Psychology 101 Notes - Chapter 3 & 4 - PDF

Natural Communication Chapter 3- Biology and Behavior Test on 16 October Human Brain Overview Makes up only 2% of body weight. Consumes 20% of oxygen and 25% of the body's glucose. Responsible for both conscious and unconscious experiences. Neural Communication System Bui...

Natural Communication Chapter 3- Biology and Behavior Test on 16 October Human Brain Overview Makes up only 2% of body weight. Consumes 20% of oxygen and 25% of the body's glucose. Responsible for both conscious and unconscious experiences. Neural Communication System Built from billions of neurons, which operate similarly in all brains. Neurons receive, integrate, and transmit information electrochemically. Parts of a Neuron The neuron passes signals, receives signals from other neurons, and assesses incoming signals. Electrical Properties of Neurons Neurons have negative charge inside and positive charge outside at rest. Excitatory input reduces negativity, inhibitory input increases it. Neurons fire action potentials if excitatory input reaches a threshold (all-or-none response). Signal strength is conveyed through frequency, not size. Myelin Sheath Fatty sheath insulates the axon, increasing the speed and efficiency of electrical signals. Signal Transmission Across Synapse Neurotransmitters are released into the synapse and bind to receptors, triggering an action potential in the receiving neuron. Receptors only respond to specific neurotransmitters. After Neurotransmitters Are Released Neurotransmitters can be reabsorbed (reuptake), detected by presynaptic neurons (autoreception), or broken down by enzymes. Agonist and Antagonist Molecules Agonists: Enhance neurotransmitter activity by increasing production, binding to receptor sites, or blocking reuptake.  Antagonists: Inhibit neurotransmitter activity by decreasing production, blocking receptor sites, or aiding in destruction within the synapse. The Brain Phrenology 1800s theory by Franz Gall that bumps on the skull represented mental abilities. Though incorrect, it introduced the concept of brain function localization. Techniques to Study the Brain Brain Lesions: Damaged brain tissue used experimentally or through injury (TBI, stroke) to study brain areas. EEG: Measures electrical activity from the scalp (good timing, poor spatial resolution). PET: Measures brain activity using a radioactive tracer. MRI: Uses magnets for high-resolution structural brain images. fMRI: Measures blood flow to detect brain activity (good spatial, poor temporal resolution). TMS: Disrupts brain activity with magnetic fields, used to temporarily shut down regions. Cerebral Cortex Surface of the brain with billions of neurons (white and gray matter). Wrinkled to increase surface area. Lobes: ○ Occipital: Vision. ○ Parietal: Touch, visuospatial processing, sensory integration. ○ Temporal: Sound, smell, language, object recognition. ○ Frontal: Motor control, executive function. Frontal Cortex Prefrontal Cortex: Handles decision-making, consequences, attention, planning, goal pursuit. Motor Cortex: Controls voluntary movements. Somatosensory Cortex Processes touch and body movement. Insular Cortex Handles taste, disgust, and bodily sensations of emotion. Basal Ganglia Coordinates motor signals, motivation, risk-taking, habit formation, and reward processing. Subcortical Structures Thalamus: Sensory switchboard directing messages to the cortex (except smell). Hypothalamus: Regulates bodily functions and motivated behaviors like hunger and sex. Hippocampus: Essential for long-term memory. Amygdala: Processes threat-related emotions, such as fear and anger, and intensifies related memories. Brainstem and Midbrain Medulla: Controls heart rate and breathing. Pons: Regulates sleep and arousal. Cerebellum: Coordinates motor movements and learning. Substantia Nigra: Involved in voluntary movement and sensory-motor relay. Brain and Body Brain Plasticity Plasticity: The brain’s ability to change in response to experiences, forming the foundation for learning. Greatest Early in Development: Critical periods exist when specific input is necessary; deprivation can lead to permanent deficits (e.g., cats and humans deprived of visual input). Experience Affects Connections: Every experience modifies the strength of neural connections. Cortical Plasticity Reorganization: Sensory areas that lack input can adapt to process other sensory information (e.g., blind individuals using their visual cortex for Braille). Functional Compensation: Damaged areas can be compensated for by new neural pathways in undamaged regions. Age-Related Decline: Plasticity decreases significantly with age. Nervous System Overview  Nervous System: Comprises all nerve cells; functions as a fast, electrochemical system. Central Nervous System (CNS): Includes the brain and spinal cord; responsible for decision-making. Peripheral Nervous System (PNS): Connects the CNS to the rest of the body, divided into: ○ Somatic Nervous System: Handles voluntary movements by sending sensory and motor information. ○ Autonomic Nervous System: Regulates internal body functions, with: Parasympathetic NS: “Rest and digest” functions. Sympathetic NS: “Fight or flight” responses. Genes and Environment Genotype vs. Phenotype: ○ Genotype: An individual’s unique genetic makeup. ○ Phenotype: Observable traits shaped by genetics and environment. Heritability: Estimates the genetic contribution to trait variability within a population. Twin Studies Used to differentiate genetic and environmental influences: ○ Identical Twins: Share 100% of genes; more similar in traits (e.g., IQ, personality) than fraternal twins. ○ Minnesota Twin Study: Found similarities in personality and intelligence in twins raised apart, despite different environments. Complications