PS120 Neuropsychology Term 2 Part 1

Question 1

Declarative memory

Answer 1

A form of memory that involves the (conscious) recollection of experiences and facts. These recollections can be communicated to someone else either verbally or by some other means (they can be declared)
The term explicit memory is often used as a synonym for declarative memory involves the “conscious recollection of previous experiences”

Question 2

Non-declarative memory

Answer 2

A form of memory that does not involve conscious recollection and that cannot be described or expressed verbally (cannot be declared). The existence of the memory is demonstrated through performance (i.e by doing something)
The term implicit memory is used as a synonym for non-declarative memory

Question 3

Lane changing

Answer 3

Lane changing is a commonly executed maneouvre
The angle-time graph shows that steering wheel movement involves two ‘phases’: a movement to the right and back to the centre (phase 1) followed by a movement to the left and back to the centre again (phase 2).
Most people are unaware that lane-changing involves a two-phase (biphasic) movement of the steering wheel, though they are quite capable of executing the maneouvre
When people are asked what kind of steering wheel movement is required they say only the first phase is needed. In a simulator participants were required to execute a lane change maneouvre without being able to obtain visual feedback about the execution. The finding was that when participants could not see the road (they were driving blind when they entered the ‘tunnel’), they did not execute both phases of the maneouvre.

Question 4

Motor skills being non-declarative

Answer 4

This an example of the memory underlying motor skill being non-declaritive, which is to say that a person can demonstrate their knowledge through doing but is not able to consciously able to retrieve information from memory concerning what exactly it is that they actually do.

Question 5

What do the findings of a non-visual lane change show?

Answer 5

These findings show that people can execute the first phase of the maeouvre but do not produce the second phase unless they can see where they are going. Thus, initiation of the second phase required feedback from execution of the first phase.

Question 6

Anterograde amnesia

Answer 6

Anterograde amnesia - a serious impairment of the ability to form memories of things that occurred after the brain was damaged it is not a loss of existing memory, it is a loss of an ability to form memories. They can hold some things in their mind for a few seconds but usually for no more than a minute or so.

Question 7

Henry Molaison

Answer 7

The most famous case study: Henry Molaison was studied for fifty years until his death in 2008. Received surgery for his severe epilepsy in 1953 involved removing the medial parts of the temporal lobe (including the hippocampus) on both sides of the brain. The hippocampus is a folded ‘terminal’ part of the cerebral cortex that lies close to the midbrain.
HM’s surgery successfully dealt with epilepsy and had little or no detectable effect on his personality, perceptual ability or intelligence. He was unable to form new memories of events in his life and new facts. This inability to remember was found to be largely confined memory as he was able to develop skill in a variety of motor taks and to retain what he had learned for many years.

HM drawing a star within a star experiment - HM was able to improve performance of the mirror tracing task and retain the improvement over an extended period, though he had no recollection on either day two or three of ever having performed the task before.

Question 8

What type of memory is involved in Pavlovian learning?

Answer 8

Non-declarative - the memories formed in non-associative and Pavlovian learning are not ‘retrieved’ from anywhere

Question 9

Why is the term procedural memory problematic?

Answer 9

Used inconsistently: sometimes to mean non-declarative memory generally, sometimes only memory that relates to behaviours involving procedures
Confusing when used to refer to memory underlying behaviours that do not involve these procedures
Confusing because a memory of a procedure is not a procedural memory: if you can declare knowledge of a procedure, it’s not a procedural memory

Question 10

Eye-blink conditioning experiment

Answer 10

Every once in a while a tone sounds and then a puff of air is blown into your eye (in a delay procedure)
CR acquisition is slow
Is this all a person learns? No people, may also learn that a tone sounded before every puff.
How do we know? Ask them and they will tell you (a declarative memory was formed)
These data came from an experiment in which people were watching a movie during the procedure
Most of them had a declarative memory of the procedure, but a few did not all
They all produced CRs: a declarative memory is NOT involved in the production of CRs
In eye-blink conditioning the non-declarative memory is the change in circuitry (CS -> CR circuit)
May also acquire the declarative memory that the puff of air was preceded by a tone
If there is no declarative memory, CRs are still acquired
Declarative memory plays no role in generating the CR (also non-declarative memory plays no role in the declaration that the tone preceded the air-puff)

Question 11

True or false a declarative memory of the CS-US relationship is also acquired during simulatenous and backwards conditioning procedures

Answer 11

True - A declarative memory of the CS-US relationship is also acquired when people experience simultaneous and backwards conditioning procedures
But no CRs are acquired: declarative knowledge is acquired, but not non-declarative knowledge
Thus learning takes place in simultaneous and backward conditioning, but it is not Pavlovian learning

