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Memory

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Memory

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  1. Memory Faezeh Dehghan. OTR. PhD student of neuroscience Iran university of medical science کارگاه تخصصیتوانبخشی حافظه از سری کارگاه های آخر هفته های شناختی

  2. Memory • the ability to take in, store, and retrieve information • Baddeley and Hitch (1974), influenced by Atkinson and Shriffin (1971), suggested that memory can be divided into three categories broadly based on the length of time information can be stored: • sensory memory • short-term store, which holds information for a few seconds • long-term store, which holds information for anything from minutes to years

  3. The Role of Attention in Memory • In order to encode information into memory, we must first pay attention, a process known as attentional capture. • Attentional Capture • In order for information to be encoded into memory, we must first pay attention to it. When a person pays attention to a particular piece of information, this process is called attentional capture. • By paying attention to particular information (and not other information), a person creates memories that could be (and probably are) different from someone else in the same situation. This is why two people can see the same situation but create different memories about it—each person performs attentional capture differently. • There are two main types of attentional capture: explicit and implicit.

  4. The Role of Attention in Memory • Explicit Attentional Capture • Explicit attentional capture is when a stimulus that a person has not been attending to becomes salient enough that the person begins to attend to it and becomes cognizant of its existence. • Very simply, it's when something new catches your focus and you become aware of and focused on that new stimulus.

  5. The Role of Attention in Memory • Implicit Attentional Capture • Implicit attentional capture is when a stimulus that a person has not been attending to has an impact on the person's behavior, whether or not they're cognizant of that impact or the stimulus. • If you are working on your homework and there is quiet but annoying music in the background, you may not be aware of it, but your overall focus and performance on your homework might be affected.

  6. Sensory Memory • During every moment of an organism's life, sensory information is being taken in by sensory receptors and processed by the nervous system. • Sensory information is stored in sensory memory just long enough to be transferred to short-term memory • Sensory memory types • Visual sensory memory—brief memory of an image or icon. Also called iconic memory. • Auditory sensory memory—brief memory of a sound or echo. Also called echoic memory • Haptic memory - Haptic memory represents SM for the tactile sense of touch. Sensory receptors all over the body detect sensations such as pressure, itching, and pain. Information from receptors travel through afferent neurons in the spinal cord to the postcentral gyrus of the parietal lobe in the brain. This pathway comprises the somatosensory system.

  7. Sensory Memory Function —process for basicphysical characteristicsCapacity—large , can hold many items at onceDuration—very brief retention ofimages 3 sec for visual info, 2 sec for auditory info Divided into two types:▪ iconic memory–visual information▪ echoic memory– auditoryinformationAttention is needed to transferinformation to working memory

  8. Short-Term Memory • Function—conscious processing of information • where information is actively worked on • Capacity—limited (holds 7+/-2 items) • Duration—brief storage (about 30 second ) • Primary memory and immediate memory refer to thememory span as measured by the number of digits that can be repeated in the correct order after one presentation (seven plus or minus two for the vast majority of people)

  9. Maintenance Rehearsal • Mental or verbal repetition of information allows information to remain in working memory longer than the usual 30 seconds • This type of rehearsal usually involves repeating information without thinking about its meaning or connecting it to other information. This is why the information is not usually transferred to long term memory • An example of maintenance rehearsal would be remembering a phone number only long enough to make the phone call.

  10. Elaborative rehearsal • Elaborative rehearsal is a type of memory rehearsal that is useful in transferring information into long term memory. • This type of rehearsal is effective because it involves thinking about the meaning of the information and connecting it to other information already stored in memory. It goes much deeper than maintenance rehearsal. • According to the levels-of-processing effect by Fergus I. M. Craik and Robert S. Lockhart in 1972, this type of rehearsal works best because of this depth of processing.

  11. Chunking • Grouping small bits of informationinto larger units of information▪ expands working memory load▪ Which is easier to remember?▪ 4 8 3 7 9 2 5 1 6▪ 483- 792- 516 • سیب با انار • گربه با سگ • قرمز با گربه • آبی با موش

  12. Long-Term Memory • the long-term store or long-term memory (LTM) is the system that stores information for longer periods of time ranging from minutes to decades. • Once information passes from sensory to working memory, it can be encoded into long-term memory • Function—organizes and stores • information • more passive form of storage than workingmemory • Unlimited capacity • Duration—thought by some to bepermanent • Encoding—process that controlsmovement from working to long-termmemory store • Retrieval—process that controls flow ofinformation from long-term to workingmemory store

  13. LTM can be understood or distinguished in various ways, including semantic, episodic, and procedural memory; visual and verbal memory; and implicit and explicit memory.

