Psych Unit 1- Biological Bases

Evolutionary Perspective

Study of how psychological traits and behaviors have evolved over time to enhance survival and reproductive success

Natural Selection

Process by which organisms with traits better suited to their environment are more likely to survive and reproduce, passing on their traits to future generations. Explains how we have evolved over time in response to environmental challenges.

Nature

Inherent biological and genetic factors that influence an individual's psychological development

Nurture

Environmental influences and experiences that shape an individual's psychological development

Twin Studies

Research examining similarities and differences between identical and fraternal twins to assess the relative influence of genetics and environment on traits and behaviors

Adoption Studies

Research investigating similarities between adopted children and their biological and adoptive families to assess the impact of genetics versus environment

Family Studies

Analysis of similarities and differences among family members to understand the interplay of genetics and environment in shaping traits and behaviors within a family unit

Heredity

Transmission of genetic information from biological parents to offspring, helps figure out how much of our traits come from genes, and how much come from the enviroment.

Genetic Predisposition

Inherited likelihood of developing specific traits or conditions due to genetic factors from biological parents

Eugenics

Belief in improving the genetic quality of a human population by controlling reproduction to increase desirable traits and decrease undesirable ones

Cerebral Cortex

Outer layer of the brain responsible for higher-level cognitive functions, such as thinking, perceiving, and decision making.

Association Areas

Parts of the brain that take information from all over the place and put it together to help us understand the world. (EX. of information is 5 senses).

Lobes of the Brain

Four main regions in which the cerebral cortex is divided (frontal, parietal, temporal, and occipital.)

Frontal Lobes

Located in the front of the brain, and involved in higher-level cognitive functions. Ex: decision-making, problem solving, planning, and personality.

Prefrontal Cortex

Region in the frontal lobe responsible for higher-level cognitive functions and executive functioning: cognitive processess that help us plan, organize, strategize, ect (goal-based behavior).

Motor Cortex

Region in the frontal lobe responsible for controlling voluntary movements of the body, and it sends signals to muscles, enabling us to walk, talk, and hold objects.

Parietal Lobes

Brain region at the top primarily responsible for processing sensory information from the body, like touch, temperature, and spatial awareness.

Somatosensory Cortex

Region in the parietal lobe responsible for processing sensations from the skin, muscles, and joints. It interprets touch, pressure, temperature/ touch stimuli from different parts of the body, allowing us to perceive and response to this stimuli.

Occipital Lobes

Brain region at the back primarily responsible for processing visual information received from the eyes. Contains primary visual cortex, allows us to perceive shapes, colors, and motion.

Temporal Lobes

Brain region on the sides involved in processing auditory information, language understanding, and memory formation. Contains auditory cortex: interprets sound signals from the ears.

Corpus Callosum

Thick band of nerve fibers connecting the left and right hemispheres of the brain, making communication and information sharing between the two hemispheres easier.

Brainstem

Oldest and most primitive part of the brain responsible for basic life-sustaining functions such as breathing, heart-rate, and sleep wake cycle. Serves as a pathway for neural signals traveling between brain and the rest of the body (cereberal to spinal).

Medulla

Vital structure at the base of the brainstem regulating essential autonomic functions such as heartbeat, breathing, and blood pressure. It relays nerve signals traveling between brain and spinal cord.

Reticular Activating System

Network of neurons in the brainstem that regulates arousal, attention, consciousness, and filters sensory information and modulates overall brain activity, helps maintain wakefulness and alertness.

Cerebellum

Structure at the back of the brain responsible for coordinating movement, balance, and posture, and it receives input from the brain to fine-tune motor movements/ ensure smooth coordination.

Limbic System

Set of brain structures beneath the cerebral cortex involved in emotions, memory, and motivation.

Reward Center

Network of brain structures in the limbic system that processes pleasurable experiences and reinforces behaviors associated with them

Thalamus

Relay station in the brain that processes and relays sensory information to the cerebral cortex. Acts as a gateway for sensory input, directing signals to the appropriate areas of the brain for processing.

Hypothalamus

small but powerful structure before the thalamus, and regulates essential bodily functions like hunger, thirst, body temperature, and the sleep-wake cycle.

Pituitary Gland

Small gland at the base of the brain, and plays a central role in controlling hormone production and discharge, and plays a huge role in coordinating hormonal activity and maintaining homeostasis.

Hippocampus

Curved structure in the temporal lobes primarily responsible for forming and consolidating new memories

Amygdala

Small, almond shaped structure deep in the brain’s temporal lobes, that is involved in processing emotions such as fear or aggression, and plays a central role in the brain’s threat detection system/ flight or fight.

Nervous System

Body's communication network consisting of a complex system of nerves, neurons, and specialized cells.

Central Nervous System

System consisting of the brain and spinal cord that serves as the command center of the body, and processes information, coordinates responses, and regulates bodily functions.

Peripheral Nervous System

System consisting of all nerves and ganglia outside the brain and spinal cord that transmits sensory information from the body to the CNS. (Communication network).

Autonomic Nervous System

Division of the peripheral nervous system that regulates involuntary bodily functions and operates automatically without conscious control. Two Branches: sympathetic nervous system and parasympathetic.

