Cognition and Cognitive neuroscience (year two)

Question 1

Briefly describe the anatomy of the brain

Answer 1

• 52 brodmann areas
• Frontal lobe- planning, problem sowing
• Temporal lobe- language comprehension, auditory memory and emotions
• Occipital lobe: Visual perception and object representation
• Parietal Lobe: sensation, attention orienting, body position.
• Basal ganglia: coordination of messages between different areas.
• Brain stem: physiological basic body functions (e.g. digestion, breathing)
• Cerebellum: coordination and control of voluntary movements and balance

Question 2

describe the two types of electrophysiological methods

Answer 2

• • Non-invasive
• brain activity
• EEG/ MEG
• Somatic nervous system activity - muscle tension, eye movements
• Autonomic nervous system energy - skin conduction, cardiovascular activity
• invasive
• Invasive EEG recording (electrocorticogram, ECOG)
• Single-Cell & Multi-Cell recording

Question 3

Describe the basic structure and function of neurons

Answer 3

• Neurons behave like electric dipoles
• this an Creates electric field along the dipole which allows the current to be conducted
• this in turn creates a magnetic field around the dipole

Question 4

Give a brief overview of the history, function and uses of EEG

Answer 4

• 1924: Hans Berger developed the electroencephalograph to record brain waves
• Modern systems use soft caps
• EEG measures the summation of electr(ochem)ical activity on the scalp over time by means of recording-electrodes attached to the surface of the scalp.
• provides useful overview of electrical activity
• Diagnostic uses: brain damage, neurological conditions e.g epilepsy

Question 5

Give the different types of brainwaves observed on an EEG

Answer 5

• Gamma waves: Hyper brain activity - learning
• Beta waves: high brain activity (conversation)
• Alpha waves: Initial brain relaxation
• Theta waves: Drifting down into sleep
• Delta waves: Deep non-dreaming sleep

Question 6

describee the structure and function of alpha waves

Answer 6

• Alpha waves:
Regular – Synchronous
8-12 Hz,
high amplitude

Synchronisation of alpha activity Indicates relaxed wakefulness

Question 7

describe WHAT EEG measures and from what neurons

Answer 7

• EEG measures the post-synaptic activity around the dendrites of pyramidal neurons in the cerebral cortex
• EEG electrode sums up the electrical potentials occurring from many thousands of brain cells
• Axons from neighbouring neurons synapse with the pyramidal neurons, triggering a local depolarisation: POSTSYNAPTIC POTENTIALS (PSPs)

• EEG detects the summation of electrical current of the dipoles created by hundred of thousand of pyramidal cells

Question 8

Describe the structure and function of pyramidal cells

Answer 8

• Pyramidal ‘ cells are distributed and spatially aligned in the most superficial layers of the cortex
• Pyramidal cells in layers 3, 4, 5 and 6 are the generators of EEG and MEG signals
• Layers 1, 2 contain the dendrites of the pyramid cells
• the EEG sources are the slow post-synaptic signals generated in these layers
• Their activity is synchronous; this produces a large signals that can be detected from the scalp

Question 9

describe how EEGs are undertaken

Answer 9

• Internationally standardised 10-20 system
• Electrodes on EEG cap positioned in specific locations
• EEG recordings translated into line tracings- ie brain waves
EEG signal is always a relative measure lie a difference in potential between one electrode and another electrode used as a reference

Question 10

Describe the function and process of ERPs

Answer 10

• Responce measured in relation to a specific event leg sensory cognitive or motor stimulus/task
• fundamental element for a clean and reliable ERP response is averaging signals from many trials and many participants
• ERPs provide excellent
• temporal resolution - can study fast cortical processes
• ERP waveforms are Characterised by: .
• Amplitude
• latency
• scalp distribution

Question 11

Describe the function and process of ERPs

Answer 11

• Responce measured in relation to a specific event leg sensory cognitive or motor stimulus/task
• fundamental element for a clean and reliable ERP response is averaging signals from many trials and many participants
• ERPs provide excellent
• temporal resolution - can study fast cortical processes
• ERP waveforms are Characterised by: .
• Amplitude
• latency
• scalp distribution

Question 12

describe time frequency analysis

Answer 12

• Visual onsets generate a reduction in occipital alpha power (8-10hz)
• Termed event related desynchronisation

Question 13

describe psychophysiological techniques

Answer 13

Electromyography (EMG)
• Detects electrical potential of the muscle cell (membrane potential is
• 90mV)
• Electroculography (EOG)
• Electrodes are placed near the eyes and record the membrane potential of the retina
• Skin conductance response (SCR)
• Change in the electrical properties of the skin, associated mainly with sweat gland activity.
• Elicited by stimuli that cause (emotional) arousal.
• Electrocardiography (ECG)
• Measure of heartbeat.
• Average heart rate of healthy adult is 70 beats per minute.

