ACT-R Workshop Schedule
Opening: ACT-R from CMU’s Perspective9:00 - 9:45 Overview of ACT-R -- John R. Anderson9:45 – 10:30 Details of ACT-R 6.0 -- Dan Bothell
Break: 10:30 – 11:00Presentations 1: Architecture
11:00 – 11:30 Functional constraints on architectural mechanisms -- Christian Lebiere11:30 – 12:00 Retrieval by Accumulating Evidence in ACT-R -- Leendert van Maanen12:00 – 12:30 A mechanism for decisions in the absence of prior reward -- Vladislav D. Veksler
Lunch: 12:30 – 1:30Presentations 2: Extensions
1:30 – 2:00 ACT-R forays into the semantic web -- Lael J. Schooler2:00 – 2:30 Making Models Tired: A Module for Fatigue -- Glenn F. Gunzelmann2:30 – 3:00 Acting outside the box: Truly embodied ACT-R -- Anthony Harrison3:00 - 3:30 Interfacing ACT-R with different types of environments and with different techniques: Issues and Suggestions.-- Michael J. Schoelles
Break: 3:30 – 4:00Panel: 4:00 – 5:30: Future of ACT-R from a non-CMU Perspective Danilo Fum, Kevin A. Gluck, Wayne D. Gray, Niels A. Taatgen, J. Gregory Trafton, Richard M. Young
Retrieval by Accumulating Evidence in ACT-R
Leendert van Maanen
University of Groningen
Memory is vital for behavior
Picture-word interference
Picture-word interference
Giraffe
Picture-word interference data
(Glaser & Düngelhoff, 1984)
Giraffe
giraffe
giraffe
0.1
ACT-R model of PWI task
ACT-R model of PWI task
ACT-R model of PWI task
ACT-R model of PWI task
ACT-R model of PWI task
ACT-R model of PWI task
ACT-R model of PWI task
ACT-R model of PWI task
Expected model of PWI task
The ACT-R retrieval process
Giraffe
Sequential Sampling framework
Acc
um
ula
tors
threshold
Sequential Sampling framework
Acc
um
ula
tors
threshold
Giraffe
Sequential Sampling
› Response time = Decision time + Additional processes
RACE/A
› Retrieval by accumulating evidence› Accumulates activation› Until a decision criterion
› Integration of cognitive architecture and sequential sampling model• Both the control structure of ACT-R• And the level of detail from sequential sampling
models (specifically, Leaky Competitive Accumulator, Usher & McClelland, 2001)
The RACE/A retrieval process
The RACE/A retrieval process
The RACE/A retrieval process
Picture-word Interference Model
Van Maanen & Van Rijn, 2007(Glaser & Düngelhoff, 1984)
Giraffe
giraffe
giraffe
0.1
RACE/A Parameters
:race-saliencyexternal activation
:ratio-ratiodecision boundary
:race-adecay rate (complements d)
:race-bspreading activation scaling factor
Baselevel activationSpreading activation (Sji)
RACE/A Parameters
:race-saliencyexternal activation
:ratio-ratiodecision criterion
:race-adecay rate (complements d)
:race-bspreading activation scaling factor
Baselevel activationSpreading activation
:race-saliency
:race-ratio
€
eAi
eAj
j
∑≥ θ
RACE/A Parameters
:race-saliencyexternal activation
:ratio-ratiodecision boundary
:race-adecay rate (complements d)
:race-bspreading activation scaling factor
Baselevel activationSpreading activation
Baselevel activation differences
:race-ratio
:race-ratio
RACE/A Parameters
:race-saliencyexternal activation
:ratio-ratiodecision boundary
:race-adecay rate (complements d)
:race-bspreading activation scaling factor
Baselevel activationSpreading activation (Sji)
Spreading activation differences
:race-ratio
:race-ratio
Giraffe
giraffe
RACE/A Parameters
:race-saliencyexternal activation
:ratio-ratiodecision boundary
:race-adecay rate (complements d)
:race-bspreading activation scaling factor
Baselevel activationSpreading activation
:race-a
:race-ratio
:race-ratio
Sequences of retrievals
› RACE/A: dependencies between declarative retrievals
:race-ratio
Retrieval 1 Retrieval 2 Retrieval 2
RACE/A may be useful for
› Models of competitive processes• Stroop task / Picture-word interference (Van
Maanen & Van Rijn, 2008)
• Classification• Absolute identification
› Models of sequences of retrievals• Language production/interpretation• (Diagnostic) reasoning• Psychological refractory period (Van Maanen et
al, in press, PB&R)
Summary RACE/A
› Integration of cognitive architecture and sequential sampling model• ACT-R• Leaky Competitive Accumulator (Usher &
McClelland, 2001) › Meant to explain
• Competitive processes in memory retrieval• Sequential processes in memory retrieval
› Especially useful in complex tasks• For example: PWI-PRP (eg. ICCM talk)
More information
› Download module + documentationhttp://www.ai.rug.nl/~leendert/race
› Contact [email protected]
› Read my thesis
Thank you for your attention!
Collaborators:
Leendert van Maanen ([email protected])
Niels TaatgenHedderik van Rijn
Multilink priming
› Mediated priming effects found (Becker, Moscovitch, Behrmann, & Joordens, 1997; Joordens & Besner, 1992)• Bull primes milk (via cow)• Evidence for spreading activation over multiple
connections
Activation in ACT-R and RACE/A
› Activation in ACT-R: based on rational analysis• Neural implementation (ACTR/NN)• Neural interpretation (Anderson, 2007)
•Shows that ACT-Rs latency equation make similar predictions as accumulator models (in the one-chunk case!)
› Activation in RACE/A: based on neurally inspired accumulator models• the RACE/A decision process is an estimate
of the optimal (=rational) decision time (MSPRT, McMillen & Holmes, 2006)