Biological Bases of Behavior - Comprehensive Notes

Developing Understanding Psychology

• Psychology is the scientific study of behavior and mental processes.
• All psychological phenomena have a biological basis.
• Unit 1 focuses on how biological systems influence physical and mental actions and responses.
• Understanding neurons, brain function, sleep, and sensation helps understand psychology and the biological basis of behavior.
• In Unit 2, biological mechanisms are vital to memory.
• In Unit 5, damage to biological structures can cause psychological disorders.

Science Practices

• 1.A: Concept application, applying psychological perspectives, theories, concepts, and research findings to various contexts.
• Use knowledge of psychological concepts to explain behaviors and mental processes.
• Compare and contrast theories.
• Draw conclusions about behavioral outcomes in particular scenarios.
• Example: Explain behaviors resulting from damage to a particular brain region.
• 2.A: Research methods and design by determining the type of research design used in a given study.
• Determine whether a study is using experimental or non-experimental methodologies.
• Experimental research is conducted by biopsychologists.
• Other methods: case studies, correlational research, and naturalistic observations.
• Engage with research articles and reports in biopsychology.
• 3.A: Data interpretation by evaluating and analyzing representations of psychological concepts in quantitative and qualitative research, including tables, graphs, charts, figures, and diagrams.
• Identify psychology-related concepts in descriptions or representations of data, as well as related variables and statistics.
• 4.A: Argumentation, making a defensible claim about a psychological perspective, theory, concept, or research finding.
• Practice articulating a claim that can be made from research results, related to sleep, for example.
• Later, provide reasoning that supports proposed claims, starting in Unit 2.

Essential Questions

• Why do we learn biology in a psychology course?
• How does knowledge of the connection between biological systems and mental processes help us live healthier lives?
• How much of who you are is determined by what’s in your brain?

AP Exam Preparation

• Focus is on functions, not structures.
• Example: Neural communication process, not neuron parts.
• Connect neurotransmitter functions with biological processes and their relation to behavior and mental processes.
• Understand how neurotransmitters work—and don’t work—as intended during the neuronal firing process.
• Understand how successful and disrupted transmission affects behavior and mental processes in disorders such as multiple sclerosis or myasthenia gravis (Topic 1.3).
• Free-response questions on the AP Psychology Exam will require engaging with research studies and argumentation skills.
• Evidence-Based Question (EBQ): Propose a defensible claim based in psychological science about a specific topic related to a set of three summarized sources (skill 4.A).
• Article Analysis Question (AAQ): Identify specific research elements presented in a peer-reviewed, summarized source, including the methodology used (2.A).

Topic 1.1: Interaction of Heredity and Environment

• Learning Objective 1.1.A: Explain the relationship between heredity and environment in shaping behavior and mental processes.
• Essential Knowledge 1.1.A.1: Heredity and environmental factors interact to shape behavior and mental processes.
  • 1.1.A.1.i: Heredity, or “nature,” refers to genetic or predisposed characteristics that influence physical, behavioral, and mental traits and processes.
  • 1.1.A.1.ii: Environmental factors, or “nurture,” refers to the external factors that one experiences, such as family interactions or education.
• 1.1.A.2: The evolutionary perspective explores how natural selection affects the expression of behavior and mental processes to increase survival and reproductive success. Some theorists have sought to apply principles of the evolutionary perspective in ways that discriminate against others (eugenics).
• 1.1.A.3: Research on the effects of genes on individual behavior and mental processes is often conducted using twin studies, family studies, and adoption studies. *Suggested Skills:
  • 1.A Apply psychological perspectives, theories, concepts, and research findings to a scenario.
  • 2.A Determine the type of research design(s) used in a given study.

Topic 1.2: Overview of the Nervous System

• Learning Objective 1.2.A: Differentiate among the subsystems of the human nervous system and their functions.
• Essential Knowledge 1.2.A.1: The central nervous system includes the brain and the spinal cord and interacts with all processes in the body.
• 1.2.A.2: The peripheral nervous system relays messages from the central nervous system to the rest of the body and includes the autonomic and somatic nervous systems.
  • 1.2.A.2.i: The autonomic nervous system governs processes that are involuntary and includes the parasympathetic and sympathetic nervous systems.
  • 1.2.A.2.ii: The somatic nervous system governs processes that are voluntary.
    *Suggested Skills:
  • 1.A Apply psychological perspectives, theories, concepts, and research findings to a scenario.
  • 3.A Identify psychology-related concepts in descriptions or representations of data.

