Memory in Psychology 101

Define sensory registers and short-term memory (working memory).
Explain relationships between sensory registers, short-term memory, and long-term memory.
Discuss different types of long-term memories.
Identify brain systems underlying long-term memory (LTM).
Describe various expressions of long-term memory.
Understand principles governing different forms of memory.
Explain encoding specificity.

Memory relies on mental representations:
- Sensory Representations: Mental “images” corresponding to sensory memories (e.g., smell, vision, auditory).
- Verbal Representations: Abstract forms of memory related to semantic concepts (e.g., “human rights”).
This encoding occurs in distinct neuron populations.
Different neurological and cognitive systems underlie various memory functions.
Memory is an active process involving:
- Encoding: Transforming sensory information into a format suitable for storage.
- Consolidation (Storage): Stabilizing a memory trace after its initial acquisition.
- Retrieval: Accessing information when needed.
Unlike passive recording (like a camera), memory serves as an evolutionary tool for survival and adaptation.

Participants are instructed to view a list of words and later retrieve them:
- Word List:
- Sour, Honey, Bitter, Heart, Tooth, Nice, Sugar, Chocolate, Taste, Tart, Candy, Soda, Good, Cake, Pie
Task: Write down all remembered words.
False Memory Example: Many participants might remember “sweet” due to related associations, demonstrating how the brain adapts based on experience.

Stimulus → Sensory Registers → Rehearsal → Short-term Memory (STM) → Long-term Memory (LTM)
Note that each stage has information that can be lost.

Holds mental representations for a very brief duration (0.5 - 2 seconds).
Functions like a “snapshot” of perceptions, maintaining detail (raw material).
- Iconic Storage: Visual representation with a duration of <1 second.
- Echoic Storage: Verbal representation lasting <4 seconds.
- Haptic Storage: Tactile representation lasting <2 seconds.
Items in sensory registers can be encoded into short-term memory (STM) through attention.

Also known as working memory, it serves as our conscious mental processing center.
Information is retained for approximately 20-30 seconds.
Working memory has a limited capacity:
- Typical span: 7 ± 2 items.
New information may interfere with current contents due to limited capacity.
Techniques to hold information:
- Cognitive Manipulation: Engaging actively with information to prevent decay.
Methods to prevent decay:
- Maintenance Rehearsal: Repeatedly reciting information.
- Elaborative Rehearsal: Forming meaningful connections with the material.

Evidence of primacy and recency effects showcasing different processing modalities:
- Primacy Effect: Tendency to remember early presented stimuli (now in LTM).
- Recency Effect: Tendency to remember most recently presented stimuli (still in STM).

LTM serves as a durable store for:
- Facts, experiences, and skills.
Differences compared to STM:
- Span: LTM capacity is massive.
- Duration: Can last years, decades, or potentially a lifetime.

Research by Karl Lashley sought the elusive “engram,” the physical trace of memory, through rat maze experiments.
Observations:
- Lesioning parts of the brain correlated with poorer maze performance.
- Rats retained some memory of the maze regardless of where lesions occurred, suggesting that memory is distributed rather than localized.

Refers to recalling information without deliberate effort; the process is automatic:
- Example skills: Riding a bike, habits, learned associations, priming.

A technique wherein exposure to one stimulus influences the response to another stimulus:
- Fill-in-the-blank exercise demonstrates connection through associations (Example: C__)

Involves conscious recollection of previously stored information:
- Recall: Generating previously remembered data, such as in essay questions.
- Recognition: Identifying previously learned information from a selection, such as multiple-choice questions.

Suggests optimal memory retrieval occurs when learning and testing environments align.
Various aspects of context impact memory retrieval, including noise and psychological state.

Performance improves when learning and testing occur in the same state of consciousness; mood states also influence memory retrieval.

Until the 1980s, the prevailing belief was that long-term memories were impervious and permanent.
- Introduction of Flashbulb Memories indicates that memories can be distorted.
- Ulrich Neisser's studies (1982) showed that all forms of long-term memory are malleable, reconstructed upon retrieval.
- Famous case study on September 11th, 2001 highlights how memories can change over time due to rehearsal and construction.

Pioneer: Hermann Ebbinghaus in the early 1900s—studied memory retention using nonsense syllables.
Documented rates of forgetting over time:
- Charted memory retention percentages over varying durations post-learning.
- Retention Curve Visualization:
- 100% retention at initial assessment decreases to significantly lower percentages over 1-31 days (specific retention rates vary).