Memory and Short-Term Memory Notes

Memory involves remembering:
- People (friends, family, dentist)
- Skills (e.g., how to boil an egg or use JASP/JAMOVI)
- Preferences (e.g., musical tastes like Depeche Mode, Sabrina Carpenter)
- Personal identity (e.g., self-recognition)
Uses of Memory:
- Decision Making: Based on past experiences (e.g., choosing between veggie or chicken)
- Appointment Keeping: Remembering event times (e.g., timing for lectures)

Consequences of lacking memory:
- Inability to recognize anyone or anything
- Inability to communicate or perform basic reading/writing tasks
- No recollection of past actions or emotions
- Total loss of sense of self

Gazzaniga (2000) defines memory as:
- "Everything in life is memory, save for the thin edge of the present."
- Processes involved: Storing, retaining and retrieving information after its original source is no longer present.

According to the multi-store model, there are distinct sensory memory stores for each sense:
- Iconic Store: Holds information from the visual modality.
- Echoic Store: Holds information from the auditory modality.
- Haptic Store: Holds information from the tactile modality.
- Example: Sparkler memories illustrate iconic memory; a sparkler twirled fast creates the perception of a continuous circle due to blending of individual snapshots.

Investigated by Johann Andreas Segner (1740):
- Segner’s experiment with a glowing coal cartwheel established that an unbroken visual circle is perceived when spun at at least 1/10 s/rotation.
- Duration of visual sensory memory deduced to be around 100 msec.

Sensory memory functions as a temporary buffer, holding environmental information briefly (0.25 – 3 sec).
Nature of information:
- Raw, unprocessed, and specific to modality.
- Very large capacity, but only attended information is transferred to STM.

Conducted a test involving a stimulus display shown for 50 msec:
- Example Stimulus: FS Q LMR BTK
Findings:
- We absorb more information than we can fully recall in STM.
- Partial recall from any row indicates that information is retained in sensory memory but may not be fully recalled in whole report tasks.

STM has three key characteristics:
1. Limited Capacity: cannot hold too much information.
2. Limited Duration: brief holding of information.
3. Affected by Encoding: the way information is stored alters its retention.

Proposed by George A. Miller (1956):
- The capacity of short-term memory typically is around 7 ± 2 items of information.
- Items can be chunked to enhance capacity (e.g., "BBC" is a single chunk vs. three individual letters for a non-viewer).

Digit Span Tests (Jacobs, 1887):
- Participants had an easier time recalling numbers (mean: 9.3) than letters (mean: 7.3).
- Exceptions included letters ‘w’ and ‘7’ due to their unusual properties.

Training can enhance STM capacity:
- Example: Ericsson et al. (1980) studied a student (SF) who increased their digit span from 7 to 79 through 230 hours of semantic chunking (e.g., 3492 as "3 min, 49.2 sec,")

In recall tasks, participants may be asked to:
- Recall words in the order presented (Serial Recall) or in any order (Free Recall).
This setup produces a Serial Position Curve showing the proportion of words recalled based on their order of presentation.

Better recall for words at the beginning of a list due to rehearsal solidifying these items into LTM, allowing them to be retrieved from LTM.

Better recall for words at the end of a list due to their presence still being held in STM, allowing for easier retrieval as they are readily accessible. Items in the middle are less recalled because they are neither rehearsed sufficiently nor fresh in memory.

Method: Participants memorize a word list, then perform a distractor task (like counting backward by 3 from 400). After a delay, they are asked to recall items.
Evidence suggests material begins to fade from STM within 3 seconds, and all material is typically lost within 15-30 seconds.
- Example List: Nine, Swap, Cell, Ring, Lust, Desk, Sword, Hold, Baby, Find

Maintenance Rehearsal: Repeating items silently can prolong retention duration in STM but information is lost rapidly without rehearsal, disappearing via decay (Nairne, 2002).

Experiment with a list of words to memorize demonstrated rehearsal limits:
- Words: Burma, Greece, Tibet, Iceland, Malta, Laos, Switzerland, Nicaragua, Botswana, Venezuela, Philippines, Madagascar
Pronunciation Time: Significant influence on the number of items stored in STM.
Research by Baddeley et al. (1975):
- Participants could remember (4.2 items) with shorter country names vs. (2.8 items) with longer names.

Naveh-Benjamin & Ayres (1986) assessed memory span for numbers among speakers of various languages (English, Spanish, Hebrew, Arabic):
- Results indicated variability in memory recall further supports the impact of pronunciation time on STM.

Encoding Defined: The process of manipulating and transforming information to create a memory code.
When recalling word lists, participants commonly employ maintenance rehearsal.
Misremembered words can indicate the type of encoding utilized, such as:
- Phonemic Encoding: Similar sounding words (e.g., moose -> goose).
- Semantic Encoding: Related in meaning (e.g., moose -> elk), though less frequently used.

Memory encompasses the processes of storing, retaining, and retrieving information after its original source ceases to exist.
Multi-store Model Overview: Memory comprises multiple stores:
- SIS, STM, and LTM.
Each sensory modality has a distinct memory store.
STM features limited duration and capacity: Miller’s Magic Number suggests capacity of 7 ± 2 items.
Rehearsal enhances STM encoding and is affected by pronunciation length.
Serial recall tasks evidencing primacy and recency effects illustrate material retrieval from STM.