  14. Types of Long-Term Memory • Explicit memory—memory with awareness; information can be consciously recollected; also called declarative memory • Implicit memory—memory without awareness; memory that affects behavior but cannot consciously be recalled; also called nondeclarative memory

  15. Explicit Memory • Declarative or conscious memory▪ Memory consciously recalled or declared▪ Can use explicit memory to directly respond to a question▪ Two subtypes of explicit • Episodic information—information about events or “episodes” • Semantic information—information about facts, general knowledge, school work

  16. semantic memory • Memory not tied to personal events▪ General facts and definitions about the world • We use semantic memory when we answer questions such as the color of a banana, the capital of Egypt, whether a cat is larger or smaller than a elephant , and the meaning of the word justice. • We have a huge store of information as to what things mean, look like, sound like, smell like, and feel like. • Does NOT depend on tying the item to your past

  17. episodic memory • Memory tied to your own personal experiences • episodic memory: Memory for personal experiences (e.g., where you spent last Christmas, when the credit card bill was paid, or what your friend asked you to do this evening) is more autobiographical to travel back in time • Episodic memory problems, like semantic memory problems, result from deficits in LTM.

  18. procedural memory • Memory for skills or routines is known as procedural memory. Learning to ride a bicycle, reading words written back to front, and learning to type are examples of procedural learning. • The primary characteristic of this kind of learning is that it does not depend on conscious recollection; instead, the learning can be demonstrated without the need to be aware of where and how the original learning took place. • For this reason, most people with memory problems show normal or relatively normal procedural learning • Some patient groups are known to show impaired procedural learning, particularly those with Huntington’s disease and Parkinson’s disease

  19. Stages in the Process of Remembering: Encoding, Storage, and Retrieval • The taking in of information is the encoding stage, retaining the information is the storage stage, and accessing the information when required is the retrieval stage. • encoding information (learning it, by perceiving it and relating it to past knowledge), storing it (maintaining it over time), and then retrieving it (accessing the information when needed). Failures can occur at any stage, leading to forgetting or to having false memories. • Encoding is the crucial first step to creating a new memory. It allows the perceived item of interest to be converted into a construct that can be stored within the brain, and then recalled later from short-term or long-term memory.

  20. Memory: Persistence of learning over time through the storage and retrieval of information • STEPS: External events  sensory memory  short term/working memory  long term memory • WM: Automatic or effortful encoding • Can be aided by the timing of rehearsals, imagery, and mnemonic devices • WM has short duration and limited capacity • LTM: is limitless and constructive • Works by leaving traces of neural impulses • Long term potentiation  permanent change in synapses • Stress hormones influence memory • We have implicit (cerebellum) and explicit (hippocampus)LTM • Retrieval of information happens by recall, recognition • Priming (unconscious), context effects, and mood congruence help us retrieve relevant information

  21. Memory Encoding • Encoding is a biological event beginning with perception through the senses. • The process of laying down a memory begins with attention (regulated by the thalamus and the frontal lobe), in which a memorable event causes neurons to fire more frequently, making the experience more intense and increasing the likelihood that the event is encoded as a memory. • Emotion tends to increase attention, and the emotional element of an event is processed on an unconscious pathway in the brain leading to the amygdala. Only then are the actual sensations derived from an event processed. • The perceived sensations are decoded in the various sensory areas of the cortex, and then combined in the brain’s hippocampus into one single experience. • The hippocampus is then responsible for analyzing these inputs and ultimately deciding if they will be committed to long-term memory. • It acts as a kind of sorting center where the new sensations are compared and associated with previously recorded ones. • It is also one of the few areas of the brain where completely new neurons can grow.

  22. There are three or four main types of encoding: • Acoustic encoding is the processing and encoding of sound, words and other auditory input for storage and later retrieval. This is aided by the concept of the • Visualencoding is the process of encoding images and visual sensory information. Visual sensory information is temporarily stored within the iconic memory before being encoded into long-term storage. • The amygdala (within the medial temporal lobe of the brain which has a primary role in the processing of emotional reactions) fulfills an important role in visual encoding, as it accepts visual input in addition to input from other systems and encodes the positive or negative values of conditioned stimuli. • Tactile encoding is the encoding of how something feels, normally through the sense of touch. Physiologically, neurons in the primary somatosensory cortex of the brain react to vibrotactile stimuli caused by the feel of an object. • Semantic encoding is the process of encoding sensory input that has particular meaning or can be applied to a particular context, rather than deriving from a particular sense.

