Can Dogs Think?

1. Can Dogs Think?

2. Solidarity Principle • 2 critical tasks for animals: • Animals must be able to predict trajectories of moving objects • Animals must be able to predict whether to approach or avoid an object • To do this: must be able to understand object occlusion- that is, how hidden objects “behave” as evidenced by: • Predictive reaching • Searching • Following a hidden object (and judging where it will emerge) • Many (if not most) animals have some degree of ability to do these tasks • Is this an innate/prewired behavior? • Is this a “learned” or experience-based behavior? • Use expectancy violation paradigm.

3. Limitations on trajectory prediction • Developmental time course to behavior • Differs across animals, with primates showing greatest capacity • Seems somewhat dependent on motor abilities • Problem: differences in data between search and expectancy violation tasks • Lack of executive ability? Mismatch between knowing and acting • Observational knowledge not same as action knowledge • Global interplay between cognitive subsystems and across settings? • What about dogs? • Evaluate search behavior when object rolled in direction of a barrier • human toddlers, adult rhesus macaques and cotton top tamarins all fail to reason about location of hidden barrrier when reaching for an invisibly displayed object • Even when show sensitivity to solidity info in expectancy violation paradim

4. Method • Subjects: • Hare’s lab • 10 Pet dogs all over 1 year of age with no formal agility or advanced obedience training • 4 female, 6 male, average age 4.5 years • many breeds; 6 were mutts • Apparatus: • Used a clear plastic tube which extended into a wooden box • 2 doors on box: far door and near door • Could reach inside each door to retrieve object • False back: researcher could place objects into box on one side or other • Basic idea: roll object down tube; barrier should block the object from rolling to far door. • False baiting: distracted dog and moved object

5. Procedure • Pretraining trials: • Dogs retrieved objects from box and generally acclimated • 3 trials with each ½ of box • Test trials: • No wall and wall trials • Three blocks of each • Mixed block, no wall and wall • Mixed block always appeared last • Barrier not in place during no wall (obviously!) • Dogs prompted to “look” and find the treat

6. Results: • Mean percent correct: • More mistakes during no wall • Wall: 85% • No wall: 75% • Mixed: 83% • Dogs tended to: • Search near location when barrier in place • Search far location when no wall • Spontaneously searched in correct location from first of each trial type • Performed correctly when mixed trials

7. Control Trials • No treat dropped down tube • Treats placed in box in different positions • If dogs not attending to dropping of treat but to experimenter cuing, should perform according to location of wall • Results showed: • No wall sides: chose far side 55% • Not significantly different from chance • Concluded that were attending to rolling treat

8. Conclusions • Dogs do show solidarity principle • Why dogs, but not non-human primates? • Selective breeding? • Experience with humans and thus human tasks? • Other explanations • Dan’s questions: • Marc Hauser was referenced on several occasions. How familiar are you with some of the controversies surrounding him and his research? • If you are familiar with them, how thin of a line is there between what Hauser did, and some of the questionable practices are commonplace amongst scientists (e.g. manipulating sample sizes, boutique statistical analyses, not reporting null findings, etc.)? • What is the expectancy violation paradigm? • Generally speaking, which animals can maintain a representation of hidden objects over time? Which ones cannot? • What are some of the explanations for why dissociations emerge between search and expectancy violation tasks? • How important is breed in the tasks examined? • The authors recommend that future research examine differences between domesticated dogs, undomesticated wolves, and different levels of socialization amongst dogs. Has this been done yet? If so, what were the findings?

9. Spatial Perseveration Errors • Detour tasks: move away from goal to get to goal • Perseveration errors: failing to shift strategies • Occur even when visible change of location of correct path, so can’t go back to old path • Dogs can solve detour tasks • But: will show perseveration errors • Dogs from deprived environments worse than dogs with experience • More experience with a solution = more perseveration on that solution • Major aim of study: • Determine if cognitive rigidity of dogs changes when change set up in simple detour task • IV: number of learning trials • IV: transparency of the barrier • If dogs able to solve task after a required change in detour path: indicate complete understanding of task dynamics • If perservation error: lack of inhibition and prominence of learned behavior over clear visual cue

10. Method and Exp 1 • Wooden barrier made from lattice garden trellis put across enclosed rectangle • Opaque condition: covered with cloth • Visible condition: uncovered • Video taped all sessions • Experiment 1: • N = 2- of mixed breeds • 4 A trials: started at either L or R • After 4th trial: barrier shifted to gap on opposite side • Then 4 B trials • If dog went straight to opening = correct; else incorrect • Results: • All dogs in both conditions solved above chance • Opaque condition slightly faster • First trial significantly slower for B • Did not unlearn previous trial as shown by more errors • Transparency of task had no effect • Did rely more on memory than on visual with more trials

