Ecological Information Makes Embodiment Possible Andrew D Wilson
Ecological Information Makes Embodiment Possible Andrew D Wilson, Sabrina Golonka Leeds Beckett University @Psych. Scientists http: //psychsciencenotes. blogspot. co. uk/
So you want to do embodied cognition… Embodied cognitive science • Goal is to solve the grounding problem of representations by making them embodied Radical embodied cognitive science • Explains behaviour using different tools with consequence that representations never show up Chemero 2009
Embodied Cognition is not What You Think It Is Wilson & Golonka (2013) “…if perception-action couplings and resources distributed over brain, body, and environment are substantial participants in cognition, then the need for the specific objects and processes of standard cognitive psychology (concepts, internally represented competence, and knowledge) goes away, to be replaced by very different objects and processes…” Wilson AD and Golonka S (2013) Embodied cognition is not what you think it is. Front. Psychology 4: 58. doi: 10. 3389/fpsyg. 2013. 00058
https: //xkcd. com/927/
We will replace you if we win
Embodied Cognition is not What You Think It Is Wilson & Golonka (2013) “…to be replaced by very different objects and processes…” Dynamical mechanistic explanations held together by ecological information
Outline Dynamical mechanistic explanations (Bechtel and others) • What they are and why we might want aspire to them Explaining behaviour with RECS (Wilson & Golonka, 2013) • Identify your task; Identify your resources; Propose a model using those resources that produces that behaviour; Science the model Worked Example • Coordinated rhythmic movement (Bingham, 2001, 2004 a, b; Golonka & Wilson, 2012) Ecological information enables mechanistic explanation in embodied cognition
Dynamical Mechanistic Explanation Bechtel & Abrahamsen, 2010 A mechanism is a structure performing a function in virtue of its component parts, component operations and their organisation. The orchestrated functioning of the mechanism, manifested in patterns of change over time in properties of its parts and operations, is responsible for one or more phenomena
Dynamical Mechanistic Explanation Bechtel & Abrahamsen, 2010 Two strategies for modelling mechanisms 1) Advance de novo proposals for mechanism; evaluate by showing this model produces the phenomenon of interest Relationship between model and actual system remains unknown 2) Formally describe mechanism made of parts independently established to be in that mechanism; use to probe the phenomenon of interest Expands the range of ways to investigate a system
Dynamical Mechanistic Explanation Bechtel & Abrahamsen, 2010 Two strategies for modelling mechanisms 1) Advance de novo proposals for mechanism; evaluate by showing this model produces the phenomenon of interest Cognitive Science (e. g. neural networks) 2) Formally describe mechanism made of parts independently established to be in that mechanism; use to probe the phenomenon of interest Biology (e. g. circadian rhythms)
Dynamical Mechanistic Explanation Bechtel & Abrahamsen, 2010 Because models in cognitive science typically don’t involve independent evidence for the involvement of their constituent parts, they struggle to provide the dynamical mechanistic explanation of a system’s behaviour that the other models can
Dynamical Mechanistic Explanation Wilson, just now Because of degeneracy (many: one structure to function mapping) and neural reuse (one: many) this modelling strategy is doomed and cannot provide evidence about the actual mechanism
Dynamical Mechanistic Explanation Silberstein & Chemero, 2013 All the good stuff in cognitive science is nondecomposable so mechanistic analyses fail Systems neuroscience, graphs, networks, etc Conflates ‘this model is handy’ with ‘this model explains’
A Research Programme Empirically identify the component parts and operations of the mechanism THEN Model it so you can poke around, make predictions etc
Wilson & Golonka (2013) 1. What is the task to be solved? 2. What are the resources that the organism has access to in order to solve the task? 3. How can these resources be assembled so as to solve the task? (Modelling time!) 4. Does the organism, in fact, assemble, and use these resources? Wilson AD and Golonka S (2013) Embodied cognition is not what you think it is. Front. Psychology 4: 58. doi: 10. 3389/fpsyg. 2013. 00058
Tasks All the Way Down Behaviour is task-specific • It has to be, or else we would never be able to pick one behaviour from the huge number available (Bingham, 1988) • It has to be, or else how can evolution and learning evaluate functionality? • It has to be in REC because we model behaviour as emerging from the real time activity of an embedded agent (i. e. embedded in a task) So what’s a task?
Task Dynamics Events in the world unfold over time in a particular way This pattern is the result of the composition and organisation of the underlying task dynamic Events are only uniquely identifiable at the level of dynamics (Bingham, 1995)
Event in the world = bouncing ball (with friction) Dynamical description = damped mass spring
Two tasks are the same if the underlying dynamic is the same (even if the parameters are different)
Two tasks are different if they have a different underlying dynamic
In order to act appropriately in a given task, we need to identify the task we are facing We therefore need to perceive the underlying task dynamic
‘‘The central question for theory of affordances is not whether they exist and are real, but whether information is available in the ambient light for [directly] perceiving them’’ (Gibson, 1979, p. 140)
The Perceptual Bottleneck Dynamics (in the world) creates Kinematics (information)
Kinematic Specification of Dynamics We can only perceive the relevant dynamics if those dynamics have kinematic consequences that we can detect Kinematics can specify dynamics (Gibson, 1979; Turvey et al, 1981; Runeson & Frykholm, 1983) Bio. Motion Lab Walker
All We Have Is Information
REC: Behaviour emerges in a context: a task • Behaviour is functional if it is appropriate with respect to that task • Tasks are only distinguishable from each other at the level of dynamics SO • Organisms need to perceive dynamics to select functional behaviour BUT • No direct access to dynamics
BUT LUCKILY • each dynamic lawfully creates different kinematic patterns in energy arrays which can specify those dynamics SO • Organisms can detect these patterns and use them • as if they were the relevant dynamics (this works because of specification; Turvey et al, 1981) • as if they were about something like language (this works because enough people agree; convention, Golonka, 2015) Patterns used this way become ecological information
If you select, coordinate and control behaviour with respect to task specific information then that behaviour will by definition be functional (task appropriate) and require no ‘mental gymnastics’ Ecological information makes radical embodied cognition possible
Wilson & Golonka (2013) 1. What is the task to be solved? 2. What are the resources that the organism has access to in order to solve the task? 3. How can these resources be assembled so as to solve the task? (Modelling time!) 4. Does the organism, in fact, assemble, and use these resources?