Topic 1.3: The Neuron and Neural Firing

• Learning Objective 1.3.A: Explain how the structures and functions of typical neurons in the central nervous system affect behavior and mental processes.
• Essential Knowledge 1.3.A.1: Two common types of neural cells in the brain are neurons (neural cells that transmit information) and glial cells (cells that provide structure, insulation, communication, and waste transport). These types of cells form the basis of the nervous system and are the building blocks of all behavior and mental processes.
• 1.3.A.2: In the spinal cord, the reflex arc demonstrates how neurons within the central and peripheral nervous systems work together to respond to stimuli. Three types of neurons work together in the spinal cord to create a reflex arc: sensory neurons, motor neurons, and interneurons.
• Learning Objective 1.3.B: Explain how the basic process of neural transmission is related to behavior and mental processes.
• Essential Knowledge 1.3.B.1: The process of neural transmission most commonly occurs in an orderly, systematic way and involves the all-or-nothing principle, depolarization, refractory period, resting potential, reuptake, and threshold. Disruptions to this process could lead to disorders such as multiple sclerosis or myasthenia gravis.
• 1.3.B.2: Each neurotransmitter has specific function(s) related to behavior and mental processes, which may depend on the neurotransmitter’s location in the nervous system. Neurotransmitters generally communicate either excitatory (making an action potential more likely) or inhibitory (making an action potential less likely) messages. Neurotransmitters related to behavior and mental processes for study in AP Psychology are limited to dopamine, serotonin, norepinephrine, glutamate, GABA, endorphins, substance p, and acetylcholine.
• 1.3.B.3: Outside of the nervous system, hormones perform actions similar to neurotransmitters. Hormones related to behavior and mental processes for study in AP Psychology are limited to adrenaline, leptin, ghrelin, melatonin, and oxytocin.
• Learning Objective 1.3.C: Explain how psychoactive drugs affect behavior and mental processes.
• Essential Knowledge 1.3.C.1: Psychoactive drugs can influence neurotransmitter function in various ways throughout the neural communication process. Some act as agonists which encourage neural firing. Some act as antagonists which discourage neural firing. Some act as reuptake inhibitors which block the reabsorption of neurotransmitters back into the cell.
• 1.3.C.2: Psychoactive drugs have psychological and physiological effects.
  • 1.3.C.2.i: Stimulants, such as caffeine and cocaine, typically cause increased neural activity.
  • 1.3.C.2.ii: Depressants, such as alcohol, typically cause decreased neural activity.
  • 1.3.C.2.iii: Hallucinogens, such as marijuana, typically cause distortions in perception and/or cognition.
  • 1.3.C.2.iv: Opioids, such as heroin, typically act as pain relievers.
• 1.3.C.3: Psychoactive drug use can lead to tolerance and/or addiction. Addiction can create significant withdrawal symptoms if the psychoactive drugs are no longer consumed. *Suggested Skills:
  • 1.A Apply psychological perspectives, theories, concepts, and research findings to a scenario.
  • 2.A Determine the type of research design(s) used in a given study.
  • 3.A Identify psychology-related concepts in descriptions or representations of data.

