PSY 101 Introduction to Psychology I 2024-2025 Fall Semester PDF

PSY 101- INTRODUCTION TO PSYCHOLOGY I 2024-2025 FALL SEMESTER INSTRUCTER: ASST. PROF. KUBRA OZKAN DEMIR THE BIOLOGICAL PERSPECTIVE  Nervous system, a network of cells that carries information to and from all parts of the body. The field of neuroscience is a branch of the...

PSY 101- INTRODUCTION TO PSYCHOLOGY I 2024-2025 FALL SEMESTER INSTRUCTER: ASST. PROF. KUBRA OZKAN DEMIR THE BIOLOGICAL PERSPECTIVE  Nervous system, a network of cells that carries information to and from all parts of the body. The field of neuroscience is a branch of the life sciences that deals with the structure and functioning of the brain and the neurons, nerves, and nervous tissue that form the nervous system. Biological psychology, or behavioral neuroscience, is the branch of neuroscience that focuses on the biological bases of psychological processes, behavior, and learning, and it is the primary area associated with the biological perspective in psychology. FUNCTIONS OF NERVOUS SYSTEM The nervous system is vital for coordinating bodily functions, processing sensory information, and enabling communication between different body parts. It facilitates communication between the brain and the body, impacting emotions, cognition, and behavior. It regulates essential activities like movement, reflexes, and even basic survival functions, ensuring the body responds appropriately to internal and external stimuli. Its ultimate role in maintaining homeostasis and facilitating interaction with the environment highlights its importance for overall health and well-being. STRUCTURE OF THE NEURON  Our entire body is composed of cells, each type of cell has a special purpose and function and, therefore, a special structure. Most cells have three things in common: a nucleus, a cell body, and a cell membrane holding it all together. The neuron is the specialized cell in the nervous system that receives and sends messages within that system. Neurons are one of the messengers of the body.  The parts of the neuron that receive messages from other cells are called the dendrites. The dendrites are attached to the cell body, or soma, which is the part of the cell that contains the nucleus and keeps the entire cell alive and functioning. The axon is a fiber attached to the soma, and its responsibility is to carry messages out to other cells. Axon terminals are the endpoint of an axon. It plays a crucial role in communication between neurons.  Axon terminal: enlarged ends of Functions: axonal branches of the neuron, Communication: When an electrical impulse (neural signal) specialized for communication travels down the axon and reaches the axon terminal, it between cells. triggers the release of neurotransmitters. Synapse Formation: The axon terminal connects with the dendrites of another neuron at a junction called a synapse. This is where neurotransmitters are released into the synaptic cleft (the space between neurons) to transmit signals to the next neuron. Signal Transmission: This process allows for the transfer of information across the nervous system, enabling complex functions like movement, sensation, and thought. GLIAL CELLS Glial cells, or glia, are non-neuronal cells in the nervous system that provide support, protection, and maintenance for neurons. Functions of glial cells Providing structural support and guidance during brain development (e.g., radial glial cells). Supplying nutrients to neurons and cleaning up dead neurons. Facilitating communication between neurons and influencing synaptic connectivity. Some glial cells have stem cell-like properties, allowing them to develop into new neurons. Research is increasingly focusing on the role of glial cells in various neurodevelopmental and psychiatric disorders, such as autism, Alzheimer’s disease, and major depressive disorder. Additionally, glia are involved in learning and neuroplasticity, influencing how neurons connect and communicate within neural networks. Overall, glial cells are integral to brain health and function.  Glial cells are also being investigated for their possible role in a variety of neurodevelopmental diseases like autism spectrum disorder, degenerative disorders such as Alzheimer’s disease, and psychiatric disorders including major depressive disorder and schizophrenia. TYPES OF GLIAL CELLS Oligodendrocytes and Schwann cells are two types of glial cells responsible for producing myelin, a fatty substance that forms an insulating sheath around axons. Oligodendrocytes create myelin in the central nervous system (brain and spinal cord), while Schwann cells do so in the peripheral nervous system. MYELIN SHEATH Myelin serves several important functions: Insulation and Protection: It wraps around axons, protecting them and improving signal transmission. Speeding Up Neural Messages: The myelin sheath allows electrical impulses to travel faster down the axon by enabling the impulse to jump between nodes (gaps in the myelin), a process called saltatory conduction. This makes communication between neurons more efficient. In the case of nerve damage, Schwann