11. Exp 2 • Same set up as Exp 1 • Changed location of barrier after 1,2 or 3 trials • N = 30 • Results: • First set: • 8/10 dogs went straight to gap in barrier after A1 • 7/10 after shift • B2 = 90% • B3 = 90% • B4=86% • None reached 100% • Second set: • A2: all dogs solved • B1: 1/10 solved • Took longer time for B1 than A1 • Reached optimal performance within 2 trials • All showed perseveration error on B1, 4 still showed on B2

12. Discussion • Dogs exhibited spatial perseveration reliably after 2 or more presentations • Failed to walk straight to new obvious goal • Began to rely on old learning rather than visual cues after 2 trials • Sam’s Questions: • What is spatial perseveration error? • Does this differ depending on species (dogs vs. humans)? • Why did the dogs make this error? • How can you tie this article with the Misbehavior literature we read earlier in the semester? • Why could the dogs not reach the 100% accuracy after this error occurred? • How can you apply this to your life as a student?

13. Means-end Analysis • Problem solving = progressing through series of mediating actions in order to reach certain end goal • Must understand series of progressive steps as means to end • Means to end understanding = key step in cognitive development of humans • What about non human animals: • Use string pulling or support problem • Tamarins, ravens/corvis, parrots, elephants all show ability • Dogs and domestic cats can retrieve distant food but fail to understand means-ends analysis

14. Why poor performance in dogs? • Dogs seem to be able to DO the task, but not show understanding of task • Not good with spatial references • Great with social cues • Thus good social cognition; poor physical cognition • Likely due to breeding/experience with humans • Is this due to lack of cognition or lack of impulse control? • Most errors are proximity errors: do the closest • Capable of efficient problem solving, but gets interrupted by other behavioral strategies • Choose based on social cues and experience rather than physical • Choice based on exclusion as last result • Training also important, especially clicker training

15. So what did the authors do? • To what extent proximity bias overrides or supports choice based on physical connection? • What do dogs choose when decision based on proximity is not possible? • examined effects of impulsivity • Examined effects of training history

16. Method • Subjects: 68 dogs and owners: • 15 males and 17 females (mean age = 6 years) made it through testing • 16 clicker trained/16 not • 17 dogs tested with object that had to retrieve and bring back to owner to get treat; 14 dogs got treat directly • Test apparatus: • Black wooden board with 2 yellow colored wooden boards mounted on top • Dog had to move yellow boards back and forth with paws to get treats/ball • Tester in cage behind apparatus so dog couldn’t interact • Procedure: • Training phase: taught to pull boards with paw using shaping • Motivation assessment: object retrieval for food treat • Test phase: 4 different conditions • Board presented with reward/object on surface (ON) • Identical reward/object on other side of board (OFF) • To obtain reward, had to pull out board with reward/object on it • Trial ended when dog investigated board that had pulled out and took reward/object if it was there • 12 trials per condition (6L 6R) • Conditions: • Same Distance • Weak proximity + support: both rewards/objects placed at far end of board but reward/object placed “on” board was slighter closer • Strong proximity + Support: much closer reward/object placed on board • Proximity against support: reward/object closer to dog was placed “off” board • Fixed factors: • Sex • Type of reward • Type of training • learning

17. Results • Same Distance: • None of fixed factors affected dogs’ performance • Dogs chose reward/object “on board” signif. more • Weak proximity + support: • None of fixed factors affected dogs • Dogs chose “on” more often • No significant difference from condition 1 • Strong proximity + Support: • Learning had an effect • Above chance by trial 6, and got better • Closeness improved performance, compared to condition 2 • Proximity against support: • Dogs rewarded with food did better • dogs were better in condition 1 than condition 4 • Proximity against support was detrimental to performance, but not that much

18. Discussion • Concluded dogs posses ability to consider means-end relationships in support problem even if proximity is a confound • Reward type did play a role • Training did not play significant role • Proximity helped only if it was exaggerated • But: performance NOT that strong overall when look at individual performance • Not support previous research that suggests dogs not have means end analysis • Difference between string test and this task? • Were researchers asking the right question? • After looking at all three studies: • Can dogs problem solve? • Do they show evidence of thinking? • Why or why not?