Lecture 9 - Memory PDF

Lecture 9 Memory  Memory: ability to store and retrieve information over time What Is Three key functions of memory Memory? Encoding: process by which we transform what we perceive, think, or feel into an enduring memory...

Lecture 9 Memory  Memory: ability to store and retrieve information over time What Is Three key functions of memory Memory? Encoding: process by which we transform what we perceive, think, or feel into an enduring memory Storage: process of maintaining information in memory over time Retrieval: process of bringing to mind information that has been previously encoded and stored  Encoding: Transforming Perceptions into Memories Memories are made by combining information we already have with new information coming in. Memories are constructed. There are three major ways to encode. Semantic encoding: process of actively relating new information in a meaningful way to knowledge that is already in memory Visual imagery encoding: process of storing new information by converting it into mental pictures Organizational encoding: process of categorizing information according to the relationships among a series of items  Based on evolutionary theories of natural Encoding of selection, memory mechanisms that help us survive should be passed down. Survival- An experiment gave three different encoding Related tasks to participants (survival-encoding Information condition, moving-encoding condition, and pleasantness-encoding condition). Survival encoding yielded better memory, perhaps drawing from elaborative, visual imagery, and organizational encoding. Superior recall is also observed for scenarios that involve planning but not survival. Storage Sensory storage: storage that holds sensory information for a few seconds or less Iconic memory: fast-decaying store of visual information Echoic memory: fast-decaying store of auditory information  Short-term storage and working memory Short-term memory (STM): storage that holds Short Term non-sensory information for more than a few Memory seconds but less than a minute; can hold about seven items Rehearsal: process of keeping information in STM by mentally repeating it Chunking: combining small pieces of information into larger clusters/chunks that are more easily held in STM Working memory: STM storage that actively maintains information  Working memory: stores and manipulates Working information Memory Working memory model Includes a limited-capacity memory system Has two subsystems whose information is coded by the episodic buffer Visio-spatial sketchpad Phonological loop  Long-term memory (LTM) Holds information for hours, days, weeks, or years Long-Term Has no known capacity limits Storage People can recall items from long-term memory even if they haven’t thought of them for years. The Hippocampus Case of HM who had his hippocampus (temporal lobe) removed to prevent seizures Had STM, but no LTM Anterograde amnesia: inability to transfer new information from the short-term store into the long-term store Retrograde amnesia: inability to retrieve information that was acquired before a particular date, usually the date of an injury or operation The Hippocampus Consolidation: process by which memories become stable in the brain Stabilizes memories Reconsolidation: memories can become vulnerable to disruption when they are recalled, requiring them to become consolidated again Memories, Neurons, and Synapses Research suggests that connections (synapses) between neurons, specifically in the hippocampus, strengthen memories. Long-term potentiation (LTP): process whereby communication across the synapse between neurons strengthens the connection, making further communication easier NMDA receptor: receptor site on the hippocampus that influences the flow of information between neurons by controlling the initiation of LTP Retrieving Memories Retrieval Cues Retrieval cues are external events that help us to retrieve information from inside our long-term memory Retrieval cues: external information associated with stored information that helps bring that information to mind Retrieval Cues: Internal and External Cues Encoding specificity principle: idea that a retrieval cue can serve as an effective reminder when it helps re-create the specific way in which information was initially encoded State-dependent retrieval: tendency for information to be better recalled when the person is in the same state during encoding and retrieval Matching encoding and retrieval contexts improves recall. Transfer-appropriate processing: memory likely to transfer from one situation to another when encoding and retrieval contexts of the situations match  The act of retrieval can strengthen a retrieved memory (especially long term); it can also cause Consequences forgetting. of Retrieval Retrieval can improve subsequent memory. Retrieval can also impair subsequent memory. Retrieval can also change subsequent memory. Types of Long-Term Memory Explicit memory: act of consciously or intentionally retrieving past experiences Implicit memory: influence of past experiences on later behaviour, even without an effort to remember them or an awareness of the recollection Implicit Memory Procedural memory: gradual acquisition of skills as a result of practice, or “knowing how” to