Physiological Psychology - Past Paper

**Psych 5: Physiological Psychology** **Physiological Psychology** The biological (physiological) approach to studying human behavior. This contains the BASIC concepts and findings in neuroscience with emphasis on the brain-body, brain-behavior, and mind-behavior relationship. **19th Century** *...

**Psych 5: Physiological Psychology** **Physiological Psychology** The biological (physiological) approach to studying human behavior. This contains the BASIC concepts and findings in neuroscience with emphasis on the brain-body, brain-behavior, and mind-behavior relationship. **19th Century** **Phineas Gage**, the railroad worker who survived through a spike in his skull. **Franz Joseph Gall**- the founder of the direct scientific link between the morphology of the skull and personality traits. One of the first scientists to consider the brain the home of all mental activities. **Psychosurgery before (mid 20th century)** Or **frontal lobotomy** was the standard treatment in mental hospitals to treat Depression, schizophrenia, mania, etc. At least 20k operations were performed in 1940s. **Egas Moniz** died after he was shot by one of his own lobotomized patients. **THE CORE CONCEPTS OF NEUROSCIENCE** **1. The brain is the body's most complex organ.** a\. There are around 86 billion neurons in the human brain, all of which are in use. b\. Each neuron communicates with many other neurons to **form circuits and share information.** c\. Proper nervous system function involves coordinated action of neurons in many brain regions. d\. The nervous system influences and is influenced by all other body systems (e.g., cardiovascular, endocrine, gastrointestinal and immune systems). e\. Humans have a complex nervous system that evolved from a simpler one. f\. This complex organ can malfunction in many ways, leading to disorders that have an enormous social and economic impact. **2. Neurons communicate using both electrical and chemical signals.** **3. Genetically determined circuits are the foundation of the nervous system.** a\. Neuronal circuits are formed by genetic programs during embryonic development and modified through interactions with the internal and external environment. b\. Sensory circuits (sight, touch, hearing, smell, taste) bring information to the nervous system, whereas motor circuits send information to muscles and glands. c\. The simplest circuit is a reflex, in which sensory stimulus directly triggers an immediate motor response. d\. Complex responses occur when the brain integrates information from many brain circuits to generate a response. e\. Simple and complex interactions among neurons take place on time scales ranging from milliseconds to months. f\. The brain is organized to recognize sensations, initiate behaviors, and store and access memories that can last a lifetime. Reflex: Simplest circuit **Neurulation:** - - **Neuronal proliferation:** - - **Neural migration:** - - **Myelination:** - - **Synaptogenesis:** - - **Apoptosis:** - - **4. Life experiences change the nervous system.** a\. Differences in genes and environments make the brain of each animal unique. b\. Most neurons are generated early in development and survive for life. c\. Some injuries harm nerve cells, but the brain often recovers from stress, damage, or disease. d\. Continuously challenging the brain with physical and mental activity helps maintain its structure and function - \"use it or lose it.\" e\. Peripheral neurons have greater ability to regrow after injury than neurons in the brain and spinal cord. f\. Neuronal death is a natural part of development and aging. g\. Some neurons continue to be generated throughout life and their production is regulated by hormones and experience. **The 2 Types of Brain Plasticity** **What is Neuroplasticity?** Brain's ability to change and adapt. **Type 1: Structural Plasticity** Experience or memories change a brain's physical structure. **Type 2: Functional Plasticity** Brain function moves from the damaged area to the undamaged area. HOW TRAUMA AFFECTS THE BRAIN **Prefrontal Cortex**- rational thinking regulates emotion such as fear responses from the amygdala; with PTSD, this has reduced volume. **Hippocampus**- responsible for memory and differentiating between past and present- works to remember and make sense of the trauma. With consistent exposure to trauma, it shrinks. **Amygdala**- wired for survival, when active it is hard to think rationally. The more hyperactive the amygdala is, the more signs of PTSD are present.  **5. Intelligence arises as the brain reasons, plans, and solves problems.** a\. The brain makes sense of the world by using all available information, including senses, emotions, instincts, and remembered experiences. b\. Emotions are based on value judgments made by our brains and are manifested by feelings as basic as love and anger and as complex as empathy and hate. c\. The brain learns from experiences and makes predictions about best actions in response to present and future challenges. d\. Consciousness depends on normal activity of the brain. **6. The brain makes it possible to communicate knowledge through spoken and written language**. a\. Languages are acquired early in development and facilitate information exchange and creative thought. b\. Communication can create and solve many of the most pressing problems humankind faces. **Broca's Area-** anterior speech cortex **Wernicke's Area-** posterior speech area **7. The human brain endows us with a natural curiosity to understand how the world works.** a\. The nervous system can be studied at many levels, from complex behaviors such as speech or learning, to the interactions among individual molecules. b\. Research can ultimately inform us about the mind, intelligence, imagination, and consciousness. c\. Curiosity leads us to unexpected but surprising discoveries that can benefit humanity. **8. Fundamental discoveries promote healthy living and treatment of disease.