Saeki, Baddeley, Hitch, & Saito. (2013). Breaking a habit: A further role of the phonological loop in action control. Memory & Cognition

Before the notes I took on the paper, the following are some notes I took concerning the notions addressed in the paper and their linkage to my dasein.  The transfer might seem a bit too far though... simply an attempt to translate the findings to my living experiences.  So to speak, imperfect translation...

Today's benchmark made... though imperfect note taking and grammatical issues... gotta go nite nite now.

Rehearsal

Something unproveable-- what it be like, the practice of the speaking out loud of my thinking process, a manifestation of either the defect or the jamming up of the rehearsal mechanism of the phonological loop?  

Jamming up as a result of the activation of the anti-psychotic task force?   Sort of like... keep the priority straight, the core is the core... all other goals are secondary... though compensating mechanisms can be established to function (at times) as vocal rehearsal.

Interesting way to see it... the phonological loop was already running short of breathe handing the long standing competition between my psychotic and antipsychotic schemata.  Additional processing... find a way to outsource.

Unless, the head is simply jammed up by the side effects of the meds and the vocalization of my thoughts is simply a means my head has to employ in order to get the phonological loop engaged.

One thing I can say for sure is that, part of the vocalization process is to help me figure out which part of the thoughts in my head is "consciously controlled" by me although it ain't no fail-safe measure either.

So, could the speak-out-loud practice makes me appear more komish? The reality is that people don't know 1 percent of how crazy I am and it's far better than my talking to my voices 24/7, I guess.

Thoughts about and beyond the notion of asymmetrical interference of physical and numerical size

It's a very interesting notion... the asymmetrical interfering impacts of judgments on physical-size and numerical size... with the judgment of the physical size to have a stronger interfering effects on the numerical size.  I guess, we do learn to judge physical sizes before learning to differentiate numerical values.  Also, learning results in neurological restructuring--the biological equivalence of encoding knowledge in LTM.  

Transferring the above notions to psychosis...

Think about it, it took much longer than 6 months for my psychotic onset to progress to institutionalizable grade... the full-blown episode... definitely sufficient amount of time for the learned part of the "thinking pattern" to be crafted, encoded, and perfected with extensive practices.  Sure, the dysregulation of neurochemistry is the precursor of it all and sustains it.  But, it's the synergistic effects of both the physical (e.g., neurochemical, structural) and "cognitive" (e.g., thinking habit) levels that sustain our worldview.  

I don't know whether anyone could think themselves out of their psychotic worldview.  The issues at the physiological level will be something harder to charge... at least not at my own will... For instance, when your brain is shrunken, how do you get it to function the same way as them normal size brain of the normal people?  Yet, for the learned thinking habit, there is more than simply hope.  As long as we can get our head to be functional enough to learn, there's a possibility for us to unlearned the learned habit (though might not entirely)... with the learned psychotic thinking habit, the schemata easily triggered by the most irrelevant environmental cues... 

Sure, the physiological part of it sounds almost like doom's day--that's why we have to bet the desregulated shrunken head on the promises of neuroplacitisity-- with learning, the way to have neuroplacitisity siding with us... whatever gain grated is a gain... can only be grateful about it.

Saeki, Erina, Baddeley, AlanD, Hitch, GrahamJ, & Saito, Satoru. (2013). Breaking a habit: A further role of the phonological loop in action control. Memory & Cognition, 1-14.

This study aimed to investigate whether the loop has executive function in a "long-term" task conflict situation when the current task goal competes with established habits.
Supporting studies
1. task switching with concurrent tasks that are assumed to disrupt only the phonological loop or both the loop and the central executive.
2.  It has been suggested that articulatory suppression prevented the retrieving and activation of goals upon task-switching
3. Results of studies using alternating-runs paradigm (i.e., task A, task A, task B, task B...) found that articulatory suppression affected repetition and switch trials equally. Thus, the effect is not confined to the switching process but a global task control process that resolved task conflicts.
4.  "As Monsell (1996) pointed out, without goal-directed executive control, our thought and action would be "a prisoner of habit."
(I am a prisoner of habitual thinking pattern sustained by the dysregulation of my out-of-whack neurochemicals and the (plausible) altered brain structure.)

Components of the study:

• Alternative form of Stroop effect: Physical and numerical size.  RT time has been found to be longer in incongruent condition than in congruent condition independent of the judgment target.
• Task switching: Judgments of physical or numerical size: the continuation group performed the same task (e.g., judging physical size only) while the change group switched the task to judging the size of a different feature (e.g., numerical to physical size)
• Dual task: control, articulatory suppression, nonarticulatory concurrent task (repeated foot tapping)

The authors also intended to test the following

• Script theory: Instruction
• Nature of switch: switching from easier to difficult?
• Source of interference: "articulatory suppression did not interact with stimuli congruity; thus, the phonological loop doesn't not contribute to resolving interference arising from activation driven by the irrelevant dimension."

Experiment 1

Participants in the change group were given instructions pertaining to the "=" sign to cue them to continue with the task and the "-" sign just before the switching from the numerical to physical judgment.

These instructions were not provided to the continuation group.

Phase 1: establish task habit.  Phase 2: the change group change the judging task.

Results: 

• Ceiling effect observed 12 participants in the continuation group and 2 participants in the change group.
• Switching from a difficult task (numerical judgment) to an easier task (physical judgment) resulted in similar findings of Saeki (2007).  Thus, the nature of how tasks are switched has no bearing on the results.
• Also, as shown in the following figure: RT is longer for the change group than for the continuation group especially in concurent-task situations when stimuli are incongruent with articulatory suppression also having a stronger impact than foot tapping. 

1. The differential impacts between articulatory suppression and foot tapping suggest the role of the phonological loop in protecting current goal from a competing and irrelevant task goal.
2. The articulatory suppression did not interact with stimuli congruity.  This seemed to indicate that the control of the phonological loop is different from what is needed to resolve issues of incongruency.

Experiment 2

Both groups were given the same instructions.

Results:

Albeit some differences, results of this experiment are pretty much consistent with previous findings such as in experiment 1 and Saeki (2007)... suppression disrupt the performance of the change group, supporting the role of the phonological loop in maintaining task goals in the face of competing goals.  The potential impact of differential instruction is also ruled out.

However, it was found that, for the change group, RTs under articulatory suppression were faster in the second half than in the first half of the experiment during phase 2.

Experiment 3

In this experiment, everything is the same as was in experiment group except participants in the continuation group performed numerical judgment throughout while those in the change group started with physical judgment before switching to the numerical task.

Results

In this experiment, the interfering effects of suppression on the change group seemed as less clear cut.  Also, foot tapping doesn't seem to have significant impact on the change group (like what was found in experiment 2).  Also, no difference between the first and the second half of the experiment during phase 2, meaning the disrupting interference of articulatory suppression persisted.

