Attention and Memory

1. Attention and Memory

2. Attention I • Visual attention operates through both automatic and effortful processes • Parallel processing • We automatically process all stimuli in a display when we’re paying attention to only a single dimension (e.g., color) • This allows us to quickly identify a target (i.e., it “pops out”), regardless of the number of distractors • Serial processing • We need to engage slow, effortful search processes when asked to identify targets defined by the conjunction of two dimensions (e.g., color and letter identity)

3. Attention II • Attention allows us to select a single source of auditory stimulation from amongst many possible sources and ignore all other incoming messages • That is, attention functions like a filter • Conversely, we’re not very good at attending to more than one auditory message at a time • We do process some unattended information, but in a weaker form than we process attended information • Unattended, but weakly processed, information can grab your attention when that information is relevant to your goals • The cocktail party phenomenon

4. Attention III • Change blindness • We often miss large objects in our visual field when we are attending to something else • Although most people do not believe they can fail to see large objects right in front of them, numerous studies show this is the case

5. Information-Processing Model of Memory • Sensory memory: it’s purpose is to hold an internal copy of physical information just long enough for the system to select something in particular to attend to; that information then gets transferred to . . . • STM: our conscious workspace • Processes that control the flow and makeup of information have their locus in STM (e.g., coding, rehearsal, retrieval strategies…)

6. Sensory memory • Representational format: Modality-specific • Iconic memory: visual sensory memory • Echoic memory: auditory sensory memory • Haptic memory: touch sensory memory • Duration • Iconic memory: 250 ms • Echoic memory: 2-3 seconds • Capacity: Modality-dependent • Forgetting: Information decays if not further processed

7. Testing the duration and capacity of iconic memory • A letter array is displayed for 50 ms • In the whole report condition, subjects try to report all the letters • In the partial report condition, subjects report only a single row of letters

8. Duration and capacity of iconic memory

9. Short-term memory • Duration: 20 sec when you are distracted and can’t rehearse • Unlimited when maintaining information through repetition that you want to remember, like a phone number; termed “maintenance rehearsal” • Format: Visual verbal stimuli are stored in STM in an acoustic format • Sound-alike errors: when they can’t remember, people might say V instead of E, but not F instead of E. • Capacity: The magical number 7+2 • Chunking (1 4 9 2 1 7 7 6 1 9 4 5) • Expertise • Retrieval: We retrieve information from STM by using a serial exhaustive search, rather than a serial self-terminating search

10. Forgetting from short-term memory • Decay theory of forgetting • Memory traces dissipate as time passes and those memories are not used (see sensory memory) • Interference theory of forgetting • Memories are lost when they are bumped out or replaced by the formation of new memories • Experiment (for the result, see the next slide) • Some subjects sees 12 items, at a rate of 1 item per second. Total time: 12 seconds • Other subjects also see 12 items, but at a rate of 4 items per second. Total time: 3 seconds. • Decay theory predicts more forgetting in the first condition because more time has gone by. • Interference theory predicts equal forgetting in both conditions because the same number of new memories are being formed.

11. Support for the interference theory of forgetting in STM

12. Working Memory • STM was described as a single system responsible for information flow and control • However, STM is also used for comprehension of language, problem solving, and visual imagery (e.g., mental rotation task) • Baddeley revamped the idea of STM and renamed it “working memory” • Working memory is a set of independent subsystems that share attentional resources

13. Some working memory findings • Memory span task: listen to simple elements and immediately report in the order of their presentation • K.F.: memory span is impaired, but IQ is spared • Dual task methodology: have subjects do two tasks concurrently, each of which taxes the interdependent systems (e.g., the auditory working memory slave system and the central executive) • Findings • (1) As auditory working memory load increases from saying “the the the …” (concurrent articulation task), to saying “1 2 3 4”, to holding six random digits in memory, reasoning task performance decreases • (2) If subjects do a memory span task and a concurrent articulation task, for which auditory working memory is responsible, memory span performance decreases • (3) Concurrent articulation eliminates sound-alike errors for visually presented materials because the scratch-pad is used instead • (4) Concurrent articulation does NOT affect memory span for visual objects that cannot be named because storage of the visual objects does not require auditory working memory • (5) Word-length effect: Memory span is shorter for longer words because longer words more quickly consume the limited resources of auditory working memory

14. Mental rotation in visuo-spatial working memory Subjects were asked whether the letter was a normal R or a mirror-reversed R. The farther away from vertical, the longer it took for the subjects to decide. Conclusion: Subjects rotate a mental image of the stimulus to it’s vertical position before deciding.