Topic 1.4: The Brain

• Learning Objective 1.4.A: Explain how the structures and functions of the brain apply to behavior and mental processes.
• Essential Knowledge 1.4.A.1: The brain stem (including the medulla) generally controls basic functioning such as breathing and heart rate.
• 1.4.A.2: The reticular activating system and the brain’s reward center generally control some voluntary movement, eye movement, and some types of learning, cognition, and emotion.
• 1.4.A.3: The cerebellum generally controls coordination of muscle movement, balance, and some forms of procedural learning.
• 1.4.A.4: The cerebral cortex is divided into two hemispheres and includes the limbic system (thalamus, hypothalamus, pituitary gland, hippocampus, amygdala), corpus callosum, and the lobes of the cortex.
  • 1.4.A.4.i: The occipital lobes generally control visual information processing and are located in the rear of the brain.
  • 1.4.A.4.ii: The temporal lobes generally control auditory and linguistic processing and are located on the sides of the brain.
  • 1.4.A.4.iii: The parietal lobes generally control association areas, which process and organize information, and the somatosensory cortex, which processes touch sensitivity. These lobes are located near the back crown of the brain.
  • 1.4.A.4.iv: The frontal lobes, located just behind the forehead, generally control linguistic processing, higher-order thinking, and executive functioning, especially in the prefrontal cortex. The motor cortex is located at the rear of the frontal lobes and controls most types of skeletal movement.
• 1.4.A.5: Split brain research, achieved by severing the corpus callosum (often a treatment for severe epilepsy), reveals that the right and left hemispheres of the brain may specialize in different activities and functions.
  • 1.4.A.5.i: Areas of the brain that affect language are typically located in the left hemisphere and include Broca’s area (responsible for speech production) and Wernicke’s area (responsible for speech comprehension). Damage to these parts of the brain can lead to aphasia.
  • 1.4.A.5.ii: Researchers test for cortex specialization with split-brain patients by showing information in each visual field, taking advantage of the brain’s contralateral hemispheric organization.
• 1.4.A.6: Brain plasticity is the ability of the brain to rewire itself or modify or create new connections throughout development and generally allows for the function of a damaged part of the brain to be assumed by a different part of the brain.
• 1.4.A.7: Research on the brain is done using scans (including EEG and fMRI), case studies, and surgical procedures (such as lesioning) to promote understanding of how the different structures of the brain work and how the brain functions together as a whole. *Suggested Skills:
  • 1.A Apply psychological perspectives, theories, concepts, and research findings to a scenario.
  • 2.C Evaluate the appropriate use of research design elements in non-experimental methodologies.
  • 2.D Evaluate whether a psychological research scenario followed appropriate ethical procedures.
  • 3.A Identify psychology-related concepts in descriptions of representations of data.

Topic 1.5: Sleep

• Learning Objective 1.5.A: Explain how the sleep/wake cycle affects behavior and mental processes throughout the day and night.
• Essential Knowledge 1.5.A.1: Consciousness has varying levels of awareness of thoughts, feelings, behavior, and events in individuals’ internal and external worlds. Sleep and wakefulness are two types of consciousness.
• 1.5.A.2: The sleep/wake cycle is a circadian rhythm, which in humans is about a 24-hour cycle. Jet lag and shift work are disruptions of the circadian rhythm.
• 1.5.A.3: The stages of sleep are identified by their specific EEG patterns.
  • 1.5.A.3.i: NREM sleep occurs in Stages 1 through 3 and decreases in duration throughout the cycle. Hypnogogic sensations occur as one enters Initial Stage 1 sleep.
  • 1.5.A.3.ii: REM sleep is considered paradoxical because it produces waves similar to wakefulness, but the body is at its most relaxed. Dreaming typically occurs in REM sleep. The frequency of REM sleep typically increases as the cycle progresses. When deprived of REM sleep, REM rebound can occur.
• 1.5.A.4: Theories regarding the structure and function of dreams include activation-synthesis and consolidation theory.
• 1.5.A.5: Memory consolidation and restoration are current theories about why sleep occurs. These theories suggest that sleep is useful for organizing and consolidating memories or restoring depleted resources used throughout a given day.
• 1.5.A.6: Many disorders interrupt healthy sleep, and their effects on waking behavior and health vary. Sleep disruptions can affect physical and cognitive performance during wakefulness. Treating sleep disorders and following regular schedules for sleeping can improve waking performance and overall well-being. Disorders commonly studied in introductory psychology include insomnia, narcolepsy, REM sleep behavior disorder, sleep apnea, and somnambulism. *Suggested Skills:
  • 1.B Explain how cultural norms, expectations, and circumstances, as well as cognitive biases apply to behavior and mental processes.
  • 2.C Evaluate the appropriate use of research design elements in non-experimental methodologies.
  • 2.D Evaluate whether a psychological research scenario followed appropriate ethical procedures.
  • 4.A Make a defensible claim.