The results, again provide evidence concerning the role of the phonological loop in goal control.

Yet, after the judging tasks were switched around, the findings on congruity effects seemed to became a bit fuzzy.  The effects of congruity itself were consistent and robust but how it interacts with other factors change:

• Unlike what was found in exp. 1 and 2, there was no interaction between congruity and group.
• Albeit the observation of an interaction between congruity and concurrent task, it was due to the effects in the tapping condition, in contrast to the effect of the articulatory suppression observed in experiment 2.

General discussion

The following table provides a summary of the results of the three-way ANOVA on RTs.

• Consistent: group and concurrent task interaction (articulatory suppression especially)
• Congruity effect with longer RTs for incongruent stimuly)
• Target task as the physical-size judgment (reflecting a larger congruity effect in change group)

The role of the phonological loop in action control

Suppression has no reliable effects on habits (even recently acquired habits) but disrupts performance when switching to a new task where there is a need to overwrite the old habits.

(Therefore, do yourself a favor, make it easier for yourself... accept false positive to save you some of the unnecessary switching around)

Albeit the slowed RTs, the performance on accuracy remained pretty high in the change group. As a result, "although the phonological loop may facilitate speedy access to the task goal, it's not necessary for accurate performance."

Congruity effects and articulatory suppression

Results found that the congruity effect was bigger in the change group when needing to compare physical size (Exps. 1 and 2) but similar between the two groups when comparing numerical size (Exp. 3 and Saeki, 2007).

So the authors averaged data from all 3 experiments to see what was going on in the first 3 blocks (i.e., phase 1).  In order to read the chart, you have to remember that except for the block 1 in the first cycle, all block 1s followed the fourth block (i.e., phase 2).

As you could see, numerical judgment in the fourth bock has a significant interfering effect on physical judgment in the first block though the effects faded away in the 2nd and 3rd blocks.  However, the performance of the continuation and change group didn't differ in the judgement of numerical size.

Some interesting asymmetry effects observed here and are in accordance to findings of existing literature...

• The impact of numerical size on physical size judgment gradually emerge during child development (Does make sense since kids learn to judgment physical size before learning their numbers.  For more time to practice the judgment of physical size as the brain structure is developing.)

(Therefore, the earlier you start to work on the ABCs of psychosis, the better.)

• The impact of numerical size on the judgment of physical size is typically smaller than the impact of physical size on the judgment of numerical size.

Thus, the authors suggested that the numerical feature dimension has to be more activated in order to compete with the physical feature dimension in response selection.

Moreover...

"a congruity effect was always observed for each type of judgment, indicating that stimulus presentation on each trial always led to some automatic activation of both the physical-size and numerical-size feature dimensions, which delayed responses on incongruent relative to congruent trials."

Think this is very important... both are activated albeit differential impacts.

(The competition between the intervening process for psychotic symptoms and simple psychotic cognitive process... Sure... like numerical size judgment to physical size judgment, the later developed intervening process might be an under dog to the simple psychotic cognitive processing.  That's fine.  As long as I can be functional, I bite the loss in efficiency.)

What about the inconsistent pattern in the interaction between articulatory suppression and congruity effect?

The issue might reside in the differences between task decision and response selection. While the phonological loop might support conflict resolution during the task decision process, the congruity effect might operate at the level of response selection... thus... the inconsistent pattern.

The phonological loop and two types of control/operation

Norman and Shallice's model of cognitive control (1986)

• The limited-capacity "supervisory attentional system
• lower-level "action schemata activated by environmental cues and compete with each other to control action

Love this wording "bias"...

• In certain circumstances, "input from the higher-level supervisory attentional system is necessary to bias the competition towards the favored schema." 
• The consistent impact of articulatory suppression indicate the role of subvocal supplementation in the biasing process during the goal/task competition.
• The lack of consistency in the effect of our concurrent tasks on the size congruity effect: Stroop-like phenomenon "may operate at a lower level of control."
• "It could be argued that subvocalization is a process whereby explicit and declarative forms of working memory are used to facilitate the implicit procedural system, providing an ongoing set of cues that protected action from disruption by recent habits."

(Can't tell you how many times when my delusional head was trying went on entertaining observations or things heard shared or not with the others... I have to come out and stop the process... with all means possible... starting from the most basic... repeating to myself... "I am delusional"... however effective it might be.)

The authors' conclusion... "the phonological loop can play an important role in the control of action."

Baddeley, Allen, & Hitch (2011) Binding in visual working memory: The role of the episodic buffer

The notion of binding is an interesting one... reminding of the paired-associations I have entertained else where...  (too many elsewhere in the dungeon of limited my words that I can keep track not where them words are.  lol 8-X)

On a lousy weather afternoon... done taking notes on this paper...  Lightening and thunder running wild on the outside paired with pouring rain when I plowed away jotting down notes on the paper "Binding in visual working memory: The role of the episodic buffer". Like splitting on the outside while binding on the inside? lol

For psychotics, one skill we have to learn is to unbind... at the feature level, object level, or in the episodic buffer or not.  The good thing, according to the following, is... you can do something to interfere... Let's jam up the limited capacity with alternative processes... imposing excessive workload to disrupt the fragile bound object!  Will it work.  Donno.

Baddeley, Alan D., Allen, Richard J., & Hitch, Graham J. (2011). Binding in visual working memory: The role of the episodic buffer. Neuropsychologia, 49(6), 1393-1400.

What is working memory for Baddeley, Allen, & Hitch?

"We use it principally to refer to a broad framework of interacting processes that involve the temporary storage and manipulation of information in the service of performing complex cognitive activities."

1. The two slave systems: Phonological loop and visuospatial sketchpad
2. The central executive (with no capacity for information storage).
3. The episodic buffer: A storage "accessible through conscious awareness and provides the milti-feature binding mechanism-- controlled by the central executive.  (Somewhere in time but I don't remember when... I remember reading that episodic buffer is sort of like a spin-off of the central executive.) 

The model as of Baddeley (2000)

1. Exploring the episodic buffer

As seen in the above diagram for the model as of Baddeley (2000), originally, it was assumed that everything bound by the buffer has to go through the central executive.  Under this assumption, it's reasonable to assume that the disruption of CE function should disrupt the binding of features into an integrated presentation... such as that ice-hockey playing elephant.

Research paradigm: using dual task methodology to study the binding of features in visually or verbally.