** a\. Experiments on animals play a central role in providing insights about the human brain and in helping to make healthy lifestyle choices, prevent disease, and find cures for disorders. b\. Research on humans is an essential final step before new treatments are introduced to prevent or cure disorders. c\. Neuroscience research has formed the basis for significant progress in treating a large number of disorders. d\. Finding cures for disorders of the nervous system is a social imperative. PARTS OF THE NEURON 1\. **SOMA-** The soma is responsible for maintaining the cell and processing information. 2\. **AXON-** Carries electrical impulses away from the cell body to other neurons, muscles, or glands. 3\. **MYELIN SHEATH-** A fatty layer around the axon, insulating it and increasing the speed at which action potentials travel along the axon. 4\. **DENDRITES-** Receive signals from other neurons and transmit these signals towards the cell body. 5\. **TERMINAL BUTTONS-** Release neurotransmitters into the Synapse. THREE MAJOR TYPES OF NEURONS \- **Neuron** is the basic information-processing and information-transmitting unit of the Nervous System. **1. Sensory Neurons** (Afferent Neurons)- nerve cells that carry nerve impulses from sensory receptors toward the central nervous system and brain. \- The information, in the form of light, sound, odors, tastes, or contact with objects, is gathered from the environment by specialized cells of the PNS called Sensory Neurons. \- Characterized as being pseudounipolar **2. Interneurons** Exclusively in CNS Most abundant Acts as a middle man Multipolar. **3. Motor neurons-** also known as efferent neurons that are responsible for carrying signals away from the CNS towards the muscle to cause movement. \- External stimuli are being detected and converted into information by the sensory neuron are then used by the motor neuron and translate it into action in our muscles and gland. **Two Types of Motor Neuron** 1\. Upper motor neurons- these are neurons that travel between the brain and the spinal cord. 2\. Lower motor neurons- these are neurons that travel from the spinal cord to the body\'s muscle body. **Unipolar neurons** [have only one structure extending from the soma]; **bipolar neurons** have [one axon and one dendrite extending from the soma.] **Multipolar neurons** [contain one axon and many dendrites]; **pseudounipolar neurons** have a [single structure that extends from the soma, which later branches into two distinct structures.] **TWO TYPES OF CELLS IN THE NERVOUS SYSTEM** **Neurons-** the structural and functional units of the nervous system. **Glial Cells-** the most important supporting cells of the CNS are the neuroglia, or "nerve glue". Glial cells surround neurons and hold them in place, controlling their supply of nutrients and some of the chemicals they need to exchange messages with other neurons. **Neurons** are responsible for the transmission of nerve impulses between the central nervous system and body while **glial cells** maintain homeostasis, providing support and protection to the neurons. **TYPES OF GLIAL CELLS** 1\. Astrocytes- [star-shaped cells] that support and protect neurons in the brain and central nervous system. \- [provide physical support to neurons and clean up debris] within the brain; [involves in providing nourishment to neurons ] **2. Oligodendrocytes-** [provide support to axons to produce the myelin sheath], in which insulates most axon from one another. - - - Some Diseases of Oligodendrocytes **Myelin Oligodendrocyte Glycoprotein Associated Disease---** an autoimmune disease in which the body\'s immune system attacks its tissues. It attacks the myelin oligodendrocyte glycoprotein or MOG. **CAUSES/CURE** ATTACKS THE IMMUNE SYSTEM. CORTICOSTEROIDS TO SUPRESS IMMUNE SYSTEM **RISK FACTORS** Children/Adolescent Recent infection or vaccination **SYMPTOMS** Optic Nerve Inflammation Spinal Cord Inflammation Brain and Spinal Cord Inflammation Seizures Headaches Fever **EFFECTS** Permanent paralysis in arms and legs Long-term bowel and bladder difficulties Blindness (one or both eyes.) Trouble with language. memory and thinking **3. Microglia** Microglia are the [smallest type of glial cells that are located throughout the brain and spinal cord of the CNS.] Also, they are [primarily responsible for the inflammatory reaction in response to brain damage]. For example, hemorrhage, brain tumor, and aneurysm. Micgroglia may play a big role also in depression, Alzheimer, autism and many more. Microglia as well are responsible for the process of phagocytosis in the central nervous system. Lastly, microglia can shape-shift and eat other neurons. **Interesting facts about the Microglia** 95% of the microglial population is formed in the first two post natal weeks Microglia help eliminate excess synapses **[ACTION POTENTIAL ]** An action potential is a rapid electrical signal that travels along the membrane of a neuron or muscle cell, caused by the movement of ions across the cell membrane, allowing communication between cells. *[Phases of Action Potential]* 1\. **Depolarization**: \[Sodium ions (Na+) influx\] \- causes the rapid change in membrane potential from negative to positive state. 2\. **Repolarization**: closing of Na+ channels and opening of K+ channels. \- a process by which the membrane potential returns to its resting value. Potassium Channel Opening Potassium Efflux Repolarization 3\. **Hyperpolarization**---a phase where some potassium channels remain open and sodium channels reset. \- When the inside of an axon becomes more negative (from resting potential) relative to the outside, it is called hyperpolarization. **Refractory Period-** responsible for setting an upper limit on the frequency of action potentials. \- Ensures the one-way propagation of the action potential down the axon away from the initial site of activation. Membrane is polarized, but Na+and K+ are on wrong sides of membrane. **Propagation**- action potential moves along the axon as depolarization opens adjacent Na+ channels, creating a wave-like transmission.