cells can facilitate repair by creating a tunnel for regrowth, unlike oligodendrocytes, which do not support regeneration as effectively. Overall, the myelin sheath is crucial for optimal neuronal function and signal speed. GENERATING THE MESSAGE WITHIN THE NEURON: THE NEURAL IMPULSE RESTING VS. ACTION POTENTIAL RESTING POTENTIAL The state of the neuron when not firing a neural impulse ACTION POTENTIAL The release of the neural impulse, consisting of a reversal of the electrical charge within the axon. RESTING VS. ACTION POTENTIAL A neuron at rest is electrically charged, with a mostly negative charge inside the cell and a mostly positive charge outside. This difference is due to the presence of ions, primarily potassium ions inside and sodium ions outside. The cell membrane is semipermeable, allowing some ions to pass through while blocking others. When the neuron is at rest, sodium channels are closed, preventing sodium ions from entering. This creates an electrical potential. When the neuron receives sufficient stimulation, these sodium channels open, allowing sodium ions to rush in. This influx of positive ions causes the inside of the cell to become positive and initiates a change in electrical charge known as the action potential, which begins at the axon hillock and propagates down the axon in a chain reaction. Each action potential occurs within about one-thousandth of a second.  As the action potential travels down the axon, it temporarily reverses the electrical charge inside the neuron, making it positive while the outside remains negative. To restore the neuron to its resting state after the action potential has passed, several processes occur: Sodium Ion Channels Close: Immediately after the action potential, the sodium channels close, preventing more sodium ions from entering the cell. Sodium-Potassium Pump: The cell membrane actively pumps sodium ions back outside, restoring the original distribution of ions. This process takes some time. Potassium Ions Exit: To expedite the return to a negative charge inside, positively charged potassium ions move out of the neuron rapidly after the action potential. As a result, the inside of the cell becomes negative again, and the outside becomes positive. Once the sodium pumps finish their work, the neuron is back at its resting potential, ready to fire another action potential when stimulated again. In summary, the action potential involves a series of ion channels opening and closing, allowing the electrical signal to propagate down the axon while restoring the neuron’s resting state.  Neurons have a threshold for firing, meaning they require a certain level of stimulation to activate. Each neuron receives multiple signals from other neurons, some encouraging firing and others inhibiting it. The neuron sums these signals, and if the excitatory signals surpass the threshold, the neuron fires in an all-or-none manner—like a light switch that is either fully on or off. The strength of stimulation affects firing frequency. A strong stimulus results in rapid, repeated firings of the neuron and can also trigger additional neurons to fire, similar to multiple lights turning on and off. Conversely, weak stimulation may not reach the threshold and thus won’t cause firing. ACTION POTANTIAL NEUROTRANSMISSION SENDING THE MESSAGE TO OTHER CELLS: THE SYNAPSE When a neural signal reaches the axon terminals, several processes occur to facilitate communication between neurons. The axon terminals contain synaptic vesicles filled with neurotransmitters, which are chemicals that transmit messages. These vesicles release their contents into the synapse, the fluid-filled gap between neurons. The neurotransmitters cross the synaptic gap and bind to specific receptor sites on the postsynaptic neuron's dendrites. This binding opens gated ion channels, allowing sodium ions to rush into the postsynaptic cell, potentially triggering its own action potential.  Neurotransmitters can have either excitatory or inhibitory effects. Excitatory neurotransmitters stimulate the next cell to fire, while inhibitory neurotransmitters prevent it from firing. Antagonists: chemical substances that block or reduce a cell’s response to the action of other chemicals or neurotransmitters. Agonists: chemical substances that mimic or enhance the effects of a neurotransmitter on the receptor sites of the next cell, increasing or decreasing the activity of that cell. This distinction is crucial for regulating neural activity, ensuring that signals are appropriately turned on or off as needed. Thus, the action at the synapse determines whether the subsequent neuron, muscle, or gland will activate or inhibit its activity. TYPES OF NEUROTRANSMITTERS Acetylcholine This excitatory neurotransmitter does a number of functions in your central nervous system (CNS [brain and spinal cord]) and in your peripheral nervous system (nerves that branch from the CNS). Acetylcholine is released by most neurons in your autonomic nervous system regulating heart rate, blood pressure and gut motility. Acetylcholine plays a role in muscle contractions, memory, motivation, sexual desire, sleep and learning. Imbalances in acetylcholine levels are linked with health issues, including Alzheimer’s disease, seizures and muscle spasms. The venom of the black widow spider causes a flood of acetylcholine to be released into the body’s muscle system, causing convulsions.  