Chapter Overview Studying and Encoding Memories Storing and Retrieving Memories Forgetting, Memory Construction, and Improving Memory

Studying Memories Memory Evidence of memory Persistence of learning over time through the encoding, storage, and retrieval of information Evidence of memory Recalling information Recognizing it Relearning it more easily on a later attempt

EBBINGHAUS’ RETENTION CURVE Ebbinghaus found that the more times he practiced a list of nonsense syllables on day 1, the less time he required to relearn it on day 2. Speed of relearning is one measure of memory retention (From Baddeley, 1982.) Tests of recognition and of time spent relearning demonstrate that we remember more than we can recall.

Studying Memories Psychologists use memory models to think and communicate about memory. Information-processing models Compares human memory to computer operations Involves three processes: encoding, storage, and retrieval Connectionism information-processing model Focuses on multitrack, parallel processing Views memories as products of interconnected neural networks Encoding Process of getting information into the memory system Storage Process of retaining encoded information over time Retrieval Process of getting information out of memory storage

Memory Models Three processing stages in the Atkinson- Shiffrin model We first record to-be-remembered information as a fleeting sensory memory From there, we process information into short-term memory, where we encode it through rehearsal Finally, information moves into long-term memory for later retrieval.

A MODIFIED THREE-STAGE INFORMATION-PROCESSING MODEL OF MEMORY Atkinson and Shiffrin’s classic three-step model helps us to think about how memories are processed, but today’s researchers recognize other ways long-term memories form. For example, some information slips into long-term memory via a “back door,” without our consciously attending to it (automatic processing). And so much active processing occurs in the short-term memory stage that many now prefer to call that stage working memory. A MODIFIED THREE-STAGE INFORMATION-PROCESSING MODEL OF MEMORY Figure 24.3

Memory Models Atkinson-Shiffrin model updated concepts Working memory, to stress the active processing occurring in the second memory stage Automatic processing, to address the processing of information outside of conscious awareness

Memory Models Working memory Involves newer understanding of short-term memory Focuses on conscious, active processing of incoming auditory and visual-spatial information, and of information retrieved from long-term memory Is handled by a central executive (Baddeley, 2002)

WORKING MEMORY Alan Baddeley’s (2002) model of working memory, simplified here, includes visual and auditory rehearsal of new information. Part of the brain functions like a manager, a central executive focusing attention and pulling information from long-term memory to help make sense of new information. Figure 24.4

Dual-Track Memory: Effortful Versus Automatic Processing Dual-track memory system Explicit memories (declarative memories) of conscious facts and experiences encoded through conscious, effortful processing Implicit memories (nondeclarative memories) that form through automatic processes and bypass conscious encoding track

Encoding Memories Automatic processing and implicit memories Implicit memories include automatic skills and classically conditioned associations. Information is automatically processed about Space Time Frequency Effortful processing and explicit memories With experience and practice, explicit memories become automatic.

Sensory memory What is sensory memory? First stage in forming explicit memories Immediate, very brief recording of sensory information in the memory system Iconic memory: Picture-image memory Echoic memory: Sound memory TOTAL RECALL—BRIEFLY When George Sperling (1960) flashed a group of similar to this for one-twentieth of a second, people could recall only about half the letters. But when signaled to recall any one row immediately after the letters had disappeared, they could do so with near-perfect accuracy. 7-5 How does sensory memory work?

Capacity of Short-Term and Working Memory Short-term memory Activated memory that holds a few items briefly (such as the seven digits of a phone number while dialing) before the information is stored or forgotten Working memory Newer understanding of short-term memory that stresses conscious, active processing of incoming auditory and visual-spatial information, and of information retrieved from long-term memory

Capacity of Short-Term and Working Memory Short-term memory George Miller (1956) Magical Number Seven: People can store about seven bits of information (give or take two) Baddeley and colleagues ( 1975) Without distraction, about seven digits or about six letters or five words Working memory Capacity varies by age and distractions at time of memory tasks

Effortful Processing Strategies Chunking: Organization of items into familiar, manageable units; often occurs automatically Mnemonics: Memory aids, especially techniques that use vivid imagery and organizational devices Peg-word system Hierarchies: Organization of items into a few broad categories that are divided and subdivided into narrower concepts and facts

Effortful Processing Strategies Spaced study and self-assessment Spacing effect: Encoding is more effective when it is spread over time. Distributed practice: Produces better long-term recall Massive practice: Produces speedy short term learning and feelings of confidence Testing effect (retrieval practice effect or test- enhanced effect): Encoding is very effective.