(As I was reading about that ice-hockey playing elephant yet another time the other day, this man on the street was talking about the elephant he was trying to sell.  When stealing a smoke outside of the cafe, I saw these two bronze elephants... and made an interesting observation...  It's more difficult to look at an elephant and try to envision it playing ice-hockey... the binding of the image doesn't go as smooth and stable as binding the image up... frame by frame not not... by retrieving the features directly through LTM. Don't know how common it is...  It was quite funny though... like the LTM-based elephant was playing ice-hockey on top of leisurely throwing out triple toes for the sake of it while the one based on both LTM and external visual stimuli could barely keep the gloves to its hand.  Funny enough... given that I am psychotic, my head should be really skilled in this binding thing since it could bind the most irrelevant stimuli... shared by the others or not... It might speak of the unmentioned power of LTM or the interfering effect of real visual input... unless the central executive was simply in a mood of chilling and didn't want to work too hard? 8-O lol 8-X)

2. Binding in visual working memory

1. Limited storage capacity: Automatic biding of features into objects with a storage capacity of 4 objects (regardless the features for the objects).
2. Limited capacity for attention: Its attentionally demanding to combine features into objects and maintain them in the visual working memory (Wheeler and Treisman, 2002) (You see Treisman... you can guess that it's about attention.)
3. The third possibility: The initial binding of features into object is automatic but the maintenance takes effects. 

(One problem of disordered thinking is that I can't stop my head from binding things together... faulty automaticity at fault... not me...)

The rationale behind the studies done to address the third possibility:  The participants had to carry out simple or complex verbal task (attention load) while performing feature and binding task (encoding phase).  Since the concurrent task is verbal in nature, shall there be interference effect, it's gotta be the issue of the workload on the central executive rather than the visuo-spatial processing.

So they say, a picture speaks a thousand words... the following figure shows you all the studies done to test the third possibility.  While a, b, c, d, and e represents how the color and shape features are presented, f and g are the recognition probe (i.e., did this appear in the previous presentation?)

Study result of presentation a: 

Counting backwards 3 digits interfered greatly with performance accuracy, which indicate the role of CE.  However, the effect was no larger for binding than for features.  Findings of this study was replicated in subsequent experiments utilizing different concurrent tasks.  These findings seemed to suggest that the binding of features into objects in visuospatial sketchpad is automatic and does not require [much] attentional resources.

The issue... could the binding of shape and color something too "basic, rapid and automatic" to impose cognitive load?

3. Binding across space, time and modality

In three sets of studies, the features were presented in separated fashion...

• c: separate presentation of features
• d: separate presentation of features in time

Results: Performance in c and d was above chance level although not as accurate as in the unitized presentation (a).

• e. separate presentation of features in modality

Results: Performance in e was as accurate as in the unitized presentation (a) and was no more disrupted by concurrent backward counting task.

Thus, "objects requiring the binding of features across space, time, or modality are no more disrupted by an attentionally demanding task than are those for which the features are unitized at presentation." Yet, such findings were inconsistent with the hypothesis that episodic buffer is at the mercy of the CE.

Love this part...

"Our finding that disrupting Gestalt principles does not engage executive processes in binding might seem to imply that the perceptual system binds all features automatically.  However, if this were the case it would surely result in perceptual chaos, potentially combining totally unrelated features to create illusory objects."

Ya... this is life with psychosis.  Like... my head's ability to bind things together is my demise.  Therefore, the pursuit to find ways to unbind.  Since normal people don't do it, it shall mean that some part of the binding between the psychotics and the normal is different... CE related or not.

4. How are bindings maintained?

Though there seems to be automaticity in binding, results of some studies found the retention of found objects to be more fragile than those of the features.

b: sequential presentation as opposed to presenting stimuli in an array
Results:

As you could see easily... recency effect... while performance on bound object suffered more than features in earlier items.  Also, when comparing sequential vs. simultaneous presentation, memory on bound object was significantly worse than feature objects in sequential presentation.  In terms of performance under the concurrent task of counting backwards in decrements of two, there was no differences between the sequential and simultaneous presentation conditions; thus, the fragility in bound object is independent of attentional load.

The unanswered question: What contributes to the differential findings in the sequential and simultaneous presentations?

What is forgetting? A reflection of limited storage or an over-write process when participants intend to register new items?

Suffix paradigm: Presenting a suffix the participants have to ignore after an array of stimuli.  If bound objects are more fragile or susceptible to overwriting, it should be more disrupted by the suffix.  The "implausible" suffix does not contain features drawn from the target set while the "plausible" suffix doe.

Implausible suffix: Small but statistically significant decrements though no major differences between object and feature memory.  It didn't matter whether the suffix changed from trial to trial or not.
Plausible suffix: As you should be able to see in the figure below, the plausible suffix caused significantly more disruption on the memory of bound object than that of features. In terms of the level of decrements, smaller decrements similar to those observed in the implausible suffix condition were observed.

The above experiments applied the probe recognition paradigm (e.g., 2f, 2g).

Cured recall experiments were conducted to replicate findings of the probe recognition paradigm.  It was found that plausible, semi-plausible (i.e., stimuli consisting features from one dimension but not the other) had equivalent effect on cued recall... both larger than the impact of the implausible suffix.

What are the lessons learned?

Disruption has nothing to do with the intent to encode the items or not but has to do with the nature of the item.  The findings also reflect two processes:

• Filtering mechanism: To-be-ignored items are required to be filtered out before entering the WM.  Given the equivalent impacts of plausible and semi-plausible suffixes, it suggests that the filtering operates at the feature level. "as stimulus-based filtering draws on knowledge of task demands and what has been previously encountered, this process reflects one way in which the products of prior experience can impinge on perceptual input before information is encoded into working memory."
• A process of overwriting:  It's assumed that anything passing the filter is automatically combined as an object.  This level is particularly susceptible to overwrite and the loss of representation... a way to explain why bound objects suffers more than features. At the same time, the assessment through recognition probe or cued recall intends to assess memory of items at the object level. With features, there is a greater redundancy since they appear both at the feature and object level.

Such findings provides supports for the assumption of the displacement in a limited capacity store rather than  feature-based interference (where fully plausible suffix should be more distruptive than semi-plausible suffix).

"Visual stimuli are at least initially represented at both the level of constituent features and of objects.... with filtering proceeding on the basis of features and overwriting particularly impacting on object representation."

How does the above have anything to do with the Working Memory model?

Features are bound into objects in the visuospatial sketchpad before being fed into the episodic buffer.  It's in episodic buffer when objects were conscious retained and manipulated as per the command of CE.

5. Does binding depend on the hippocampus?

Findings of a lot of studies seem to show that binding seemed to involve hippocampus.

Then, along came Jon who had reduction of about 50% of both left and right hippocampal regions while, in comparison to the performance of 6 undergraduate students from the University of work, his performance in a range of visual binding tasks as described earlier didn't seem to differ all that much from the college students... In reality... better at times...

This other lady with a left medial splenoid ridge meningioma removed was found to have a very marked deficit in the short-term binding of color and shape although the intact ability in long-term visual or short-term verbal binding.

6. Binding and the episodic buffer

What about verbal binding?