Question 12

Retrograde amnesia

Answer 12

Loss of memory about life events experienced prior to the damage and factual information acquired prior to the damage

Question 13

The hippocampus

Answer 13

The hippocampus is an infolding of the cerebral cortex along the inner edge of the temporal lobe. It is clear that it is a folded section of cortex when viewed in coronal section. The hippocampus is a key region in AA: damage it and
long term declarative memory formation is impaired,
damage the neighboring regions and it isn’t
▪ However, damage to the hippocampus is not the only kind of
damage that leads to amnesia

Question 14

Korsakoff’s syndrome

Answer 14

Korsakoff’s syndrome (caused by thiamine deficiency,
usually as a result of long-term alcohol abuse) results in
amnesia (both retrograde and anterograde) that affects
declarative but not non-declarative memory
Brain damage
▪ The neuropathology in Korsakoff’s syndrome is widespread,
but there is relatively little effect on the hippocampus
Regions damaged in Korsakoff’s syndrome that are responsible for
memory dysfunction are the mamillary bodies, the parts of the thalamus
to which they connect, and regions of frontal cortex

Question 15

Can amnesics develop CRs? Eye-blink conditioning procedure

Answer 15

A delay procedure was
used with a delay interval
of 1.25 seconds
▪ A group of normal people and a group of anterograde
amnesics with hippocampal damage served as participants
▪ Results: normal
participants
acquired CRs
Conditioning in amnesics
▪ And so did the
amnesics
▪ None of the amnesics formed a declarative memory of having
undergone the procedure, all the normals did (though some
failed to notice the CS-US relationship)

Question 16

Eye-blink conditioning procedure - trace conditioning

Answer 16

The amnesics failed to acquire CRs

Question 17

Results of eye-blink conditioning experiment

Answer 17

▪ These results are consistent with a role for the hippocampus
in the acquisition of memories when information needs to be
retained over time
Conditioning in amnesics
▪ But the hippocampus is not needed for retention: damage to
the hippocampus does not produce retrograde amnesia in
people (no loss of existing memories) and does not abolish
CRs acquired using trace procedures in rats
▪ Retention of information about the CS over the trace interval
is needed if its relationship with the US is to be discovered

Question 18

Hippocampus and cerebellar cortex damage

Answer 18

▪ The results indicate that the hippocampus is crucial for holding information over time during the acquisition of long term memories, particularly declarative ones, but in some
cases in non-declarative ones also
Conditioning in amnesics
▪ The hippocampus is not involved in delay conditioning, but
there is a structure that may play a similar role – the
cerebellar cortex
▪ If the cerebellar cortex is damaged, CR acquisition is no
longer possible in eye-blink conditioning and a number of
other instances of Pavlovian learning using the delay
procedure
▪ A kind of anterograde amnesia (though for a non-declarative
memory)
▪ As with the hippocampal removal, removal of relevant parts of the
cerebellar cortex do not abolish CRs that have already been acquired (no
retrograde amnesia type deficit)
Conditioning in amnesics
▪ For different types of memory, we find structures in the brain that are
involved in acquisition but not retention (other structures are involved in
retention)
▪ If the structures involved in acquisition are damaged, new longer term
memories cannot be formed (called anterograde amnesia when
declarative memories are involved) but old ones are left intact (no
memory loss)
▪ If the structures involved in retention are damaged, old memories are lost
(called retrograde amnesia when declarative memories are involved)
▪ But brain damage is not a common reason for memory loss – we will
discuss forgetting and unlearning next (in the context of Pavlovian learning)

Question 19

What two circumstances are there in which people may what to undo the effects of prior learning?

Answer 19

▪ (1) You may want to rid yourself of a bad technique or habit
that you have acquired so that you can perform better at
some skilled behaviour (such as a sport)
▪ (2) You may want to rid yourself of an acquired irrational
fear (phobia): you may want to stop being afraid of spiders,
open spaces, confined spaces, flying, public speaking etc.

Question 20

What are the two ways of actively ‘undoing’ the effects of learning?

Answer 20

1. Erase the memory (memory is lost) or erase the means
   of retrieving it – erasure
2. Suppress the memory or suppress the means of retrieving it (memory is still there and so is the means of retrieval, but you can’t get it/use it) - suppression

Question 21

What are the two phases to undo Pavlovian conditioning?

Answer 21

Phase 1: training with a forward conditioning protocol in
which CS is paired with a US until learner acquires a CR
Phase 2: exposure to a sequence of presentations of the
same CS but without presentation of any USs

Question 22

What is extinction procedure?

Answer 22

A procedure that follows conditioning and involves
presenting the CS without the US is a called an extinction
procedure

Question 23

Spontaneous recovery

Answer 23

If the ‘memory’ had been erased, then the behaviour could
not reappear but it can. Recovery tends to be greater for longer intervals.