Question 14

Magnetoencephalography

Answer 14

• Detects electromagnetic field generated by the neurons’ electrical activity
• super - conducting quantum interference device (SQUID sensors) allow recording of the small neuromagnetic signals generated in the brain
• Can see almost all of cortex, fissural activity emphasized
• Signal unaffected by skull, meninges
• Detects only tangential dipoles - fissural activity emphasized
• High temporal resolution
• Good spatial resolution ( combined with MR1)
• Very expensive and limited availability

Question 15

describe the differences between strcutural and functional imaging

Answer 15

• Structural imaging
• To explore brain Structure and changes in it (e.g contrast x-ray, computed tomography, magnetic resonance)
• Different types of tissues have different physical properties , which are exploited to create static maps of brain structure
• Functional imaging
• To explore brain cognitive (dis-)functioning (e.g. functional Magnetic Resonance, Positron Emission Tomography)
• Neural activity produces physiological changes on site, which are used to create dynamic maps of the moment-to-moment activity of the brain.

Question 16

give a brief overview of x-ray computed tomography

Answer 16

• Amount of X-ray a tissue can absorb is exploited
• Bones absorb most x-rays 1=white)
• Cerebrospinal fluid absorbs the least Cerebrospinal fluid absorbs the least (= black)
• Gray/white matter are intermediate ( = gray)
• Multiple x-ray tubes shot x-rays from many angles which are reached by detectors on the opposite site. These rotate around the head on the same horizontal plane. A computer combines the readings to create an image of a horizontal slice of the brain.
• Then both tubes and detectors move rostrally along the vertical axis of the body. The cyle repeats until the whole brain has been imaged.

Question 17

explain how CT scans work

Answer 17

• The amount of water (H2O H+ OH-) in each tissue exploited
• Different tissues contain different amount of water. The single protons (H+) in the water have magnetic fields, which are randomly oriented.
• When a strong magnetic field is applied from the scan (constantly), the magnetic fields of protons align with it.
• At this point a brief radio-wave pulse is applied, and the orientation of the protons is knocked by 90 degrees.
• As the protons spin (precess) in the new state, they produce the detectable signal.
• The protons are eventually pulled back to the original state of alignment with the magnetic field (relaxation)

Question 18

describe the process of MRI scans

Answer 18

1. H+ Protons in tissues’ water with randomly orientated fields
2. External magnetic field applied
3. H+ magnetic fields align
4. Radio frequency coil generates brief radio wave pulse. H+ orientation is knocked by 90’
5. Protons are pulled back - relaxation time of decay of signal (T1 and T2 relaxation time)

Question 19

describe functional neuroimaging

Answer 19

• Reflects energy metabolism
• Neural activity requires a lot of energy / which needs to be metabolised
• Energy metabolism: Rate at which neurons produce and consume ATP

• ATP production in neurons requires GLUCOSE and OXYGEN uptake from the blood.

Question 20

describe how PET scans wrk

Answer 20

• Exploits high uptake of biologic molecules (glucose) by metabolically active neuronal cells.
• A carrier molecule (eg deoxyglucose) is combined with a radioisotope (e.g. 18-Fluoro[F]), which is an unstable radionuclide
• Radionuclide: It is a radioactive atom, also called RADIO- ISOTOPE.
• Unstable ratio neutron/proton in the nucleus (too many neutrons or too many protons).
• RADIOACTIVE DECAY: spontaneously going back to stable state by throwing particles in the space = releases positrons
• This tracer is injected in the blood stream and can be absorbed by tissues (≠ molecules: ≠ tissues).
• Once the tracer is inside the cell, it undergoes radioactive decays (releases positrons).
• Each positron interacts with an electron in the surrounding cell milieu. This interaction (= collision) causes annihilation of both particles, releasing two photons that speed off in opposite directions.
• Produces gamma rays detectable by the PET machine

Question 21

describe how functional MRIs work

Answer 21

• Oxygen consumption during high metabolic activity exploited
• when neurons are active, there is an increase in oxygenated blood supply
• The active areas take up more oxygenated hemoglobin than they need for their energy requirements.
• There is thus greater proportion of oxygenated hemoglobin to deoxygenated hemoglobin in active areas.
• fMRI detects differences in magnetic properties between oxygenated and deoxygenated blood.
• Deoxyhemoglobin normally creates magnetic inhomogeneity (this alters the relaxation time of nearby H+ protons).
• In active areas there is more oxygenated hemoglobin which restore a more homogenous magnetic field. This results in a longer T2 relaxation time and brighter signal in active areas.

Question 22

describe thee process of TMS

Answer 22

• TMS disrupts activity in a brain area by creating a magnetic field under a coil, placed over the targeted area.
• A large electrical field is passed through the coil, and generates magnetic pulse that passes through the skull.
• Magnetic fields induce electrical activity in the target area, and affect its normal function.

