Psychology Chapter on Memory

Memory

• Memory illusion is a false but compelling memory, like recalling "sleep" in an experiment. The brain fills in gaps with past information that fits stimuli.
• Memories are retrieved by reconstructing them in the present moment. There isn't a storage shelf for memories, the brain reconstructs them based on current information.
• Memory follows a three-component model: sensory, short-term, and long-term.
• Primacy effect: remembering initial information.
• Recency effect: remembering last information.
• Visual stimuli studies show that people can accurately identify photos they've seen before, even after several days (85% accuracy). However, accuracy drops significantly with time. Memory recall degrades with time.
• Library analogy: Memory is like a book filed in a library.

Long Term Memory

• Memories last from minutes to years.
• Larger than short-term memory.
• Permastore: a type of long-term memory that appears permanent.
• Long-term memory can be split into categories, including explicit and implicit memory.

Short Term Memory

• Retains information for limited durations (10-15 seconds).
• Also called working memory.
• Decay and interference can affect short-term memory.
• Information is held while we are processing or attending to it.
• Capacity is approximately, 7 +/- 2 items.
• Chunking helps to increase the capacity of short-term memory by grouping items into larger, more meaningful units.

Encoding, Storage, and Retrieval

• Encoding is the process of getting information into memory.
• Storage is the process of holding information in memory.
• Retrieval is the process of getting information out of memory.
• Problem: Our memories should be flawless if storage metaphor was correct but memory is not flawless due to inconsistencies with contemporary research.

Forgetting

• Forgetting is the deterioration in learned behavior that occurs when information is not practiced or reviewed after a period. The learned behaviour becomes weaker over time.
• Is retention interval, the time between learning and testing the retention of information, the cause of forgetting? Are memories erased, or altered with time?
• Is forgetting the reconstruction process is an instance of learning?

Sensory Memory

• Sensory memory is the first component of memory.
• A brief storage of perceptual information from sensory receptors e.g eyes and ears.
• Holds information for approximately 1.5 seconds.

Memory as a network

• Memory can be represented as a network.
• Concepts are like "nodes," linked together in a network. The farther the lines are, the weaker the relationship between concepts.
• Favored model due to similarities with neural network models.

Long-Term Memory

• Relatively enduring retention of information, facts, experiences.
• LTM (is much longer than) STM.
• Capacity is larger than STM.
• Information can last hours to years; some seemingly permanent.

Explicit Memories

• Explicit: memories we intentionally recall.
• Episodic (past events), Semantic (knowledge of the world).

Implicit Memories

• Implicit: memories we do not intentionally recall.
• Procedural (motor skills, habits) and Priming.

Neural Basis of Memory Storage

• Engram: A theoretical physical location for a memory trace.
• Memories are likely not localized in a single brain area, but scattered throughout the brain.
• Lashley's work, aiming for an engram, suggests memories are not in a specific area but instead distributed throughout the brain.

Hebbian Learning

• When neurons interact regularly (fire together,wire together).
• When one neuron excites another, a chemical process occurs, enabling the first neuron to become better at stimulating the second.
• Key to forming memories.

Long-Term Potentiation (LTP)

• A strengthening of synapses that enhances signal transmission.

Amnesia

• Loss of memories, from the past.
• Retrograde: Loss of memories before an injury.
• Anterograde: Inability to form new memories after an injury.

Consolidation

• Hypothetical process converting info to long-term memory.
• Involves the hippocampus and amygdala.

Alzheimer's

• A progressive, degenerative disease.
• Primarily affects memory and cognition, often resulting in dementia.

Infantile Amnesia

• Lack of early childhood memories.

Flashbulb Memories

• Vivid, detailed memories of emotional and significant events.

Cryptomnesia

• Unconsciously repeating an idea that was learned elsewhere.
• Mistaking something from one's own personal experience as one's own idea.

Motivation and Emotion

• Motivation is a process that influences the type of behavior expressed and its persistence and the capacity to carry out a behaviour. Motivation is not an explanation but a vague description.
• Drive reduction theory explains motivation as internal tension that pushes us towards actions that reduce tension.
• Incentive theory explains the push towards desired objects/goals (incentives).
• Expectancy theory emphasizes the drive to fulfill goals e.g. expectancy that a behavior will result in a goal x value of the goal.
• Intrinsic motivation refers to internal goals like passion whereas extrinsic motivation refers to external incentives like rewards.

Physiology of Hunger

• Glucostatic theory suggests that hunger is triggered when blood glucose levels drop.
• Homeostasis is maintained by short-term signals (like hunger pangs) and long-term signals (related to appetite and weight).
• Hormones like ghrelin and leptin are implicated in feelings of hunger/fullness, which signal to the brain to increase/decrease appetite.

Cognitive Perspective

• Expectations about eating, palatability, quantity available, and variety influence eating behavior.

Eating Disorders

• Obesity is associated with psychological factors, genetic components (40-70%), and environmental factors like lifestyle.
• Bulimia nervosa involves cycles of binge eating and compensatory behaviors like purging.
• Anorexia nervosa involves extreme weight loss due to food restriction and fear of weight gain.

Emotion

• Cognitive component: subjective experience of emotion (e.g., fear, anxiety, love).
• Physiological component: autonomic responses associated with emotion (e.g., increased heart rate, sweating).
• Behavioral component: overt expressions of emotion (e.g., smiling, crying).

Polygraph Tests

• Measures physiological signs associated with stress, not necessarily lying.
• Guilty knowledge tests are used in this approach.

Display Rules

• Cultural norms regarding expressing emotions publicly or privately.