Question 24

Renewal

Answer 24

▪ Observation 2: renewal
▪ The subject is conditioned in one context (e.g., a particular
room or cage – context A) and then is transferred to a
different context (B) where an extinction procedure is
administered.
▪ After extinction, the subject is either transferred back to
context A or to a completely new context (C)
▪ Back in context A (or in context C), the animal is tested with
the CS alone – it is found that conditional responding is
present again (it has been renewed)
▪ Renewal effect is stronger in the ABA context sequence
than it is in the ABC sequence

Question 25

Reinstatement

Answer 25

▪ Following extinction, the subject is presented with an aversive or otherwise arousing stimulus (often the US used in training) ▪ The CS again elicits the CR

Question 26

Effect of Extinction

Answer 26

EFFECT of EXTINCTION: extinction procedures do not erase what has been previously learned (memories); previous learning is retained, it just isn’t (always) possible to express it in behaviour – it is suppressed.

Question 27

Mechanism of suppression

Answer 27

▪ During the extinction procedure, the trainee learns to suppress the acquired stimulus-response relationship so that the conditional responses are no longer produced ▪ This is new learning that counteracts the effects of prior learning ▪ The neural process that produces suppression is inhibition, so the result of learning during extinction is likely to be an inhibitory stimulus-response connection of some kind ▪ The conditional reflex pathway (memory) is intact, but an inhibitory pathway formed as a result of extinction prevents the CR from occurring

Question 28

Why suppress learning rather than erase?

Answer 28

A clue in the finding that extinction is context sensitive. ▪ Recall that renewal demonstrates this sensitivity ▪ Reinstatement also demonstrates context sensitivity ▪ Reinstatement occurs provided retention test is in the same context as that of the prior experience Context sensitive suppression of prior learning (rather than erasing it) means that what has been learned is not completely lost, but is available in contexts where it might still be relevant and useful

Question 29

Thorndike Cat Puzzling

Answer 29

Observed that cats tried to squeeze through the cage and tried to bite and squeeze the wired. The measured time taken to escape from the box decreased - by the end of day 2, the cat pulls on the loop almost immediately after being placed in the box.

Question 30

Box K cat puzzling

Answer 30

Box K was quite complex with 3 actions needed to open the door: press down on bar, pull down on loop and press on treadle. ▪ The cats’ behaviour changes as a result of its consequences Instrumental learning ▪ The behaviour change consists (primarily) of two things: (1) some behaviours become more likely over repeated experiences, (2) some behaviours become less likely over repeated experiences ▪ Note that no new behaviours are acquired – the cats could already do what was necessary to escape ▪ The cats’ learning process is a kind of trial and error learning ▪ The cat tries things out (things it can already do) and changes its behaviour according to whether the trial is a success or a failure (error)

Question 31

Law of Effect

Answer 31

▪ It is important to recognise that the Law of Effect is an hypothesis with several components ▪ It asserts that satisfaction/ dissatisfaction is evoked by certain events (e.g., escape evokes satisfaction as does eating) ▪ Satisfaction/dissatisfaction changes the strength of these connections ▪ The organism has pre-existing connections between stimuli and behaviours (responses) ▪ The organism does not have connections between behaviours and their consequences or the satisfaction/ dissatisfaction that they evoke

Question 32

S-R Theory

Answer 32

Situational stimuli come to elicit a single behaviour (or set of behaviours) in a reflex-like fashion. The experienced cat does not pull the loop in order to get out, it does so because situational stimuli elicit loop pulling called S-R theory ▪ According to S-R theory animals do not do things in order to achieve specific outcomes

Question 33

Reinforcement

Answer 33

▪ In everyday language, reinforcement has two basic meanings: (1) the act or process of strengthening something; (2) the thing(s) that does the strengthening ▪ In the context of learning theory, reinforcement is used in the first sense, but not the second: ▪ The process of strengthening a ‘connection’, such as a stimulus-response connection ▪ Something that leads to the strengthening of a connection when it is delivered/produced as a consequence of behaviour is called a reinforcer

Question 34

Positive reinforcement

Answer 34

▪ Delivery or production of a stimulus item (like food) that results in strengthening of a connection/behaviour is called positive reinforcement Some terminology ▪ The term ‘positive’ is used to denote the fact that something is added or delivered to the situation (not to denote that the reinforcer is ‘good’ or delivers a ‘positive experience’)

Question 35

Negative reinforcement

Answer 35

A behaviour/connection can also be strengthened by removing something from the situation – this is called negative reinforcement ▪ Positive reinforcement is reinforcement by addition, negative reinforcement is reinforcement by subtraction ▪ This is usually achieved by removing something aversive/ unpleasant