Glutamate. This is the most common excitatory neurotransmitter of your nervous system. It’s the most abundant neurotransmitter in your brain. It plays a key role in cognitive functions like thinking, learning and memory. Imbalances in glutamate levels are associated with Alzheimer’s disease, dementia, Parkinson’s disease and seizures. Gamma-aminobutryic acid (GABA). GABA is the most common inhibitory neurotransmitter of your nervous system, particularly in your brain. It regulates brain activity to prevent problems in the areas of anxiety, irritability, concentration, sleep, seizures and depression. Glycine. Glycine is the most common inhibitory neurotransmitter in your spinal cord. Glycine is involved in controlling hearing processing, pain transmission and metabolism. Serotonin. Serotonin is an inhibitory neurotransmitter. Serotonin helps regulate mood, sleep patterns, sexuality, anxiety, appetite and pain. Diseases associated with serotonin imbalance include seasonal affective disorder, anxiety, depression, fibromyalgia and chronic pain. Medications that regulate serotonin and treat these disorders include selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs).  Histamine. Histamine regulates body functions including wakefulness, feeding behavior and motivation. Histamine plays a role in asthma, bronchospasm, mucosal edema and multiple sclerosis. Dopamine. Dopamine plays a role in your body’s reward system, which includes feeling pleasure, achieving heightened arousal and learning. Dopamine also helps with focus, concentration, memory, sleep, mood and motivation. Diseases associated with dysfunctions of the dopamine system include Parkinson’s disease, schizophrenia, bipolar disease, restless legs syndrome and attention deficit hyperactivity disorder (ADHD). Many highly addictive drugs (cocaine, methamphetamines, amphetamines) act directly on the dopamine system. Epinephrine. Epinephrine (also called adrenaline) and norepinephrine (see below) are responsible for your body’s so-called “fight-or-flight response” to fear and stress. These neurotransmitters stimulate your body’s response by increasing your heart rate, breathing, blood pressure, blood sugar and blood flow to your muscles, as well as heighten attention and focus to allow you to act or react to different stressors. Too much epinephrine can lead to high blood pressure, diabetes, heart disease and other health problems. As a drug, epinephrine is used to treat anaphylaxis, asthma attacks, cardiac arrest and severe infections.  Norepinephrine. Norepinephrine (also called noradrenaline) increases blood pressure and heart rate. It’s most widely known for its effects on alertness, arousal, decision- making, attention and focus. Many medications (stimulants and depression medications) aim to increase norepinephrine levels to improve focus or concentration to treat ADHD or to modulate norepinephrine to improve depression symptoms. Endorphins. Endorphins are your body’s natural pain reliever. They play a role in our perception of pain. Release of endorphins reduces pain, as well as causes “feel good” feelings. Low levels of endorphins may play a role in fibromyalgia and some types of headaches.  Problems with other parts of nerves, existing diseases or medications you may be taking can affect neurotransmitters. Also, when neurotransmitters don’t function as they should, disease can happen. For example: Not enough acetylcholine can lead to the loss of memory that’s seen in Alzheimer’s disease. Too much or little serotonin is possibly associated with autism spectrum disorders. An increase in activity of glutamate or reduced activity of GABA can result in sudden, high-frequency firing of local neurons in your brain, which can cause seizures. Too much norepinephrine and dopamine activity and abnormal glutamate transmission contribute to mania. Depression is often linked to low levels of serotonin and norepinephrine. Anxiety Disorders: is caused by imbalances in serotonin, norepinephrine, and GABA are commonly implicated. Schizophrenia is associated with excess dopamine activity in certain brain areas. NERVOUS SYSTEM: CNS VS PNS Our nervous system works by sending messages, or electrical signals, between your brain and all the other parts of your body. CENTRAL NERVOUS SYSTEM Central Nervous System (CNS): It is composed of the brain and spinal cord. These parts are composed of neurons and glial cells. Brain: The control center of the body, responsible for processing sensory information, regulating vital functions, enabling complex behaviors, coordinating movements, and higher cognitive functions such as thinking and memory. Spinal Cord: It is serving as the main pathway for transmitting signals between the brain and the body. It controls reflexes and processes sensory information, playing an ultimate role in motor coordination and response. Inner section- Gray matter: made up of neuron cell bodies, responsible for reflex actions. Outer section- White matter: Myelinated axons and nerves. Carry messages between body and brain.  