Psychology: Memory Processes and Models

Memory Processes

• Memory involves acquiring, storing, retrieving, and retaining information.
• Explicit (declarative) memories are expressed verbally.
• Implicit (non-declarative) memories are not expressed verbally; these include priming, conditioning, and procedural memories (e.g., walking, swimming).
• Memory processes include encoding (creating), retention (storing), and retrieval (accessing).
• Memory examination methods include free recall, cued recall, and recognition.
• Memory tasks have three phases: learning/encoding, consolidation/retention, and retrieval/testing.

Memory Models

• The Atkinson-Shiffrin model (1968) outlines three memory systems: sensory memory, short-term memory (STM), and long-term memory (LTM).
• Sensory memory briefly holds incoming information. Unattended information is lost. Visual (iconic) and auditory (echoic) sensory memory exist.
• Short-term memory (STM) temporarily holds information (seconds to minutes). Rehearsal is crucial. STM has limited capacity. Information not rehearsed is lost.
• Long-term memory (LTM) stores information for extended periods. LTM has unlimited capacity. Information can be lost if not retrieved regularly.
• Information in sensory and STM is episodic, recording when and where the information was learned.
• Information in LTM can be episodic or semantic. Semantic memory stores information without remembering its context.
• The serial position effect (primacy and recency effects) suggests that rehearsal is important for transferring information from STM to LTM.
  • Primacy effect: Better recall of items at the beginning of a list, due to rehearsal and transfer to LTM.
  • Recency effect: Better recall of items at the end of a list, due to being in STM at recall. Recency effect disappears with delay.
• Neurophysiological evidence supports this modal memory. Patients with medial temporal lobe (MTL) damage have intact STM but cannot transfer new information to LTM (anterograde amnesia).
• Other research suggests models of STM need refinement due to different components of STM.

Sensory Memory (Iconic Memory)

• Iconic memory (visual) holds a large amount of visual information briefly. Duration is very short.
• Capacity and duration are critical aspects of iconic memory.
• Jevon (1963) and Averbach (1963) investigated iconic memory capacity. Picture complexity and presentation speed limit it (e.g., up to 8 items).
• Sperling (1960) demonstrated iconic memory's large capacity and rapid decay (masking/interference). The image is initially available, fading quickly.
• Langaman et al. (2003) suggested longer iconic memory durations (1600ms).
• Issues linger if sensory memory is a separate system or part of STM.

Short-Term Memory (STM)

• STM tasks include digit span (verbal) and Corsi (visual-spatial).
• Working Memory Model (Baddeley and Hitch, 1970): STM is complex, with multiple components.
  • Visuospatial Sketchpad: Temporary visual and spatial storage. Shows better performance for visual-spatial tasks (Brooks, 1967). Dual tasks (e.g., mental rotation, rotor pursuit) suggest separate visual spatial and verbal systems.
  • Phonological Loop: Temporary storage for verbal information. Supported by phonological similarity effect (Conrad & Hull, 1964), and word-length effect (Baddeley et al., 1975).
  • Central Executive: Control center, prioritizing information and allocating it to components. A supervisory attention system (Norman & Shallice, 1982), controlling behavior, and distributing attention.
  • Episodic Buffer: Added component to account for LTM influence on STM. Accounts for chunking, and better sentences recall. Temp storage from multiple cognitive systems.
• Alternative models of STM include embedded process, feature, and dual component model, as well as simpler models viewing STM and LTM as similar.

Long-Term Memory

• Information remembered for more than a few minutes is long-term memory.

• Explicit LTM includes episodic memory (events) and semantic memory (facts). Explicit initially is episodic, but over time becomes semantic as context is forgotten.

• Implicit LTM includes procedural memory (skills), conditioning, and priming.

• Ebbinghaus pioneered LTM research, measuring relearning times. Memory savings (faster relearning) decreases with time between learning sessions.

• Spaced learning is superior to massed learning (one study session), and retrieval practice (testing) boosts recall more than additional learning.

• The forgetting curve describes information retention/recall decline over time. Initial rapid forgetting is followed by a slower decline, with some information remaining.

• Wixted (1990, 1997) modeled forgetting using a power equation (y=ax^-b).

• Bahrick’s (1984) research on Spanish vocabulary learning revealed an initial rapid decline in retention, followed by stabilization.

• Bahrick et al. (1975) studied professor-student face recognition. Recognition declined less than recollection (no choices/options); recognition followed the forgetting curve (rapid initial decline, followed by stabilization), whereas identification (no choices) decreased substantially over time.

• Rubin and Wenzel (1996) demonstrated a power function’s accuracy in describing the decline of autobiographical memory.

• Rubin et al. (1986) examined factors affecting autobiographical memory, including childhood amnesia (difficulty recalling early childhood) and the reminiscence bump (strong recall of adolescence/early adulthood).

• Memory of language, faces, and personal experiences share similar forgetting trends to nonsense syllables.

• Standing (1973) found higher recognition rates for pictures than words.

• Konkle et al. (2010) discovered superior image recall when foils are from different categories. General concepts are retrieved more efficiently than detailed images.