Animal timing, continued Temporal bisection The information processing model and relative time (again) Do animals plan ahead? Psy 362S 2007, Lecture 7.2 slide 1 Temporal bisection: relative timing again Training: Discrimination between 2 intervals 8 s tone Ë press left lever 2 s tone Ë press right lever Testing: Present tones of intermediate durations Which lever does the rat press? Which duration Ë 50:50 choice of right and left? 2 3 4 5 6 7 8 right left 5 s = Halfway between 2 and 8 (arithmetic middle) Is this what the rats choose? Psy 362S 2007, Lecture 7.2 slide 2 Temporal bisection: results 100 % choice of 8 s lever 50 0 The psychological middle = 4, not 5 Ratio comparison 4:2 = 8:4 2 3 4 5 6 7 8 signal duration Psy 362S 2007, Lecture 7.2 slide 3
How does interval timing work? The information processing model Pacemaker (generates pulses) Working Memory Reference Memory Relative timing results suggest that times are compared as ratios Comparator (WM and RM same or diff?) don t respond respond Psy 362S 2007, Lecture 7.2 slide 4 Interval and circadian timing compared Cognitive modularity -- two different kinds of information processing Different biological functions: Circadian: synchronizes activity with local day and night Interval: tracks short intervals of time e.g. time between prey items in foraging Planning implies sensitivity to time ( now vs the future ) -- so do any animals plan ahead? Do animals plan for the future? Migration, hibernation, hoarding? Using semantic (reference) memory? Performing behaviors reinforced in the past? Tests of self control e.g. choice between 2 food pellets after 2 seconds vs. 8 food pellets after 6 seconds Animals tend to choose the immediate small reward Possible examples from the wild. Psy 362S 2007, Lecture 7.2 slide 6
Chimpanzees using tools: Planning ahead? (2 short videos) Tool transport. Remote cameras recorded chimpanzees arriving at termite nests carrying puncturing and/or fishing tools on 45 occasions. All tools were transported by adults and were appropriate for the type of termite nest being approached.. A chimpanzee arrived carrying both a stout stick and a fishing probe on seven occasions. All were arrivals at subterranean nests, which necessitate puncturing before fishing. Sanz, Morgan & Gulick, American Naturalist, 2004 Psy 362S 2007, Lecture 7.2 slide 7 So are animals stuck in time? The Bischof-Kohler hypothesis says yes : animals are bound to current needs Evidence against it requires: Novel action or combination of actions Appropriate to motivational state other than the one the animal is in the moment Psy 362S 2007, Lecture 7.2 slide 8 The Naqshbandi & Roberts study 2 squirrel monkeys Choose in their home cages: 1 date + water 30 mins later vs. 4 dates + water 3 hrs later Dates make them thirsty -- do they anticipate future need by choosing 1 date? Rats also tested, with raisins. Psy 362S 2007, Lecture 7.2 slide 9
Monkeys: % choice of 4 dates in blocks of 6 trials (Baseline and 30 experimental trials) Psy 362S 2007, Lecture 7.2 slide 10 Do scrub jays plan for breakfast? Breakfast room No-breakfast room Training phase (6 days): Eat powdered pine seeds in the evening in B In the morning: 2 hours in A with pine nuts 0r 2 hours in C with no food Psy 362S 2007, Lecture 7.2 slide 11 Do scrub jays plan for breakfast? Testing Whole pine nuts in B in the evening Caching trays in A and C Only one trial Do they cache where food will be needed most? Psy 362S 2007, Lecture 7.2 slide 12
Do scrub jays plan what to have for breakfast? Dog kibble for breakfast Peanuts for breakfast Training: Powdered foods in the evening Breakfast in the morning in one room, difft foods. Test: Only one trial, with whole foods in the eve. Do they cache each food where it will be needed most? Psy 362S 2007, Lecture 7.2 slide 13 Each food hoarded more in the different room Psy 362S 2007, Lecture 7.2 slide 14 So are animals stuck in time? How does the scrub jay study measure up?: Novel action or combination of actions Appropriate to motivational state other than the one the animal is in the moment Flexible or part of the hoarding system? Why is this interesting? Mental time travel, as in episodic-like memory. Developmental and neuropsych evidence from people Role of language? Psy 362S 2007, Lecture 7.2 slide 15