Neuron Types: Afferent (Sensory) Neurons: Carry sensory messages from the senses to the spinal cord. (ACCESS) Efferent (motor) Neurons: Transmit responses from the spinal cord to muscles and glands. (EXIT) Interneurons: Connect afferent and efferent neurons within the spinal cord and brain. Reflex arc: Example: Touching a hot surface triggers an afferent neuron to send a pain message to the spinal cord, where an interneuron processes it and sends a quick response via an efferent neuron, causing the finger to pull back rapidly. Reflexes are faster than messages traveling to the brain, allowing for quick protective responses. PERIPHERAL NERVOUS SYSTEM Peripheral Nervous System (PNS): It is made up of all the nerves and neurons not contained in the brain and spinal cord. Somatic Nervous System: It is a part of the nervous system responsible for voluntary movements and sensory processing. Sensory Pathway:Comprised of afferent neurons that carry messages from the senses to the central nervous system. Motor Pathway:Made up of efferent neurons that transmit commands from the central nervous system to voluntary skeletal muscles, enabling actions like walking, raising hands, or moving toward an object. PERIPHERAL NERVOUS SYSTEM Autonomic Nervous System (ANS): It regulates involuntary bodily functions, controlling organs, glands, and muscles. It activates various physiological changes: Pupils dilate to take in more light. Heart rate increases, directing blood away from nonessential organs (like the skin) and enhancing oxygen delivery to muscles. Breathing rate increases to supply more oxygen. Adrenal glands release stress hormones into the bloodstream, further stimulating target organs such as the heart and lungs. Digestive processes are inhibited, leading to reduced saliva production and digestive activity. It has two main divisions: Sympathetic Nervous System: Prepares the body for "fight or flight" responses (anger or fear) during stressful situations. Helping the body for arousal. Parasympathetic Nervous System: Promotes "rest and digest" activities, helping the body conserve energy and relax. Restores body to normal functioning after arousal. (eat-drink-rest system) THE ENDOCRINE GLANDS Neurons communicate via neurotransmitters in the synapse, leading to fast, localized effects. In contrast, glands use chemical communication that can be more widespread and slower. Glands: Exocrine Glands: Secrete chemicals directly onto tissues through ducts (e.g., salivary and sweat glands). These affect bodily functions but not behavior. Endocrine Glands: Secrete hormones directly into the bloodstream without ducts. Hormones travel to target organs, where they bind to receptors and exert effects. Hormonal Communication: Generally slower than synaptic communication, as it takes time for hormones to reach their targets. Behavioral and emotional responses can occur hours, weeks, or even years later. Hormones can influence behavior and emotions by stimulating muscles and organs. Some theories suggest that hormone surges can trigger emotional reactions. Brain Influence: Certain hormones produced by endocrine glands also affect brain activity, leading to excitatory or inhibitory effects. PITUATARY GLANDS The pituitary gland, located just below the brain and connected to the hypothalamus, is often called the master gland because it controls other endocrine glands. It secretes several hormones that regulate growth, reproductive functions, and various bodily processes. Key Functions: Growth Hormone: Regulates size increase from infancy to adulthood. Sex Hormones: Stimulate the release of male and female sex hormones, influencing reproductive organs and secondary sex characteristics during puberty. Oxytocin: Involved in pregnancy-related functions such as milk production and labor onset. It's also associated with social behavior and is often referred to as the "love hormone" or "trust hormone« Vasopressin: Regulates salt and water balance in the body.  Research on Oxytocin: Oxytocin's role in forming social bonds has been studied in animals, but its effects on human social behavior are still being researched. Effects can vary based on individual circumstances; for example, men with less social proficiency showed improved empathic accuracy after receiving oxytocin, while more socially skilled men did not. There is growing interest in oxytocin's potential as a treatment for psychiatric behaviors, especially where social interactions are affected (e.g., autism, social anxiety). Oxytocin's effects may depend on individual beliefs about social relationships and could also lead to increased aggressive responses in some contexts. OTHER ENDOCRINE GLANDS Pineal Gland: It is located in the brain, above the brain stem. It secretes melatonin, which regulates biological rhythms and the sleep-wake cycle, and influences seasonal behaviors (like breeding and molting) in some animals. Thyroid Gland: It is located inside the neck. It produces hormones, including thyroxin, that regulate growth and metabolism, playing a critical role in body and brain development. Pancreas: It controls blood sugar levels by secreting insulin and glucagon. Imbalances can lead to diabetes (too little insulin) or hypoglycemia (too much insulin), affecting hunger and weight. Gonads: Called as sex glands (ovaries in females and testes in males) that secrete hormones regulating sexual behavior and reproduction. While hormones influence sexual behavior, psychological factors like attractiveness also play a significant role.  