How do you study and understand a complex system?

How do you study and understand a complex system? For example, how might one study and understand the complex system entailed by cognitive performance in artificial laboratory reading tasks.

How do you study a complex system? Describe the aggregate structure of relations that may potentially constrain the dynamics of a cognitive performance (“...what your head’s inside of”)

For Instance Describe the aggregate statistical structure of a printed language Constraints implicit in a culture of literacy (“...what your head’s inside of”)

How do you understand a complex system? Focus on stability: MULTISTABLE relations between spelling, phonology, and semantics predict performance in artificial laboratory reading tasks-- A vast literature, perhaps the largest in experimental psychology.

The plan of this talk Introduce the term MULTISTABILITY using a simple connectionist network Describe the topology of laboratory performances in terms of MULTISTABILITY Resolve the question of phonology and reading in the dilemma of homophone errors Comment on the meaning of models in behavioral science

A Connectionist Network   COMPETITION  COOPERATION COMPETITION  

Invariance Symmetry Consistency Harmony   COMPETITION  COOPERATION COMPETITION  

Ambiguity Multistability Inconsistency   COMPETITION  COOPERATION COMPETITION  

Relative Frequency   COMPETITION  COOPERATION  COMPETITION  

Statistical Structure of ENGLISH SPELLING/PHONOLOGY  SEMANTICS “person” “bird” “avoid” “femaleDUCK” “evade” “fabric” “etc????” “submerge” “truck” D /d/ U /u/ C /k/ K

Topology of Reading Performance PHONOLOGY…………………………….. SEMANTIC BASEDBASED FASTER/BETTER……..Performance………SLOWER/WORSE

Statistical Structure of ENGLISH SPELLING  PHONOLOGY CONSONANTS vs VOWELS D /d/ U /u/ /uI/ C /k/ K

Topology of Reading Performance CONSONANTS……….VOWELS PHONOLOGY…………………………….. SEMANTIC BASEDBASED FASTER/BETTER……………..Performance………………SLOWER/WORSE

Statistical Structure of ENGLISH SPELLING  PHONOLOGY ”Regular and Consistent” Word DUCK D /d/ U /u/ C /k/ K

Statistical Structure of ENGLISH SPELLING  PHONOLOGY “Regular and Inconsistent” Word MINT M /m/ /I/ I /n/ /aI/ N /t/ /n/ T /t/

Statistical Structure of ENGLISH SPELLING  PHONOLOGY “Exception and Inconsistent” Word PINT P /p/ /aI/ I /n/ /I/ N /t/ /n/ T /t/

Statistical Structure of ENGLISH SPELLING  PHONOLOGY “Strange Exception” Word QUAY Q /k/ U /kw/ A /ee/ Y /æ/

Topology of Reading Performance CONSONANTS……….VOWELS PHONOLOGY…………………………….. SEMANTIC BASEDBASED FASTER/BETTER…………………..Performance……………………SLOWER/WORSE DUCK…....…MINT……………....PINT……….…………….QUAY “Regular “Regular “Exception “Strange Consistent” Inconsistent” Inconsistent” Exception”

Statistical Structure of ENGLISH SPELLING  PHONOLOGY “Homograph” Word LEAD /l/ /ē/ L /d/ E A /l/ D /ě/ /d/

Topology of Reading Performance CONSONANTS……….VOWELS PHONOLOGY…………………………….. SEMANTIC BASEDBASED FASTER/BETTER…………………..Performance……………………SLOWER/WORSE DUCK…....…MINT……………....PINT……….…………….QUAY “Regular “Regular “Exception “Strange Consistent” Inconsistent” Inconsistent” Exception MINT……………....PINT……….…………….LEAD “Regular “Exception “Homograph” Inconsistent” Inconsistent”

Statistical Structure of ENGLISH SPELLING PHONOLOGY “Feedback Consistent” Word MINT M /m/ I /i/ N /n/ T /t/

Statistical Structure of ENGLISH SPELLING PHONOLOGY ”Feedback Inconsistent” Word HEAT H /h/ E A T /ē/ E /t/ E T

Statistical Structure of ENGLISH SPELLING  PHONOLOGY “Homophone” Word SENT S E N /s/ T /ě/ /n/ C /t/ E N T

Topology of Reading Performance CONSONANTS……….VOWELS PHONOLOGIC …………………………….. SEMANTIC FASTER/BETTER…………………..Performance……………………SLOWER/WORSE DUCK….…..MINT……………....PINT……….…………….QUAY “Regular “Regular “Exception “Strange Consistent” Inconsistent” Inconsistent” Exception MINT……………....PINT……….…………….LEAD “Regular “Exception “Homograph” Inconsistent” Inconsistent” MINT……………...HEAT……….……………SENT “Feedback “Feedback “Homophone” Consistent” Inconsistent”

Is Skilled Reading Mediated by Words’ Phonology? Over 100 years of reading research has failed to answer this question to the general satisfaction of reading scientists. Perhaps we have been posing the question the wrong way.