Question 23

Describe the advantages of TMS over lesion and neuroimaging studies

Answer 23

Advantages over Lesions:
• In real damaged brain, reorganization and compensatory strategies may have developed.
• No problem of too difficult tasks for patients
• It recruits general population (often the number of patients with a similar lesion is low)
Advantages over Neuroimaging:
• Does not investigate mere correlations, but causal relations.
• Allows investigation on timing of cognitive functions,
• Allows investigation on the necessity of a brain area
• Allows investigation on dynamic connectivity between areas

Question 24

Describe the case of HM

Answer 24

• 19 years old
• severe epilepsy from motor accident
• source (locus) of abnormal electrical activity (seizures) was in temporal lobes
• Scoville’s approach: cut portions of right/left medial temporal lobes to stop seizures
• Operated on in 1953 - was successful, seizures stopped
• Developed severe memory problems affecting verbal/ non-verbal info, other cognitive abilities were normal
• Main issues were retaining new info more than seconds/minutes
• Memories up to 3 years prior to surgery were intact
• Short term memory (digit span test) also normal and could obtain new skills
• Bilateral medial lobe surgery can no longer be performed

Question 25

Describe the importance of the HM case

Answer 25

• First of its kind
• Well documented
• Specific lesions/impairments
• Described by Scoville
• Surgical removal not the result of pathological conditions that may cause additional/widespread damage
• Lashley: memories are widely distributed throughout the cortex
• Milner’s later work of patients with unilateral MTL (mediotemporal lobes) lobeectomies revealed content specific memory deficits
• Left MTL responsible for verbal memories
• Right MTL responsible for pictorial and spatial memories

Question 26

GIve some potential causes of amnesia

Answer 26

• HM: A “pure” form of organic amnesia
• Many other conditions produce amnesia or less severe memory impairments:
• Anoxic or ischaemic episodes (e.g. cardiac arrest, brain aneurysms, strokes)
• Progressive disorders such as dementias (e.g. Alzheimer’s disease)
• Chronic alcoholism (e.g. Korsakoff’s syndrome) related to thiamine (Vitamin B1) deficiency (usually due to poor diet)
• Viral or bacterial infections of the brain (e.g. meningitis, herpes simplex encephalitis)
• Brain tumours
• Closed or penetrating head injury (accident or surgical intervention)

Question 27

Describe the areas of damage in amnesia

Answer 27

• The medial temporal lobes
• Hippocampus
• Adjacent cortical areas (parahippocampal cortex, perirhinal cortex)
• Thalamus
• Anterior and dorsomedial nuclei
• Fornix & Mammillary bodies
• Basal forebrain
• Interconnected structures

Question 28

What is impaired in organic amnesia?

Answer 28

• Anterograde amnesia: Impaired memory for events and facts experienced after the onset of amnesia
• Patients can vary from mild to severe
• Retrograde amnesia: Impaired memory for event and facts learned before the onset of amnesia
• Can cover an extensive or very short period of time

Question 29

what is preserved in organic amnesia?

Answer 29

• Intelligence, perception, attention, language all seem to be fine across amnesics
• But depending on aetiology and extent of brain damage some patients might have additional problems
• Some forms of learning and memory
• New skills, classical conditioning and intact priming
• Short–term and Working memory
• Can retain and process a small amount of information for a brief period of time (e.g. digit span task) and can manipulate information.

Question 30

describe the organisation of long-term memory

Answer 30

• Memory is related but distinct from information processing
• You can be intelligent and amnesic
• Long-term memory is not a unitary structure
• There are multiple forms/expressions of LTM that are anatomically dissociable
• New classification of long-term memories
• Explicit/direct/declarative/knowing what vs implicit/indirect/non-declarative/procedural/knowing how

Question 31

describe explicit memories

Answer 31

• What we usually regard as memory
• Conscious retrieval of information (tests of recall and recognition)
• Depend on structures damaged in amnesia (MTL, diencephalon, basal forebrain)

Question 32

describe implicit (non-declarative) memories)

Answer 32

• Assessed by changes in behaviour (more accurate, faster, treating items we have experienced differently to new items)
• Do not require consciousness
• Cannot be accessed or manipulated directly (i.e. cannot memorise, cannot recall riding a bike)
• Involve structures not damaged in amnesia
• Different forms of implicit memory will rely on different structures

Question 33

describe the process of skill learning

Answer 33

• Probabilistic learning
• Learning to associate specific combos of cards with a specific outcome
• People with damage to basal ganglia like patients with Parkinson’s disease are impaired in this task.
• The same areas are more active when the task is implicit (i.e. no need to memorise the combination-outcome association) and the MTL are inactive.
• When the task is made explicit (people encouraged to remember the combination-outcome association), the pattern of activity reverses.

Question 34

describe the process of priming

Answer 34

• Priming is the facilitation of processing of repeated items.
• A change in the ability to identify or produce an item as a result of a specific prior encounter with the item (or a semantically related item).
• Priming tests do not require conscious recollection of previous experiences unlike tests of recall and recognition.
• One common distinction is between perceptual vs. conceptual priming
• Facilitation due to repetition of form vs. facilitation due to repetition of concept

Question 35

describe priming in amnesia

Answer 35

• Importance of instruction in tapping different forms of memory
• Top graph
• Amnesics would progressively name the word or object at an earlier stage showing some form of memory.
• Bottom graph
• Amnesics would show normal performance in an indirect memory task that asked to complete word stems with the first word that came to mind (more studied words were produced)
• Amnesics were impaired when asked to complete the same stems with words they had seen before at study.