Adrenal Glands: Location: On top of each kidney. Structure: Comprised of the adrenal medulla and adrenal cortex. Adrenal Medulla: Releases epinephrine and norepinephrine during stress, aiding sympathetic arousal. Adrenal Cortex: Produces over 30 hormones (corticoids) regulating salt intake, stress reactions, and providing sex hormones. Notably, cortisol is released during stress, supplying energy by releasing glucose and fatty acids into the bloodstream. HORMONES AND STRESS General Adaptation Syndrome (GAS): Syndrome describes the body’s physiological responses to stress in three stages: Alarm Stage:The body’s immediate reaction to a stressor activates the sympathetic nervous system. The adrenal glands release hormones, increasing heart rate, blood pressure, and blood sugar, resulting in a burst of energy. Common reactions include fever, nausea, and headaches. Resistance Stage:As stress continues, the body enters a state of resistance, maintaining sympathetic activity and hormone release.Early alarm symptoms subside, and individuals may feel better temporarily.This stage continues until the stressor is removed or resources are depleted. Notably, stress hormones like norepinephrine can reduce pain sensitivity, leading to temporary analgesia. Exhaustion Stage:Once the body’s resources are exhausted, it enters exhaustion, which can lead to stress- related diseases (e.g., high blood pressure, weakened immune system) or even death without external help. After the stressor ends, the parasympathetic division activates to help replenish resources.  Key Insights: The alarm and resistance stages are common experiences that help individuals adapt to life’s demands. Prolonged secretion of stress hormones during exhaustion can lead to harmful health effects, supporting the link between stress and diseases of adaptation, such as hypertension and peptic ulcers. While a relationship between stress and certain diseases exists, research indicates that long-term stress may not always correlate with chronic high blood pressure, and the stress-ulcer connection remains debated. IMMUNE SYSTEM AND STRESS Stress Response Similar to Infection:Stress triggers a response in the immune system similar to that of an infection. When the body encounters an infection, immune cells (white blood cells) release enzymes and antibodies into the bloodstream, activating the vagus nerve, which signals the brain that the body is sick. Stress Activates Immune Response:Stress activates the immune system starting from the brain, leading to chemical changes that can "prime" the immune response. Research shows that animals subjected to isolation or stress display similar immune system activations as those experiencing infection. Short-term vs. Chronic Stress: Short-term stress can enhance immune activity, aiding in the body's ability to respond to threats. However, chronic stress leads to exhaustion of the body's resources, resulting in a weakened immune system and potential diseases like high blood pressure. Evolutionary Perspective:The stress response is evolutionarily designed for short-term situations, such as escaping a predator. Modern humans, however, experience prolonged stress in non-life-threatening situations, which can disrupt immune function. ALLOSTASİS AND ALLOSTATİC LOAD Allostasis refers to the body's ability to maintain stability through change in response to perceived and anticipated demands. Unlike homeostasis, which focuses on a constant internal environment, allostasis recognizes the dynamic adjustments the body makes during stress. Activation: The body engages the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis, releasing stress hormones like adrenaline and cortisol. This process helps the body manage stressors but can lead to allostatic load when stress is prolonged, resulting in wear and tear on the body and brain.  