PSYC 251 Exam 2

*Briefly explain three possible causes of infantile amnesia and why you may still have "memories" of your life as an infant

1. Hippocampus and frontal cortex take time to fully develop 2. Self-recognition is not developed for 1 and a half to 2 years so can't place yourself in memories 3. Infants could be encoding the memories but because they are preverbal we can not access them as adults We have "memories" from very young but really we are just remember the stories told to us.

*Describe several ways in which the central executive is able to control cognition and manipulate the contents of the working memory, providing common behavioral tests and real-world examples of each

1. controlled updating of short-term memory buffers (N-back task) 2. goal setting and planning (Tower of Hanoi) 3. task switching (Wisconsin card sorting test) 4. stimulus attention and response inhibition (Stroop task)

*Explain some basic behavioral effects on declarative memory encoding (depth of processing, organization / background knowledge), storage/retention (forgetting curve and consolidation period), and retrieval (retrieval cues, transfer-appropriate processing)

A basic principle of memory is that new information is easier to remember if you can relate it to things you already know. Sheer repetition of information is not enough to remember rather struggling to learn new information generally promotes better long-term retention. A third general principle is that the more deeply you analyze information the more likely you are to successfully encode it in memory. A basic principle of retrieval is that it is more likely to be successful if the conditions at recall are similar to those that occurred during encoding. Another principle states that memory will be best when the way in which information is processed at encoding matches the way it is processed at retrieval. Cues also make for better recall. Free recall is the hardest, cued recall helps and recognition is the easiest.

Describe the concept of a consolidation period, and discuss how ECT affects it

A consolidation period is the length of time during which new episodic and semantic memories are vulnerable and easily lost or altered; each time a memory is recalled, it may become vulnerable again until it has been "reconsolidated." If a electroconvulsive shock is given newer memories are at risk of being lost while older memories are relatively unaffected.

Consolidation

A hypothetical process involving the gradual conversion of information into durable memory codes stored in long-term memory

Describe the relationship between episodic and semantic memories (how the formation of each might depend on the other) and the effect of repeated exposure and memory strength for each type

Current research points to the idea that semantic memory represents information we have encountered repeatedly often enough that the actual learning episodes are blurred and only the semantic memory remains. Similarly you can be told stories about experiences as a baby but those are still semantic memory because it is not your memory of the event. Repeated exposure can help to build stronger semantic memory where as repeated exposure to similar stimuli can weaken episodic memory.

Basal forbrain in declarative memory

Damage to the basal forbrain can lead to amnesia because a group of cells called the medial septum in it produce neurotransmitters acetylcholine and GABA. Axons from the medial septum project to the hippocampus and may help to determine whether and when the hippocampus will process and store information.

*Compare and contrast declarative (explicit) and non-declarative (implicit) memories

Declarative memory is a broad class of memories, both semantic and episodic, that can typically be verbalized/declared or explicitly communicated in some other way. Nondeclarative memory is a broad class of memory that includes skill memory and other types of learning that do not fall under either episodic or semantic memory categories and that are not always consciously accessible or easy to verbalize.

Describe the roles of different subdivisions of the prefrontal cortex in different working memory functions and interactions with declarative memory processes

Dorsolateral PFC: central executive Left Ventrolateral PFC: phonological loop; anterior= semantic information, posterior= phonological information Left posterior cortical speech and language areas: verbal information Right ventrolateral PFC: visuospatial sketchpad Right posterior cortical visual areas: object and location information

Compare and contrast episodic memories and semantic memories (see table)

Episodic memory is event related "I remember" and semantic memory is factual "I know." Both can be communicated flexibly in a formate other than that which it was acquired and are consciously. Episodic memory is attached to spatial and temporal context while semantic is not necessarily. Episodic memory has to be experienced personally while semantic memory can be personal or general information. Episodic memory is learned in a single exposure and can be weakened by exposure to similar events while semantic memory can be learned in a single exposure but can also be strengthened by repetition.

*Describe and provide examples of the way memory might fail: false memories

False memory for events that never actually happened. For example after eating out with friends they ask if you remember the argument at the table next to you and you can explain the whole thing when in reality this did not happen.

H. M. Case Study: brain damage, impaired abilities, and preserved abilities

H. M.'s medial temporal lobes were surgically removed bilaterally to prevent severe seizures. He could no longer form new memories for facts and events, remember what he had eaten for breakfast or why he was in the hospital. He was told his favorite uncle died experienced intense grief but then later told again would have the same reaction. His personality remained the same and his IQ actually went up. As long as he paid attention to a task he could perform well but as soon as he sifted his focus he would completely forget.

Explain the role of the prefrontal cortex in declarative memory encoding and retrieval

Helps determine what information we store and what information we forget. Areas of the prefrontal cortex were more active when the participant was actively trying to forget then when tryin to remember. One possible explanation is that certain areas of the prefrontal cortex inhibit the hippocampus. The frontal cortex may also help us bind contextual information to event memory.

Briefly explain the relationship between working memory and measures of intelligence

Intelligence is defined as the capacity for learning, reasoning, and understanding. It has less to do with the brain's processing speed and more to do with executive control of working memory. General intelligence seems to be associated with a strong working memory.

*Describe and provide examples of the way memory might fail: proactive and retroactive interference

Interference is the reduction in the strength of a memory due to overlap with the content of other memories. Proactive interference is disruption of new learning by previously stored information. For example when learning a new language you might forget the word in that language but remember it in your native language. Retroactive interference is the disruption of old previously stored information by more recent learning. For example trying to remember your childhood street address but only coming up with your current one.