  23. Encoding Specificity • When conditions of retrieval are similar to conditions of encoding, retrieval is more likely to be successful– You are more likely to remember things if the conditions under which you recall them are similar to the conditions under which you learned themContext effects—environmental cues to recall • State dependent retrieval—physical, internal factors • Mood Congruence—factors related to mood or emotions

  24. Flashbulb Memories • Recall of very specific images or details about a vivid, rare, or significant event • May seem very vivid and specific, but they are not more accurate than ordinary memories • A flashbulb memory is a detailed and vivid memory that is stored on one occasion and retained for a lifetime. Usually, such memories are associated with important historical or autobiographical events. • Flashbulb memories are thought to require the participation of the amygdala, a brain structure involved in emotional memory, and possibly other brain systems which regulate mood and alertness.

  25. MEMORY STORAGE • Storage is the more or less passive process of retaining information in the brain, whether in the sensory memory, the short-term memory or the more permanent long-term memory. • Each of these different stages of human memory function as a sort of filter that helps to protect us from the flood of information that confront us on a daily basis, avoiding an overload of information and helping to keep us sane. • process of consolidation, the stabilizing of a memory trace after its initial acquisition

  26. MEMORY RECALL/RETRIEVAL • Recall or retrieval of memory refers to the subsequent re-accessing of events or information from the past, which have been previously encoded and stored in the brain. • In common parlance, it is known as remembering. • During recall, the brain "replays" a pattern of neural activity that was originally generated in response to a particular event, echoing the brain's perception of the real event. • In fact, there is no real solid distinction between the act of remembering and the act of thinking.

  27. Forgetting Theories • Encoding failure▪ Interference theories▪ Motivated forgetting▪ Decay

  28. Attention External events Sensory memory Short- term memory Long- term memory Encoding Encoding Encoding failure leads to forgetting Forgetting as encoding failure • Some information is encoded without effort • Some information requires effortful encoding or it never enters long-term memory

  29. Interference Theories • Memories interfering with memories” • Forgetting NOT caused by mere passage of time • Caused by one memory competing with or replacing another memory▪ Two types of interference

  30. Attention Encoding External events Sensory memory Short-term memory Long-term memory Encoding Retrieval Retrieval failure leads to forgetting Forgetting as retrieval failure • Forgetting can result from failure to retrieve information from long-term memory

  31. There are two main methods of accessing memory: recognition and recall.  • Recognition is the association of an event or physical object with one previously experienced or encountered, and involves a process of comparison of information with memory, e.g. recognizing a known face, true/false or multiple choice questions, etc. • Recognition is a largely unconscious process, and the brain even has a dedicated face-recognition area, which passes information directly through the limbic areas to generate a sense of familiarity, before linking up with the cortical path, where data about the person's movements and intentions are processed.  • Recall involves remembering a fact, event or object that is not currently physically present (in the sense of retrieving a representation, mental image or concept), and requires the direct uncovering of information from memory, e.g. remembering the name of a recognized person, fill-in the blank questions, etc.

  32. Recognition is usually considered to be “superior” to recall (in the sense of being more effective), in that it requires just a single process rather than two processes. • Recognition requires only a simple familiarity decision, whereas a full recall of an item from memory requires a two-stage process (indeed, this is often referred to as the two-stage theory of memory) in which the search and retrieval of candidate items from memory is followed by a familiarity decision where the correct information is chosen from the candidates retrieved. • Thus, recall involves actively reconstructing the information and requires the activation of all the neurons involved in the memory in question, whereas recognition only requires a relatively simple decision as to whether one thing among others has been encountered before. • Sometimes, however, even if a part of an object initially activates only a part of the neural network concerned, recognition may then suffice to activate the entire network

  33. Free recall is the process in which a person is given a list of items to remember and then is asked to recall them in any order (hence the name “free”). • This type of recall often displays evidence of either the primacy effect (when the person recalls items presented at the beginning of the list earlier and more often) or the recently effect (when the person recalls items presented at the end of the list earlier and more often). • Cued recall is the process in which a person is given a list of items to remember and is then tested with the use of cues or guides. When cues are provided to a person, they tend to remember items on the list that they did not originally recall without a cue, and which were thought to be lost to memory. • This can also take the form of stimulus-response recall, as when words, pictures and numbers are presented together in a pair, and the resulting associations between the two items cues the recall of the second item in the pair. • Serial recall refers to our ability to recall items or events in the order in which they occurred, whether chronological events in our autobiographical memories, or the order of the different parts of a sentence (or phonemes in a word) in order to make sense of them.