Topic 1.6: Sensation

• Learning Objective 1.6.A: Explain how the process of sensation is related to behavior and mental processes.
• Essential Knowledge 1.6.A.1: Sensation is the process of detecting information from the environment that meets a certain threshold and transducing stimuli into neurochemical messages for processing (perception) in the brain. The absolute threshold occurs when a stimulus can be detected at least 50% of the time.
• 1.6.A.2: Detection of change in stimuli or diminished sensitivity to stimuli can be explained by the just-noticeable difference and sensory adaptation. Weber’s law describes the degree to which stimuli need to be different for the difference to be detected.
• 1.6.A.3: The sensory systems constantly work together in a process called sensory interaction. Synesthesia is an experience of sensation in which one system of sensation is experienced through another.
• Learning Objective 1.6.B: Explain how the structures and functions of the visual sensory system relate to behavior and mental processes.
• Essential Knowledge 1.6.B.1: The retina is the photosensitive surface at the back of the eye. Cells in the retina capture visual information that is transduced to the brain for processing. Evidence of incomplete images captured by the retina is demonstrated by the presence of the blind spot, where the visual nerve exits the eye. The brain fills in the gaps in the incomplete retinal images to perceive a relatively complete picture of the world.
• 1.6.B.2: Visual stimuli are focused onto the retina by the lens via a process called accommodation. When this process is altered, nearsightedness or farsightedness can result.
• 1.6.B.3: Cells that lie in the periphery of the eye and detect shapes and movement, but not color, are called rods. These cells are mainly activated in low-light environments. These cells play a role in light and dark adaptation.
• 1.6.B.4: Color vision is explained by both the trichromatic theory and the opponent-process theory.
  • 1.6.B.4.i: Photoreceptor cells located in the fovea of the eye that process color and detail are called cones. Researchers have identified blue (detecting short wavelengths), green (detecting medium wavelengths) and red (detecting long wavelengths) cones in the retina.
  • 1.6.B.4.ii: Afterimages result when certain ganglion cells in the retina are activated while others are not. The ganglion cells involved in this opponent process are red/green, blue/yellow/ and black/white.
  • 1.6.B.4.iii: Color vision deficiency involves damage or irregularities to one or more cones or ganglion cells (red/green, blue/ yellow). Color vision deficiency includes dichromatism or monochromatism.
• 1.6.B.5: Damage to parts of the brain responsible for vision (mainly the occipital lobes) can result in disorders such as prosopagnosia (face blindness) and blindsight.
• Learning Objective 1.6.C: Explain how the structures and functions of the auditory sensory system relate to behavior and mental processes.
• Essential Knowledge 1.6.C.1: Sound occurs through the movement of air molecules at different wavelengths (called pitch) and amplitudes (called loudness).
• 1.6.C.2: Theories that help explain pitch perception include place theory, volley theory, and frequency theory.
• 1.6.C.3: Sound localization describes how we identify where sounds in our environment are coming from.
• 1.6.C.4: Hearing difficulties can result from aging and various kinds of damage to auditory structures. Types of hearing loss include conduction deafness and sensorineural deafness.
• Learning Objective 1.6.D: Explain how the structures and functions of the chemical sensory systems relate to behavior and mental processes.
• Essential Knowledge 1.6.D.1: Structures in the nose and brain process and/ or transduce olfactory stimuli. Smell is the only sense not processed first in the thalamus of the brain. Pheromones produce chemical messages for the olfactory system.
• 1.6.D.2: Gustation is the sense of taste, and types of tastes include sweet, sour, salty, bitter, umami, and oleogustus.
• 1.6.D.3: Structures in the tongue, mouth, and brain process and/or transduce basic tastes. The number of taste receptors on the tongue is related to how sensitive people are to tastes, classifying them as supertasters, medium tasters, or nontasters.
• 1.6.D.4: The chemical senses interact to create the sensation of taste. Without the sense of smell, taste sensations are either muted or not experienced.
• Learning Objective 1.6.E: Explain how the structures and functions of the touch sensory system relate to behavior and mental processes.
• Essential Knowledge 1.6.E.1: Structures within the skin and brain process and/or transduce touch stimuli. The sensation of “hot” is produced by the activation of warm and cold receptors in the skin.
• Learning Objective 1.6.F: Explain how the structures and functions of the pain sensory system relate to behavior and mental processes.
• Essential Knowledge 1.6.F.1: Pain is processed both in the body and in the brain. Gate control theory is one attempt to describe the complexities of pain. Phantom limb sensation occurs when people who have lost limbs report sensation or pain where the limb used to be.
• Learning Objective 1.6.G: Explain how the structures and functions that maintain balance (vestibular) and body movement (kinesthetic) relate to behavior and mental processes.
• Essential Knowledge 1.6.G.1: The vestibular sense controls balance and is primarily detected by the semicircular canals and structures in the brain.
• 1.6.G.2: Kinesthesis the sense of one’s body movement. Kinesthesis allows the body to move in coordinated ways without having to look at the various parts of the body as it moves. *Suggested Skills:
  • 1.A Apply psychological perspectives, theories, concepts, and research findings to a scenario.
  • 2.B Evaluate the appropriate use of research design elements in experimental methodology.
  • 3.B Calculate and interpret measures of central tendency, variation, and percentile rank in a given data set.
  • 3.C Interpret quantitative or qualitative inferential data from a given table, graph, chart, figure, or diagram.