"As with the visuo-spatial binding experiments just described, we found no interaction between concurrent load and binding. The binding of words into chunks therefore appears to reflect automatic processes, this time clearly involving long-term memory. It does not appear to depend on the central executive."

Automaticity or at least semi-automatic.

Following is the revised model of working memory as of 2011.

.
To end this note... in the authors' own words...

"Our results do however place constraints on such models, requiring an explanation of (1) the lack of an effect of attentional load on the capacity to bind the features of shape and color, (2) the fragility of such binding, (3) the capacity to filter out “implausible” but not “plausible” suffixes and (4) the mechanism by which plausible suffixes disrupt the retention of bound objects."

Baddeley, Alan. (2000). The episodic buffer: a new component of working memory?

Baddeley, Alan. (2000). The episodic buffer: a new component of working memory? Trends in Cognitive Sciences, 4(11), 417-423.

The concept of working memory by Baddeley and Hitch:

1. It abandoned the concept of a unitary store in favour of a multi-component system
2. It emphasized the function of such a system in complex cognition, rather than memory perse.

Anatomical affiliation

• Phonological loop (BA40, BA44)
• Visuospatial sketchpad (BA6, 19, 40, 47)
• Central executive (... frontal lobe areas)

Also... the loop... is it designed for language acquisition while the sketchpad, visual semantics?

My thoughts on the notion of language... 

1. What is a language? 
2. What is a vocabulary?  
3. What is grammar?  
4. What is syntax?...

(Why entertaining this/these?)

Back to the paper, where does the component of Episodic Buffer come from?

Problems for the current model (as of 2000)

1.1. The phonological loop: limits and limitations

The phonological contains both a temporary storage and the articulatory rehearsal process. Without the articulatory rehearsal process, traces of the auditory memory decays within a few seconds.

This model use useful in explaining the following phenomena:

• The phonological similarity effect: Items more similar in sounds are harder to remember although visual or semantic similarities have no impact.
• The word-length effects: Because longer words takes longer time to rehearse and reproduce, the longer time requires to do these makes it easier for traces of memory to deteriorate.  
• The effect of articulatory suppression: When people are prevented from rehearsing items to be remembered, their recall performance decline and the word-length effect disappears.
• Transfer of information between codes: Articulatory suppression removes the phonological similarity effect for visually presented items but not for auditory ones.

(Come to think about it... there is something interesting about the transfer of information between codes... In times when I was very drugged out though not yet to the state of from 2-3 words, I had problems reading while comprehending the texts.  Yet, I found out that I had no problem listening to the same texts in auditory format.  So I had the computer reading the texts to me.  Also, sometimes, when typing, I had to type things out without looking at the screen and that's how thoughts can flow out... Feels as if these have something to do with the notion of transferring information between codes.)

• Neuropsychological evidence: What is essential for rehearsal is the central rehearsal code (i.e., speech motor code in dyspraxic patients) rather than its over operation.

There are phenomena that doesn't fit the model

• 1. Recall on visual representation of sequences of numbers do not suffer traumatically with the concurrent articulatory suppression task (i.e., pronounce words such as "the").  Generally, the digital span only drop from 7 to 5.
• 2. Patients with impaired phonological memory can recall about 4 digits when stimuli were presented visually.

What about visuospatial sketchpad? Theoretically, it's for the storing of patterns... not suited for digits.

Visual similarity effect?  In Logie et al., the authors found visual similarity effect except the effects are small and not limited to the articulatory suppression condition. (Under the assumption that, if you can count on the phonological loop, visual similarity or not should be an issue.)  Since the visual similarity effect is present during non-suppressed condition, it means the performance is not all based on the phonological loop... therefore, the info from these two slave systems might be combined somewhere.

1.2. Prose recall

With unrelated words, people can remember up to 5-6 words before starting to make errors.  However, in the context of a meaningful sentence, the span can be as high as 16... a manifestation of Miller's "chunking." Based on knowledge in LTM, the sentence is broken down to smaller chunks with the capacity set by the number of chunk as opposed to words.  But where are the chunks stored?  In phonological loop, LTM, or a different storage space?

The phonological loop hypothesis doesn't fly in the case of patient "PV." Patient "PV" had the loop capacity of 1 word and intact LTM has a sentence span of five.

This reminds me of the recurrent eras of from 2-3 words.  I was so drugged out that I couldn't read and couldn't understand people if they spoke in longer sentences because, when they get to the end of the sentence, I would have forgotten what they said before.  It was the drug effect.  What I eventually had to learn to do is... when reading, because my digit span went as low as 1 (like... what was the last word I read? Forgotten already), instead of trying to comprehend the sentences (extremely high tech), if not simply terms, I identified key words or chunks of words and deliberately tried to find them from LTM.  Sure, it took an awful lot of time to finish a sentence or two, and what was read was already forgotten, the way I saw it... at least some part of LTM got activated... path strengthened... and hopefully, it would make it easier for me to read the same texts again when, if, one day, I could grow out of from 2-3 words.  Did it work and did anything got retained?  I don't know.  One thing I do know is I did get to read something with a digit span of from 1, 2, 3 words.  

Also, while severely amnesic patients are uniformly bad at recall after a 20-minute delay, their immediate recall of a prose paragraph containing 15-20 idea units could be relatively normal.  The issues.... the amount of items far exceed the capacity of phonological loop with the recalling process might overwrite what's in it.   What about visuospatial sketchpad? Theoretically, it's unsuitable for serial recall and there is no evidence that only imageable sequences can be recalled.  What about the central executive?  Theoretically, it has no storage capacity.

It takes both the retrieval of knowledge in LTM and the manipulation on what gets retrieved to envision an ice-hockey-playing elephant. Sure the process can take place in LTM.  Yet, there is no evidence claiming patients with normal intelligence and grossly impaired LTM cannot get the elephant envisioned.

Also, Tulving had seen a densely amnesic patient to play a good game of bridge and win the game.  He apparently could keep track of what was going on and which cards had been played... a task beyond the assumed capacity of the two slave systems.

1.3. The problem of rehearsal

Think about the notion of rehearsal in phonological loop... equivalent to subvocal rehearsal adults often do when trying to memorize something.  The subvocal rehearsal is more advantageous than rehearsal in other modalities in two ways: First, people can generate the items by speaking them out... making it easier to be in a covert format.  Second, digits and words have intrinsic lexical representation, making it easier to repair the deterioration of memory during the rehearsal process.

Yet, how could the rehearsal be done in the visuospatial sketchpad or the other back-up store?

1.4. Consciousness and the binding problem

Existing studies showed the role of consciousness in information processing.

In this section, this author tried to explain to the readers that the model is lacking a component where complex info from different channels in all modalities (e.g., slaves systems, LTM) could be stored, manipulated, integrated, and controlled by the central executive.... a solution to the binding issue.