Question 36

Punishment

Answer 36

Punishment: The delivery or production of a stimulus that has punishing effects (a punisher) as a consequence of a behaviour. ▪ Punishing effects are opposite to the effects of reinforcement: a reduction in the likelihood of a behaviour, a decrease in its strength/vigour and/or an increase in its latency

Question 37

True or false a punisher is almost always an aversive stimulus of some sort

Answer 37

True

Question 38

Positive punishment

Answer 38

▪ Positive punishment is the delivery/production of a punishing stimulus (like a smack)

Question 39

Negative punishment

Answer 39

Negative punishment is the removal of a desirable or rewarding stimulus

Question 40

Instrumental conditoning procedure

Answer 40

These procedures involve setting up an experimental situation in which executing a particular behaviour which results in the delivery of reinforcement or punishment.

Question 41

What is it called when a labortatory training protocol uses only teinforcement or punishment?

Answer 41

Instrumental conditioning procedure or operant conditioning procedure

Question 42

Thorndike R-O associations

Answer 42

According to Thorndike, stimuli and outcomes do not become connected (associated) in the learner’s ‘mind’ (or brain) and neither do responses and outcomes. The learner doesn’t acquire any knowledge about outcomes of responses (R-O associations) or about the circumstances in which those outcomes come about (S-O associations).

Question 43

How do we prove Thorndike's theory is not always the case in animals?

Answer 43

The most important body of evidence for R-O theory comes from a technique called outcome (or reinforcer) devaluation. The idea is a simple one: if the organism produces a behaviour because it is motivated to obtain the outcome/ reinforcer associated with it, then decreasing motivation should reduce the likelihood of the behaviour.

Question 44

Reinforcer devaluation - rats case study Colwill & Rescorla, 1986

Answer 44

Rats were trained using an instrumental conditioning procedure: a reinforcer was delivered for pushing a rod on the right or on the left. The rats had the choice of pushing the right or left rod: if they pushed it to the left they would receive a sugary reward (sucrose solution), if they pushed to the right they would receive a savory food reward. The training establishes both responses: sometimes the rat will push the left rod to drink sugary water, sometimes it will push the right one to eat a tasty snack. Following this initial instrumental training, one of the reinforcers was devalued using a taste/smell aversion procedure. No reinforcers were delivered in the test phase to ensure that only what the animals had previously learned would affect their behaviour. Reinforcer devaluation typically reduces the likelihood of a behaviour being executed (or of otherwise reducing the strength of a behaviour), demonstrating that the value of the outcome affects responding. Indicates that organisms learn about response-outcome relationships and use this ‘knowledge’ for deciding whether or not to perform a behaviour

Question 45

Why in some situations does a learned behaviour produced regardless of whether the reinforcer's value is reduced or not?

Answer 45

Can happen following very extended periods of ‘training’. ▪ Habits are sometimes described as ‘over-learned’, because it seems as though ‘too much’ learning leads to inflexible behaviour.

Question 46

Habitual behaviour

Answer 46

An instrumental behaviour whose production is insensitive to the value of its outcome or associated reinforcer

Question 47

Goal-guided behaviour

Answer 47

an instrumental behaviour whose production is sensitive to the value of its outcome or associated reinforcer

Question 48

Is it true that instrumental learning is just the strengthening and weakening of S-R connections?

Answer 48

No, it also involves learning about response-outcome associations (and associations between situations and outcomes as well)

Question 49

Is it true that animals do things in a reflex fashion without any intent or aim to achieve a specific outcome? If true, are we different? Why?

Answer 49

No, animals can learn to do things in order to achieve outcomes/gain rewards (goal-guided) Extensive training/experience can lead to habitual behaviours that are stimulus-elicited rather than goal-guided

Question 50

Shaping

Answer 50

A method of training a response by reinforcing a sequence of progressively closer and closer approximations to a target behaviour.

Question 51

Learning to change gears

Answer 51

We know that there is much more to learning sequential actions like these than simply performing the correct elements in the correct sequence ▪ A classic example is learning to change gears in a car with a manual transmission ▪ The novice driver knows how to perform each element in the sequence, they just need to make sure that they do them in the right order (and with the right overlap) ▪ But novice performance is strikingly different from that of experts in several different ways ▪ The learner is aware of having to make a conscious decision to execute each component ▪ The learner is aware of having to make a conscious decision to execute each component

Question 52

Fluency and blending - expert/novice differences in joining dots

Answer 52

▪ The expert is more fluid: no pauses between elements in well practiced sequences ▪ Elements run smoothly together and the movements/ muscle contractions involved in their execution overlap with one another ▪ In the novice it is typically easy to tell where the performance of one element ends and where the next element begins ▪ In the expert the boundaries are blurred and may be impossible to detect

Question 53

What are the three stages of skill acquisition?