Sympathetic Nervous System

Branch of the autonomic nervous system responsible for activating the body's "fight or flight" response in times of stress or danger. Ex: increase heart rate, dilate airway redirects blood flow to essential organs.

Parasympathetic Nervous System

Branch of the autonomic nervous system responsible for promoting relaxation and restoring the body to a calm state after stress. Ex. slows heart rate, constricts airways, enhances digestion to conserve energy and recover from stress.

Somatic Nervous System

Division of the peripheral nervous system responsible for controlling voluntary movements and relaying sensory information from the body to the CNS

Neurons

Specialized cells that serve as the building blocks of the nervous system, and transmit electrical and chemical signals throughout the body. Dendrite, axon, soma.

Glial Cells

Support cells of the nervous system that provide structural support, insulation, and nourishment to neurons. They play an essential role in maintaining brain health and neuron function.

Motor Neurons

Nerve cells that transmit signals from the central nervous system to muscles, glands, and organs. It initiates and controls voluntary and involuntary movements.

Sensory Neurons

Specialized nerve cells that transmit sensory information from sensory receptors (skin, muscles, organs) to the central nervous system. They detect stimuli, and convert them into electrical signals that can be processed by the brain.

Interneurons

Nerve cells that serve as connectors within the central nervous system, and relay signals between sensory neurons and motor neurons.

Reflex Arc

Neural pathway that controls reflex actions, allowing for fast, automatic responses to stimuli without conscious thought for protection.

Neural Transmission

Process by which neurons communicate with each other through electrical and chemical signals

Threshold

Level of stimulation required to trigger an action potential in a neuron; the minimum amount needed to produce a response

Action Potential

Brief electrical impulse that travels along the axon of a neuron when the neuron receives a stimulus that causes the inside of the cell to be more positively charged than the outside.

All-or-Nothing Principle

Principle stating that once a neuron reaches its threshold of excitation, it will fire an action potential at full strength. If stimulus is strong enough, neuron will respond with a full-strength impulse. If it is below threshold, it will not fire at all.

Depolarization

Phase of action potential where the inside of the neuron becomes less negative due to the stream of positively charged ions. The change in electrical charge triggers neuron to fire action potential.

Refractory Period

Brief period following an action potential during which a neuron is unable to generate another action potential

Resting Potential

Stable, negative electrical charge across the membrane of a neuron when it is not transmitting signals. Maintained by unequal distribution of ions.

Reuptake

Process in which neurotransmitters released into the synapse are reabsorbed by the presynaptic neuron from which they were originally released

Multiple Sclerosis

Chronic autoimmune disease affecting the central nervous system where the immune system attacks the protective myelin sheath surrounding nerve fibers, occurs when immune system mistakenly attacks the protective myelin sheath.

Myasthenia Gravis

Chronic autoimmune disorder affecting the neuromuscular junction/ where nerve impulses are transmitted to muscles. Occur when immune system produces antibodies that destroy the receptors for acetylcholine.

Neurotransmitters

Chemical messengers that transmit signals between neurons, allowing for communication within the nervous system. They go into the synaptic cleft, where they bind to specific receptor sights on post-synaptic neurons, leading to neural impulse.

Excitatory Neurotransmitters

Chemicals released by neurons that increase the likelihood of an action potential occurring in the postsynaptic neuron. They bind to receptor sites on postsynaptic membrane, causing depolarization, increasing the likelihood.

Glutamate

Primary excitatory neurotransmitter in the CNS involved in most normal brain operations including thinking, long-term memory, and learning. Most common neurotransmitter in the brain. Too much can cause migraines or seizures from overstimulation.

Inhibitory Neurotransmitters

Chemicals released by neurons that decrease the likelihood of an action potential occurring in the postsynaptic neuron

GABA

Inhibitory transmitter that slows things down, calming the CNS by increasing sleepiness, and decreasing anxiety and alertness. Too much: overly relaxed, and normal reactions (sleep/eating) are impaired.

Dopamine

Pleasure chemical released into pleasure centers of the brain; related to reward. Associated with addition and motivation, and people will repeat actions that lead to dopamine. Too much: schizophrenia, drug addiction. Too little: depression, memory disorders, ADHD.

Serotonin

Neurotransmitter connected to feelings of well-being and happiness; regulates emotion. Also regulates the sleep cycle along with melatonin, and is apart of many drug treatments for depression and anxiety. Too much: hallucinations too little: depression and anxiety disorders.

Endorphins

Neurotransmitters produced by the brain that act as natural pain relievers and mood enhancers; released during exercise, excitement, pain. Too much: no adequate warning about pain, artificial highs. Too little: body experiencing alot of pain.

Substance P

Neurotransmitter involved in transmitting pain signals in the nervous system

Acetylcholine (ACh)

Principal neurotransmitter involved in thought, learning, and memory. Also involved in activation muscle action like contraction, memory, and learning. Too much: severe muscle spasm. Too little: Alzheimer’s disease and lack of muscle movement/ paralysis.