15. Serial position effect • Since we cannot directly observe them, how do we know these two mental structures -- called STM and LTM -- actually exist? • Experiment • All subjects are presented 15 words, one at a time, for 2 seconds each. • Some subjects are asked, immediately after the words have been presented, to recall as many words as they can, in any order. • Serial position effect • Memory performance is better for the first few words (the “primacy effect”) and the last few words (the “recency effect”) that have been presented. • For other subjects, there is a delay of 30 seconds after the list has been presented. • During this delay, the subject may, for example, be asked to count backwards by 4’s from 569. • See next slide for result

16. Short-term vs. long term memory • The 30 s delay eliminated the recency effect, but did not impair the primacy effect. • This indicated that the recency effect must be due to STM, while the primacy effect must be due to LTM.

17. Long-term memory (LTM) • Memory for information that is no longer being rehearsed. • If a person is distracted for a couple minutes from rehearsing a new phone number, yet remembers the number, then it must have been stored in LTM. • Capacity: infinite • Duration: permanent • Forgetting: retrieval failure • Memories are available, but not necessarily accessible • Format: meaning (semantic) and visual (episodic) • At least for explicit long-term memory • You’re using your explicit long-term memory when you intentionally retrieve information from a specific episode (episodic memory) or you intentionally retrieve a fact (semantic memory) • You’re using your implicit long-term memory when you unintentionally retrieve information from a specific episode and the retrieval of that information affects your current behavior • See slides 19, 21, and 22.

18. Long-term memory Three key phases of the LTM process • Encoding • The mental processes we use to process information determine the strength and longevity of memory for that information. • Storage • There are many different types of long-term memory. • Retrieval • The circumstances under which one tries to retrieve memories, such as the nature of the memory test, influence the success of that retrieval.

19. LTM Systems

20. Declarative (Explicit) Long-Term Memory • Conscious retrieval and declaration of past events and known facts • We often retrieve information from LTM into STM and then consciously respond in a particular manner • Two forms of declarative memory • Episodic memory and semantic memory • Episodic memory • Includes where, when, and to whom something happened • Reexperiencing, often in visual terms, of a past event

21. Nondeclarative (implicit) memory • Unconscious (automatic) retrieval of information that influences behavior; responses are, in some respects, not mediated by STM • Skills and habits: reading, typing, bike riding, tying shoes, brushing teeth, washing dishes • Priming: any influence of a single past episode on current behavior that occurs without a person’s intentional retrieval or awareness • Simple conditioning: cat and can opener • Nonassociative learning: Habituation and sensitization

22. Explicit vs. Implicit memory • Amnesic patients (like H. M.) and normal controls were tested for memory for words that had been previously studied • Amnesics performed poorly on the explicit memory tasks • Amnesic performance on implicit memory tasks was like that for control subjects • Conclusion: Amnesics can form memories for studied words – at least implicit memories – even though they can’t tell you what words they’ve studied

23. Encoding into (explicit) LTM • Four factors affecting the strength of (explicit) LTM • Elaborative rehearsal (processing information for meaning) promotes better LTM for facts than maintenance rehearsal (i.e., rote rehearsal or repetition) • Regardless of how you rehearse, spaced rehearsal is better than massed rehearsal • It’s better to study 1 hour of information for an hour at 3 different times than for 3 hours all at one time • Dividing attention during encoding impairs LTM • Use of imagery to code information in a visual format also promotes better LTM • Picture superiority effect: pictures are remembered better than words

24. Semantic memory: Schemas • Schema: Knowledge representations, built through integrating similar experiences across time, which allow us to predict the nature of repeated activities (e.g., birthday parties) and environments (e.g., offices) • Schemas are used to construct long-term memories of the stimulus at encoding and to reconstruct long-term memories at retrieval • Sometimes this can be beneficial, as in the following passage from Bransford & Johnson (1972) • Sometimes this can be costly, as in the following Brewer & Treyens (1981) picture of the office

25. Read this passage before going to the next slide • The procedure is actually quite simple. First you arrange items into different groups. Of course one pile may be sufficient depending on how much there is to do. If you have to go somewhere else due to lack of facilities that is the next step; otherwise, you are pretty well set. It is important not to overdo things. That is, it is better to do too few things at once than too many. In the short run this may not seem important but complications can easily arise. A mistake can be expensive as well. At first, the whole procedure will seem complicated. Soon, however, it will become just another facet of life. It is difficult to foresee any end to the necessity for this task in the immediate future, but then, one never can tell. After the procedure is completed one arranges the materials into different groups again. Then they can be put into their appropriate places. Eventually they will be used once more and the whole cycle will then have to be repeated. However, that is part of life.

26. Schema benefits • When subjects read the preceding passage without a title or when subjects were given a title to the passage after they had read it, comprehension scores and recall scores were low. • However, subjects given the title “Washing Clothes” before reading the passage scored twice as well in both comprehension and recall tests.