Levels of Processing Verbal information processed at different levels which affect long-term retention. Shallow processing encodes on a very basic level (word’s letters) or a more intermediate level (word’s sound) Deep processing encodes semantically based on word meaning

Retaining Information in the Brain Past research Whole past is contained in memory—waiting to be relived. Newer findings Flashback during surgery are new creations of stressed brain. Information is not stored in single, specific spot. Perception, language, emotions and more require brain networks

Explicit- Memory System: Hippocampus And Frontal Lobes Is dedicated to explicit memory formation Registers and temporarily holds elements of explicit memories before moving them to other brain regions for long-term storage. Neural storage of long- term memories is called memory consolidation. Separate brain regions process explicit and implicit memories During sleep, the hippocampus and brain cortex display rhythmic patterns of activity, as if they were talking to each other (Ji & Wilson, 2007; Mehta, 2007). Researchers suspect that the brain is replaying the day’s experiences as it transfers them to the cortex for ong-term storage. Weidenfeld & Nicolson archives spacing effect the tendency for distributed study or practice to yield better long- term retention than is achieved through massed study or practice. Testing effect enhanced memory after retrieving, rather than simply rereading, information. Also sometimes referred to as the retrieval practice effect or test-enhanced learning. THE HIPPOCAMPUS

Implicit-Memory System: The Cerebellum and Basal Ganglia Implicit memory system: Cerebellum and basal ganglia Cerebellum plays important role in forming and storing memories created by classical conditioning. Memories of physical skills are also implicit memories. Basal ganglia help form memories for these skills. Infantile amnesia Conscious memory of first three years is blank. Command of language and well-developed hippocampus needed.

Review Key Memory Structures in The Brain Frontal lobes and hippocampus: explicit memory formation Cerebellum and basal ganglia: implicit memory formation Amygdala: emotion-related memory formation

Retaining Information in the Brain Excitement or stress trigger hormone production and provoke amygdala to engage memory. Emotions often persist with of without conscious awareness. Emotional arousal causes an outpouring of stress hormones, which lead to activity in the brain’s memory-forming areas. Flashbulb memories occur via emotion-triggered hormonal changes and rehearsal.

Synaptic Changes Long-term potentiation (LTP) Increase in a synapse’s firing potential. After LTP, brain will not erase memories Believed to be a neural basis for learning and memory. Kandel and Schwartz (1982) Pinpointed changes in sea slugs neural connection. With learning more serotonin released and cell efficiency increased—number of synapses increase. ©Donna Ikenberry/Art Directors &TRIP Alamy MEMORY SLUG The much-studied California sea slug, Aplysia, has increased our understanding of the neural basis of learning. After LTP has occurred, an electric current passing through the brain won’t erase old memories. Before LTP, the same current can wipe out very recent memories.

Doubled receptor sites Electron microscope image (a) shows just one receptor site (gray) reaching toward a sending neuron before long-term potentiation. Image (b) shows that, after LTP, the receptor sites have doubled. This means that the receiving neuron has increased sensitivity for detecting the presence of the neurotransmitter molecules that may be released by the sending neuron. (From Toni et al., 1999.) Figure 25.3

Memory Retrieval Cues Retrieval cues Priming Context-dependent memory State-dependent memory Serial position effect

Memory Retrieval Cues Memory retrieval Priming Memories held in storage by web of associations. Retrieval cues serve as anchor points for pathways to memory suspended in this web. Best retrieval cues come from associations formed at the time a memory is encoded. Priming Activation, often unconsciously, of particular associations in memory

Retrieval Cues PRIMING—AWAKENING ASSOCIATIONS After seeing or hearing rabbit, we are later more likely to spell the spoken word as h-a-r-e. Associations unconsciously activate related associations. This process is called priming. (Adapted from Bower, 1986.)