Hormones

Chemical messengers produced by glands in the endocrine system that travel through the bloodstream to target cells or organs, where they regulate physiological processes and behaviors.

Ghrelin

Hormone produced primarily by the stomach that stimulates appetite and promotes hunger; often called the hunger hormone (increased before meal, decrease after).

Leptin

Hormone produced primarily by fat cells that regulates energy balance and appetite by suppressing appetite and increasing energy use.

Melatonin

Hormone that regulates the sleep-wake cycle and circadian rhythms in the body, plays a crucial role in maintaining body’s internal clock and ensuring good sleep.

Oxytocin

Powerful hormone that acts as a neurotransmitter regulating social interaction and sexual reproduction; often called the love hormone. Huge role in pair bonding.

Adrenaline (Epinephrine)

Hormone produced in high stress or exciting situations that provides physical boost and heightened awareness; involved in fight or flight response. It increases heart rate, dilates airways, and increases blood flow to muscles and oxygen in lung.

Norepinephrine

Neurotransmitter and hormone involved in the body's fight or flight response. It increases heart rate and blood pressure (through contracting blood vessels), and alertness during times of stress or danger.

Plasticity

Brain's ability to reorganize and adapt throughout life in response to experiences, and the brain can adapt and rewire itself to regain lost functions or learn new ones.

Split Brain Research

Studies of individuals who have undergone corpus callosotomy, which disconnects the two hemispheres, and mostly done to treat severe epilepsy.

Contralateral Hemispheric Organization

Phenomenon where each hemisphere of the brain controls the opposite side of the body, sensory information received by one side is processed by the opposite hemisphere.

Hemispheric Specialization

Concept that each hemisphere of the brain has specialized functions and abilities

Linguistic Processing

Complex cognitive processes involved in understanding and producing language, example being when you hear someone and instantly understand what they mean.

Broca's Area

Located in Left hemisphere of the brain, specifically the Region in the left frontal lobe responsible for speech production and language processing. Crucial role in producing grammatically correct sentences and the coordination of the muscles involved in speech.

Broca's Aphasia

Language disorder caused by damage to Broca's area in the left hemisphere, resulting from stroke or brain injury. Has difficulty forming and producing fluent speech and grammatically correct sentences, and speech may be slow and effortful.

Wernicke's Area

Region in the left hemisphere, specifically the temporal lobe, and involved in language comprehension and understanding spoken and written language.

Wernicke's Aphasia

Language disorder caused by damage to Wernicke's area often from stroke or brain injury, and the person has fluent speech, but they may use nonsensical words or sentences, and they have difficulty understanding spoken and written language.

Electroencephalogram (EEG)

Non-invasive neuroimaging technique that records electrical activity of the brain using electrodes placed on the scalp, and is used to diagnose and monitor neurological conditions, like epilepsy, sleep disorders, and brain injury.

Functional Magnetic Resonance Imaging (fMRI)

Neuroimaging technique that measures brain activity by detecting changes in blood flow and oxygen levels, it provides detailed images of the brain, allowing researches to observe which areas are active during specific tasks.

Lesioning

Research technique used to study brain function by intentionally damaging or destroying specific areas of the brain in experimental animals

Sensation

Pure data coming from our sensory receptors; receiving information but not interpreting it

Transduction

Conversion of sensory stimuli into neural impulses that can be understood by the brain, transformation of physical energy into electrochemical signals, allowing for the brain to interpret sensory information.

Perception

How we interpret the information from our senses

Absolute Threshold

Minimum amount of stimulation required for a stimulus to be detected by a sensory system, point where stimulus is noticeable at least 50% of the time by an individual.

Just-Noticeable Difference (JND)

Smallest change in a stimulus that can be detected by an individual

Sensory Adaptation

Diminished sensitivity as a result of constant stimulation

Weber's Law

Principle that perceived difference in a stimulus must be proportional to the original intensity of the stimulus. Bigger something is, the more you need to change it to notice a difference.

Synesthesia

Condition in which stimulation of one sensory pathway leads to automatic, involuntary experiences in another sensory pathway. Ex. See color when hearing sound.

Retina

Light-sensitive inner surface of the eye containing photoreceptor cells that convert light into neural signals

Blind Spot

Area on the retina where the optic nerve exits the eye, which lacks photoreceptor cells, and vision is absent as there is no light-sensitive cells to detect visual stimuli.

Optic Nerve

Nerve that transmits visual information from the retina to the brain

Lens

Transparent structure in the eye that focuses light onto the retina by adjusting its shape in order to refract light, enabling clear vision at different distances.

Accommodation

Process by which the lens of the eye changes its shape to focus on objects at different distances, allows for clear vision of nearby and distant objects.

Nearsightedness (Myopia)

Vision condition where close objects appear clear but distant objects appear blurry; occurs when eyeball is too long or the cornea is too curved, leading to light to focus in front of the retina instead of on it.

Farsightedness (Hyperopia)

Vision condition where distant objects are seen more clearly than close ones; occurs when eyeball is too short or cornea is too flat, causing light to focus behind the retina rather than on it.

Photoreceptors

Specialized cells in the retina (rods and cones) that detect light and convert it into neural signals