ch 6 memory

Memory Processes

• Memory is the ability to store and retrieve information over time.
• Encoding, storage, and retrieval are the three basic aspects of memory.
• Encoding involves transforming perceived, thought, or felt information into a lasting memory.
• Storage is the process of keeping information in memory over time.
• Retrieval involves calling to mind previously encoded and stored information.
• Memories are constructed by combining existing knowledge with new sensory information, therefore memories are constructions, combining what we know with new input
• Encoding methods include:
  • Semantic encoding: relating new information to existing knowledge (e.g., remembering events, not digits). Active areas are the lower left frontal lobe and the inner left temporal lobe, greater activity here correlates with better recall.
  • Visual imagery encoding: creating mental images to store information. Relating new info to already existing memories helps this process.
  • Organizational encoding: categorizing information based on relationships.

Semantic Judgments

• Three types of semantic judgments involve thinking about the meaning, sound, or appearance of words.

Sensory Memory vs. Short-Term Memory

• Sensory memory holds information briefly (seconds or less).
• Two types of sensory memory:
  • Iconic memory (visual)
  • Echoic memory (auditory)
• Short-term memory holds information for longer durations (seconds to minutes).

Short-Term Memory

• Capacity: approximately 7 meaningful items.
• Rehearsal: repeating information to maintain it in short-term memory.
• Serial position effect: better recall of first and last items in a list (primary and recency effects).
• Primary effect: better recall of initial items due to greater rehearsal opportunities.
• Recency effect: better recall of final items due to recent presence in short-term memory.
• Chunking: combining small bits of information into larger, manageable chunks to increase short-term memory capacity.

Working Memory

• Working memory actively maintains information in short-term storage; uses multiple subsystems:
  • Visuospatial sketchpad: for visual images.
  • Phonological loop: for verbal information.
  • Episodic buffer: combines visual and verbal information into a single code, acts as a gateway to long-term memory.
  • Central executive: coordinates subsystems and the episodic buffer.

Long-Term Memory

• Holds information for extended periods (hours, days, weeks, years).
• Brenda Milner’s work was crucial in identifying the critical role of the hippocampus in long-term memory formation.
• Long-term memory involves processing and transferring information from short-term memory into long-term storage.
• Anterograde amnesia: inability to transfer new information from short-term into long-term memory.
• Retrograde amnesia: inability to retrieve information acquired before a certain date/point.
• Consolidation: the process of making memories stable in the brain.
• Reconsolidation: a process where retrieved memories are potentially altered before being stored again.
• Neural Synapses in Memory:
  • Neurons that fire together wire together (more firing strengthens connection).
  • Long-term potentiation (LTP): strengthens synaptic connections, resulting in easier communication between neurons. LTP is involved in memory formation.
  • Changes in neural synapses support both short and long-term memory storage; increased neurotransmitter release = short-term; new synapse growth = long-term.

Retrieval

• Retrieval is bringing previously stored information to mind.
• Retrieval cues: external information that helps access stored memories.
• Encoding specificity principle: retrieval is enhanced when the context of retrieval matches the context of encoding (e.g., studying in the same room as the test).
• State-dependent retrieval: retrieving information more effectively when in the same physiological or emotional state as during encoding.
• Transfer-appropriate processing: matching the contexts of encoding and retrieval situations enhances retrieval.
• Retrieval-induced forgetting: retrieving an item impairs the recall of related items.

Types of Long-Term Memory

• Explicit memory: conscious retrieval of past experiences.
• Implicit memory: past experiences influence later behavior without conscious effort or awareness.
  • Procedural memory: gradually acquired skills; automatic execution of tasks (e.g., playing an instrument).
  • Priming: enhanced ability to process a stimulus due to prior exposure.
    • Perceptual priming: recalling sensory features of an item.
    • Conceptual priming: recalling the meaning of a word or object.
• Semantic memory: network of associated facts and concepts (general knowledge).
• Episodic memory: collection of personal experiences at specific times and places (autobiographical).

Collaborative Memory

• Collaborative memory: groups can sometimes recall more than individuals, but certain limitations and social dynamics can also negatively affect recall.
  • Transitive memory: specific individuals in close relationships remember certain pieces of information.

Seven Sins of Memory

• Transience: forgetting over time.
• Absentmindedness: lapses in attention.
• Blocking: temporary inability to retrieve information.
• Misattribution: assigning memories to incorrect sources.
• Suggestibility: incorporating misleading information.
• Bias: present knowledge influencing recall.
• Persistence: intrusive memories that can't be forgotten.

Factors Affecting Memory

• Interference: retroactive (later learning impairs earlier) and proactive (earlier learning impairs later).
• Childhood amnesia: few memories from early childhood.