27. Study this picture for 30 s before going to the next slide

28. List as many objects as you can recall from the photograph you just saw.

29. Schema Costs • Many subjects recall seeing books in the picture of the office, when there are no books in the picture. • Another example • Roediger & McDermott (1995) • Present subjects with lists of words (e.g., bed, rest, awake, tired, dream, wake, night, blanket, doze, slumber, snore, pillow, peace, yawn, and drowsy) • Many subjects recall having heard the word “sleep” in the list, even though it was not presented

30. Semantic memory I • Semantic memories are knowledge representations that are built through integrating similar experiences across time • Each time you are told that the sun rises in the east leaves an episodic memory of that event • But once you have many episodic memories of being told that fact, then you forget the episodes in which you learned that fact and you just remember the fact itself • This process is sometimes termed “abstraction” and the memory left is sometimes described as an “abstract” form of memory • Many different types of semantic memory • Words and their meanings • Facts: “George Washington’s face is on a $1 bill.” • Categories: “A canary is a type of bird.” • Schemas (see slides 24-29 for explanation)

31. Semantic Memory II: Semantic Networks • Our semantic memory is organized by meaning, like a thesaurus • In contrast, a dictionary is organized alphabetically • Each concept is represented as a node • When the word “red” is presented, the node for red becomes activated and, if that activation is sufficient, you • Become conscious of that word • Become conscious of the meaning of that word • Are able to say that word or respond to that word

32. Semantic Memory III • Spreading activation • When red becomes activated, the activation spreads from red to other concepts that are connected to red • Three examples of spreading activation at work • Free association • If you’re asked to say the first word that comes to mind when you’re presented the word red, you’ll say blood or roses or fire engine or apple or . . .; but you won’t say words that are unrelated to red • Automatic activation of task relevant knowledge • When someone says to you, “Please set the table for dinner.”, there are many things left unsaid, such as what to set on the table, in what arrangement to set those things, how many places to set, etc. Your semantic memory fills in that missing information when activation spreads from table and dinner to related concepts. • Semantic priming (see next slide)

33. Semantic Memory IV: Semantic Priming • Semantic priming • Imagine a task where you are presented two words in succession and your task is to say just the second word; the experimenter is going to measure how long it takes you to say the second word • If a word unrelated to red, like the word box, is presented before the word red, you will be relatively slow to say the word red (it will take you about ½ sec) • However, if a word related to red, like the word apple, is presented before the word red, you will be relatively fast to say the word red (it will take you about 1/3 sec) • The difference in speed is called a semantic priming effect • The reason you’re faster to say red after apple than after box is because the activation of apple spread to red and, as a result, red already had a head start when the word red was actually presented.

34. Encoding-Retrieval Similarity • Enhancing the similarity between conditions at study and test can improve the rate at which information is successfully retrieved from LTM. • The physical environment (i.e., environmental context) • The stimulus environment • Encoding specificity principle • Emotional state (mood) • Physiological state (drugs) • Psychological state (depression) • Cognitive processes that are involved in processing information • Transfer-appropriate processing

35. Searching for the engram I • Engram: physical site of memory storage • The medial (i.e., middle) section of the temporal lobes is important for many aspects of declarative memory • The medial temporal lobe includes cortical structures, such as the rhinal cortex, and subcortical structures, such as the hippocampus and amygdala • Consolidation • Transfer of information from short-term to long-term memory • Reconsolidation • After you retrieve a memory from LTM, you must re-store that memory back into LTM • When you re-store a memory back into LTM, it is often altered by the mental environment into which it had been retrieved • Spatial memory • Taxi drivers, especially experienced ones, have a larger hippocampus than people that do not drive taxis

36. Brain and Memory • The limbic system is critical for memory formation and recall • Hippocampus: Critical for forming new explicit (conscious) memories • Amygdala: Important role in emotional memories • H.M.’s hippocampus was removed in both hemispheres and he suffered from anterograde amnesia

37. H.M.’s surgery

38. Searching for the engram II • The frontal lobes are also important for many aspects of memory • Damage to the frontal lobes impairs • Memory for the time sequence of events • Memory for the source of information (i.e., where, when, and from whom information was learned) • The ability to deeply process information (i.e., process it for its meaning) • Working memory and leads to an inability to follow a planned sequence of steps, such as using a recipe to bake a cake

39. Searching for the engram III • The amygdala plays an important role in memory • It does so by controlling the effects of memory modulating neurotransmitters, such as norepinephrine • This is especially true during events associated with reward, fear or other emotions, and arousal • These events cause an increase in norepinephrine and an increase in the strength and durability of memory • Occasionally, these processes can produce overstrong memories or can “burn these events into memory” • Often, patients with post-traumatic stress disorder (PTSD), cannot forget events that they would like to forget • Drugs (e.g., propranolol) that block norepinephrine receptors reduce the duration and strength of emotional memories

