Memory

• Memories are records of experiences, perceptions, thoughts and feelings.
• Explicit or declarative memory involves conscious awareness.
• Implicit or procedural memory involves unconsciously expressed recollection.

Explicit Memory Forms

• Recall involves the ability to retrieve and express information.
• Recognition entails the capability to identify information.
• Recognition is easier than recall.

Explicit Memory List Patterns

• When remembering a list of words, uniquely salient items will stand out.
• Early list items are recalled due to the primacy effect.
• Later list items are remembered due to the recency effect.
• First and last items benefit from the serial position effect because of extra practice and less interference.

Memory Mechanisms

• Encoding converts experiences into mental representations.
• Storage retains mental representations over time.
• Retrieval accesses mental representations when needed.

Encoding Types

• Visual encoding: mental image.
• Phonological Encoding: Auditory sounds, such as the number sequence of 7054743450.
• Motor encoding: physical movement sequences.
• Semantic encoding: meaning and associations, such as Truth, Hate, Love.

Effortful Encoding

• Maintenance rehearsal involves repetition to keep information in mind.
• Organized information can be easier to recall.
• Chunking creates meaningful groups of information, like job, study, goal; rabbit, tree; battery death.
• Mnemonics are techniques that improve memory, such as the Method of Loci (Memory Palace) and Acronyms like OCEAN or Roy G. BIV.

Elaborative Encoding

• The goal of this memory process is to create links between new information and previously created memories.
• Encoding new information using surface characteristics results in shallow processing.
• Encoding new information via meaningful connections to existing knowledge results in deeper processing.
• Types of elaboration are imagery, chunking, distinctiveness, and self-reference

Memory Storage Systems

• Sensory memory is where initial stimuli is processed..
• Working memory processes or manipulates information in short-term memory (STM).
• Long-term memory (LTM) is for permanent storage.

Sensory Memory Register

• It momentarily preserves accurate images of sensory information.
• Information will be lost if not rapidly transferred to short-term memory.
• Iconic memory stores icons.
• Echoic memory stores echoes.
• Memory durations are specific to each of the 5 senses, and last between 0.5-2 seconds.

Short Term Memory

• STM typically can store 7 +/- 2 units of information.
• Retains info for a brief period, roughly 15-30 seconds.

Working Memory

• Closely related to short-term memory.
• It uses mental processes to manipulate or retrieve information for basic comprehension, interpretation, or problem-solving.
• It involves levels of conscious awareness.

Baddeley's Working Memory Model

• Contains components that are all interlinked: central executive, visuospatial sketchpad, episodic buffer, phonological loop, visual semantics, episodic LTM, and language.
• Conscious Awareness and Multimodal Integration are key pieces.

Visuospatial Sketchpad

• Is it an "inner eye"

Phonological Loop

• Is an "inner voice"
• Verbal memory is reliant on language inner articulation.
• Inner eye and inner voice function like external perceptions, recruiting the same brain regions.
• Certain Mistakes → evidence of an Inner Voice, ex. Hearing 'Cheese' instead of 'Please' as they Sound alike
• American Sign Language speakers do not rely on the inner voice

Episodic Buffer

• Episode in your Life - Integrated Multimodal reconstruction
• Includes examples like: timeline of events, characters, people, ongoing perceptions, thoughts & emotions, hanging out with some friends, family dinners and reliving exciting or bad experiences.

Long-Term Memory (LTM)

• Activating one or more experiences associated with a previous memory may trigger the full memory.
• Long-term memory is responsible storing for long-term storage.
• The is strength and maintenance rely on repeated activation.
• Salient and emotional events typically transfer to LTM more quickly.
• Memories are reconstructed using available information at recall.
• These reconstructions are usually correct.

LTM Super Stars

• Highly Superior Autobiographical Memory (HSAM) aka Hyperthymesia involves near-perfect recall of autobiographical events.
• It is a rare condition affecting less than 100 individuals.
• HSAM is associated with a larger amygdala and hippocampus.

Biological Basis of Memory

• Memory formation involves chemical and structural changes at the neuron level.
• STM alters a neuron's ability to release transmitters.
• LTM involves long-term potentiation (LTP), which increases the strength of synaptic responsiveness.
• Hebbian Learning: Neurons that fire together, wire together, and Contiguity breeds Connectivity.
• The Hippocampus is critical in moving STM into LTM; but is no longer required once it is formed.
• LTM is neurally distributed throughout the brain, including sensory, visceral, emotional, cognitive, and self-reflective experiences.
• Most memories are stored in groups of roughly 1000 neurons.
• Reactivating long-term memories entails a neural network.

Famous Memory Case Study - H.M.

• H.M, Henry Gustav Molaison (1926-2008), had intractable epilepsy.
• He underwent brain surgery at 27 years old that included bilateral hippocampi removal.
• He suffered permanent amnesia but provided major insights into memory formation.

Memory Loss

• Retrograde amnesia: Cannot Recall or Recognize Past memories.
• Anterograde amnesia: Cannot form New memories.
• HM had anterograde amnesia.
• H.M. was still able to function in short-term memory and working memory.
• H.M. could also still form procedural memories.

Errors Of Omission According to Schacter

• info cannot be brought to mind (missing)
• Transience: memory for any particular event tends to degrade over time
• Absent-mindedness: memories unavailable → failure to encode them in the first place
• Blocking: not enough distinctive cues available to retrieve a specific memory

Errors Of Commission According to Schacter

• false or unwanted info brought to mind
• Misattribution - errors in the Memory source
• Suggestibility - misinformation effect on memory
• Bias - pre-existing knowledge or beliefs Distort existing memories or memory formation
• Persistence - unwanted memories activated; often from embarrassing events

Models of Forgetting

• Decay: Information fades away if not used or accessed; neuronal connections break down neurons are destroyed
• Replacement: Due to limited memory storage, New information replaces Old; creating memory corruption.
• Interference: Similar info gets mixed up during storage or retrieval.
• Cue-Dependent: Failure to retrieve existing memories because there are insufficient memory cues; so retrieval cues cannot reactivate memories.