Memory Retrieval Cues Context-dependent memory Involved improved recall of specific information when the context present at encoding and retrieval are the same Encoding specificity principle Suggests cues and contexts specific to a particular memory will be most effective in helping recall

Retrieval Cues State-dependent memory Mood-congruent memory Involves tendency to recall events consistent with current good or bad mood (mood-congruent memory) Mood-congruent memory Involves tendency to recall experiences that are consistent with one’s current good or bad mood Serial position effect Involves tendency to recall best the last (recency effect) and first primacy effect) items in a list.

Forgetting and the Two-track Mind Humans have two distinct memory systems, controlled by different parts of the brain. Forgetting has several causes Encoding failure Storage decay Retrieval failure Interference Motivated forgetting

Forgetting: Encoding and Storage Decay Encoding failure Age: Encoding lag is linked to age-related memory decline Attention: Failure to notice or encode contributes to memory failure. Storage decay Course of forgetting is initially rapid, and then levels off with time. Physical change in the brain occur as memory forms (memory trace). Storage decay Amnesia, literally “without memory”, involves a loss of memory, often due to brain trauma, injury, or disease

FORGETTING AS ENCODING FAILURE We cannot remember what we have not encoded. FORGETTING AS ENCODING FAILURE

Reason for Failure Events and memories are not available because these were never acquired. Memories have been discarded due to stored memory decay. Insufficient information to access memories make these out of reach. Sometimes even stored information cannot be accessed, which leads to forgetting.

Forgetting Interference Motivated forgetting Proactive: Occurs when older memory makes it more difficult to remember new information Retroactive: Occurs when new learning disrupts memory for older information Motivated forgetting Freud: Repressed memories protect self-concept and minimize anxiety. Today: Attempts to forget more likely when information is neutral, not emotional.

WHEN DO WE FORGET? Forgetting can occur at any memory stage. As we process information, we filter, alter, or lose much of it.

Memory Construction Errors Misinformation and imagination effects Misinformation effect occurs when a memory has been corrupted by misleading information. Imagination effect occurs when repeatedly imaging fake actions and events can create false memories.

Memory Construction Errors Source amnesia (source misattribution) Involves faulty memory for how, when, or where information was learned or imagine déjà vu Is sense that “I’ve experienced this before.” Suggests cues from the current situation may unconsciously trigger retrieval of an earlier experience

Discerning True and False Memories False memories feel like real memories and can be persistent but are usually limited to the gist of the event. False memories are often result of faulty eyewitness testimony.

Children’s Eyewitness Recall Ceci and Bruck Researchers studied effect of suggestive interviewing techniques 58 percent of preschoolers produced false stories about one or more unexperienced events. Children often accurately recall events and actors Neutral person Nonleading questions soon after event containing words children can understand

Repressed or Constructed Memories of Abuse? The debate between memory researchers and some well-meaning therapists focuses on whether most memories of early childhood abuse are repressed and can be recovered during therapy using “memory work” techniques using leading questions or hypnosis. What do you think?

Repressed or Constructed Memories of Abuse? Those committed to protecting abused children and those committed to protecting wrongly accused adults have agreed on the following: Sexual abuse happens. Injustice happens. Forgetting happens. Recovered memories are commonplace. Memories of things happening before age 3 are unreliable. Memories “recovered” under hypnosis are especially unreliable. Memories, whether real or false, can be emotionally upsetting.

Improving Memory SQ3R (Survey, Question, Read, Retrieve, Review) study technique used in this book incorporates several learning strategies. Rehearse repeatedly Make the material meaningful Activate retrieval cues Use mnemonic devices Minimize interference Sleep more Test your own knowledge, both to rehearse it and to find out what you do not yet know.