Encoding: Memory and Information Processing

• Memory is an information processing system, comparable to a computer
• Memory encodes, stores, and retrieves information over different periods

Encoding

• Encoding occurs as information enters the memory system.
• The brain labels/codes sensory information once received.
• Information is organized, relating new concepts to those already existing.
• Automatic processing encodes details like time, space, frequency, and word meaning without conscious awareness.
• Recalling what you ate for lunch or the last time you studied for a test are examples of automatic processing.
• Effortful processing requires work and attention to encode information.
• It is easier to recall a meaningful sentence than a meaningless one

Types of Encoding

• Semantic encoding encodes words and their meaning.
• Visual encoding encodes images.
• Acoustic encoding encodes sounds, particularly of words.
• Semantic encoding is a deeper level of processing compared to visual or acoustic encoding
• The self-reference effect enhances semantic encoding, because people have better memory for information that relates to oneself

Storage

• Storage creates a permanent record of information.
• Memories move through three stages to enter long term storage:
• Sensory Memory
• Short-Term Memory
• Long-Term Memory
• This model is the Atkinson and Shiffrin's model, based on the belief that memories are processed similarly to computer functions.
• The working memory model, proposed by Baddeley and Hitch (1974), stores memories in short-term memory much like opening files on a computer to add information.
• Visual-spatial and spoken/written material memories are stored in three short-term systems.
• visuospatial sketchpad
• episodic buffer
• phonological loop
• A central executive supervises information flow to and from the systems, moving information into long-term memory.

Sensory Memory

• Sensory memory stores brief sensory events, up to a couple of seconds.
• Sensory information about sights, sounds, smells, and textures deemed not valuable is discarded.
• Valuable information is moved into short-term memory.

Short-Term Memory (STM)

• Short-term memory (STM) is a temporary storage system for processing incoming sensory memory.
• STM connects memories from sensory memory to existing long-term memories.
• It lasts for 15 to 30 seconds.
• STM is what you see on your computer screen
• STM either goes to long term memory or is discarded

Rehearsal

• Rehearsal moves information from short-term memory to long-term memory
• During active rehearsal, information is repeated to be remembered
• During elaborative rehearsal, information is linked to existing knowledge
• The deeper you think about something, the better you remember it.

Memory Capacity

• Most people's short term memory capacity is 7 plus or minus 2 items.
• Working memory capacity is 4 plus or minus 1 item.
• Recall is better for random numbers than for random letters.
• Acoustic encoding leads to better recall than visual.

Memory Retention

• Memory trace decay and interference affect short-term memory retention.
• Short-term memory decays in 18 seconds.
• Proactive interference affects short-term memory retention.
• Previously learned information impairs the ability to learn new information
• Memory trace decay and proactive interference affect short-term memory.
• Information must be consolidated to reach long-term memory, requiring both synaptic and memory system changes over hours to weeks.

Long-Term Memory (LTM)

• Long-term memory (LTM) is the continuous storage of information and is believed to have unlimited storage capacity.

Semantic Network

• Memories are organized in semantic networks with multiple routes to access information.
• Frequency of which items are associated determines the strength of links
• Spreading activation describes how activating a part of the network also activates related concepts.

Types of Long-Term Memory

• There are two types of long-term memory:
• Explicit
• Implicit
• Explicit memories are consciously retrieved, and reported
• Explicit memory can be put into words.
  • Declarative Memory
• Implicit memories are outside of our awareness, demonstrated through task performance.
  • Procedural, Priming, Emotional Conditioning

Explicit Memory

• Episodic memory stores information about personally experienced events.
• Episodic memory are events reported as a story
• Episodic memory involves recollection of visual imagery and familiarity
• Semantic memory stores knowledge about words, concepts, and language-based facts
• Sematic memory are facts reported as facts

Implicit Memories

• Procedural memory stores information about how to perform actions and skills.
• Priming is when exposure to a stimulus affects the response to a later stimulus.
• Emotional conditioning involves classically conditioned emotional responses tied to different stimuli

