cognition noun The mental process of acquiring knowledge and understanding through thought, experience, and the senses. Researchers study how sleep affects memory and other aspects of cognition. + perception noun The way something is understood, noticed, or interpreted through the senses or the mind. Public perception of the new policy shifted quickly after the scandal broke. + stimulus noun Something that causes a reaction or response in a person, animal, or system. A sudden loud noise is a stimulus that triggers an automatic startle response. + response noun A spoken or written answer, or a reaction to something that has happened. The company issued a formal response to the complaints within twenty-four hours. + reinforcement noun Additional support, material, or personnel sent to strengthen something that already exists. The general called for reinforcement after the front line began to weaken. + schema noun A structured plan, outline, or mental framework that organizes information or shows how something is arranged. The database schema defined how each table of customer information connected to the others. + psyche noun The human mind or spirit, especially as the source of a person's thoughts, feelings, and behavior. Years of criticism from his coach left a lasting mark on the young athlete's psyche. + neuron noun A nerve cell that transmits electrical and chemical signals in the brain and nervous system. A single neuron can connect to thousands of other neurons through tiny branches. + synapse noun The junction between two nerve cells where electrical or chemical signals pass from one to the other. Signals cross the synapse between neurons through the release of chemical messengers. + hormone noun A chemical substance produced by a gland that travels through the blood to regulate specific organs or tissues. Insulin is a hormone that helps the body control blood sugar levels. + libido noun A person's overall sexual drive or desire. Stress and lack of sleep can lower a person's libido over time. + trauma noun A deeply distressing or disturbing experience, or the lasting emotional or physical harm it causes. Years after the accident, she still worked through the trauma with a therapist. + phobia noun An intense, irrational fear of a specific object, activity, or situation. His phobia of heights kept him from ever climbing the observation tower. + amnesia noun Partial or complete loss of memory, typically resulting from injury, illness, or severe shock. After the accident, he suffered amnesia and couldn't remember the crash itself. + insomnia noun A persistent inability to fall asleep or stay asleep, even when tired. Stress from work gave her insomnia that lasted for several weeks. + anxiety noun A persistent feeling of worry, nervousness, or unease about an uncertain outcome. The exam gave her a wave of anxiety that lasted until she saw the results. + depression noun A mental health condition marked by persistent feelings of sadness, hopelessness, and loss of interest. She was diagnosed with depression after months of feeling exhausted and withdrawn. + hallucination noun A perception of something, such as a sight or sound, that seems real but is not actually present. The fever caused him to have a hallucination of insects crawling on the wall. + delusion noun A false belief held firmly despite clear evidence that it is not true. His delusion that he could win the lottery led him to overspend recklessly. + temperament noun A person's characteristic way of thinking, behaving, and reacting to situations, especially in terms of mood. Even as a baby, she had a calm temperament that rarely startled at loud noises. + conformity noun Behavior that matches accepted standards, rules, or the behavior of most other people in a group. The strict dress code enforced conformity among all the students. + obedience noun Compliance with an order, rule, or authority, or the practice of following instructions willingly. The recruits were trained to show immediate obedience to every command from their officers. + attachment noun A strong feeling of affection or emotional connection to a person, animal, or thing. The child formed a deep attachment to the stray kitten they found in the yard. + empathy noun The ability to understand or share another person's feelings and perspective. Listening without interrupting helped her show empathy for her frustrated friend. + cognitive dissonance noun The mental discomfort felt when holding two contradictory beliefs, values, or attitudes at the same time. She felt cognitive dissonance after criticizing waste while buying more than she needed. + classical conditioning noun A learning process in which a neutral stimulus becomes associated with a meaningful one, eventually triggering the same response. Pavlov's dogs demonstrated classical conditioning when they began salivating at the sound of a bell. + operant conditioning noun A learning process in which behavior becomes more or less likely based on rewards or punishments that follow it. Operant conditioning explains why the dog now sits automatically after learning that sitting earns a treat. + short-term memory noun The capacity to hold a small amount of information in mind for a brief period, typically seconds to a minute, without long-term storage. She repeated the phone number aloud to keep it in her short-term memory long enough to dial it. + long-term memory noun The part of memory that stores information for extended periods, from hours to a lifetime. Repeating new vocabulary helps move it from short-term into long-term memory. + confirmation bias noun The tendency to favor information that confirms one's existing beliefs while ignoring contrary evidence. Confirmation bias led him to read only articles that supported his political opinions. + fight-or-flight noun The body's automatic physiological reaction to a perceived threat, preparing it to either confront the danger or escape it. Her heart raced and her palms sweated as the fight-or-flight response kicked in during the near-collision. + self-actualization noun The process of realizing and fulfilling one's own talents and potential, especially as the highest human psychological need. According to Maslow, people pursue self-actualization only after their basic needs for safety and belonging are met. +