Question 36

describe semantic priming

Answer 36

• An example of a semantic priming task:
• Study: table, guitar, apple, sofa, train
• Test: Write down the first type of fruit that comes to mind
• Priming: People are more likely to say apple when they have just seen apple than if they had not

Question 37

give general facts about priming and the brain

Answer 37

• Priming activity: Primed – Novel (unprimed)
• Priming activity involves a subset of processing areas
• There is no single locus of priming.
• Several different processing stages can be facilitated by repetition (orthographic, phonological, semantic etc.).
• Priming activity is often reduced compared to activity generated by non-primed items
• Primed

Question 38

describe neuroimaging studies of object priming

Answer 38

• Perceptual and conceptual priming depend on partially distinct neural networks.
• Conceptual priming involves an area in the inferior frontal gyrus (dorsal & inferior prefrontal cortex) which has been implicated in semantic processing (A and B on the maps).
• Perceptual priming involves areas in extrastriate cortex, which is also responsible for higher level perceptual analyses (C and D on the maps).
• There is also (some) evidence that when processing in these areas is temporally disturbed (by TMS), priming is impaired.

Question 39

describe theoretical accounts of repetition suppression

Answer 39

• According to one account, repetition suppression is due to a “sharpening” of the underlying representation.
• Over trials, task irrelevant information (represented as white circles) is no longer activated.
• At neurophysiological level that takes the form of reduced neuronal firing whereas behaviourally is represented by reduction in response times (Wiggs & Martin, 1998)
• Another account suggests that repetition suppression is due to lowered thresholds for activating, pre-existing representations.
• According to this account only familiar stimuli with pre-existing representations, can be primed (Henson & Rugg, 2003).

Question 40

describe episodic memory deficits

Answer 40

Episodic memory (Tulving 1983): Memory for events (episodes) which contain additional information about a stimulus such as contextual information (Who, What, When) but can extend to additional associative information.
• Tulving (1983) describes the experience of episodic memory as a uniquely human quality and a form of time travel.
• Semantic memory: Memory for facts, ideas concepts that are not related to a specific experience.
• Semantic memories start initially as components of episodes but then the original episode is forgotten.

Question 41

descibe the creation of new memories

Answer 41

Episodic memory (Tulving 1983): Memory for events (episodes) which contain additional information about a stimulus such as contextual information (Who, What, When) but can extend to additional associative information.
• Tulving (1983) describes the experience of episodic memory as a uniquely human quality and a form of time travel.
• Semantic memory: Memory for facts, ideas concepts that are not related to a specific experience.
• Semantic memories start initially as components of episodes but then the original episode is forgotten.

Question 42

describe functional differentiation models

Answer 42

• The hippocampus supports memory for associations between separate items of information (Eichenbaum et al, 1994).
• Associative, relational processing is impaired. Relational memories can be used flexibly in different contexts (unlike procedural memories).
• Hippocampus links information sources/storage sites creating a flexible representation
• The hippocampus and parts of the diencephalon are involved in episodic memory; perirhinal and other parts of the diencephalon involved in non-episodic memory (Aggleton & Brown, 1999).
• Distinct functional networks within the MTL and diencephalon
• The hippocampus is involved in the binding of item and context information (Diana et al. 2007).
• Perirhinal and parahippocampal cortex deal with item and context, respectively.

Question 43

give evidence of selective episodic memory deficits

Answer 43

• Three young people who suffered hippocampal damage at a young age showed impaired recall memory and memory for new associations despite having IQ scores and semantic knowledge within the normal range (Vargha-Khadem et al. 1997).
• There were impairments in visual recall in the Rey-Osterreith Complex Figure test (see graph on the right ), as well as verbal recall of short stories (graph below).

Question 44

Describe Aggleton & Brown, 1999 model for episodic memory deficits

Answer 44

• Two complimentary behavioural-anatomical systems involving both MTL and diencephalic structures
• Some previous models have attempted to distinguish between MTL and diencephalic amnesia with little success
• The systems involve network of structures
• If one part of network is affected, the network stops working
• The two systems are independent but interacting
• Damage of one system does not stop the other from operating
RECOLLECTION SYSTEM
• Supports the ability to remember episodes (contextual and relational memories similar to previous accounts- e.g. Eichenbaum & Cohen)
• Assessed by tests of recall or tests of recognition that require people to recollect specific details (where, when)
• What did you have for breakfast yesterday?
• Or, present a studied item (recognition) and ask if participants recognise it and if so, if they remember additional information from the study episode
• It involves the hippocampus, anterior thalamus and mammillary bodies
FAMILIARITY SYSTEM
• Mediates our sense of familiarity, the feeling that something has been experienced before in the absence of additional information
• The butcher on the bus
• Assessed in tests of recognition memory
• Present a studied item and ask if participants recognise it and if so, if they remember additional information from the study episode
• Failure to remember additional details suggests familiarity based memory
• More difficult to assess than recollection
• It involves the rhinal cortex (entorhinal and perirhinal), parahippocampal cortex and dorsomedial thalamus

