Evolution, Genes and Behavior

Evolution and Psychological Processes

• Evolution fundamentally shapes psychological processes.
• Genetic variations leading to adaptive behaviors are favored and passed on.

Charles Darwin and Natural Selection

• Charles Darwin proposed the theory of evolution by natural selection.
• Organisms with advantageous variations are more likely to survive, reproduce, and gradually change over time.

Genotype vs. Phenotype

• Genotype: An individual's genetic blueprint, or the set of genes they inherit.
• Phenotype: The observable expression of those genes, including physical and biological traits, influenced by both genetics and the environment.

Chromosomes, DNA, and Genes in Heredity

• Every cell contains a genome made of chromosome pairs containing tightly coiled DNA.
• Genes are short segments of DNA that encode instructions for building proteins, contributing to trait expression.

Sensory, Motor, and Interneurons

• Sensory (afferent) neurons: Carry messages from sensory organs to the brain.
• Motor (efferent) neurons: Carry messages from the brain to muscles and glands.
• Interneurons: Carry messages between other nerve cells within the brain and spinal cord.

Synaptic Transmission

• When an action potential reaches a neuron's terminal bulb, neurotransmitters are released into the synaptic gap.
• Neurotransmitters bind to receptor sites on the adjacent neuron, potentially initiating a new electrical signal.

Brain Plasticity

• Brain plasticity: The brain's ability to adapt and modify its structure and function in response to experience or injury.
• It allows the brain to compensate for damage and adjust to new learning.

Sympathetic vs. Parasympathetic Nervous System

• Sympathetic division: Prepares the body for "fight or flight" responses in stressful situations by increasing heart rate and arousal.
• Parasympathetic division: Returns the body to a calm, resting state.

Endocrine System

• The endocrine system communicates via hormones, chemical substances released into the bloodstream.
• Hormones influence various functions, behaviors, and emotions.
• Pituitary gland: Oversees the endocrine system and receives signals from the hypothalamus; called the "master gland."

Brain Stem

• Brain stem: An extension of the spinal cord that regulates basic life processes and instinctual responses.
• Key components: Medulla (regulating breathing and heart rate) and pons (regulating sleep and dreaming cycles).

Memory Tasks

• Encoding: Transforming sensory information into a usable form.
• Storage: Retaining the encoded information over time.
• Retrieval: Accessing and bringing stored information into consciousness.

Stages of Memory

• Sensory memory: Briefly holds vast amounts of sensory information for a few seconds.
• Working memory: Selectively takes information from sensory memory and connects it with long-term memory; holds about 7 +/- 2 chunks for 20–30 seconds.
• Long-term memory: Stores information potentially for a lifetime.

Chunking

• Chunking: Organizing information into meaningful units or chunks.
• Grouping pieces of information increases the amount that can be held in working memory.

Procedural vs. Declarative Memory

• Procedural memory: Long-term memory for how to do things, involving learned skills and habits (e.g., riding a bike).
• Declarative memory: Long-term memory for facts and events that can be consciously recalled (e.g., remembering what you ate for breakfast).

Childhood Amnesia

• Childhood amnesia: The inability of adults to remember episodic memories from the first few years of life (typically before age three).
• Possible explanations: Immaturity of brain structures like the hippocampus and the development of a sense of self and language.

Hippocampus

• Hippocampus: Plays a crucial role in forming new declarative memories (facts and events).
• The case of H.M., whose hippocampi were removed, demonstrated loss of the ability to create new conscious memories of facts and events.

Implicit vs. Explicit Memory

• Implicit memory: Affects behavior without conscious awareness (e.g., knowing how to ride a bike).
• Explicit memory: Requires conscious effort and awareness for retrieval (e.g., recalling information for a test).

Encoding specificity principle

• It states that retrieval cues matching how information was encoded are more effective in triggering memory.
• Studying in a similar environment to the testing environment or anticipating test questions can improve recall.

Seven Sins of Memory

• Examples of the "seven sins": Transience (weakening of memory), absent-mindedness (lack of attention), and blocking (temporary inability to access stored information).

Method of Loci

• Method of loci: A mnemonic strategy associating items to be remembered with a sequence of specific physical locations.
• "Placing" each item in a familiar location improves recall.

Conscious vs. Nonconscious Processing

• Conscious processing: Involves focused attention and awareness of information (e.g., solving a math problem).
• Nonconscious processing: Occurs outside of our awareness and can handle multiple tasks simultaneously (e.g., breathing while reading).

Freud's Iceberg Model

• Conscious (tip of the iceberg, current awareness)
• Preconscious (just below the surface, easily retrievable information)
• Unconscious (vast submerged portion, repressed motives and memories)

Core functions of consciousness

• Restriction: selectively attending to some stimuli and ignoring others.
• Combination: integrating information from various sources into a coherent mental representation.
• Manipulation: allowing us to create and manipulate mental models of the world.

Daydreaming

• Daydreaming is a mildly altered state of consciousness where attention turns inward to thoughts, memories, and desires, often with vivid imagery.
• It can be helpful for planning and creative insights but also can interfere with focus and memory for recently learned material.

Circadian Rhythms

• Circadian rhythms: Physiological patterns that repeat approximately every 24 hours, like the sleep-wake cycle.
• Hypothalamus: Primary brain structure responsible for regulating our "biological clock."

REM vs. NREM Sleep

• REM sleep: Rapid eye movements, vivid dreaming, and sleep paralysis.
• NREM sleep: Divided into stages with different brain wave patterns and typically involves less vivid or no mental activity.

Freud's Dream Theory

• Manifest content: Literal storyline and images of a dream.
• Latent content: Supposed symbolic meaning of the dream, reflecting unconscious desires or conflicts.