Answer 53

STAGE 1: COGNITIVE STAGE – highly attention demanding; requires awareness of what you’re doing; use of explicit working memory; slow STAGE 2: Fixation Stage – components of action grouped into ‘chunks’; fewer decisions, less explicit memory demand STAGE 3: Autonomous Stage – execution proceeds “automatically” without thinking; no demand on explicit working memory; low attention demand

Question 54

The cerebral cortex

Answer 54

Like a walnut, the brain appears to be divided into two parts This is true for the part you can see here and for some of the parts you can’t see The cerebral cortex comes in two separate wrinkled sheets – one on the left that forms a kind of ‘skin’ of the left hemisphere, and one on the right Customary to divide the cerebral cortex on each side into lobes

Question 55

Lobes of the cerebral cortex

Answer 55

- Frontal lobe - the frontal lobes comprise a big chunk of the cerebral cortex - Patietal lobe - Occipital lobe

Question 56

Where is the primary cortex (M1) located/occupying?

Answer 56

Precentral gyrus

Question 57

Motor cortical regions

Answer 57

A role in motor function for most of these areas was originally determined from the behaviour of people who had damage or pathologies that affected them We will see in week15 that the motor speech area (Broca’s area) was first identified based on the effects of damage to this area due to stroke One exception is the primary motor cortex (M1), the motor function of which was determined by direct electrical stimulation of the brain surface when the head was opened for surgery

Question 58

Damage to frontal motor areas

Answer 58

Damage to primary motor cortex → problems coordinating and controlling muscles in voluntary movement; tight (contracted) musculature (hypertonia) Damage to frontal motor areas Damage to the more rostral motor areas does not affect muscle control, but has effects on planning, selecting and initiating acts and/or courses of action For example, damage to Broca’s area does not affect the ability to produce speech sounds, say words or to move those parts of the body associated with speaking It affects a person’s ability to produce comprehensible speech – speech lacks grammatical structure and other qualities that make the intended message understandable (more about this in week 15)

Question 59

Unilateral damage to SMA

Answer 59

▪ Patients with unilateral damage have a symptomatology associated with the contralateral upper limb here the left arm and hand ▪ No abnormal experiences of ownership: patient knows that the limb is their own limb ▪ No abnormal perceptual/sensory experiences: tactile and kinesthetic sensation and perception are normal ▪ Abnormal action execution: limb seems to act autonomously (no intention), performing actions appropriate for the environment This is called Anarchic Hand Syndrome

Question 60

Bilateral damage to the supplementary motor area

Answer 60

▪ Bilateral damage to the SMA and nearby areas results in a symptom called utilization behaviour ▪ Spontaneous performance of object appropriate actions when the person sees an object (regardless of time, context or ownership) ▪ E.g., patient sees toothbrush, picks it up and begins cleaning teeth (but it’s not their toothbrush and it’s not the bathroom)

Question 61

Summary of damage to supplementary motor area

Answer 61

▪ Damage to SMA is often associated with the unintended execution of actions directed at objects in the environment ▪ If damage is unilateral, patient denies responsibility for performance (Anarchic Hand Syndrome) ▪ Limb sensations and perceptions are normal and ownership is unaffected (alien hand syndrome is associated with more widespread damage) Damage to SMA: Summary ▪ Execution itself is normal, just the intention is missing ▪ If damage is bilateral, patient acknowledges responsibility after performance (utilization behaviour)

Question 62

Organisation of voluntary action

Answer 62

Anarchic hand syndrome and utilization behaviour are well-learned, voluntary behaviours that are directed at external objects (use-type behaviours) have a kind of reflexive (S-R) structure that is normally regulated by volitional (intentional processes) Frontal cortex is involved in inhibitory control that stops a response from occurring. Therefore voluntary decision to act means releasing a circuit from inhibition.

Question 63

How does voluntary action occur?

Answer 63

▪ Given that we can mime and perform actions based on memory (rather than current stimulation), there must also be excitatory connections to the response production circuits ▪ It was once thought that learning established the S-R structure in subcortical mechanisms: development of automaticity involved a transfer of command generation from cortical to subcortical circuits ▪ This has turned out to be an oversimplification: volition and cognitive control do require cortical circuits, but acquired automatic behaviour involves both cortical and subcortical circuits

Question 64

Case of Phineas Gage

Answer 64

▪ Gage was engaged in the act of tamping the charge when his accident occurred ▪ He did not pass out, but remained fully conscious, was able to speak and (with assistance) to get himself to his lodgings, where he sat and waited for the physician (arrived ½ hour after the explosion)

Question 65

What happened to Phineas Gage?