  34. Testing of serial recall by psychologists have yielded several general rules: • more recent events are more easily remembered in order (especially with auditory stimuli) • recall decreases as the length of the list or sequence increases; • there is a tendency to remember the correct items, but in the wrong order; • where errors are made, there is a tendency to respond with an item that resembles the original item in some way (e.g. “dog” instead of “fog”, or perhaps an item physically close to the original item); • repetition errors do occur, but they are relatively rare; • if an item is recalled earlier in the list than it should be, the missed item tends to be inserted immediately after it; • if an item from a previous trial is recalled in a current trial, it is likely to be recalled at its position from the original trial.

  35. Colour may have an effect on our ability to memorize something.People remember colour scenes better than black-and-white ones, although only if naturally (as opposed to falsely) coloured.In particular, warm colours, like red, yellow and orange, may help us to memorize things by increasing our level of attention (our ability to select from information available in the environment). 

  36. Memory development • The development of memory in children becomes evident within the first 3 years of a child's life as they show considerable advances in declarative memory. • This enhancement continues into adolescence with major developments in short term memory, working memory, long term memory and autobiographical memory • Recent research on the development of memory has indicated that declarative, or explicit memory, may exist in infants who are even younger than two years old. For example, newborns who are less than 3 days old demonstrate a preference for their mother’s own voice

  37. Declarative memory develops very rapidly throughout the first 2 years of life; infants of this age show evidence of cognitive development in many ways (e.g., increased attention, language acquisition, increasing knowledge). • There is a difference in the brain development of explicit and implicit memory in infants. • Implicit memory is controlled by an early-developing memory system in the brain that is present very early on, and can be explained by the early maturation of striatum, cerebellum, and brain stem, which are all involved in implicit learning and memory.

  38. Development of explicit memory depends on a later developing memory system in the brain that reaches maturity between 8 and 10 months of age. • Explicit memory depends heavily on structures in the medial temporal lobe, including the hippocampus and the parahippocampal cortex. Much of the brain system is formed before birth, however the dentate gyrus within the hippocampal formation has about 70% of the number of cells in adults

  39. Working Memory • According to Baddeley's model of working memory, working memory is composed of three parts. First is the central executive which is responsible for a range of regulatory functions including attention, the control of action, and problem solving. Second, the phonological loop, which is specialized for the manipulation and retention of material in particular informational domains. • Finally, the visuospatial sketchpad stores material in terms of its visual or spatial features. The strength of the relationships between the three components of working memory vary; the central executive is strongly linked with both the phonological loop as well as the visuospatial sketchpad which are both independent of each other. Some evidence indicates linear increases in performance of working memory from age 3-4 years through to adolescence

  40. Central Executive • In children from 2-4, the memory storage capacity limitation constrains complex comprehension processes. As the child grows older however, less processing is necessary which opens more storage space for memory • Phonological Loop • Evidence indicates linear increases in performance from age 4 years through to adolescence. Prior to about 7 years of age, serial recall performance is mediated by the phonological store which is one component of the phonological loop. • Preschool aged children do not use a subvocal rehearsal strategy to maintain decaying phonological representations in the store but instead they identify visual features of pictures in order to remember them. • At the age of seven, children begin to use a subvocal rehearsal process to maximize retention in the phonological store.

  41. Visuospatial Sketchpad • Younger children (under the age of 5) may be dependent than older children or adults on using the visuospatial sketchpad to support immediate memory for visual material. • Older children adopt a strategy of verbally recoding pictures where possible and also use the phonological loop to mediate performance of the “visual” memory task. • Between the ages of 5 and 11, visual memory span increases substantially and it is at this point when adult levels of performance are reached

  42. Memory rehabilitation • Data is important! • Accurate input = Accurate recall • Coding –decoding (all sensory system) • First start with procedural memory