Question 45

describe how to test the episodic memory deficit theory

Answer 45

• Fornix (bridge) connects the hippocampus with the anterior thalamus and mammillary bodies
• Colloid cysts in the 3rd ventricle produce hydrocephalus and can be fatal if they are not removed
• Rare condition/few patients
• Enlargement of the ventricles (as a result of hydrocephalus) or attempts to remove the cyst can sometimes damage the fornix
• Damage to the fornix should disrupt the recollection network but leave the familiarity network unaffected

Question 46

describe the relationship between mammillary bodies and memory

Answer 46

• Mammillary bodies show atrophy following fornix damage

* The size of the mammillary bodies predicts memory performance in colloid cyst surgery patients

Question 47

Compare recall and recognition

Answer 47

• Patients with large mammillary body (LMB) volumes tended to do better at recall (recollection network) than patients with small mammillary body (SMB) volumes
• There was no difference for recognition (which could also be supported-at least partly) by the familiarity network.
• The same patients showed a deficit in recollection but not familiarity when tested at the remember/know task (Vann et al. 2009).
• Patai et al (2015) found similar dissociations between recall and recognition in patients with hippocampal damage due to perinatal complications.
• Hippocampal volume was reduced significantly (see below left).
• IQ, literacy, and numeracy scores were within the normal range but episodic memory (MQ) was impaired (see below right).
But other studies have failed to find similar dissociations.
• Manns and Squire (1999) tested six anoxic hippocampal patients on the Doors and People test and found impairments in both visual and verbal recall and recognition.

Question 48

describe the role of the perirhinal cortex

Answer 48

• Patient NB: resection of parts of the left perirhinal cortex (Bowles et al., 2007)
• Familiarity memory was impaired but recollection memory was not affected
• Taken together with the fornix data, they show a double dissociation between the functional effects of hippocampal and perirhinal damage.

Question 49

describe remote memories

Answer 49

• Ribot’s Law states that in cases of an organic memory deficit, the older the memory the less likely it is to be affected. Older memories ≠ recent.
• A temporally graded retrograde amnesia as in HM

Question 50

describe consolidation

Answer 50

• Some evidence suggests memories undergo changes with the passage of time which make them more resistant to disruption. This is called consolidation or systems consolidation.
• Electroconvulsive Treatment (ECT) for depression shows that patients have problems recollecting memories for events that occurred in the 6 months prior to the treatment but older memories are relatively intact (Fraser et al, 2008).
• But, symptoms could also be related to encoding deficits due to severe depression.
• The rate of forgetting is faster for recent that remote memories. Recent more fragile than remote.
• Some evidence that retroactive interference affects more recent than remote learning.
• Temporally graded retrograde amnesias.

Question 51

define and explain the standard consolidation theory

Answer 51

Squire & Alvarez, 1995)
• Links system consolidation with the hippocampus.
• The hippocampus is involved in encoding of new memories. It is part of the memory engram that involves a network of sites distributed in the neocortex.
• Memories are stored in the neocortical sites and the hippocampus stores an index of these sites. Through the hippocampus we can reactivate (retrieve) the memory.
• The involvement of the hippocampus is time-limited. With the passage of time, connections between the cortical storage sites strengthen. Remote retrieval can be accomplished without the hippocampus’ involvement.
• Damage to the hippocampus should affect recent memories more than remote, with in-between memories showing degrees of impairment proportionate to time since acquisition.
• It will produce a temporal gradient of impairment (temporally graded amnesia) as predicted by Ribot’s law.
• More extensive damage (hippocampus + adjacent cortical areas or frontal cortex) should produce flat gradients because it will affect the actual sites (neocortex) or the search mechanisms (frontal cortex).
• BUT at least two things are unclear:
1. How long does it take for consolidation to complete?
Could it be decades?
2. What is the mechanism by which long-term consolidation is achieved?
Sleep related?

Question 52

describe the multiple trace theory

Answer 52

• (Nadel & Moscovitsch, 1997)
• Makes a distinction between episodic and semantic memories.
• Episodic memories are always dependent upon the hippocampus for retrieval. No time-limited role for the hippocampus in memory.
• Semantic memories are still subject to consolidation. They become independent of the structure with the passage of time.
• MTT does not dismiss outright the concept of consolidation but limits it to semantic memories.
• The MTT predicts that complete hippocampal damage should affect all remote memories, producing a flat gradient.
• It also suggests that evidence of temporal gradients (Ribot’s gradients) are not the result of consolidation but replication of hippocampal traces over time.
• Re-encoding of older memories creates new hippocampal traces. As a result, incomplete hippocampal lesions will affect recent memories (few traces) more than remote memories (more traces) in a probabilistic manner.