Consequences of Allostatic Load Prolonged exposure to stress mediators can impair immune function and increase vulnerability to stress-related diseases, affecting mental and physical health. Chronic stress contributes to coronary heart disease (CHD) by disrupting immune response and liver function, which can lead to arterial plaque buildup and other health issues. Stress also affects metabolic processes, contributing to diabetes and cardiovascular disease. Workplace stressors, such as job insecurity and long hours, heighten these risks. Impact of Stress on Cancer While stress does not directly cause cancer, it can suppress immune function, making it easier for cancer cells to proliferate. Stress hormones can interfere with the immune system's ability to combat tumors, and chronic stress has been linked to changes in cellular function that promote cancer growth. Other Health Issues Related to Stress Stress is associated with higher incidences of illnesses like diabetes, particularly Type 2 diabetes, which is linked to obesity and poor health behaviors. Research shows that ongoing family stress can lead to increased illness in children, although in children, stress may sometimes enhance immune function. Cerebral Cortex: Surface of the brain Gyri (singular: gyrus) are the raised or bulging parts on the outer surface of the brain. These structures help increase the surface area of the brain, allowing for more neurons to be accommodated. Sulci (singular: sulcus) are the grooves or furrows that exist between the gyri. These grooves help distinguish between different regions of the brain, organizing its functional areas. The most prominent sulcus, known as the longitudinal fissure, is the deep groove that separates the brain into two halves or hemispheres: the left hemisphere and the right hemisphere.  Cortex is getting more and more wrinkled as the brain increases in size and complexity. The cortex is wrinkled to increase its surface area. This wrinkling allows for more neurons to be packed into a limited space, enhancing the brain's processing power. The folds (gyri) and grooves (sulci) create more surface area without increasing the overall size of the brain, which is important for cognitive functions and efficiency. Additionally, this folding helps organize different brain regions, facilitating communication between them. LEFT AND RIGHT HEMISPHERS Split-brain research is pivotal in understanding the brain's lateralization—how certain cognitive functions are divided between the two hemispheres. The left hemisphere specializes in language, speech, handwriting, calculation (math), sense of time and rhythm (which is mathematical in nature), and basically any kind of thought requiring analysis. The right hemisphere appears to specialize in more global (widespread) processing involving perception, visualization, spatial perception, recognition of patterns, faces, emotions, melodies, and expression of emotions. It also comprehends simple language but does not produce speech.  CORPUS CALLOSUM The two hemispheres are connected by a thick band of neural fibers known as the corpus callosum, consisting of about 200 million axons. The corpus callosum allows the two hemispheres to communicate with each other and allows for information being processed on one side of the brain to be shared with the other side. LOBES OF THE BRAIN 4 main parts of brain 1.Frontal lobe 2.Parietal lobe 3.Temporal lobe 4.Occipital lobe PARTS OF THE FRONTAL CORTEX Motor cortex: involved in planning and coordinating movement; Prefrontal cortex: responsible for higher-level cognitive functioning; and Broca’s area, which is essential for language production.  FUNCTIONS OF FRONTAL LOBE Frontal lobes: areas of the brain located in the front and top, responsible for higher mental processes and decision making as well as the production of fluent speech. Main functions: Executive Functions: This includes planning, decision-making, problem-solving, and organizing tasks. Motor Control: The primary motor cortex, located in the frontal lobe, controls voluntary movements of the body. Speech Production: Broca's area, typically found in the left frontal lobe, is crucial for speech production and language processing. Emotional Regulation: The frontal lobe plays a role in regulating emotions and social behavior. Personality and Behavior: It is involved in the development of personality traits and the ability to understand social norms. Attention and Focus: The frontal lobe helps in maintaining attention and concentration on tasks. MIRROR NEURONS Mirror neurons are a type of brain cell that respond both when an individual performs an action and when they observe someone else performing that same action. They are thought to play a key role in various functions, including: Imitation: Mirror neurons are believed to be involved in learning through imitation, helping individuals understand and replicate behaviors. Empathy: By mirroring the emotions and actions of others, these neurons may facilitate empathic responses, allowing people to connect with and understand each other's feelings. Social Learning: They contribute to learning in social contexts, helping individuals understand the intentions behind others' actions. Motor Planning: Mirror neurons may also assist in planning and executing movements by allowing the brain to simulate actions. Mainly found in prefrontal cortex and motor regions but also in parts of the brain involved in vision, audition. PARIETAL LOBE The parietal lobes are at the top and back of the brain. The parietal lobes contain the somatosensory cortex, which processes touch, temperature, and body position information. TEMPORAL LOBE Temporal lobes are areas of the cortex located along the side of the brain, starting just behind the temples, containing