of Nature vs. Nurture Different Responses to Environment: Individuals with varying genotypes may react differently to the same environmental factors (e.g., why some mistreated children commit violent crimes while others do not). Caspi et al. Study (2002): Examined vulnerability to maltreatment based on monoamine oxidase gene alleles. Epigenetics Gene Regulation by Environment: Environmental factors can turn genes "on" or "off"; even identical twins can have different epigenetic experiences (affected by stress, diet, pollution). Transgenerational Effects: Epigenetic changes can be passed to offspring. Chapter 4: Consciousness Consciousness and the Unconscious Consciousness Definition: Moment-to-moment subjective experience of the world; inherently subjective. States of Consciousness: ○ Normal waking state. ○ Altered states (e.g., sleep, meditation). Limitations: ○ Consciousness is a unified stream. ○ We can only fully process a limited amount of information. Change Blindness Definition: The failure to notice large, unattended changes in the environment. Key Insight: We are often blind to information that we do not consciously process, especially if changes do not affect the meaning of what we observe. Attention and Its Limits Definition: The process of focusing mental resources on specific information. Conscious Processing: Selective attention allows us to consciously process selected information, while unattended information is mostly lost. Multitasking Myth: True multitasking is a myth; we switch attention rapidly between tasks, which can slow reaction times. Types of Attention Endogenous Attention: Deliberate and voluntarily directed attention. Exogenous Attention: Involuntarily directed attention triggered by external stimuli (e.g., a loud noise). Capturing Attention Certain sensory information can automatically capture our attention, such as: ○ The cocktail party effect (hearing your name in a noisy environment). ○ A crying baby. ○ Pain stimuli. Consciousness and Brain Activity  Specific neural activity patterns correspond to particular conscious experiences. Techniques like fMRI can observe what individuals are thinking. Beyond Conscious Awareness Priming: Recent exposure to a stimulus facilitates the processing of related stimuli (e.g., completing words). Subliminal Perception: Processing information without conscious awareness, with limited effects on behavior: ○ It may briefly prime information (e.g., odor influencing likeability). ○ Generally does not affect complex behavior. Processing Types Automatic Processing: Well-practiced tasks that require minimal attention. Controlled Processing: Tasks that require focused attention. Overview of Consciousness and Attention Adaptability: The limitations of conscious processing help avoid wasting mental resources on irrelevant information. Exogenous Attention: Ensures we attend to essential stimuli and events in our environment. Altering Consciousness Conscious Experience Influence of Actions and Attention: Our conscious experience is shaped by where we focus our attention and how we act. Meditation Definition: Intense contemplation leading to calmness. ○ Types: Mindfulness and concentrative meditation. Possible Effects: ○ Lowered blood pressure. ○ Reduced stress. ○ Increased focus. Brain Changes: Potential reduction in the loss of gray matter. Losing the Self Experiences: ○ Runner's High: Euphoria experienced during prolonged exercise.  ○ Religious Ecstasy: Often achieved through dance, chanting, and music. ○ Flow State: A highly focused engagement in enjoyable activities where self-awareness and time perception diminish. Escaping the Self Escapist Activities: These activities divert attention and enable avoidance of problems, including: ○ TV ○ Internet ○ Food ○ Video/computer games Distracting vs. Fulfilling: Some activities provide distraction, while others may offer fulfillment. Altering Consciousness Hypnosis: ○ Sociocognitive Theory: People act according to their expectations of being hypnotized. ○ Neodissociation Theory: Awareness is dissociated from other aspects of consciousness. ○ Applications: Useful in pain treatment, but not mind control. Brain Injuries Effects of Traumatic Brain Injuries: They can lead to significant changes in conscious experience, varying in nature and severity. Coma: Characterized by a lack of responsiveness, complicating the assessment of consciousness. Chronic Traumatic Encephalopathy: A neurodegenerative condition often associated with repeated brain injuries. Psychoactive Drugs Definition: Chemicals that alter perceptions, mood, consciousness, cognition, or behavior by affecting neural transmission. Types: ○ Depressants: Slow neural activity (e.g., alcohol, sedatives, opiates). ○ Stimulants: Speed up bodily functions (e.g., caffeine, nicotine). ○ Opioids: Pain relief and pleasure enhancement (e.g., morphine, heroin). ○ Hallucinogens: Distort perceptions and evoke sensory images (e.g., LSD). Specific Drug Effects  Depressants (Alcohol): ○ Decreases inhibitions, increases impulsive behavior. ○ Impairs motor skills, judgment, and memory (disrupts REM sleep). ○ Long-term effects: Brain shrinkage, cognitive impairment. Stimulants: Increase neural activity and bodily functions. Opioids: Mimic endogenous opioids and activate dopamine receptors; repeated use reduces endorphin production. Addiction Definition: Compulsive drug craving and use despite negative consequences. Tolerance: Needing larger doses for the same effect; can lead to dangerous situations during rehabilitation. Dependence: ○ Physical: Body's adaptation results in tolerance and dependence. ○ Psychological: Cravings and emotional challenges. Withdrawal: Symptoms may include anxiety, cravings, and physical effects (nausea, fever, aches). NEUOTRANSMITARES (QUESTION)on the TEST