Question 53

describe the relationship between selective hippocampal lesions and retrograde amnesia

Answer 53

• (Reed & Squire, 1998)
• Four patients with amnesia- two with selective hippocampal damage (AB & LJ: hypoxic) and two with more extended damage affecting surrounding cortex (EP & GT: post-encephalitic).
• AB & LJ had normal retrograde memory for facts; EP & GT were impaired.
• Autobiographical memory was relatively impaired for AB but not for LJ. EP showed some preservation of very early memories whereas GT showed no gradient.
• Cipolotti et al. (2001) presented patient VC who became amnesic at 67 following a series of epileptic seizures and episodes of tachyrythmia. Substantial hippocampal atrophy (a).
• VC had severe AA accompanied by a severe RA.
• Remote memory for facts (public events [b], famous faces) was impaired (although recognition was better than recall).
• Remote autobiographical memories were also severely affected (c).
• No evidence of a temporal gradient; impairment affected all periods of life (although remote semantic memories seem to show some preservation).

Question 54

describe the role of neuroimaging in memory

Answer 54

• Do autobiographical memories behave differently to semantic memories?
• Many previous studies had attempted to investigate autobiographical memories but most have a serious flaw.
• They ask participants to provide them with incidents from their past which are then asked to fully recall in the scanner.
• This is problematic:
• Memories are self-selected
• Activity may become contaminated by this procedure which makes people rethink of their memories.
• Gilboa et al (2004) avoided this by asking friends and relatives of the participants to provide pictures relating to autobiographical events.

Question 55

Give Schacter’s (1999) classification of memory errors

Answer 55

• Transience: forgetting memories (iconic/echoic memory, forgetting from working memory/long-term memory)
• Absent-mindedness: Memory errors due to attentional failures at encoding or retrieval.
• Blocking: Inability to retrieve information although it has been encoded deeply
• Tip of the tongue feeling
• Bias: Memory distortion of previous experiences due to influences of present knowledge, beliefs, and feelings.
• Misattribution: Accurate memories assigned to the wrong source.
• Suggestibility: Memories which incorporate inaccurate information from an external source.
• Persistence: Inability to avoid unwanted, intrusive memories of traumatic or arousing events.

Question 56

Describe and explain incidental forgetting

Answer 56

• Decay: mnemonic traces simply fade away with time
• Causes of forgetting?
• Interference
• Proactive: previous learned information interferes with new memories
• Retroactive: newly learned information interferes with old memories
• Retrieval failure: memories present but inaccessible
• Context dependency: changes in environment between encoding and retrieval affect recall of information
• Directed forgetting: conscious, deliberate forgetting

Question 57

Describe the Ebbinghaus forgetting curve

Answer 57

• Ebbinghaus Forgetting curve
• Rate of forgetting is non-linear with maximum loss shortly after learning and little additional loss of information at longer delays.
• Forgetting curves for different types of information and different degrees of learning are comparable.
• Forgetting has been linked to interference between current and past information.
• Proactive and retroactive interference effects.

Question 58

describe and explain suppression of memory

Answer 58

• One of the basic elements of Freudian theory is the notion of “repression” or “suppression”.
• Undesirable or painful feelings, images and thoughts are pushed out of memory to stop them interfering with our everyday lives.
• According to Freud this banishment of unwanted memories can be either a conscious or an unconscious process.
• Sometimes repression is used for unconscious and suppression for conscious forgetting

Question 59

describe the item method

Answer 59

• Aim: Can we induce forgetting?
• In the item-method, after each item is presented at encoding, participants are asked to either remember or forget the preceding item
• At tests they are asked to retrieve all items and participants retrieve more remember than forget items
• The effect is found for both pictures and words and in both recall and recognition tests suggesting deficits at encoding than difficulties at retrieval
• Perhaps, the memory was not created at the first place
• What is behind the item-method forgetting?
• The Selective Rehearsal hypothesis suggests that people restrict elaborative processing of the Forget items
• There is more cognitive effort in Remember than Forget trials
• The Encoding Suppression hypothesis suggests that forgetting is an active process
• There is more cognitive effort in Forget than Remember trials
• There is evidence that reaction times to a secondary task is slower after Forget than Remember items (Fawcett & Taylor, 2008)
• One possibility is that there are fewer resources available in Forget trials because Forget trials involve additional processing

Question 60

Describe the list method

Answer 60

• Interferes with retrieval processes
• In the list-method, two lists are presented. At the end of one list and without expecting it, participants are asked to forget the preceding items.
• At test, they are asked to retrieve all items and participants retrieve more from the remember than the forget list.
• The effect is found only in recall (recognition memory is not impaired) suggesting the deficit affects locating the memory (i.e. retrieval).