The episodic buffer

The episodic buffer is episodic because "it holds episodes whereby information is integrated across space and potentially extended across time, which makes it resembles Tulving's notion of episodic memory.  However, it is temporary and can feed and receive information from LTM. It's a component that interface with multiple systems and codes.  It's capacity is assumed to be limited due to the high demands in the tasks involved.  Also, it can be accessed "by the central executive through the medium of conscious awareness" and CE can therefore decided what to do about the information... attending to it or not, creating new cognitive representation or not, etc.

There is something interesting about the notion of episodic buffer and it's relation with LTM.  Reminds me of the strange psychotic experience of the reenactment of past psychotic episodes.  How did it happen? Either the central executive went out of whack and decided to do some recherche du tempt perdu through replaying some past psychotic episode.  Or, the out-of-whack potentially automatic and effortless process of knowledge retrieval decided to get the whole set of episodic memory replayed.  Regardless, the entire muti-modal episode need to be placed somewhere... a perfect place to be... episodic buffer.  At the same time, though I had no control over the retrieval and reenactment of the episode in my head, I was capable of trying my best to keep it running in the back of my head... albeit the inevitable bodily sensation.

2.1. How is the buffer implemented biologically?

fMRI studies showed greater right frontal activation for integrated info while the activation of unintegrated retention were more in the posterior areas (verbal and spatial WM).

2.2. So what's new?

Episodic buffer as a new component or a fractionation of Central excecutive.

The revised model:

• WM as multi-component
• WM is not simply the activated portion of LTM
• Reject the view that "the slave systems merely represent activations within the process of visual and verbal perception and production." (Bye bye to dual channel)
• WM is considered a seperate system from LTM and perceptual and motor function because it has it's own "dedicated storage process.

Some outstanding issues

"conscious monitoring of the evidence supporting an apparent memory plays a crucial role in separating accurate recall from false memory, confabulation and delusion."

Not quite sure where the notion of delusion comes from.. since I have entertained this notion else where... in short, a multi-dimensional concept.

Baddeley, Alan. (1996). Exploring the Central Executive.

It took me a good 2-week time to reread this paper five times... including the last time when I took the notes down.

After 2 weeks, what I learned about this paper (and based on what I read in Dr. Baddeley's more recent publications... all the way into 2013) is that it was as he was at a point of trying to figure out whether the central executive should be considered the homunculus or whether it should be fractionated?  It was as if he was at the point of wondering whether the functions of the central executive include components like the coordination and plan-switching of the WM slave systems, the attention controller, and the selection and manipulation of information in Long-Term memory (inhibition and "excitation"?).

In this paper, what he was doing was really "Exploring the central executive"--as stated in the title of the article... and, in the end, he frankly stated that he was not sure yet which way the future might lead... fractionation or not.

I don't know why my head wanted me to drill this paper this hard.  Yet, interestingly, when reading his more recent paper including those targeting the model revision, it put things in a different perspective... the process of becoming of the theory itself.

I like it!

My two cents on Fractionating the CE

Thinking back to my psychotic experiment for my psychotic dissertation... where... I didn't realize till later than I was making people hear voices and see things.  8-X

Given the 99% principle, I am hardly sure about no nothing.  Yet, I am almost 100% confident that the data collection and analysis adhered strictly to the protocol... including the processing of the random assignments of participants to the control and experiment groups (controlling for gender, ESL status)... not to mention the post-experiment interviews... all the way to the last data point collected... right before the Apocalypses kept on coming back like a broken record.

There is something strange about how it worked.  How certain executive function could remain intact (relatively) when the mental status was at the institutionalizable grade.  Sure, towards the hospitalization, I was hallucinating and being "all" delusional as the experiment was taking place... no different from any of my cohorts in the psychiatric ward.

How can psychotics with manageable symptoms perform tasks and hold jobs?  An interesting question.

Perhaps, because of the intact executive functions albeit the dysfunctions in the rest?  Something to support the fractionation notion of the central executive, I guess. 

The following notes are for myself.  Might be too detailed for you... At the same time, how the notions etc in this paper are relevant to psychosis... might need to do it in another post since this one is already too long.


Baddeley, Alan. (1996). Exploring the Central Executive. The Quarterly Journal of Experimental Psychology Section A, 49(1), 5-28.

Strategies for analyzing the central executive

The executive as ragbag

In this section, Baddeley acknowledge the fact that their initial specification of the central executive (CE) was vague and CE is "little more than a ragbag" stuffed with things like strategy selection, planning, retrieval checking.  In 1986, the theorists finally attempted to specify CE in greater details... relying heavily on the Supervisory Activating System (SAS) component of Norman and Shallice's (1980) model of attentional control.

The central executive and the frontal lobes 

Abundant evidence showed that disordered executive control are associated with damages to the frontal lobes (Shallice, 1982, 1988).  While the author regarded highly of the neuropsychological evidence, he also cautioned that if the CE is identified exclusively with frontal function, there is a risk of excluding executive processes because they are not frontally located or considering functions as executive simply because they are based in frontal lobe.

"I shall make extensive use of neuropsychological evidence, much of it from patients who have damage to the frontal lobes, but I do not propose to use anatomical localization as a defining criterion for the central executive."

Although this section is short, it provides us with Baddeley's view on the role of neuropsychological evidence in his theory.

Psychometric approaches to the central executive

Two separate but related lines of research:

1. Traditional concept of intelligence
2. Working memory involves the simultaneous storage and manipulation of material (Baddeley and Hitch, 1974)

The more traditional psychometric approach is based on the assumption that "intelligence measures reflect the operation of a central cognitive processor, which could potentially be identified with the central executive of working memory."

Intelligence... What is intelligence?  An interesting question people have been entertaining since its inception.    Is one one single general capacity that could be captured by Spearman's g, or could it be broken down into subprocesses... and what might these subcomponents entail?  Also, how do the performance on the subcomponents relate to each other?

Reminding me of Dweck... fixed entity or incremental in nature... intelligence.  Since I am definitely getting old, with the synergistic effects of aging, my mental health conditions and the side effects of meds, I would like to subscribe to the fixed notion.  At the same time, since I have lived many a time from 2, 3 words, incremental might serve my ego better. 8-O lol 

The Homunculus: Friend or Foe?

What approach does Baddeley adopt? "...we adopt neither the anatomical nor the classic psychometric approach."

Should CE be considered the homunculus or be fractionated?  Starting from treating it as the homunculus before the evidence tells otherwise... and the path traversed so far...

1. The coordination of the WM slave systems as the function of CE... research on patients with Alzheimer's disease.
2. The link between CE to the SAS system by Norman and Shallice... research on random generation... plain switching
3. CE could act as an attention controller
4. CE's capacity in the selection and manipulation of information in Long-Term memory

The following provides more detailed description on the path traversed mentioned above.