40. Forgetting: The three sins • Transience • Forgetting over time • Ebbinhaus’s forgetting curve (see next slide) • Decay vs. interference • Interference! (see slides 10 & 11) • Types of interference • Proactive vs. retroactive (see slide 42) • Absentmindedness • Inattentive or shallow encoding of events • Change blindness • Blocking • A temporary inability to remember something that is known because some other, similar, information is interfering with your memory • Broussard Park? Bourgeois Park? No, it’s Burroughs Park! • Tip-of-the-tongue phenomenon

41. Ebbinghaus’s Forgetting Curve • Over the first three days, the rate of forgetting is very high • % correct drops from 57% to 25% • Over the next 27 days, the rate of forgetting is very low • % correct drops from 25% to 21% • In summary, the rate of forgetting is initially very high, but becomes very low

42. Interference and Forgetting

43. Distortion: The sins of persistence and misattribution • Persistence • The resurgence of unwanted memories that we would like to forget • See slide 39 for the role of the amygdala and norepinephrine in creating such memories • Misattribution of source (and source amnesia) • The source of information • Knowing who told you something (or when, where, and how you learned something) is important for evaluating that information • We often misremember the source of information (source misattribution) or forget the source of information (source amnesia) and, when we do so, this leads us to evaluate that information differently • The false fame effect • The sleeper effect • Cryptomnesia: Unintentional plagiarism • False memories

44. Distortion: The sin of suggestibility and the misinformation effect • Suggestibility • The misinformation effect (Loftus) • Subjects are shown a slide show in which a Datsun runs a stop sign and hits a pedestrian. • Later they are asked “Did another car pass the Datsun as it reached the yield sign?” • Later, 30% more of these subjects incorrectly said that they had been shown a slide with a yield sign than if they had not been asked the “leading question”, many with a high degree of confidence. • The misinformation effect implies that eyewitness testimony many often be unreliable • For the first 130 people nationwide whose guilty verdict was overturned because of DNA evidence, mistaken eyewitness identification played a role in over 75% of the cases. • http://www.innocenceproject.org/understand/ • Eyewitnesses that are wrong are often just as confident, and sometimes even more confident, than eyewitnesses that are correct

45. Distortion: The sin of suggestibility and illusory memories • Illusory memories • Students (N = 24) were presented a booklet in which there were four stories of childhood events. • Three of these stories were true. • The three true stories had been gathered by previously contacting the family of the student. • One of the stories, about being lost in a mall, was false. • Subjects were asked to try to remember these events and to describe what they remembered in detail. • If they didn’t remember, they were told to say so. • After first reading the booklet, 7 of 24 subjects “remembered” being lost in the mall. • In follow-up interviews, 6 of 24 subjects continued to remember being lost in in the mall.

46. Distortion: Implications of illusory memories • Recovered memories or false memories? • According to Freud, repressed memories are memories of (typically) traumatic events that people have forced from their conscious memory into their unconscious • People sometimes claim to recall traumatic events (such as childhood sex abuse) after having forgotten these events for many years • If these events really occurred, were forgotten, and were later remembered, then these are called recovered memories. • If the memories of these events were really the product of suggestions made by an unwitting therapist to the patient, then these are called false memories (a special type of illusory memory).

47. Distortion: The sin of bias • People’s memories of their past attitudes, behaviors, or knowledge are often adjusted (biased) to be consistent with their current attitudes, behaviors, or knowledge. • Subjects who are newly persuaded of the value of brushing their teeth report that they brushed their teeth more often in the past two weeks than those that were not persuaded (Ross, 1989). • “I really knew all along how important it was to brush my teeth and, in fact, I’ve been doing so.” • “It is common for caterpillars to become butterflies and then to maintain that in their youth they had been little butterflies. Maturation makes liars of us all,” (Vaillant, 1977).

48. Other important memory concepts • Flashbulb memories • Very clear, visual, detailed memories of a new, important, emotional event. • They are not necessarily 100% accurate, but they are more accurate than memories for everyday events. • Autobiographical memory • As we age, we tend to remember most our adolescence and early adulthood • We especially remember transitional firsts, such as 1st and 4th years of college • Prospective memory • Memory for things that need to be done in the future • Remembering to do some thing at a particular time and remembering what to do at that time • Keeping the script for the to-be-done activity in an activated state helps prospective memory • Metamemory • People’s knowledge of their own memory skills and abilities • The accuracy with which people guess how likely it is that they will remember something or how effective some memory strategy or learning strategy may be for them • Your metamemory has failed you when you think you’ve studied enough for an exam, but then do poorly.