Question 61

Describe the think-no think paradigm

Answer 61

• Motivated forgetting
• Anderson et al. (2004)
• Phase 1-Training
• Ss learn a series of unrelated word-pairs
• …pen-cherry, table-crane, glass-fur…
• Phase 2-Experimental session (multiple presentation of cues)
• Some pairs (pen-cherry) are tagged as
respond (Think):
• “when you see the cue
pen think of its pair”
• Some pairs (table-crane) are tagged as suppress (No Think):
• “when you see the cue table do not think of its pair”
• Some pairs (glass-fur) are not repeated (Baseline)
• Phase 3-Test
• All pairs are tested and participants are asked to try hard to remember
• “….try to remember the word that was paired with pen”

Question 62

Describe the results of the think-no think paradigm

Answer 62

• Recall for No Think pairs worse than the baseline (but no difference for Think pairs).
• Forgetting increases (recall drops) with successive suppression attempts.
• Forgetting under strategic, executive control.
• Active inhibition of retrieval.
• No Think-Think contrast.

Question 63

Describe brain imaging findings from the think-no think paradigm

Answer 63

• In blue (circled) are areas showing reduced activity during suppression (Forget!) trials.
• Bilateral anterior hippocampi
• In yellow/red (squared) are areas showing increased activity during suppression (Forget!) trials.
• Ventrolateral prefrontal cortex (VLPFC)
• Dorsolateral prefrontal cortex (DLPFC)
• Anterior cingulate cortex (ACC)
• Intraparietal sulcus (IPS)
• Increased activation in DLPFC & left VLPFC predicted increased memory inhibition in the behavioural task.
• Other non-memory but similar tasks that also require subjects to override strong responses also activate the DLPFC, the VLPFC and the ACC.
• The hippocampal reductions are in agreement with the well known role of the hippocampus in memory processes and in memory encoding in particular. Suppressed activity of the hippocampus may explain the fact that these items were subsequently less likely to be remembered.
• In addition, the study provided some evidence of executive control over the hippocampus. Increases in DLPFC correlated with increased suppression for SF items in the right hippocampus.

Question 64

Discuss evidence of induced forgetting

Answer 64

• There is strong evidence that we can explicitly and to a certain extent control what information we will remember or forget.
• This can be accomplished not just by controlling encoding (i.e. pay more attention) to the information we wish to remember but by actively suppressing unwanted memories.
• Studies using the think/no think paradigm have also revealed a network of brain structures which interact to suppress memories.
• Not all studies have replicated the results of the think/no think paradigm; the neural correlates of conscious and unconscious suppression mechanisms are still under investigation.

Question 65

Describe emotional bias

Answer 65

When asked to note memories that come to their mind effortlessly, people show a tendency to retrieve more pleasant than unpleasant memories.
• In one study, 49% were pleasant and only 19% unpleasant (Bernsten, 1996).
• We also tend to remember the positive more than the negative feedback that we receive (Sedikides & Green, 2000).
• This does not extend to all negative information.
• We remember negative feedback directed towards others especially those we do not personally know!

Question 66

Describe the inconsistency-negativity neglect model

Answer 66

• The Inconsistency-Negativity Neglect Model (Sedikides & Green, 2000)
• Individuals are “motivated to neglect the processing of information that challenges their positive self-conceptions […] The more challenging the information is, the more likely the individual will be to neglect it.” (p. 909)
• Feedback inconsistent with self image and which targets central self-conceptions is seen as particularly threatening because it affects the stability of the self-concept.
• Ignoring negative feedback ensures stability of self-concept.

Question 67

Describe emotional bias in the elderly

Answer 67

• Older adults show a positive affect bias in their learning and memory.
• Although overall memory performance drops with age, older people remember a greater proportion of positive than negative stimuli compared to the young.
• This relates to both the encoding of new information and retrieval of autobiographical memories.
• Similar effects have also been found with Chinese participants suggesting cultural independence.

Question 68

Describe socioemotional selectivity theory

Answer 68

(Mather & Carstensen, 2005)
• Socioemotional selectivity theory suggests that the consideration of one’s “time horizon” (how much we think we have left to live) influences our goals and motivation.
• With a short time-horizon, greater emphasis is placed on emotional states and improving our sense of wellbeing.
• Under normal conditions, elderly have a shorter time-horizon and that explains their memory (and also attentional) bias.
• When the time-horizon for younger people changes (e.g. terminal illness), a positive affect bias also emerges. Conversely, if older people believe that their lives can be extended, the positive bias reduces.

Question 69

Explain own race face bias

Answer 69

• Own race face bias (ORB) (also known as the cross race or other race face effect):
• People tend to remember faces of their own race better than faces of other races
• For example, white participants will have worse memory for black than white faces and vice versa

Question 70

Describe the Deese, Roedinger & McDermott paradigm (DRM)

Answer 70

• Ps are shown a series of words which are all highly associated with a lure word that is NOT studied:
• study: thread, pin, sewing…sharp, haystack, injection
• they are all strongly associated with needle (related lure-not presented)
• On free recall and recognition memory tests the related lure was retrieved as often as any of the presented words, the true targets.
• Not only were the lures retrieved but these memories were also judged to be as vivid and rich in contextual detail as any true memory (look at remember scores at bottom graph).