Approaches to fractionating the executive

Following are the areas of research investigating Central Executive (CE).

Dual-task performance

The attempt to devise a measure on Central Executive (CE) stemmed from the intention to study Alzheimer's patient's deficit memory. It was hypothesized that this might reflect the problem of CE in coordinating the slave systems of working memory.

Many a thing we know about stem from what's deviated from the norm.  A good way to message my own already too much in the grandiosity end of ego.

First set of studies: Tracking task plus 1 distraction task: articulartory suppression, reaction time to a tone, digit span.

Dual-task		AD patients vs. Elderly and young controls
Visuospatial	pursuit tracking
Phonological loop (Distraction task)	Articulatory suppression	No significant difference though significant impairment in AD patients reported elsewhere
	Reaction time to tones	significant decrements in speed and accuracy than the control
	Digit span	Significantly decrease in tracking and memory performances in AD patients than the control

Results are consistent with the hypothesis that it might reflect AD patients' problems of CE in coordinating the slave systems of working memory.

Other interpretations:
a. The cost of the peripheral task rather than the issue in coordination

1. Difficulty levels adjusted for all group.  There is no reason to assume the control groups are not devoting all their resources to perform the task.
2. Deficit found in AD patients in this study and others are not found in normal aging.  As some function of WM does appear to decline with age, it supports the notion of fractionating the CE.

b. A reflection of overall deficit such as the notion of general intelligence.

1. The results of dual-task performance did not support this notion given the performance of elderly control.
2. It replaces problems associated with CE with those with intelligence.

Second set of study:

• Varying task difficulties without increasing the demand for dual-task coordination 
• Yntema and Mueser (1960) had shown that the time it takes to categorize a word would increase when there are more categories to select from.
• The category judgment task intended to assess the impact of the number of simultaneously presented categories on the time to decide whether a word belongs to a category.  The participants were asked to decide whether the items they were provided belonged to the target categorie(s).  If the answer is yes, they have to press the key responses on the screen (Guess this is the visiospatial part). There was a-six month interval between the tests during which the disease in the patients have progressed.

Following are factors showing significant results with key pressing the visiospatial task (I think) and categorization the Phonological task:

		Dual-task (modulating difficulty level through the number of categories)
	Var	Correct	misses	correct RT
Time 1	AD patients	Substantial drop between 1 to 2 and 1 to 4 categories	Substantial drop between 1 to 2 categories	Substantial drop between 1 to 2, 2 to 4, and 1 to 4 categories
	Elderly control	ND	No sig difference	deteriorate with increasing numbers of categories.
	Group differences	yes	yes	yes
Time 2	AD patients	Results of two-way ANOVA with repeated measures found AD patients' performance to deteriate significantly over time and their performance to be poorer when the number of categories increase.  However, no significant interaction effect.	Misses increase significantly with the number of category but not significant in test session or the interaction term.	Response time increase significantly with the number of category but not significant in test session or the interaction term.
	Elderly control			Response time increase significantly with the number of category but not significant in test session or the interaction term.

Based on these results, the authors concluded that, though the notion of difficulty level is a tricky one, the increase in task difficulty level will make the task more sensitive to the disease progress.

On the brain side: Executive task might be link with frontal-lobe function.

Disinhibited behaviours: "disturbed attention, increased distractibility, a difficulty in grasping the whole of the complicated state of affairs... while able to work along old routine lines... but cannot learn to master new types of task."

1. Verbal fluency task is associated with left frontal lobe and the executive process of search and retrieval from long-term memory.
2. Wisconsin Card Sorting Test... preservative errors are linked to frontal-lobe damages. 
3. Expert opinions on disinhibited behaviour

"disturbed attention, increased distractibility, a difficulty in grasping the whole of the complicated state of affairs... while able to work along old routine lines... but cannot learn to master new types of task."

This was (hopefully was) so very me... an example... when I was trying to work on the marketing report before first institutionalization.  Something I have to make sure... don't allow myself to progress back to this stage.  Also, no truer words... the failure to select the focus of attention although different (kaputt) executive processes might differentially associated with overt behavior problems or symptomatology isn't etiology though they could be related.  At the same time, albeit the differential physiological basis, there might be similarities in how the dysfunctions come about.  Something interesting though... everything was dedicated to psychotic processing... though there was still some behavioral control since I didn't yell at all passersby crossing my path.

The study was conducted using the computerized tracking task and found that patients with or without disinhibited behaviours do not different in their performance in verbal fluency or Wisconsin Card Sorting performance.  However, those with behavior disorder demonstrated clear decrease in performance in the dual task condition where the box-crossing and digit span tasks were combined.  The results was similar to that of Alderman where patients failing to benefit from the token economy system had more problems with the dual-task test than with standard "frontal" tests.  Both pointed to the association between poor dual-task performance and behavioral problems.

Methodological and assessment issues: Inconsistencies in existing dual-task research led to the question of how to combine tasks and calculate the performance score.

The concluding words of the author about lessons learned from the dual task research is that "the capacity to carry out two tasks simultaneously appears to be a candidate for one separable feature of executive function"  although more research needed.

As for the quote on "the capacity to carry out..."... There are times when things are within our control, in this kind of condition, if multitasking is impossible, let go of it as the trade-off of functionality... till... maybe... one day, you can work with music in the background.

Coordination: I definitely have problems coordinating multiple tasks, starting from coordinating between my psychotic and non-psychotic kinda thing.  Worst off, after the accident, my already not so well-endowed department sensory motor coordination became even more kaputt with the even the body doesn't quite pay me no mind either. 8-O lol

Multitask: Multitasking is especially difficult when the condition is bad.. More exactly, only one default task is set to be performed--psychotic processing.

Random generation

Encoding is hard.  Alright... never promise you a rose garden.  Yet, the good news is... if you are careful about what you encode.... retrieval seems to be a process close to automatic--the limited role of the attentional process in retrieval. Interesting notion I came across here---random generation as a manifestation of knowledge retrieval.

Results of studies on random generation of letters and studies where random generation was combined with a card-sorting task were consistent with the notion that the process of random generation was dependent on a system with limited capacity-- the faster the rate, the less random the output, and the larger the pool of selection, the slower the generation rate.

The author found Norman and Shallice's (1980) model to be of great help in explaining the aforementioned research.  Norman and Shallice's model posited two sources of control of actions: the schemata (learned habits that might have reached automaticity) and the Supervisory Attentional System (SAS: an attentional system capable of overriding habitual behaviors and initiate new ones).

From this viewpoint:
Random generation of letters for instance involves:

• Schemata: Generation is the manifestation of the habitual letter-retrieval schemata at work
• SAS: SAS makes the generation random by constantly breaking up the stereotyped sequence in the schemata.