Answer 65

Loss of virtually all the prefrontal cortex of the left hemisphere, minor damage to the right probably (but extent unclear) ▪ Both the superior region and the inferior regions ▪ Gage survived for 12 years, but ultimately died from complications arising from the injuries sustained ▪ He was able to function relatively effectively – though not as before ▪ As far as we can tell from the records, his memory and language (comprehension and speech) were preserved ▪ It seems that his personality was altered – sparse records of people’s impressions suggest he was a changed man

Question 66

Lobotomy

Answer 66

▪ The most important figure in the development of the operation was Egaz Moniz ▪ Grey matter not destroyed (allegedly): operation cuts through the fibres of the white matter Lobotomy ▪ Severs connections to and from the prefrontal cortex ▪ A method for performing the operation that could be done in the patient’s home – transorbital lobotomy – was developed in Italy and the USA soon after WWII ▪ Walter Freeman developed and used the procedure in the US

Question 67

Tissue destruction in lobotomy

Answer 67

▪ What tissue was actually destroyed was difficult to control as the practitioner can’t see what’s they’re doing and all brains are slightly different – some grey matter would be lesioned, how much was impossible to determine at the time ▪ It is also inconceivable that the grey matter of the sulci in the superior prefrontal cortex was left intact ▪ Given the point of entry, the tool would have penetrated the orbitofrontal cortex, but the extent of the damage produced was uncontrolled and unknowable

Question 68

Impairments and psychological effects of lobotomies

Answer 68

▪ Transorbital lobotomy severed a significant proportion of the fibres in the white matter tracts within the prefrontal cortex, together with a unknown degree of damage to grey matter in the orbitofrontal cortex and in the superior, medial and temporal regions of the prefrontal cortex ▪ The nature of the impairments/alterations observed after frontal damage depends upon the extent and location of the lesions ▪ One feature shared by all those lobotomized was significant ‘personality’ changes: patients typically became withdrawn, inactive, rather docile and compliant (making them easy to manage) Impairments and psychological effects ▪ Depressed patients reported being less depressed, anxious patients reported feeling less anxious and fearful ▪ Excessive or inappropriate emotions were reduced or eliminated – indeed all emotional experience was reduced or eliminated (though not necessarily emotional behaviour)

Question 69

What are components of the sympathetic branch of the ANS?

Answer 69

- Dilates pupils; stimulates tear glands - Inhibits salivation - Dilates salivation - Dilates bronchi - Accelerates heartbeat - Decreases digestion in stomach - Decreases digestion in intestines - Inhibits bladder emptying - Inhibits genitals - Increased heart rate - Increased respiratory rate - Increased sweating and decreased salivation (dry mouth) - Pupil dilation, blood vessel dilation

Question 70

Autonomic responses to threat and danger

Answer 70

▪ The systemic effects of sympathetic neuronal activity are further enhanced by release of epinephrine (adrenalin) from the adrenal medulla ▪ This all happens quite quickly, stress hormones are also released but take longer to be released and have their effects ▪ Mechanisms differ, but all responses to threat are controlled by the hypothalamus

Question 71

Hypothalamus

Answer 71

Hypothalamus is a small region of the forebrain that lies just superior to the midbrain It is a cluster of several distinguishable nuclei

Question 72

Hormonal responses to stressors

Answer 72

Pathway 1: Stressor Hypothalamus releases CRH Pituitary gland releases ACTH Adrenal gland releases stress hormones Increases energy release, suppresses inflammatory response and suppresses immune response. Pathway 2: Stressor Hypothalamus Sympathetic Nervous System Adrenal Medulla (releases adrenaline and norepinephrine Increases cardiovascular response, increases respiration and perspiration, send blood to muscles, stimulates mental activity and increases metabolism.

Question 73

Components of emotional response

Answer 73

▪ Fear and emotions more generally are regarded as having three components 1. A skeletomotor component (motor behaviours such as fight or flight responses) 2. A physiological component (which includes both the autonomic and hormonal responses) 3. An experiential, subjective component or ‘feeling’

Question 74

Recall the three possibilities for how emotional experience and emotional responses are related

Answer 74

1. The experience comes before the skeletomotor and autonomic reactions have begun 2.The experience comes after the skeletomotor and autonomic reactions have begun 3. The three components begin almost simultaneously

Question 75

James-Lange Theory of Emotion

Answer 75

- Bodily responses evoke sensory signals and it is the sensations and perceptions they produce that cause the experience of an emotion – fear, sadness, anger, happiness, shame, surprise, etc. - You don’t run because you are afraid, you are afraid because you are running (+ other bodily reactions) - James and Lange went even further – these sensory experiences are the emotion: “our feeling of the [bodily] changes as they occur IS the emotion” (James, 1884, p. 189) - Likewise, you don’t cry because you are sad, you are sad because you are crying (+ other bodily reactions)