Question 71

Describe the results of the DRM paradigm

Answer 71

Rate of false memories is very high, comparable or slightly lower than that of true memories.
• Participants’ subjective experience does not discriminate between true & false memories.
• False memory can be more robust than true memory:
• Increasing the number of unrelated words in the list affects true but not false memories.
• Levels of processing does not affect false recognition.
• Repeated tests following a single presentation increases the false memory rate.
• Tested at longer delays false memories are better retained than true memories.
• Divided attention at either study or test impairs both true & false memories.
• BUT false and true memories differ in reported sensory detail

Question 72

Describe and explain activation of associative responses as a theory of false memories

Answer 72

• Roediger & McDermott (1995):
• During encoding, the processing words which are semantically linked to a target word will also activate by association the target word.
• Because the target word has been activated by a number of different words its overall activation level is high.
• At test, participants retrieve information on the basis of its activation strength making it likely that a target word will be falsely retrieved.
• …Or, because the target was activated at study by association, participants believe that they have actually experienced the item whereas in fact they have only thought about it. False memory then is similar to a source error

Question 73

Describe and explain gist memory and sensory reactivation as a theory of false memories

Answer 73

• Schacter (1999):
• Presentation of word lists consisting of semantically related items creates a certain theme, a well organised representation of the “gist” of the study list.
• Participants then approach the task by relying on their memory for the “gist” rather than individual features and as a result they make more semantically related errors.

Question 74

Give evidence from functional neuroimaging of false memories

Answer 74

• In this study, participants heard lists of words (related lists) spoken by two different speakers.
• At test, while in the scanner, they were asked to recognise studied, related false and unrelated false words. 
• As expected they showed high levels of related false alarms.
• Brain (haemodynamic) responses to related false items were almost identical to studied items in prefrontal and hippocampal sites. These areas were influenced by semantic similarity.
By contrast, parahippocampal cortex which is involved in perceptual processing classified related and unrelated false alarms together as neither class of item had a pre-existing perceptual record.

Question 75

describe and explain false autobiographical memories

Answer 75

• It is possible to convince people that specific events happened during their childhood to the extent that they can then produce false memories related to the event.
• Studies have intermixed false and true events and asked people to recall their memories of these events.
• The number of people that are susceptible to false recall varies considerably among studies possibly due to a number of factors including the plausibility of the event, their emotional significance, scoring method among others.
PROCEDURE
• Technique involves:
• Participants get a description of several real and one false childhood event
• True events supplied by family acting as confederates
• Asked to remember details of the events over 2-3 interview sessions
• Wade et al. (2004) went a step further and manipulated pictures of events to involve the participants when were children. Pictures…
• Are considered objective, reliable, undisputed evidence of a plausible event
• Provide a lot of detail that can be used to construct a memory narrative

Question 76

Give the three stages of implantation

Answer 76

• An individual…
1. Accepts that the event is plausible
2. Generates contextual information for the event (could be a mental image, a story, etc.)
3. Misattributes the created event to personal experience rather than a mental construction
• Other precondition: weak memory for specific life period

Question 77

Describe social influence and memory errors in the case of the Oklahoma city bombing

Answer 77

• On 19th April 1995, Tim McVeigh and an accomplish carried out a bombing attack on a federal building in Oklahoma City, USA.
• The bomb killed 168 people and injured more than 680 others.
• McVeigh was arrested, sentenced to death and executed by lethal injection.
• The Oklahoma city bombing represents the deadliest domestic terrorism attack in the USA.
• As part of their investigation into the Oklahoma city bombing, the FBI were looking for an additional accomplice who together with the main perpetrator (T. McVeigh) had rented the car that was used in the attack.
• Although McVeigh had accomplishes, they were not with him when he rented the car.
• The misleading information was due to eyewitness testimony:
• Witness 1 claimed to have seen a second man
• Witness 2 initially denied the man’s existence but later changed his testimony.
• It later emerged that witness 2 changed his testimony after discussing the incident with witness 1.

Question 78

Define informational influence

Answer 78

• Motivated by the need to be accurate. Subject adopts the opinions of others as evidence about reality
• Sensitive to degree of uncertainty
• Proposed to explain the formation and change of social norms
• Informational influence likely to result in both public conformity & private change
• Present when S is tested individually
• Can persist for a long time (permanent change)

Question 79

describe normative influence

Answer 79

• Motivated by the need to be accepted and considered part of the group.
• The subject conforms to the opinions of the majority even when there is little doubt that the majority view is incorrect
• Sensitive to size of majority, attractiveness of the group, interdependence between individual and group
• Reduced when dissenter is present
• Proposed to explain the influence of the group even to matters of undisputed fact
• Normative influence likely to result in public conformity BUT NOT private change
• Eliminated when S is tested individually
• Asch’s results more likely to be due to normative influences

Question 80

Describe the role of misinformation in false memories

Answer 80

• Misinformation studies show evidence of memory conformity (Loftus, 1975)
• Ss witness an event and then at retrieval receive incorrect suggestions
• ”Did the car stop at the stop sign?” when in fact it was a yield sign.
• Misinformation is provided in the form of written instructions from the experimenter so there is an indirect social component