tự điều chỉnh và điều hành)

Self-regulation is the ability to control one's thoughts, emotions, and behaviors in pursuit theo đuổi of long-term goals. It is closely linked to executive functions in the prefrontal cortex.

• Executive Functions: Include planning, attention, impulse control, and goal monitoring. (Bao gồm lập kế hoạch, chú ý, kiểm soát xung động và theo dõi mục tiêu.)

• Hot Emotional System: Driven by immediate impulses (limbic system). Hệ thống cảm xúc nóng: Được thúc đẩy bởi các xung động tức thời (hệ thống limbic).

• Cool Cognitive System: Supports reflection and long-term planning (prefrontal cortex).

Improving Self-Regulation

• Selective Attention: Focus on cues that support long-term goals, avoiding temptations.

• Cognitive Reappraisal: Reframe situations to reduce the appeal of immediate rewards.

• Environmental Control: Change surroundings to minimize exposure to temptations.

• Visualization: Imagine future consequences to strengthen self-control.

Cải thiện sự chú ý có chọn lọc tự điều chỉnh: Tập trung vào các tín hiệu hỗ trợ các mục tiêu dài hạn, tránh cám dỗ. Đánh giá lại nhận thức: Điều chỉnh lại các tình huống để giảm sức hấp dẫn của phần thưởng ngay lập tức. Kiểm soát môi trường: Thay đổi môi trường xung quanh để giảm thiểu tiếp xúc với những cám dỗ. Hình dung: Tưởng tượng hậu quả trong tương lai để tăng cường khả năng tự chủ

Research Highlights

• Self-regulation in childhood (e.g., the "Marshmallow Test") predicts later success in health, academics, and finances, though socioeconomic factors also play a role.

• Self-regulation is a skill that can be developed through practice and environmental support.

Additional info: The notes above integrate and expand upon the provided material, including definitions, examples, and research findings relevant to biological psychology and self-regulation.