Question 76

True or false James-Lange theory involves interpreting bodily emotions e.g your heart is pounding and you interpret you are going to have a heart attack and then you panic

Answer 76

FALSE Note: James-Lange theory is NOT that emotions are evoked by bodily feedback indirectly E.g., if you feel pain in your guts, you might experience fear and anxiety because you have interpreted that pain as an indication of a serious illness This is quite different from what James & Lange were talking about – their theory proposes that sensory experience gives rise to emotion directly, without intervening processes The James-Lange account of what is going on when the interpretation of a bodily sensation gives rise to an emotional reaction would go something like this:  You feel pain in your guts and interpret it as an indication of a serious illness, this causes autonomic arousal, which (in turn) gives rise to sensory experiences and these to an emotion

Question 77

Some results are consistent with James-Lange Theory

Answer 77

People without bodily sensation should not experience emotion Loss of sensation is associated with spinal cord injury Emotions should be reduced and more so the higher the level of injury Changes in the intensity of emotional experiences following spinal injury have been studied. Some studies have reported a reduction in intensity that is greater the higher the level of the injury.

Question 78

The holding a pencil between your teeth and cartoon watching study

Answer 78

It has been found that feedback from facial muscles contributes to emotional experience In one study participants were asked to hold a pencil between their teeth (required muscular contractions similar to smiling) Or between their lips (required muscular contractions similar to frowning) Cartoons were experienced as more amusing when the pencil was held between the teeth

Question 79

Canon-Bard Theory

Answer 79

An alternative theory was proposed by Walter Canon and Philip Bard  Theory supposes that the experiential and bodily responses arise simultaneously in different neural structures and do not cause each other (they are distinct effects of the same cause)  There are results that support this theory over the JamesLange theory: injection of epinephrine produces autonomic responses associated with emotions like fear or anger, but does not produce these emotional experiences  Possible to have bodily responses but not experience the emotion

Question 80

Is the Cannon-Bard or James-Lange theory correct?

Answer 80

 Both and neither  Cannon-Bard correct in supposing that there are two systems that are activated in parallel  James-Lange correct in supposing that emotional experiences can be induced (or at least modified) by feedback from the body  Emotional experiences/states can be evoked and modulated by external stimuli, bodily feedback and thought/imagination  Conversely, emotional states can evoke and modulate bodily reactions, the contents of thought/imagination and (by motor action) external stimuli

Question 81

What part of the brain did Cannon propose was primarily responsible for the production of emotional experiences?

Answer 81

Based on results that were available at the time (1920s), Cannon proposed that the thalamus was the structure primarily responsible for the production of emotional experiences  According to Cannon there is no emotional experience without the thalamus – the thalamus is the source of emotional experience

Question 82

Review the Papez Circuit

Question 83

Beyond Papez understanding emotion and the brain

Answer 83

 Soon after Papez proposed his circuit, it was found that complete ablation of the temporal lobes in animals lead to a loss of fear and loss of emotional reactivity more generally  Temporal lobe structures/regions are important for emotional experience and expression – but which ones?  Paul MacLean suggested a more complex system of interconnected structures that added more elements to the Papez circuit including additional cortical regions  He added the whole limbic cortex  MacLean also added the amygdalae

Question 84

What is the amygdalae?

Answer 84

Clusters of small nuclei (13 at the last count) that form ‘lumps’ on the ends of the tails of the caudate nuclei

Question 85

What structures form MacLean's limbic system?

Answer 85

Hypothalamus Thalamus Cingulate gyrus Amygdala Parahippocampal gyrus Hippocampus Since MacLean’s first description, the limbic system concept has been extended to include several other structures as these were discovered to play a role in emotion

Question 86

MacLean and the 'emotional brain'

Answer 86

MacLean’s limbic system has been called the ‘emotional brain’ Believed that the system is alone responsible for generating emotional experience and expression He believed that emotion is something separate from other processes/functions such as memory, thought, perception and other cognitions Since MacLean the limbic system concept has been extended to include several other structures as these were discovered to play a role in emotion

Question 87

Threat conditioning

Answer 87

Threat conditioning is a key empirical tool for studying how the brain learns to organize responses to threat and danger Works quickly and reliably: CRs are acquired with relatively little training (compared to, e.g., eyeblink conditioning) Learned effects very long-lasting: can persist for a lifetime (at least in rodents) Operates in a range of species from humans to invertebrates Neural circuits have been worked out in some detail (are not the same as those involved in eye-blink conditioning

Question 88

Auditory threat conditioning circuitry

Answer 88

Auditory receptors transmit signals to neurons in the brainstem auditory nuclei For learning to take place, signals evoked by the two stimuli must be brought US together somewhere CS and US information converges in the amygdalae Specifically, to one of the internal nuclei of the amygdalae called the lateral nucleus (LA) The lateral nucleus (LA) sends signals to the central nucleus (CE) which in turn sends signals to regions that generate responses The CE connects to the CG, LH and PVH

Question 89

What response does the CG generate?