the neurons responsible for the sense of hearing and meaningful speech. primary auditory cortex and the auditory association area. The auditory cortex, the main area responsible for processing auditory information, is located within the temporal lobe Wenicke’s area: responsible for language comprehension Broca's Area Location: Typically found in the left frontal lobe, specifically in the posterior part of the frontal gyrus. Function: Responsible for language production, speech formation, and grammar. It plays a crucial role in the motor aspects of speaking. Impact of Damage: Damage to Broca's area can result in Broca's aphasia, characterized by difficulty in forming complete sentences. Individuals may speak in short, broken phrases and struggle with grammatical rules, though their comprehension generally remains intact. Wernicke's Area Location: Located in the left temporal lobe, specifically in the posterior part of the superior temporal gyrus. Function: Involved in language comprehension and the processing of spoken and written language. Impact of Damage: Damage to Wernicke's area can lead to Wernicke's aphasia, where individuals may produce fluent but nonsensical speech. They often have significant difficulties understanding language and may not realize their speech lacks meaning. OCCIPITAL LOBE Occipital lobe: located at the rear and bottom of each cerebral hemisphere containing the primary visual centers of the brain. Primary visual cortex: processes visual information from the eyes. Visual association cortex: helps identify and make sense of the visual information from the eyes. SPATIAL NEGLECT Spatial neglect condition produced most often by damage to the parietal lobe association areas of the right hemisphere and occipital lobes of the cortex resulting in an inability to recognize objects or body parts in the left visual field. MAIN CATEGORIES OF THE BRAIN  The three primary divisions are the hindbrain, midbrain and forebrain. The hindbrain includes the medulla, pons, and cerebellum. The midbrain is important for both sensory and motor functions. The forebrain includes the cortex, basal ganglia, and the limbic system. HINDBRAIN The parts of hindbrain Medulla Pons Reticular Formation Cerebellum MEDULLA The medulla controls the automatic processes of the autonomic nervous system, such as breathing, blood pressure, and heart rate. So it controls life-sustaining functions. The medulla is involved in reflexes such as swallowing coughing, sneezing, and vomiting. It plays a role in controlling sleep patterns and alertness. It is in the medulla that the sensory nerves coming from the left and right sides of the body cross over, so that sensory information from the left side of the body goes to the right side of the brain and vice versa. PONS The pons serves to connect the hindbrain to the rest of the brain. It plays role in left-right body coordination It also is involved in regulating brain activity during sleep. RETICULAR FORMATION The reticular formation is a complex network of neurons located in the brainstem that plays a crucial role in various vital functions such as arousal and alertness, attention, sleep regulation. These neurons are generally responsible for people’s ability to attend to certain kinds of information in their surroundings. Basically, the RF allows people to ignore constant, unchanging information (such as the noise of an air conditioner) and become alert to changes in information (for example, if the air conditioner stopped, most people would notice immediately). CEREBELLUM The cerebellum receives messages from muscles, tendons, joints, and structures in our ear to control balance, coordination, movement, and motor skills. Damage to cerebellum causes to uncoordinated behaviors. Spinocerebellar degeneration is a disease that the first symptoms are tremors, an unsteady walk, slurred speech, dizziness, and muscle weakness. The person suffering from this disease will eventually be unable to walk, stand, or even get a spoon to his or her own mouth ( MIDBRAIN=LYMBIC SYSTEM It includes the thalamus, hypothalamus, hippocampus, amygdala, and the cingulate cortex. In general, the limbic system is involved in emotions, motivation, and learning. THALAMUS It is a part of the forebrain that relays information from sensory organs to the cerebral cortex. Hearing, sight, touch, taste Smell is the only sense that does not have to first pass through the thalamus. (olfactory bumbs) HYPOTHALAMUS The hypothalamus regulates body temperature, thirst, hunger, sleeping and waking, sexual activity, and emotions. HIPPOCAMPUS The hippocampus is instrumental in forming long-term (permanent) declarative memories that are then stored in the brain. ACh, the neurotransmitter involved in muscle control, is also involved in the memory function of the hippocampus. People who have Alzheimer’s disease, for example, have much lower levels of ACh in that structure than is normal, and the drugs given to these people boost the levels of ACh. AMGYDALA The amygdala is involved in fear responses and memory of fear. Information from the senses goes to the amygdala before