luke a. rosedahl & f. gregory ashby · • own wikipedia page • has spread to many different...
TRANSCRIPT
![Page 1: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/1.jpg)
Luke A. Rosedahl & F. Gregory AshbyUniversity of California, Santa Barbara, CA 93106
![Page 2: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/2.jpg)
• Google Scholar returns 2,480 hits
• Over 130 videos online
• Own Wikipedia page
• Has spread to many different fields Many areas of cognitive psychology outside traditional
categorization (e.g., recognition memory) Social psychology All areas of linguistics
Provides good fits to lots of data
![Page 3: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/3.jpg)
Previously has lacked a detailed neural interpretation
Limits its explanatory power for behaviors such as:1: Button-Switch Interference (Ashby et al. 2003)
2: Feedback Delay Effects (Smith et al. 2014)
3: Retinal Specific Learning (Rosedahl, Eckstein, & Ashby, 2018)
![Page 4: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/4.jpg)
Medial Temporal Lobe Explanations (e.g. Sakamoto & Love, 2004)
Predicts MTL damage should decrease performance
Not in general true (e.g. Janowsky et al. 1989; Bayley, et al. 2005; Filoteo et al. 2001)
Minimal task-related MTL activity during learning (Seger & Cincotta, 2005; Seger et al. 2010)
![Page 5: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/5.jpg)
Exemplar theory is mathematically equivalent to a simplified version of the COVIS procedural system Ashby & Rosedahl (2017, Psychological Review)
I will then discuss using this result to predict categorization difficulty for tasks targeting the procedural system.
![Page 6: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/6.jpg)
Nosofsky (1986, 2011)
The probability of responding A to stimulus k:
= the frequency that stimulus I is presented with category J feedback
![Page 7: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/7.jpg)
reinforcement learning
![Page 8: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/8.jpg)
Ashby & Rosedahl (2017, Psychological Review)
Visual Cortex
reinforcementlearning
![Page 9: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/9.jpg)
Assumption: Noise terms are independent random samples from identical double
exponential distributions
Yellott, 1977
![Page 10: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/10.jpg)
F is a monotonically increasing function called an activation function in standard Firing Rate models.
Selecting the natural log for F gives:
![Page 11: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/11.jpg)
Striatal activity is equal to the weighed most active input
Where I is normalized visual activity (i.e. ranges between 0 and 1)
Assuming one neuron will respond optimally for each stimulus:
![Page 12: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/12.jpg)
if trial n was a correct category A response
All weights start very small and are updated via reinforcement learning.
Assumption: error trials do not change synaptic strengths
Standard Three Factor
Learning
![Page 13: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/13.jpg)
Solving for w(n):
![Page 14: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/14.jpg)
stimulus valueon dimension 1 stimulus value
on dimension 2
Commonly modeled as Gaussian Radial Basis Functions (RBFs)
![Page 15: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/15.jpg)
Consider a trial when stimulus k is presented,then activation in visual unit i equals:
![Page 16: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/16.jpg)
Ashby & Rosedahl (2017, Psychological Review)
Visual Cortex
![Page 17: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/17.jpg)
Ashby & Rosedahl (2017, Psychological Review)
![Page 18: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/18.jpg)
We ran the model for the Dimensional, Criss-Cross, Interior-Exterior, and Diagonal Conditions of Nosofsky
1986.
The average r2 between the model with and without assumptions was .983, so removing the assumptions has
little impact on the model’s performance
The average r2 between the GCM and the model without assumptions was .992 (lowest was .990), so relaxing the
assumptions does not lead to behaviors that fall outside of GCM
![Page 19: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/19.jpg)
So if the assumptions are required for mathematical equivalence, why are the models
still equivalent without them?
![Page 20: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/20.jpg)
Summed Similarity is Equivalent to Kernel Density Estimation with RBFs (Ashby & Alfonso-Reese 1995)
KDE is the sum of the Radial Basis Functions
![Page 21: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/21.jpg)
Summed Similarity is Equivalent to Kernel Density Estimation with RBFs (Ashby & Alfonso-Reese 1995)
KDE is the sum of the Radial Basis Functions
Reinforcement Learning (RL) with RBFs is also the sum of RBFs
![Page 22: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/22.jpg)
Summed Similarity is Equivalent to Kernel Density Estimation with RBFs (Ashby & Alfonso-Reese 1995)
KDE is the sum of the Radial Basis Functions
Reinforcement Learning (RL) with RBFs is also the sum of RBFs
Therefore:
Summed Similarity = Summed RBFs = RL with RBFs
![Page 23: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/23.jpg)
Expands Exemplar Theory to explain results such as:1: Button-Switch Interference (Ashby et al. 2003)
2: Feedback Delay Effects (Smith et al. 2014)
3: Retinal Specific Learning (Rosedahl, Eckstein, & Ashby, 2018)
4: Task-Related Striatal Activity (Seger et al. 2010)
![Page 24: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/24.jpg)
We can build off of the results here to derive a difficulty measure for procedural categorization tasks for a human performer.
![Page 25: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/25.jpg)
![Page 26: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/26.jpg)
![Page 27: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/27.jpg)
ALFONSO-REESE, ASHBY, AND BRAINARD, 2002
![Page 28: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/28.jpg)
ALFONSO-REESE, ASHBY, AND BRAINARD, 2002
![Page 29: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/29.jpg)
Ashby & Maddox, 1992
![Page 30: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/30.jpg)
R2 = .96
![Page 31: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/31.jpg)
The neural version of exemplar theory:• expands exemplar theory to be compatible with almost all
patient and neuroimaging categorization data
• can be used to develop a difficult measure applicable to a wide range of category structures and stimulus types• Potentially useful when providing computer assistance
during categorization tasks
![Page 32: Luke A. Rosedahl & F. Gregory Ashby · • Own Wikipedia page • Has spread to many different fields Many areas of cognitive psychology outside traditional categorization ... Feedback](https://reader034.vdocuments.net/reader034/viewer/2022042316/5f0525007e708231d4117dc1/html5/thumbnails/32.jpg)
Funding: National Science Foundation Graduate Research Fellowship under Grant No. 1650114, NIMH Grant
MH3760-2
Laboratory for Computational Cognitive Neuroscience
F. Gregory Ashby