310 Ch 7 Episodic and Semantic Memory

association cortex

other cortical areas - meaning they are involved in associating information within and across modalities - helps us link the words dog with the visual image of a dog and with semantic information about what dogs are like and linguistic information about how to pronounce and recognize the spoken word itself

metamemory

our knowledge of, and ability to think about, our own memories

typing in an old password

proactive interference

transient global amnesia

transient or temporary disruption of memory

Proactive interference

where old information can disrupt new learning

Depth of processing effect

Deeper processing at encoding of new information improves the ability to remember that information later

Source amnesia

Occurs when we remember information but cannot remember the source at all

Creating false memories in the lab

Researchers pasted childhood pictures of adult participants into a photograph of a hot air balloon ride. When prompted to recall details for he trip, about half the participants claimed they could remember the episode - even though none had ever been in a hot air balloon

free recall

Simply asked an open ended question and you supply the answer from memory

amnesia

memory loss

anterograde amnesia

patients lose the ability to form memories for events that occurred after the injury

memories

the facts we know and the autobiographic events we remember

Shared features of semantic and episodic memory

- Can be communicated flexibly, in different formats than the one in which they were originally acquired - Both consciously accessible

Are there different brain substrates for episodic and semantic memory?

- hippocampus is critical for the acquisition of new autobiographical or episodic information but not for new semantic information - Semantic learning depends on medial temporal areas, including the entorhintal cortex and perirhinal cortex

Sensory agnosias

- some are caused by damage to the corresponding areas of sensory cortex

Anterograde amnesia

A severe loss of the ability to form new episodic and semantic memories

Functional amnesia

A sudden, massive retrograde memory loss that seems to result from psychological causes, in contrast to organic amnesia, which arises from obvious physical causes, such as brain injury - lose memory for specific episodes in their lives or may even lose their identity. This very rare form of amnesia seems to result from psychological trauma rather than any physical cause

Consolidation period

A time window during which new memories are vulnerable and easily lost

The radial arm maze experiment

After many trials in which the rat is allowed to explore the maze until it finds food located at the end of the "goal arm", it will eventually learn to run straight to the goal arm, indicating it has semantic memory for where the food is located in the maze

Electroconvulsive therapy

Electroconvulsive shock is administered to provide temporary relief from certain kinds of mental illness, particularly severe depression.

Multiple trace theory

Episodic memories are encoded by an ensemble of hippocampal and cortical networks, and the cortical networks never, in normal circumstances, become fully independent of the hippocampal networks. In this view, individuals with hippocampal damage effectively lose all their episodic memories.

Associative visual agnosia

Have difficulty recognizing and naming objects, even though they an see the objects. If shown a pen or cup, may be unable to name it or say what it is used for, though she may be able to name the object based on feel if it is placed in her hand

retrograde amnesia

Loss of memories for events that occurred before the injury.

Tactile agnosia

May be able to recognize an object by sight or description but not by feel.

Semantic memories

Memories for facts and general knowledge about the world, as well as for personal information such as your own name and your favourite food - it is not tagged in time and space

False memoreis

Memories of events that never actually happened

Successful retrieving is governed by two key principles:

Memory retrieval is better when study and test conditions match More cues mean better recall

Three basic principles that govern how successfully a new episodic or semantic memory is encoded, or stored in memory

Mere exposure to information does not guarantee memory Memory is better for information that relates to prior knowledge Deeper processing at encoding improves recognition later

Passive forgetting

Occurs as a function of time: older information is more likely to be forgotten than more recently acquired information. Here, people tested in the 1980s could correctly recognize the names of more TV shows that had aired in the prior year than of shows that had aired a decade previously

Direct forgetting

Occurs when information is forgotten on demand

Two kinds of forgetting

Passive forgetting and directed forgetting

Anterograde amnesia in patient E.P

Shown a complex picture, a healthy control participant can generally copy it accurately and can do a reasonably good job if asked to draw the figure form memory 15 minutes later. Patient E.P could also copy the drawing well but asked to draw it form memory after the delay, he had essentially forgotten everything about it.

The medial temporal lobe in humans

The medial portion of the temporal lobe contains the hippocampus, the amygdala, and several other cortical areas. Damage limited to the hippocampus was sufficient to disrupt memory.

Cued recall

You are given some kind of promote or clue to the correct answer

Recognition

You pick out the correct answer from a list of possible options

hippocampus

a brain structure located in the medial temporal lobe that is important for new memory formation

Basal forebrain

a collection of structures that lie at the base of the forebrain - includes nucleus basal is and medial septal nuclei, which contain neurson that produce the neuromodulator acetylcholine and distribute it throughout the brain

Damage to basal forebrain, the dienecephalon, or the fornix can result in __

amnesia

diencephalon

area near the core of the brain just above the brainstem - includes the thalamus, hypothalamus, mammillary bodies

Memory retrieval is better when study and test conditions match

- Deep processing during encoding may help only if the test requires deep processing. If the test instead involves the physical attributes or sounds of a word, superficial processing may be preferable - Physical context on memory retrieval is important - recall is slightly better if the retrieval conditions are similar to the encoding conditions - No effect on performance when finals were administered in the same room where the course had been taught or in a novel classroom