Combined with card-sorting

• SAS: SAS is also required when sorting cards into different categories

Disruption of CE operation

Shiffrin and Schneider's (1977) notion of automaticity comes handy here with automaticity referring the state when stimulus will get response invoked... not need for the attentional demands.

From this viewpoint:
Random generation is the opposite of automaticity where the goal of the task is to minimize the association of what's to be generated with what got generated before.

Informed by these theoretical notions, the author wanted to know what random generation can tell us about the limited capacity executive system through a studying combining random generation through keypressing with performance on a memory span task (recalling sequences ranging from the length of 1 to 8 items).  The study hypothesized that: "If performance depends upon a general purpose system, then there should be interference between the verbal memory task and the visuo-spatial generation task. Furthermore, if the system reflects a limited-capacity working memory, then the degree of disruption of random generation should increase with concurrent memory load."

Random generation competes for the same limited capacity as is necessary for performance of tasks depending more on the functioning of central executive.

1. Articulatory suppression (counting 1 to 6) had no significant effect on random generation.
2. Category generation significantly disrupted the performance on random generation
3. Verbal fluency seems to depend heavily on executive resources (susceptibility to concurrent digit span)
4. impairments of patients with dysexecutive syndrome
5. Patients' impairment to perform AH3, a test of fluid intelligence, which can be considered as an index of executive function and depending on the functionality of frontal lobes (Duncan, 1993).

Yet, in the dual-task condition where keypressing and number generation is combined, participants seemed to have performed well with concurrent digit generation, category generation, and holding a sequence of digits of span length had similar impact on the randomness of keypressing.  Yet, asymmetrical interferences observed because concurrent keypressing was found to have less impact on digit generation.

Physical ability developed before numerical?

A model similar to Roediger's (1993) simpler retrieval version  of SAM model (Raijmakers and Shiffrin, 1981) was proposed to explain the processes underlying random generation.  The model involves setting up a retrieval plan, running it, checking for suitable randomness, and generate output at the appropriate time if passing the randomness check.

• Time-limit imposes issues in the switching of retrieval plans.
• No time limit: Subjects should be able to switch plans all the time and there's no need to check randomness.
• Repeated use of the same plan will result in stereotyped and non-random responses.
• Interference with plan switching will increase redundancy

What the plan switching notion would, thus, predict a general reduction in randomness rather than catastrophic breakdown when the plans can be operate simultaneously (e.g., keypressing and digit generation).

Testing the switching hypothesis

Trails test from the Halstead-Reitan battery: joining numbered squared (Trails A) and alternating between lettered and numbered squared when connecting the squared A-1-B-2-C-3 (Trails B).  Patients with frontal-lobe damages seems to have problems with the alternating task.

Since you can't make people do the keypressing task and do the Trails test at the same time, the verbal equivalent of the Trails test was used in the study.
Study 1
Keypressing alone or with a concurrent task

1. Reciting alphabets: no
2. Counting digits: no 
3. Verbal equivalence of Trails B "A-1-B-2-C-3": detectable effect on the randomness of keypressing

Study 2
Verbal equIvalence of Trails B starting from F-9 (F-9-G-10-H-11-I-12...) caused disruption in keypressing performance and the task itself was disrupted as well.

The authors concluded from results of these studies that the random generation's demand to constantly switching retrieval plans might be what disrupt the operation of CE... though more research needed.

Issues to be addressed... how does random generation assert its influence?

• the need to switch plans?
• the problem to access plans?
• the monitoring of outputs?

Moi, get done with the need to switch... manually insert the new default to acounteract the biological defects.

Baddeley et all (1984): a degree of automaticity in the retrieval process.

Automaticity? Drill, drill, and drill.

Craik (1995): RT task and word retrieval.... RT was not affected by whether subjects were instructed to focus principally on retrieval or RT. Based on the study results, Craik suggests that learning depends on the available attention, retrieval depends on the operation of the retrieval mode.  Also, encoding is more associated with the left frontal lobe while retrieval, right frontal lobe.

You just be damn sure that you get the right stuffs encoded.

Selective Attention

Selective attention--one more plausible component of CE... the ability to attend to something while discarding the others.

Unfortunately, results of existing research on the impact of aging are inconsistent and make it difficult to come up with a cogent hypothesis about how it really works.

The problem of conducting theoretically driven studies on aging is that almost everything eventually decline with age somewhat.  When the elderly performed poorly on a task, it's difficult to know exactly underlines the observed performance unless all possible factors can be ruled out.

Research on aging deficit using single measure

1. General intelligence (Rabbitt, 1983)
2. Speed of processing (Salthouse, 1991)
3. Reduced capacity for inhibition (Hasher & Zacks, 1988)

Study:
After partialing out the effects of general intelligence and speed of process, try to figure out whether there are additional factors impacting the participants' performance.  If so, it would be a evidence to support the fractionation of CE.

Research paradigm:
Pressing key as fast as possible when the target stimuli occurred.  (The additional task of counting the number of stimuli didn't change the pattern of the result.)
Manipulation of attentional demands: 1. irrelevant stimuli the participants had to ignore (Exp. 1 in other modality while Exp. 2 and 3, also in the same modality). 2. Instructions requiring them to switch from responding signals in one modality to those in the other.

Since it is not a published article, I tried my best to restructured the results in my own way here... shall you be able to comprehend.

I don't know why it was not published (unless published under a different title) but I think there are some interesting experiments.

In the first two experiments, results consistently showed that irrelevant stimuli in the unattended modality slowed down the RT with the elderly slower than the younger.  However, controlling for the effect of "fluid intelligence," the age effect disappeared.

The condition in which the participants were asked to switch their attention to stimuli in the other modality was taken out from the third experiment because slower RT, especially the first response after switching, were observed and the age effect disappeared after partialling out the fluid intelligence factor in the first two sets of the experiments.  The authors suspected that it might be the manifestation of negative priming.

Negative priming... still related to worldview--> the inability to wsitch since you have been thinking this way since you became psychotic.

In the third set of the experiment, the authors added the scenario of irrelevant stimuli in the same modality (i.g., visual, auditory).  Controlling for the effects of "fluid intelligence" and "processing speed" (defined by the mean reaction time to ignore irrelevant stimuli in the unattended modality), there was still age effect on the time it takes to respond to target stimuli while having to ignore the irrelevant stimuli in the same modality.

The author stated that the findings were in line with Hasher and Zacks' (1988) proposal that "age limits the capacity for utilizing inhibition to sharpen attentional focus and limit distraction."  Since age effect disappeared when the distractors were in a different modality, it means there is no general deficit.  Thus, CE might have multiple components.

Low latent inhibition? We age faster? 8-O

The author also speculated what the differential inhibition abilities between the young and the elderly might be.