Describe Sperling's classic study of iconic memory using the partial report technique

Participants were shown a card with three rows of letters. When asked to recall after looking they could only come up with 4 or 5 letters. Sperling then showed the card and when it was removed played a tone to indicate saying the 1,2, or 3 row participants were then able to report about 75% of the letters all over.

Describe common behavioral and cognitive consequences of damage to the prefrontal cortex, with case studies.

Phineas Gage had damage to his prefrontal cortex which caused behavioral changes such as profanity, impatience, inability to stay on task, and general change in personality. This kind of damage can also cause poor memory updating, poor planning, poor task switching, and poor overall IQ.

Describe basic findings of research on semantic and episodic memory in nonhuman animals

Radial arm maze: can be used to test rat's semantic memory; place the rat in the start arm and food in the goal arm and then over trials the rat learns which is the goal arm Gorilla communication: King the gorilla was taught fruits and humans with cards then throughout the day he was given different fruit by different humans 24 hours later he could match the humans and fruit from the day before signaling episodic memory Scrub jays: they know where they have hidden food and were permitted to go back to the food hours or days later they usually prefer worms over nuts and go for them first but after days the worms would rot so they went for the nuts first again showing episodic memory

Briefly describe how semantic memories may be stored in a distributed fashion throughout the cerebral cortex, including the role of sensory and association cortex and category-specific areas. Describe evidence of a semantic memory "hub" from semantic dementia and indicate its location.

Some areas if the cerebral cortex specialize in processing specific kinds of sensory information; these include the somatosensory cortex, visual cortex and the auditory cortex. Many of the remaining cortical areas are association areas of the cerebral cortex involved in associating information within and across sensory modalities. Semantic dementia is the progressive degeneration of left anterior temporal lobe which is the semantic hub linking sensory and category-specific cortical areas.

*Describe and provide examples of the way memory might fail: source memory errors and cryptomnesia

Source monitoring error is remembering information but being mistaken about the specific episode that is the source of the memory. For example hearing from a friend about what's going on in the news but thinking you read it in a newspaper. Cryptomnesia is remembering someone else's ideas as one's own. An example of this is when a musician comes up with an idea for a song and later finds out that song already exists. The source of the memory was not his own brain rather he heard it on the radio.

*Explain the roles of the lateral prefrontal cortex and more posterior cortical regions to working memory

The DLPFC is a critical brain region supporting the maintenance of items in the working memory. The top-down signals from the DLPFC might enhance and maintain internal representations of relevant sensory stimuli in different posterior sensory and motor center until those representations are required for subsequent actions and decisions.

*Define the Ribot gradient and explain how standard consolidation theory and multiple memory trace (MTT) theory account for consolidation and the Ribot gradient

The Ribot gradient is a pattern of retrograde memory loss in which recently acquired memories are more prone to disruption than older memories. Standard consolidation theory is the theory that the hippocampus and related medial temporal lobe structures are required for storage and retrieval of recent episodic and semantic memories but not older ones. Multiple trace theory is the theory that episodic memories are encoded by an ensemble of hippocampal and cortical neurons and that both the hippocampus and cortex are normally involved in storing and retrieving even very old memories. Over time after many retrivals the episodic content becomes blurred but the rich semantic content remains stored in the cortex independent of the hippocampus.

*Describe the gradient of abstract-to-concrete goals in lateral prefrontal cortex

The gradient of abstraction from general plans and goals to more specific action plans follows a physical gradient beginning at the front of the frontal lobes and moving back.

*Describe the role of the medial temporal lobes in declarative memory, using examples from human neuropsychology, animal lesions (non-match to sample task with long delay, radial arm maze, scrub jays) and fMRI (subsequent memory, depth of processing, and false memory effects)

The most studied role of the human hippocampus is the storage of new declarative memories and the most obvious impairment in humans with damage to the medial temporal lobe is the loss of this function. H.M.'s inability to form new declarative memories is an example of this. Researchers can use fMRI to look at the hippocampus during learning and recall. When a participant could correctly recall something the activation looked similar to encoding but when they could not the activation looked much less similar. Hippocampal-region lesions in rats and scrub jays caused them to be unable to find the food even after practice indicating there was no episodic memory.

Show that the prefrontal cortex is important in working memory function with evidence from anatomy, neuropsychology, neural recordings, and fMRI activity

The prefrontal cortex helps us to remember the source of the information. It also might be "holding in mind" information needed to make a later response.

Describe superior autobiographical memory

There are a handful of people who have this memory. They can remember everything from every day of their life and can access it readily.

*Define and describe the three components of working memory, according to Baddeley's tripartite model

This model consists of two material-specific temporary stores for short-term maintenance of information; a visuospatial sketchpad for object and location information and a phonological loop for verbal material, that are controlled by a central executive. it also distinguishes between two general processes of working memory: maintenance and manipulation.

Compare and contrast characteristics of the three basic memory components of Atkinson and Shiffrin's modal model of memory and describe their interactions

This model depicts incoming information as flowing first into sensory memory-shown as having distinct visual , auditory, and haptic and other sensory registers. Elements of sensory information that are attended to are then transitioned to short-term memory. There they go through various control processes and in some cases are transferred into long-term memory.

Describe, compare, and contrast transient global amnesia and functional amnesia (e.g., probable causes, memory impairments)

Transient global amnesia is a temporary disruption of the memory including elements of both anterograde and retrograde amnesia. It can be caused by an apparent precipitating event such as vigorous exercise or emotional stress that might have affected the flow of blood to the brain. Functional amnesia is a sudden retrograde memory loss that seems to result from psychological causes rather than physical causes such as brain injury. Some cases involve memory lose of a traumatic event but others lose all memory of their identity.

Retrieval

the process of bringing to mind information that has been previously encoded and stored

Encoding

the processing of information into the memory system—for example, by extracting meaning