do things Implicit Memory Priming: enhanced ability to think of a stimulus as a result of a recent exposure to the stimulus; less cortical activation (perceptual and conceptual priming) Priming makes some information more accessible. Things remembered are automatically translated into actions. Two types of Priming Perceptual priming Conceptual priming  Procedural memory and priming do not rely on the hippocampus. Implicit Priming is associated with reduced activity in Memory various regions of the cortex that are activated when performing unprimed tasks. Different areas of the brain are activated for different types of priming Perceptual: regions toward the back of the brain – e.g. the visual cortex Conceptual: regions toward the front of the brain – e.g. the frontal lobes Explicit Memory: Semantic and Episodic Semantic memory: network of associated facts and concepts that make up our general knowledge of the world Episodic memory: collection of past personal experiences that occurred at a particular time and place  Episodic Memory Episodic memory Divergent creative thinking Helps to envision personal Generates creative ideas by futures through divergent combining different types of creative thinking information in new ways Allows combination of elements AUT of past experiences in new ways Coupling between core and to mentally enable different executive networks is key versions of what might happen feature of divergent creative thinking  Decay Theory: memories often fade away on their own simply because they are neglected or not used for a period of time Why do we The forgetting curve: a pattern of rapid memory loss that's followed by a stable retention of any Forget? information that's left Interference: Forgetting is affected by what happens before and after we learn something. Proactive interference: competing information that's learned before the forgotten material Retroactive Interference: learning of new information that disrupts previously recalled information Memory Failures 1. Transience 2. Absentmindedness 3. Blocking 4. Memory Misattribution 5. Suggestibility 6. Bias 7. Persistence  Transience: forgetting what occurs with the passage of time; rapid forgetting 1. Transience Memory fades more quickly at first, then more slowly over time. Involves a switch from specific to more general memories Common types of forgetting Retroactive interference Proactive interference Infantile or childhood amnesia  Absentmindedness: lapse in attention that results in memory failure 2. There is less activity in the frontal lobe when Absentmindedness attention is divided. We don’t always remember to remember. Prospective memory: remembering to do things in the future External reminders Intention offloading 3. Blocking Blocking: failure to retrieve information that is available in memory even though you are trying to produce it Tip-of-the-tongue phenomenon Increases with injury and age  Memory misattribution: assigning a recollection or an idea to the wrong source Frontal lobe intimately involved 4. Correct memories can be attributed to wrong Misattribution source Source memory: recall of when, where, and how information was acquired Misattribution happens to us all False recognition: feeling of familiarity about something that hasn’t been encountered before Same brain activation as true recognition (including hippocampus)  Suggestibility: tendency to incorporate 5. misleading information from external sources into personal recollections Suggestibility People can develop false memories in response to suggestions. Visual imagery influence Social pressures Accuracy or inaccuracy of childhood memories recalled during psychotherapy  Bias: distorting influences of present knowledge, beliefs, and feelings on recollection of previous 6. Bias experiences Consistency bias: tendency to reconstruct the past to fit the present Change bias: tendency to exaggerate differences between what we feel or believe now and what we felt or believed in the past Egocentric bias: tendency to exaggerate the change between present and past in order to make ourselves look good in retrospect  Persistence: intrusive recollection of events that we wish we could forget 7. Persistence Often occurs after disturbing or traumatic events Emotional experiences better remembered than unemotional ones Flashbulb memories: detailed recollections of when and where we heard about shocking events Amygdala involved in emotional memory The Amygdala’s Influence on Memory The amygdala, located next to the hippocampus, responds strongly to emotional events. Individuals with amygdala damage are unable to remember emotional events any better than nonemotional ones (Cahill & McGaugh, 1998). Are the Seven “Sins” Each of the seven sins can cause trouble in our Vices or lives. However, each has an adaptive side, too. Virtues? Sins should be viewed as the costs we pay for benefits of a memory that works well most of the time. Other Memory Mishaps Jamais Vu: a lack of familiarity with a particular experience when this should clearly not be the case Time-Gap Experience: when we complete a task but have no recollection of having completed it Cryptomnesia: when we believe that something was our original creation, but in fact was actually someone else's; unintended plagiarism.