What distinguishes episodic from semantic memory?ea form which several arms branch off like the spokes of a wheel. The toy of the ma

- Episodic memoreis concern specific events that occurred at a particular place and time - Semantic memories involve factual information: you do not need to remember where and when you learn this information - Episodic memory is always autobiographical: it must have happened to you - Semantic memory can be personal or general factual information - Episodic memory is acquired in a single exposure: the event itself - Semantic memories can be acquired in a single exposure too, particularly if the information is sufficiently interesting or important. But, it weight take you several exposures to memorize a fact. - Repeated exposures can strengthen semantic memory, but repeated exposure to very similar events may weaken episodic memory

Electroconvulsive shock training with rats

- If shock given 20 seconds after the end of training, the rats' memory of the conditioned response was severely disrupted - If the shock was given an hour or more after training, there was little disruption - Intermediate delays produced intermediate levels of disruption - The consolidation period for this type of learning in rats appears to extend for a few minutes; older memories are relatively stable and difficult to disrupt; more recent memories are highly vulnerable to disruption

The medial temporal lobes and memory storage

- Medial temporal lobes in humans contain the hippocampus, the amygdala, and nearby cortical areas, including the entorhinal cortex and peripheral cortex - most widely studied role of hippocampus is in storage of new episodic and semantic memory

Mere exposure to information does not guarantee memory

- Sheer repetition of either verbal or visual information isn't enough to ensure its being remembered.

Passive forgetting curves

- Suggest that if you can still remember a fact or event after a few months,t hen the odds are good that you'll remember it permanently (or at least for a very long time)

Korsakoff's disease and the diencephalon

- consistently damages two areas of the diencephalon: the mammillary bodies and part of the thalamus - develop same kind of anterograde amnesia and time graded retrograde amnesia observed in HM - may confabulate

Animals with broad lesions of the hippocampal region

- difficulty learning new information - impaired at episodic-like learning that involves memory of unique events set in a particular scene

More cues mean better recall

- free recall is harder than cued recall, which in turn is harder than recognition.

Memory is better for information that relates to prior knowledge

- new information is easier to remember if you can relate it to things you already know

Individuals with frontal cortex damage

- prone to source amnesia - an inability to remember where and when an event occurred

TGA

- starts suddenly, persists for several hours, and then gradually dissipates over the course of a d ay or so - during amnesic episode, shows severe anterograde amnesia, some degree of retrograde amnesia for events that occurred within the preceding decade or so

Electroconvulsive shock

A brief pulse of electricity passed through the brain via electrodes on each side of the head

declarative memory

A broad class of memories, both semantic and episodic, that can typically be verbalized or explicitly communicated in some other way

nondeclarative memory

A broad class of memory hat includes skill memory and other types of learning that do not fall under the heading of episodic or semantic memory and that are not always consciously accessible or easy to verbalize

explicit memory

A category of memory that includes semantic memory and episodic memory and consists of memories of which the person is aware: you know that you know the information

Korsakoff's disease

A condition caused by a deficiency in thiamine that sometimes accompanies chronic alcohol abuse

Retrograde and anterograde amnesia

A healthy adult may be able to recall most of what happened today and will recall progressively less about events that happened weeks, months, years ago. In contrast, a persons tin bilateral hippocampal damage may suffer anterograde amnesia, a loss of the ability to form new episodic and semantic memories since the injury, as well as retrograde amnesia, or emery loss for events that occurred days or weeks before the injury. If the brain damage extends beyond the hippocampus into nearby cortex, retrograde amnesia may be much more severe and may extend back for decades longer

Category sensitive neurons in the human brain

A patient with electrodes implanted in the right hippocampus was shown photos of famous celebrities and landmarks. Great response of the neuron to pictures of Steve Carell but not to photos of other celebrities such as Bill Clinton or Whoopi Goldberg

The standard consolidation theory

An episodic memory consists of many components, such as sight, sound, texture, and other features, stored ins sensory and association cortex. Initially, the hippocampal region helps link these components into single episodic memory. Over time, the components become linked to one another directly, and hippocampal involvement is no longer required

The effects of organization on memory

An experimenter read aloud to participants a short story describing scene. Participants who heard the paragraph alone (no picture) recalled a few items, but participants who saw the picture in and then heard the paragraph (picture before story) recalled more items. Participants who saw the picture only after hearing the paragraph performed no better than those who had never seen the picture

Effects of ECT on memory

Before ECT, patients with depression show a forgetting curve similar to that of non depressed adults. After the patients undergo ECT, retrieval of recent memories is temporarily disrupted. Many of the disrupted episodic and semantic memories return with time. Only the memories for a short period before and after the ECT are gone forever

The subsequent memory paradigm

Brain imaging (fMRI) records activity while participants make categorization judgements on a series of words. Later, participants are given a recognition test; typically, they correctly recognize some but not all of the previously viewed words. Some areas of the brain, including the left medial temporal lobe and left prefrontal cortex, are more active during initial viewing of words that will subsequently be remembered compared with initial viewing of words that will subsequently be forgotten

implicit memory

Memory that occurs without the learner's awareness

Directed forgetting

Occurs when we intentionally try to suppress memory. Here, participants' memory was worse for studied word pairs they and been instructed to forget than for pairs they'd been instructed to remember or control pairs they hadn't seen since the original study phase

Misattribution

Occurs when we remember information but mistakenly associate it with an incorrect source

What does the ability to form new facts and even memories depend on?