Answer 89

Central grey (CG) area generates freezing

Question 90

What response does the LH generate?

Answer 90

Lateral hypothalamus (LH) generates autonomic responses

Question 91

What response does the PVH generate?

Answer 91

Parventricular hypothalamus (PVH) generates endocrine responses

Question 92

What does lesion studies show about when the LA is removed?

Answer 92

LA is where CS and US information is brought together, it is a possible site for changes in synaptic strength (memory)  Damaging or destroying the LA impairs or prevents CR acquisition  Lesion studies have demonstrated that damaging/removing the LA after training abolishes the acquired CRs  Overall conclusion is that the LA is the major site of learning and memory in threat conditioning  Single cell studies have demonstrated synaptic changes associated with threat conditioning occur in the LA 

Question 93

In people this (subcortical) circuitry (auditory threat conditioning circuitry) operates beneath the level of conscious awareness

Answer 93

 A threat CS or US presented subliminally (person unaware of the stimulus), behavioural and physiological responses are elicited  Participants do not report any feelings of fear, neither spontaneously nor when instructed to introspect  Brain imaging has shown that the amygdalae are activated when a person is unaware of the threatening stimulus

Question 94

Acquisition of CRs can occur beneath the level of conscious awareness

Answer 94

 In amnesic patients with damaged hippocampi, CRs are acquired in threat conditioning, but no declarative memory of being conditioned  Conversely, when the hippocampus is intact but the amygdalae are damaged, CRs are not acquired, but there is a declarative memory of the conditioning procedure

Question 95

The role of the cortex (1) Sensory cortical areas are important for fine discriminations between CSs

Answer 95

 E.g., during training an animal experiences two novel, neutral auditory stimuli that are quite similar – one is paired with the shock US and the other is not  Following training, animal responds (CRs) only to the stimulus (CS) that was paired with the US  If auditory cortex is then lesioned or deactivated, the animal responds to both stimuli – as if they both signalled shock  Only coarse sensory analysis is possible at the subcortical level

Question 96

What is the sensory cortex responsible for?

Answer 96

Sensory cortex is responsible for discrimination between stimuli of similar type, identification of distal stimuli (what is it that is threatening)

Question 97

The role of the hippocampus - (2) Hippocampus is critical for contextual learning

Answer 97

Know that the hippocampus is crucial for explicit learning about the CS-US contingency  Also critical for contextual learning  In any conditioning procedure, the training occurs within a certain situational context (e.g., training cage, testing room)  If threat conditioning occurs in a particular context, then that context is associated with the aversive US and the trainee can learn about this association  Contextual cues alone can evoke CRs (though typically weak); strongest CRs when CS + contextual cues are also present Contextual effects are reduced or absent if the hippocampus is damaged or removed

Question 98

(3) Cortex is responsible for feelings

Answer 98

Feelings of fear are elicited by CSs following training (if person is aware of the CS)  Feelings require cortical regions beyond the hippocampus and sensory cortices (removal does not eliminate feelings)  Many different cortical areas are associated with emotional experiences and some of these are connected to the amygdalae and/or sensory cortical areas

Question 99

Extinction and the threat circuit

Answer 99

During extinction of threat conditioning, an inhibitory pathway is activated/strengthened  Both acquisition and retention require cortex (unlike simple fear conditioning)  Inhibitory pathway descends from the cortex to the amygdalae

Question 100

What is the vertical line between the two brain hemispheres called?

Answer 100

Longitudinal fissure

Question 101

The Primary Somatosensory Cortex - symmetry of structure and function

Answer 101

Left postcentral gyrus receives somatosensory information from the right side of the body and Right postcentral gyrus receives somatosensory information from the left side of the body.

Question 102

Functional specialization

Answer 102

If a structure/region of the central nervous system performs one particular function, then it is said to be specialized for that function

Question 103

Functional localization

Answer 103

If a particular function is carried out only in one specific region or structure within the CNS, then it is said to be localized to that region/structure

Question 104

Functional laterlaziation

Answer 104

If a particular function is carried out in one side of the CNS but not in the other, then that function is said to be lateralized

Question 105

Return to week 15 lecture 1

Question 106

What happens if the auditory cortex is lesioned?

Answer 106

The animal responds to both stimuli as if they both signalled the shock

Question 107

What happens if the sensory cortex is lesioned?

Answer 107

Cannot tell differences between similar stimuli (will respond to all even those non-threatening)