Retrieval

• Retrieval is the act of getting information out of memory storage and back into conscious awareness.
• Three ways to retrieve information:
• Recall - access information without cues
• Recognition - identifying previously learned information after encountering it again
• Relearning - learning information previously learned

Brain Involvement In Memory

• Key brain areas are the:
• amygdala
• hippocampus
• cerebellum
• prefrontal cortex
• Engram neurons serve as the "physical representation of memory”
• The equipotentiality hypothesis states if part of a memory area is damaged, another part can take over that function

Amygdala

• It regulates emotions, such as fear and aggression.
• Amygdala plays a role in storing memories because storage is influenced by stress hormones.
• The amygdala assists in memory consolidation.
• It facilitates encoding memories at a deeper level during emotionally arousing events.

Hippocampus

• Researchers have found the hippocampus functions in memory processing
• In particular with object recognition and maze running.
• It is involved in normal recognition memory and spatial memory tasks.
• It projects information to cortical regions and assists with memory consolidation.
• Injury to this area leads to an inability to process new declarative memories.

Cerebellum and Prefrontal Cortex

• The cerebellum creates implicit memories
• The prefrontal cortex seems to be involved when using brain scans, including positron emission tomography (PET) scans, to learn how people process and retain information.
• Encoding: Left Frontal Activity
• Retrieval: Right Frontal Activity

Neurotransmitters

• Neurotransmitters, such as epinephrine, dopamine, serotonin, glutamate, and acetylcholine are involved with the process of memory.
• Communication among neurons is critical for developing new memories.

Arousal Theory

• Strong emotions trigger stronger memories.

Flashbulb Memory Phenomenon

• Strong emotional experiences are remembered clearly
• A flashbulb memory is an exceptionally clear recollection of an important memorable event.

Problems with Memory

• Memory can fail
• There can be inaccuracies, distortion and forgotten

Amnesia

• Amnesia is the loss of long-term memory due to disease, physical or psychological trauma.

Types of Amnesia

• Anterograde amnesia where you cannot remember new information
• Retrograde amnesia where there is loss of memory of past events

Memory Construction

• The formulation of new memories is sometimes called construction
• The process of bringing up old memories is called reconstruction
• Distortions occur as memories are altered or modified

Suggestibility

• Memories can be easily misled due to the problem of suggestibility.
• Suggestibility is misinformation from external sources, leads to false memories

Eyewitness Misidentification

• Despite fragility of memory and reconstruction, officials rely on eyewitness testimony
• This results in faulty identifications and wrongful convictions

The Misinformation Effect

• The misinformation effect paradigm, holds where a person misremembers anoriginal event with inaccurate information after exposure

Controversies Over Repressed and Recovered Memories

• Memories of traumatic events can be repressed and surface later, which remains a topic of debate with proponents on both sides

False Memory Syndrome

• Inaccurate recall of false autobiographical memories.

Forgetting

• Forgetting refers to loss of information from long-term memory

Encoding Failure

• Encoding failure is caused where the information never enters our memory in the first place.
• You can't remember it if you never encoded it actively.
• Many people don't encode basic information, such as the details on a penny.

The Seven Sins of Memory

• Psychologist Daniel Schacter identifies seven ways memory fails:
  • Forgetting
  • Distortion
  • Intrusion

Forgetting

• Transience: Accessibility of memory fades over time
• Absentmindedness: Lapses in attention cause forgetting
• Blocking: Information is temporarily blocked/inaccessible

Distortion

• Misattribution: Source of memory is confused
• Suggestibility: False memories
• Bias: Memories distorted by current belief system

Intrusion

• Persistence: Unwanted/undesirable memories are unable to be forgotten.
• Storage decay: Unused information fades over time.

Ebbinghaus Forgetting Curve

• An average person will lose of 50% information after 20 mins and lose 70% of information after 24 hours

Distortion

• Misattribution, suggestibility and bias are distortion errors

Miasattribution

• When you confuse the source of your information.

Suggestibility

• When you create the false memory entirely on your own

Bias

• Bias affects memory
• Schacter says that one's feelings and view of the word can actually distort memory of past events

Types of Bias

• Stereotypical Bias involves racial and gender biases
• Egocentric Bias involves enhancing our memories of the past