the upper part of the brain is even involved, so that people can respond to danger very quickly, sometimes before they are consciously aware of what is happening. The amygdala plays a vital role in forming emotional memories. Near to hippocampus CINGULATE CORTEX It is found right above the corpus callosum in the frontal and parietal lobes and plays an important role in both emotional and cognitive processing. The cingulate cortex can be divided into up to four regions that play different roles in processing emotional, cognitive, and autonomic information. Dysfunction in the cingulate cortex has been implicated in various psychiatric conditions, including ADHD, depression, anxiety, and schizophrenia, as well as chronic pain disorders. SENSATION AND PERCEPTION Sensation refers to the initial detection of physical stimuli from the environment by our sensory organs (such as eyes, ears, skin, etc.). Sensation is a passive, physiological process—essentially, it's the input that we get from the world. Example: The light entering your eyes or the sound waves reaching your ears. Perception is the process by which the brain organizes, interprets, and makes sense of the sensory information. It's an active process that takes the raw data (sensation) and turns it into meaningful experiences or understanding. Example: Recognizing a face in a crowd or understanding the meaning of a song you're hearing. Sensation is about detecting stimuli, while perception is about interpreting those stimuli. SENSATION Sensation occurs when special receptors in the sense organs—the eyes, ears, nose, skin, and taste buds—are activated, allowing various forms of outside stimuli to become neural signals in the brain. This process of converting outside stimuli, such as light, into neural activity is called transduction. For example, the photoreceptor cells in the eye convert light energy into electrical signals, which are then processed by the brain as visual perception. Similarly, in the ear, sound waves are transformed into mechanical energy and then converted into neural signals. SENSORY RECEPTORS The sensory receptors are specialized forms of neurons, the cells that make up the nervous system. A stimulus is a detectable input from the environment. Each type of receptor responds to a specific form of energy: Eyes: Light Ears: Vibrations (sound) Touch receptors: Pressure or temperature Taste and smell receptors: Chemical substance These receptors convert (transduce) the physical stimulus into an electrical signal The electrical signal either depolarizes or hyperpolarizes the receptor cell, affecting its firing rate based on the intensity and timing of the detected stimulus. EIGHT SENSORY SYSTEM Visual input (sight) Gustatory input (taste) Tactile input (touch) Hearing input (auditory) Olfactory input (smell) Vestibular input (balance) Proprioceptive input (movement) Interoceptive input (internal)  Visual input (sight): Visual input refers to the information the brain receives from the eyes, which detect light, colors, shapes, and movement in the environment. This helps us navigate the world, recognize objects, and understand spatial relationships. Gustatory input (taste): Gustatory input is the information we receive through taste receptors on the tongue, which detect five basic tastes: sweet, salty, sour, bitter, and umami. This helps us identify flavors and assess the quality of food, contributing to our enjoyment and survival. Tactile input (touch): Tactile input comes from the sensory receptors in the skin that detect physical sensations like pressure, temperature, and pain. This sense allows us to interact with objects, feel textures, and respond to environmental changes like heat or cold.  Hearing input (auditory): Auditory input is the information received through the ears, which detect sound waves. These sound signals are then processed by the brain to help us understand speech, identify sounds, and detect environmental noises, contributing to communication and awareness. Olfactory Input (Smell):Olfactory input is the information gathered from the nose, where smell receptors detect airborne chemicals (odor molecules). This sense helps us identify odors, warn of danger (like smoke or spoiled food), and plays a role in taste and memory.  Vestibular Input (Balance):Vestibular input refers to the sensory information from the inner ear that helps us detect changes in head position and movement. It’s crucial for maintaining balance, coordination, and posture, allowing us to sense whether we’re upright, moving, or rotating. Proprioceptive/Kinesthetic Input (Movement): Proprioceptive input is the sense that provides information about the position, movement, and tension of muscles and joints. It helps us understand where our body parts are in space, contributing to coordinated movement and body awareness. Interoceptive Input (Internal):Interoceptive input refers to the sensory information that comes from inside the body, such as sensations of hunger, thirst, pain, heart rate, and body temperature. It helps us monitor and respond to our internal state, ensuring homeostasis and well-being.