Memory Li Kristoffer Daniel Lee Seoui What is

Memory Li, Kristoffer Daniel Lee, Seoui

What is Memory? An active system that receives information from the senses, puts that information into usable form, organises it as it stores it away, and then retrieves the information from storage (adapted from Baddely, 1996, 2003)

Three Processes of Memory Encoding Retrieval Storage

Encoding The set of mental operations that people perform on sensory information to convert that information into a form that is usable in the brain’s storage system.

Storage Holding on to some information for a period of time.

Retrieval Getting information that is in storage into a form that can be used

Models of Memory Information-Processing Model Levels of Processing Model Parallel Distributed Processing (PDP) Model

Information-Processing Model of memory that assumes the processing of information for memory storage is similar to the way a computer processes memory in a series of three stages.

Parallel Distributed Processing Model A model of memory in which memory processes are proposed to take place at the same time over a large network of neural connections.

Levels of Processing Model Information processed according to its meaning, rather than sound or physical characteristics of the word, will be remembered more efficiently and for a longer period of time.

The Information-Processing Model: Three Memory Systems

Sensory Memory: How does it work? the very first stage of memory, the point at which information enters the nervous system through the sensory systems.

Iconic Sensory Memory Visual sensory memory, lasting only a fraction of a second.

Capacity of Iconic Sensory Memory The capacity of iconic memory is everything that can be seen at one time.

Duration of Iconic Memory In real life, information that has just entered iconic memory will be pushed out very quickly by new information, a process called masking (Cowan, 1988). Research suggests that after only a quarter of a second, old information is replaced by new information.

Although it is rare, some people do have what is properly called eidetic imagery, or the ability to access a visual sensory memory over a long period of time.

Echoic Sensory Memory echoic memory is the brief memory of something a person has just heard. It is limited to any can be heard at any one moment and lasts about 2 -4 seconds.

Short-Term Memory the memory system in which information is held for brief periods of time while being used. This is possible through the process of selective attention, the ability to focus on only one stimulus from among all sensory input

Selective Attention First Stage: incoming stimuli in sensory memory are filtered on the basis of simple physical characteristics. Second Stage: the processing of only the stimuli that meet a certain threshold of importance.

Working Memory an active system that processes the information in shortterm memory.

Techniques to Remember Chunking Maintenance Rehearsa

Long Term Memory the system of memory into which all the information is placed to be kept more or less permanently.

Elaborative Rehearsal method of transferring information from STM into LTM by making that information meaningful in some way.

Types of Long-Term Information Procedural (Nondeclarative) LTM • Implicit Memory Declarative LTM • Semantic Memory • Episodic Memory

Procedural LTM Includes memory for skills, procedures, habits and conditioned responses. These memories are not conscious but are implied to exist because they affect behaviour; also Implicit Memory.

Declarative LTM Contains information that is conscious and known; also, explicit memory.

Semantic Memory Type of declarative memory containing general knowledge.

Episodic Memory Type of declarative memory containing personal information that are not readily available to others.

LTM Organisation: Semantic Network Model

Retrieval of Long Term Memories

Encoding Specificity The tendency for memory of information to be improved if related information that is available when the memory is first formed is also available when the memory is being retrieved.

Recall vs Recognition

The Serial Position Effect Tendency of information at the beginning (Primacy Effect) and end (Recency Effect) of a body of information to be remembered more accurately than information in the middle.

False Positive Error of recognition in which people think they recognise some stimulus that is not actually in memory.

Automatic Encoding Tendency of certain kinds of information to enter LTM with little or no effortful encoding.

Flashbulb Memories Type of automatic encoding that occurs because an unexpected event has strong emotional associations for the person remembering it.

The Reconstructive Nature of Long-Term Memory Retrieval How Reliable Are Memories?

Constructive Processing of Memories • Memories are rarely completely accurate and become less accurate over time. • Loftus and others have suggested that memory retrieval is a constructive process; memories are “built” at the time of retrieval. • Hindsight bias – “knew-it-all-along”

Memory Retrieval Problems • The Misinformation Effect o Misleading information can become part of the actual memory, affecting its accuracy.

Reliability of Memory Retrieval • False memory syndrome o Creation of inaccurate or false memories through the suggestion of others, often while the person in under hypnosis

1. The event must be made to seem as plausible as possible. 2. Individuals are given information that helps them believe that the event could have happened to them personally.

Forgetting

Mnemonist

The Forgetting Curve

• Distributed practice o Produces far better retrieval than massed practice (cramming) • Encoding failure o Nonattended information is not encoded into memory

• Memory trace decay o Over time, if not used, neuronal connection can weaken or decay • Interference o Other information interferes with accurate retrieval o Proactive: previously learned o Retroactive: newly acquired

Neuroscience of Memory

Different brain areas are associated with different types of memory • Procedural memories: cerebellum • Short-term memories: prefrontal cortex and temporal lobes • Semantic and episodic long-term memories: frontal and temporal lobes

Consolidation • Several physical change in brain are associated with memory formation o Changes at receptor • Long-term potentiation – changes in the sensitivity of the synapse through repeated stimulation o Changes in dendrites • 4 E-BP 2

H. M.

Hippocampus • Plays a vial role in the formation of new declarative longterm memory.

Organic Amnesia • Caused by problems in brain function associated with brain trauma, disease or aging. • Retrograde o Loss of memory from the point of injury backwards • Anterograde o Loss of memory from the point of injury forwards

Infantile Amnesia • Memories before age 3 are likely implicit, not explicit. • Social relationships o Children develop autobiographical memory.