Geoffrey P Bingham Indiana University Coordinated Rhythmic Movement
0° & 180° the only stable states 0° more stable than 180° V = -a cosφ –b cos 2φ Other coordinations (e. g. 90°) can but must be learned
1. Identify the Task To produce this dynamic, experiments reveal that you will need: • Two things moving rhythmically, in parallel and coupled to each other (φ uniquely defined) • The two things can belong to different people, but at least one thing must belong to a person (the coupling is not neural, but perceptual) http: //psychsciencenotes. blogspot. co. uk/2010/11/perceptionaction-model-of-coordination. html
2. Identify Resources Two oscillators producing parallel harmonic motion so as to move at some relative phase to each other Information about that motion and that relative phase to couple the oscillators and allow error correction to maintain that relative phase
2. The Action Resources Key results: • Limit cycle stability (overall dynamic is non-linear) • Phase resetting (overall dynamic must be autonomous) • Inverse frequency/amplitude relation (↑ stiffness) Kay, Kelso, Saltzman & Schöner, 1987; Kay, Saltzman & Kelso, 1991
2. The Information Resources The oscillators must be coupled by a variable that • specifies relative phase • is composed only of state variables (to preserve autonomy) • is most readily detected at 0°, then at 180°, not at all at 90° (basic phenomena) • detection varies with frequency
2. The Information Resources The information should • be detectable by both vision (e. g. Bingham et al 1999, 2001; Zaal et al, 2001) and proprioception (Wilson et al, 2003) • only be defined for parallel movements (Bogaerts et al, 2003; Wilson et al, 2005; Wimmers et al, 1992) • be available throughout the trajectory but vary with relative speed (Bingham, 2004)
Information Perceived relative phase (rho) Relative Speed (noise) Ρ = sgn(sin(Φ 1) sin(Φ 2) + α(Vi – Vj)3 Nt ) Relative Direction (information) Relative direction (kinematic information) specifies relative phase (dynamical property) 0°: relative direction always the same 180°: relative direction always different 90°: relative direction maximally variable
3. Model Built From Those Resources. x¨ 1 + b x 1 + kx 1 = c sin (Φ 2) Ρij. x¨ 2 + b x 2 + kx 2 = c sin (Φ 1) Ρji where: Φ = arctan (Vn / x) Ρ = sgn(sin(Φ 1) sin(Φ 2) + α(Vi – Vj)3 Nt ) Bingham (2001, 2004 a, b)
4. Science!
4. Science!
4. Science! Unexpected discovery: not everyone uses relative direction at 0° and 180°!
4. Science! • Explains why effects persist between people • Explains why effects persist without movements • Explains why effects go away if the feedback removes relative direction (and motivated new feedback) • Explains why learning rates vary (faster close to 0°)
4. Science! • Successfully predicted perceptual learning would improve movements (Wilson et al, 2010) • Successfully predicted transfer of learning between unimanual and bimanual versions (Snapp-Childs et al, 2015) • Successfully predicted relative speed is relevant noise term (Snapp-Childs et al, 2011)
Replacement via Winning HKB Dynamic Patterns Approach Ecological Information Approach • 0° and 180° are attractors, therefore behaviour is stable there • Attractors make learning harder • Φ defined with respect to muscles • Behaviour organised with respect to Φ • Information & therefore behaviour is stable there, therefore they are attractors • Stable info makes learning easier • Effects persist between people, in judgments, etc • Behaviour organised with respect to information
Dynamical Mechanistic Explanation in REC Formally describe mechanism made of parts independently established to be in that mechanism; use to probe the phenomenon of interest Bechtel & Abrahamsen, 2010 1. What is the task to be solved? 2. What are the resources that the organism has access to in order to solve the task? 3. How can these resources be assembled so as to solve the task? (Modelling time!) 4. Does the organism, in fact, assemble, and use these resources? Wilson & Golonka, 2013
Coupling & Constitution Coupling The Body The World creates Mechanism Harmonically oscillating limbs Information couples The elements of this mechanism constitute coordinated rhythmic movement
Tasks are identified at level of dynamics Task dynamics creates information Information specifies but is not identical to dynamics Behaviour is organised with respect to information • Information stands in for dynamic that created it: laws (Turvey et al 1981) • Information stands in for something else: convention (Golonka, 2015) Behaviour is therefore functional with respect to the task dynamics Ecological information makes embodiment possible
“COST is a unique means for European researchers, engineers and scholars to jointly develop their own ideas and new initiatives across all fields of science and technology through trans-European networking of nationally funded research activities. ” Applying to start a COST action dedicated to developing an ecological approach to neuroscience Come talk to me or email Sabrina (s. golonka@leedsbeckett. ac. uk) if you’d like to discuss
Thanks! Andrew D. Wilson School of Social, Psychological, & Communication Sciences Leeds Beckett University https: //cognitioninaction. wordpress. com/ Notes from Two Scientific Psychologists http: //psychsciencenotes. blogspot. co. uk/ Twitter: @Psych. Scientists
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