Transcript
Page 1: University of Pennsylvania · Shape to condition assignments and effect events counterbalanced 1 2 1 2 cause cause cause cause effect effect effect effect Participants used a combination

From the Structure of Experience to Concepts of Structure

Many object categories (i.e., most artifacts) criticially rely on causal properties – one reason they include members with differ-ent surface features. Here we ask:

1. What aspect of experience do causal properties of objects come from? Can they be extracted from predictive information presented in naturalistic event streams?

2. How spontaneously and automatically do we form generaliz-able causal categories?

Experiment 1: How do we assign causal properties to objects

in naturalistic event streams?

Experiment 2: Do learners sponta-neously form generalized

causal categories?

generalization testwhich objects is this most similar to?

same motion & same causality

different motion & same causality

same motion & different causality

different motion & different causality

cause+ motion+

cause+ motion-

cause- motion+

cause- motion-

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Percent of Subjects Choosing

n=18

Motion match F(1,17) = 15.36, p < .001Causal match F(1,17) = 5.52, p < .05

Why is this important?

Predictive structure is a pervasive part of experience that can be ex-tracted using straightforward learning mechanisms. But it can also be leveraged to gain abstraction, as predictive relations can be gener-alized across participating events and sensory features. Together, this could account for bot-tom-up abstraction of sensory experience and the formation of novel kinds generalizing across sen-sory features. do

wnl

oad

me!

similarity judgments using a spatial sorting task

Linear regression with motion model : c cells = 0 , others = ; causal model : m cells = 0 , others = 1, fit on individual data, betas subjected to t-test.

Linear regression with a single factor:mixture model: c cells = .5 and m cells = .5, others = 1

more sim

ilarm

ore di�erent

light causer 1

light causer 2

light reactor 1

light reactor 2

light causer 1light causer 2light reactor 1light reactor 2

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C

m

m

Casual modelt(17) = 2.42, p < .05

Motion model t(17) = 2.39, p <.05

Mixture model t(17) = 3.53, p < .01

normalized screen distances

University of PennsylvaniaAnna Leshinskaya & Sharon L. Thompson-Schill*

*[email protected]

other-object effect

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Blue Object Green Object

Task: determine what each object causes.

Stimuli: sequence of 250 animated visual events order governed by markov chain.

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Sentence Acceptability Measure

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ty (e

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1 2 3 4 5definitely false definitely trueunsure

“The green object seemed to cause the multi-colored stars to appear”

1. Causality: E�ect Event

“The green object seemed to cause the bubbles to appear”

2. Causality: Other-Object E�ect Event

“When the green object was present, multi-colored stars appearing happened more often than when the blue object was present”

3. Frequency: E�ect vs. Other-Object E�ect Event

Each object appeared with all ambient events, but only one of those events also depended on its movements.

Causality can be assigned on the basis of higher-order event structure: an event de-pendency that depends on the object’s presence.

Causers Reactors

Shape to condition assignments and effect events counterbalanced

1 2 1 2cause cause cause cause

effect effect effect effect

Participants used a combination of motion and causality/predictive structure to group objects.

Task: learn as much as possible about the object and press a button when anything unexpected happens.

Experiment 3: Is causal generalization automatic?

1.2s

Task: hit a key whenever an event repeats

cause effect

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cause effect

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same effect object 2

random 1 random 2 random 3

cause effect

different effect object

same effect object 1

familiarity forced choice test

Event assignments counterbalanced

When the same event was predictable (v.s., radom), learning was automatically facilitated, indi-cating automatic generalization.

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example

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* t(167) = 2.16, p = 0.032

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