On the medial temporal lobes, but many other kinds of memory and cognitive function do not

The depth of processing effect

Participants were shown words and asked either to generate a mental image of a place described by the word (image condition) or to imagine pronouncing the word backwards (pronounce condition) Laater when shown a second list and asked whether or not each word had been previously viewed, participants recognized many more words from the "image" condition than from the "pronounce" condition. fMRI scans conducted during the encoding phase of this task revealed several brain areas that were significantly more active during the "image" condition than during the "pronounce" condition

False memory for studied words

People were first asked to learn lists of words organized around an unstated theme (sweet). Later, participants were generally accurate at recognizing the studied words and at rejecting (failing to recognize) novel, unrelated words. But they would also claim to recognize the unstudied theme words

Frontal cortex

Regions of cortex that lie within the frontal lobes, may help determine what information we store (and remember) and what information we don't store (and therefore forget)

Transfer-appropriate processing effect

Retrieval is more likely to be successful if the cues available at recall are similar to those that were available at encoding E.g. if you are initially shown a series of pictures of objects and then later are given a recognition test in which some of the objects are presented as pictures and some as words, most people show better recognition if the format is the same at encoding as at testing: if objects presented as words are tested as words, and objects presented as pictures are tested as pictures

Episodic like memory in birds

Scrub jays were permitted to cache worms and nuts int eh compartments of sand filled ice cube trays. Four hours later, the birds tended to dig int he compartments where they had buried worms (their favourite food) But after a delay of 124 hours, during which time the worms would have rotted, the birds went after the nuts instead. This suggests that the birds remembered what they had buried where and how long ago - an episodic like memory

agnosia

Selective disruption of the ability to process a particular kind of semantic information

Different regions of the cerebral cortex that are specialized to process particular kinds of sensory information

Somatosensory cortex in the parietal lobe Visual cortex in the occipital lobe Auditory cortex in the temporal lobe

Semantic memory and the cerebral cortex

Some areas of the cerebral cortex specialize in processing specific kinds of sensory information; these include areas in the parietal lobe, occipital lobe, and superior temporal lobe. Many of the remaining cortical areas are association areas that link information within and across modalities, forming a basic substrate for semantic information

Standard consolidation theory

The hippocampus and related medial temporal lobe structures are required for the initial storage and retrieval of an episodic memory but that their contribution diminishes over time until the cortex is capable of retrieving the memory without hippocampal help

Auditory agnosia for speech

They can hear sounds and echo them, but they are unable to understand the meaning of spoken words, though they can often recognize written words

cryptomnesia

When a person mistakenly thinks that his thoughts are novel or original when he's actually remembering information he learned from somewhere else

confabulation

When questioned about past events, many individuals with basal forebrain damage will respond with highly detailed but false memories

Interference

When two memories overlap in content, the strength of either or both memories may be reduced

radial arm maze

a maze with a central area from which several arms branch off like the spokes of a wheel. The top of the maze is open so that a rat placed in the maze can see out and use landmarks in the room, such as the placement of windows or posters, to help navigate

Episodic memory

a memory for a specific autobiographical event - includes information about the spatial and temporal context: where and when the event occurred

Why could basal forebrain damage lead to amnesia?

although the hippocampus is undamaged, it can't work effectively without neuromodulation from the basal forebrain telling it when to store new information

fornix

arch like fiber bundle in the basal forebrain and diencephalon

Thalamus

consists of several nuclei, many of which help relay sensory information from sensory receptors to the appropriate areas of sensory cortex

sensory cortex

cortical areas that specialize in one kind of sensory information

Directed forgetting

fMRI images show the hippocampus to be less active while people were actively truing to forget than while they were actively trying to remember. Several prefrontal areas, however, were more active while participants were trying to forget

hypothalamus

important role in regulating involuntary functions such as heartbeat, appetite, temperature control, and the wake/sleep cycle

trouble remembering old password when you just recently change it to a new one

retroactive interference

Ribot gradient

retrograde memory loss is worse for events that occurred shortly before the injury than for events that occurred in the distant past

mnemonics

techniques that make information easier to memorize - using acronyms, rhymes, etc

medial temporal lobes

the inner or medical surfaces of the temporal lobes, which contain the hippocampus, the amygdala, and several nearby cortical areas

temporary failure of memory

the memory is inaccessible at the moment but may resurface later tip of the tongue phenomenon

dissociative fugue

type of functional amnesia patients lose all memory of their identity

dissociative amnesia

type of functional amnesia patients lose memory of a specific, traumatic event

Retroactive interference

where new information can disrupt old learning