Homophones, like ROWS, are sometimes mistaken for their sound-alike mates (e.g., ROSE). Such homophone errors may be observed in everyday reading and writing. Supplying a homophone for its mate is a common spelling error, and homophone substitutions are likely to slip past proofreaders of all ages.

Homophone errors can be systematically induced, as when participants mistake ROWS for a flower or SENT for money in a categorization task. Such homophone errors can be induced to both familiar (ROWS) and unfamiliar (ROZE) homophones in a variety of laboratory tasks, in different languages, and by readers at all skill levels.

So why don’t homophone errors settle the question? The crux has always been whether skilled readers are constrained by the phonology of highly familiar words such as SENT Narrow Context money SENT = Homophone Errors Broad Context object SENT = NO Errors

The question of phonology and reading has always been posed to a simple system in which effects are transparent to mediating causes. Homophone Error  Presence of Phonology NO Homophone Error  Absence of Phonology

In simple systems one may sometimes discover causes as necessary and sufficient conditions for an effect, such as a homophone error. Not so for Complex systems.

Perhaps nature requires that questions of reading performance and other cognitive performances be posed to a complex system. Complex systems are exquisitely context sensitive; they are causally intertwined with their context of observation. Innumerable multiple causes are always present in phenomena.

One cannot isolate causes; one cannot recover the necessary and sufficient • conditions of phenomena. • In such a system one adopts a different • research strategy. • One tries to understand how factors combine to control a system’s behavior.

Homophone Attractor Topology Multistable Potential Function “errand” /s ěnt/ “penny” /s ěnt/   

Statistical Structure of ENGLISH SPELLING  PHONOLOGY “Homophone” Word SENT S E N /s/ T /ě/ /n/ C /t/ E N T

CONTROL Parameter SENT “errand” /s ěnt/   “Stimulus” as Control

CONTROL Parameter SENT money “penny” /s ěnt/   Stimulus and Context Combine as a Ratio in Control

CONTROL Parameter SENT object “errand” /s ěnt/   Stimulus and Context Combine as a Ratio in Control

CONTROL Parameter SENT DisSim Spell Hi Frq CENT Good Speller Task, etc. money Similar Spell Lo Frq CENT Poor Speller Task, etc. “errand” /s ěnt/ “penny” /s ěnt/    Stimulus, Context, History, Task, etc. Interact in Control-- The interaction is always present even when “effects” are not obvious

But aren’t models of cognitive performance models of the mechanisms of mind? NO! Things people do have been mistaken for things of which they are composed Tasks do not pick out component mechanisms

MODEL = HUMAN PERFORMANCE PERFORMANCE “Equals” Refers to Accounts for is Tested by Symbolizes

things outside of modeled Human Performance that are necessary (not sufficient) to bring a particular performance into existence? History of Science and Methods Social Constraints entailed by Participation Detailed History of Participant Task Demands and Strategies Instructions and so on…

Performance can be equated with Measurement, so call this the Situated Measurement Problem Necessary Contextual backdrop for the taking of a measurement, its analysis, and interpretation

Off-Load the Problem We study language to develop a theory of language That theory will explain how participants understand and orient themselves with respect to instructions

What Off-Loading Entails(its loan on credibility) Language Performance refers to a distinct cognitive function that can be realized as a component mechanism Actual Language Performance must be transparent to the self-same mechanism

Off-Loading is no Wondermiddel its note has come due—Its risky circularity becomes clear

Circularity Every off-loaded human performance confronts the same problem, it too is situated in its context of measurement Measurement always draws on sources of constraint that fall outside the purview of modeled performance Human Performance entails a Control Loop that extends into the context in which the performance is situated

Situated Measurement Problem reflects natural phenomenological entailments of Situated Human Performance Always a necessary context of history, meaning production, intentional contents, interpretation, that cannot be realized within the model. Models are essentials conceptual tools, existence proofs, gedanken experiments….. But they are not mechanisms

How do you study and understand a complex system?