Tool Use and Causal Understanding

Tool Use and Causal UnderstandingMarch 3rd, 20091OverviewIntroduction to Tool Use and Causal UnderstandingWhat is learned - associative learning of causal understanding? 3 Case Studies:Tool SelectionGravityTool ManufactureHow are causal relations learned?2I. Introduction3

Tool Use

4Whats important about tool use?Insight & CreativityUsing the environment in novel ways to achieve goalsPlanning & ForethoughtThinking aheadResponding to stimuli that arent in sightCausal UnderstandingFolk PhysicsUnderstanding something about how the world worksMediating forces5Causal UnderstandingWhat is learned? Associative vs. CausalEventOutcomeAssociative learning: Predict the outcome what is going to happen next?

Causal understanding: WHY and HOW does the outcome occur?

6Causal UnderstandingWhat is learned? Associative vs. CausalAssociative: Yellow ball moves after contact with blue ball

Causal: Mediating forces force imparted by blue ball is blocked by the barrier

7Causal UnderstandingMediating forces:Different levels of complexityVisible factorsInvisible factorsPsychological factors

Explanatory Attitude8II. Case Studiesa. Tool Selection9Tool SelectionCan non-human animals recognize the functional properties of tools?Hauser and colleagues cottontop tamarins

10Tool SelectionHauser and colleagues cottontop tamarins

11Transfer testsVaried colour, texture, shape and sizeColour & texture are not functional changesShape & size could be functional changesAll canes set in the correct spatial arrangement12Transfer TestsMonkeys preferred the non-functional changesSensitive to changes in potential functionality

13More transfer testsSimilar results found with capuchinsFujita, Kuroshima & Asai, 2003Included transfer tests in which an obstacle or a trap was on drag pathCapuchins failed on these transfersUnderstand spatial relationship between tool and food, but not tool, food and environment

14Tool selection in corvidsNew Caledonian crowsSelect tools of appropriate length in sight and out of sight

15Betty & Abel

In sight:

Out of sight (Abel only)Two strategies:Match distance orChoose longestWhat if length was un-usable?Abstract representation (keep representation of tool and intended goal in mind)16II. Case Studiesb. Gravity17The Trap-tube task18Capuchins & ChimpsTrap in the middle of the tubeLearned the task:1 out of 4 capuchins2 out of 5 chimpsTransfer tests showed that capuchins used a distance based rule19ChimpsChimps didnt use distance based ruleAssociative rule still possibleInsert stick on side of trap

20CriticismsFailure to adjust behaviour on inverted testsBut theres no penalty for not adjusting!Human adults dont adjust eitherInstructional problem?Too many factors?Tool, food and environmentAdjusted task to remove tool use21Modified Trap-tubeAllows subjects to pull or pushPrefer to pullDistance and trap rules are not available

22Modified Trap-tubeNew Caledonian crowsSimilar transfer tests: 3/6 solved the transfers plus a trap-table task

23II. Case Studiesc. Manufacturing tools24Elephants fly switchingIn the wild, elephants commonly use branches to repel fliesToo long or too bushy branches presented to captive elephants25

26New Caledonian CrowsIn the wild, tear pandanus leavesBarbed edges of leaf can be used to fish for insects in dead woodcultural variation in tool manufactureNaive birds can create pandanus tools without teaching27New Caledonian crowsIn the lab:http://users.ox.ac.uk/~kgroup/tools/movies.shtmlAlways inserted straight wire firstInsightful?

28III. How is causal understanding learned?29Causal Bayes nets

30RatsBlaisdell, Sawa, Leising & Waldmann, 2006

Test: Intervene-Tone or Observe-ToneCommon CauseCausal ChainLightToneLightFoodLightToneLightFood31RatsCausal explanation:If Tone just occurs, maybe Light came on first and was missed Check for food!If I caused the Tone to occur, Light didnt happen dont check for foodAssociative explanation:If there is an association between the tone & food, shouldnt matter whether you caused it or not check for food at same rate.Chain always check

32RatsRats respond in accordance with causal reasoning, not associative processes

33ProblemCausal Markov conditionDuring common-cause condition, tone and light should be causally independentBut, rats receive only tone or food following the light they are NOT independent of each otherThus, does not strictly follow causal Bayes net34Instructional problemsCriticism:Lack of evidence could be based on inability to properly instruct animalshttp://www.youtube.com/watch?v=FZmx0jml1jkhttp://www.youtube.com/watch?v=pIAoJsS9Ix8&feature=related

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