Ain't got no doubt that I have reduced ability in the inhibition department.  Also "subjects were slower in responding when they had to ignore irrelevant stimuli, particularly when these occurred within the same sensory dimension." No doubt... no wonder the work would suffer... take the phonological loop for instance... gotta maintain auditory hallucinations and verbal information together... overworked la!

For me, it sounds almost like... if the attentional focus is represented by a bell-shaped distribution with the target at the center, it's almost like the distributions (attentional focus) between the young and the elderly differ in the kurtosis perspective of the distribution (and of course... shall the mean and skewness of the distribution be set to zero).

Activation of long-term memory

A major portion of what I have run my mouth on is about the encoding and retrieval of LTM.  Nelson and Narens and Flavell all had spoken of LTM... Didn't really grasp the importance of LTM until Chi.

CE can activate long-term memory temporarily.

The story of KJ: KJ was an amnesic patient whose performance on the logical memory subset of Wechsler Memory Scale was above average although half an hour later, neither could he recall the stories and nor did he remember having been told these story.  The question is... how did he get the above average performance?

The author speculated that, in order to comprehend, KJ would have to set up a mental model about the stories using components of LTM.

Whether the mind come into existence is a tabula rasa is not the topic of discussion here--though possibly not... Based on studies conducted on "non-newborns," it appears that the phonological loop is no tabula rasa  and it is a system "developed on the basis of the phonological experiences of the remember."

Think about auditory hallucinations... where did they come from...  they never sound like Greek to me (since I don't understand Greek).

According to the author, the view of STM represents active LTM components itself seems theoretically insufficient since it provides no insight into the processes involved.  He is more interested in the differences between how these components behave in the phonological loop and visuospatial scatchpad, or the role of the slave systems in the encoding of memories of multimodality.

Research on the role of WM in the retrieval and encoding of LTM:

1. Recency effect (Baddeley& Hitch, 1993)
2. Working memory span (Daneman & Carpenter, 1980): The simultaneous need for the participants to process and store information by presenting them with a series of sentences and ask them to recall the last word of each sentence.  The maximum number of sentences to be processed while retaining the final word is the working memory span, which typically range between 2-5.

1. Turner and Engle (1989) replaced arithmetic operation with the sentence verification component of Daneman-Carpenter task.  This provided evidence for a more general limited-capacity system as opposed to a language processing system.  Score correlated highly with intelligence but exactly what it means... the author seemed to be unsure.
2. Cantor and Engle (1993) adapted the fan effect (Anderson, 1974) assumptions and techniques.  Anderson (1974) found out that it took participants less time to verify an object with fewer attributes/propositions than those with more. He explained the pattern by stating that each unit of the sentence triggers a limited amount of activation that spread to the associated features.  Since the amount of the activation is limited, the link to the associated features would be weaker when there are more features/propositions.  Cantor and Engle found that "the slope relating set size to verification time is steeper for subjects with a low working memory span (i.e., Daneman & Carpenter, 1980)" than for those with a high working memory span-- high-working-memory span subjects might have more activation available.  

"working memory might reflect the temporary activation of areas of long-term memory, with high-span subjects being able to activate more extensive regions of long-term memory."  Low latent inhibition... we psychotics? 8-O lol

Fan effect: like the example used in the analogy study on how to treat cancer patients... be targeted, identify the attributes of the symptoms--the themes-- rather than incidence by incidence.  Without the language, patients and people in general actually already do it automatically.  Since patients with thought disorder are already thinking too much (preferable or not), we should be able to learn to think thematically--a way to help unrest our brains to learn to think.

• Working memory span, fan effect, and Sternberg's "internal memory scanning mechanism" (the time it takes to decide whether a probe cames from a set is dependent on the set size.)

1. Conway and Engle (1994) conducted a study linking the fan effect and Sternberg's finding.  Participants were taught 2, 4, 6, and 8 letters to the extent that they can recall them perfectly and they can identify whether a letter belong to a given group.  The reaction time increased with the increase in set size and the slope between the set size and reaction time was steeper for than low-working-memory span group than the high group.  In addition, by delaying the presence of the probe after showing the set to be considered, Conway and Engle found that working memory span has no influence on the time to retrieve the info but the time it takes to perform verification.  It was thus concluded that the task of memory retrieval is automatic (imposing no stress on the limited-capacity system) though the time it takes to verify is dependent on the capacity of the system. (My question... is the retrieval from the STS or from the LTM?)

Love this part... "the data described so far are captured well by a model that assumes that individual differences in working memory reflect differences between subjects in the amount of activation available.  However, despite of this supportive evidence, Engle reports two further observations that cause him to abandon this hypothesis."  (Holly cow!  I really admire these researchers... like... not kosher... dumb it out?!)

First, what affects the high-working-memory group fail to have impact on the low-working-memory group

1. Dual task condition with category-generation task and something else
2. Having subjects to learn a subset of items to not include in category generation... even when the category they learned to exclude was totally different from the category they had to generate from.  Second, even more for the excitation hypothesis... how Sternberg's paradigm was applied... in Conway and Engle (1994).  Engle was concern that there were redundancies in the letters he used in the four sets in Conway and Engle (1994) and decided to run new experiments ridding off the redundancy issue.  In the results of these new experiments, the group difference in the slopes disappeared.  As a result, Engle entertained the notion of an executive with limited capacity to inhibit irrelevant information.

The concluding words of Baddeley for this section: "The presence of individual differences in inhibitory capacity does not, of course, rule out the possibility that excitatory processes also differ across individual.  However, Engle's results suggest at the very least that we need to look very carefully at claims for such differences."

The plausible automaticity in knowledge retrieval: As in the FOK research, FOK might not be accurate.  Yet, false positive is OK (all's symptom)... thus no need for verification as as to minimize the workload of WM.  Considering that our WM might not be so sharp, though might not be doing anything constructive, no nothing detrimental at least... Do no harm.

This is why I have a liking about the notion of fuzzy algorithm... something I really have no inkling about.  No need to be exact since the purpose is to survive... not to conduct scientifically based research.

Sure, there are individual differences in our capacity and we all have our own bottleneck.  At least, we have our own bottleneck to push and our own best to strive to perform in the face of life.

Conclusion: Should we sack the Homunculus?

More work needed... the future is yet to be seen.


The notion of low and high capacity kept on surfacing in this line of research.  The way I see it, having the realization of how the capacity can be constrained as a result of the medication and symptoms, let me accept the reality that I belong to the low capacity group.  As a result, I have to make extra effort on the things I attend to because what I attend to is likely to be encoded in my hard drive and be retrieved in the future.  The notion of phonological loop as no tabula rasa, for instance, also supports my way of thinking... that is... the operation of CE is partially dependent on what you have in LTM... remember the classic notion in data analysis... garbage in, garbage out... be ware what you put into the analysis engine. Grand delusional systems did not get built in one day... It's built through the constant recycling of disordered thoughts encoded in LTM.