Hypnosis

• Hypnosis: An induced state of awareness with heightened suggestibility, deep relaxation, and focused attention.
• Application: Pain management during childbirth or dental procedures.

Meditation

• Meditation: A state of consciousness induced by repetitive behavior, specific body positions, and minimized external stimuli.
• Effects: Relaxation, reduced stress, and altered states of awareness.

Psychoactive Drugs

• Hallucinogens: Alter perception and create hallucinations (e.g., LSD).
• Depressants: Slow down mental and physical activity (e.g., alcohol).
• Stimulants: Speed up nervous system activity (e.g., caffeine).

Key Terms

• Biopsychology: The study of the interaction of biology, behavior, and mental processes
• Evolution: The gradual process of biological change in a species as it adapts to its environment.
• Natural Selection: Darwin's "weeding out" of individuals w/ traits better suited to their environment are more likely to survive and reproduce.
• Genes: Short DNA segment that encodes instructions for development
• Genotype: An individual's complete set of genes.
• Phenotype: The observable characteristics of an individual, resulting from the interaction of genotype and environment.
• Neuron: Cell specialized to receive, process, and transmit information to other cells.
• Action Potential: Nerve impulse caused by an electrical charge that travels the axon of a neuron when stimulated
• Neurotransmitters: Chemical messengers released by neurons that transmit signals across the synaptic gap to other neurons or target cells.
• Synaptic Gap (Synapse): The small space between two neurons where neurotransmitters are released and received. Brain Plasticity: The brain's ability to adapt and modify its structure and function in response to experience or injury.
• Nervous System: The network of nerve cells that transmit nerve impulses between different parts of the body.
• Endocrine System: A system of glands that secrete hormones into the bloodstream to influence bodily functions, behaviors, and emotions.
• Hormones: Chemical substances released by endocrine glands that carry messages through the bloodstream.
• Brain Stem: The most primitive layer of the brain, located at the base, which regulates basic life processes.
• Limbic System: A collection of brain structures surrounding the thalamus, involved in emotions, memory, and maintaining bodily equilibrium.
• Cerebral Cortex: The outer layer of the cerebrum, responsible for higher-level cognitive functions.
• Cerebrum: The largest part of the brain, consisting of two hemispheres, responsible for most complex mental functions.
• Encoding: The initial processing of information that allows it to be stored in memory.
• Storage: The retention of encoded information over time.
• Retrieval: The process of accessing and bringing stored information into consciousness.
• Sensory Memory: The initial stage of memory that briefly holds sensory information.
• Working Memory: A temporary storage system that holds information we are currently aware of and actively processing.
• Long-Term Memory (LTM): The final stage of memory, capable of storing information for long periods, even a lifetime.
• Chunking: Organizing information into meaningful units to expand the capacity of working memory.
• Procedural Memory: Long-term memory for skills and habits, often implicit.
• Declarative Memory: Long-term memory for facts and events, which can be consciously recalled, divided into semantic (facts) and episodic (personal experiences) memory.
• Implicit Memory: Memory that affects behavior without conscious awareness.
• Explicit Memory: Memory that requires conscious effort and awareness for retrieval.
• Recall: A retrieval method that requires reproducing previously presented information with minimal cues.
• Recognition: A retrieval method in which previously presented information must be identified from a set of options.
• Encoding Specificity Principle: The idea that retrieval cues that match the encoding context enhance memory recall.
• Transience: The weakening or loss of memory over time.
• Absent-Mindedness: Forgetting caused by a lack of attention during encoding or retrieval.
• Blocking: The temporary inability to access stored information.
• Misattribution: Assigning a memory to the wrong source, time, place, or person.
• Suggestibility: The creation or distortion of memories due to external suggestions or information.
• Bias: The distortion of memory by current knowledge, beliefs, or feelings.
• Mnemonic Strategies: Techniques for improving memory by making connections between new material and information already in long-term memory.
• Consciousness: The process by which the brain creates a mental model of our experience, most ordinarily occurring during wakefulness.
• Nonconscious Processing: Mental processes occurring outside of awareness.
• Preconscious: Freud's theory, an unconscious storehouse of information not currently in consciousness but readily available. In cognitive terms, equivalent to long-term memory.
• Unconscious: Freud's theory, a reservoir of primitive motives and threatening memories hidden from awareness. In cognitive terms, any nonconscious process.
• Circadian Rhythms: Physiological patterns that repeat approximately every 24 hours, such as the sleep-wake cycle.
• REM Sleep: Rapid Eye Movement sleep, a stage of sleep characterized by rapid eye movements, vivid dreaming, and muscle paralysis.
• NREM Sleep: Non-Rapid Eye Movement sleep, stages of sleep without rapid eye movements, generally with less vivid or no dreaming.
• Manifest Content: Freud's dream theory, the surface story line of a dream.
• Latent Content: Freud's dream theory, the underlying symbolic meaning of a dream.
• Hypnosis: An induced state of awareness characterized by heightened suggestibility, deep relaxation, and focused attention.
• Meditation: A state of consciousness induced by repetitive behavior, assuming certain body positions, and minimizing external stimuli.
• Psychoactive Drugs: Chemical substances that alter perceptions, mood, or behavior.
• Hallucinogens: Psychoactive drugs that alter perception, creating hallucinations.
• Opiates: Highly addictive drugs derived from opium that suppress physical sensation and response to stimulation.
• Depressants: Psychoactive drugs that slow down mental and physical activity.
• Stimulants: Psychoactive drugs that speed up the nervous system.
• Tolerance: Reduced effect of a drug with repeated use, requiring higher doses for the same effect.
• Physical Dependence: A state in which the body has adjusted to a drug and requires it to function normally; discontinuation leads to withdrawal symptoms.
• Addiction: A compulsive craving for and use of a drug despite harmful consequences; can be physical and/or psychological.