Serial Order Behavior: Planning

Planning

the process of thinking about and organizing the activities required to achieve a desired goal

Serial Search Strategy (Basic Serial Order Task)

not based on planning

where is A? select A. where is B? select B

over time, this will create a linear plot that gets faster and faster

Collective Search Strategy

animal is actively planning, sets out plan of action

sees where A is, sees where B is, etc. plans and then executes the task

long latency to the first item, then a flat line since they are executing all at once

chimps, humans, and monkeys all display what appears to be a collective search strategy

Evidence Against Collective Search Strategy: Eye Movement Study

how often did the subjects scan all items before making their first response? according to a collective search strategy, a subject should be scanning all items before responding - found that actually no subjects scan all items

after finding A, do subjects respond to it immediately or do they continue to search for one or more additional items? after finding A, humans will try and browse where B is - monkeys will not browse and will immediately respond to A

seen vs. not seen (are latencies shorter if you are responding to an item you previously saw while browsing): monkeys have no difference in response latency if they had seen an item before in their search - humans answered faster if they had seen the item before in their search

why are we seeing evidence of a collective search strategy in monkeys on the graph if they are not actually using it? humans had a button to press to indicate that they were ready to see the stimuli, but monkeys did not - monkey was not prepared to answer which explains the latency in selecting item

Evidence for Planning in Animals: Switch Trials

as soon as you press A, B and C switch positions

performance should decrease or latency should increase if you are using a collective search strategy because it indicates that you must be planning at least one stop ahead

chimps: decreased accuracy in switch trials - don’t show much of a latency effect but show a performance deficit - clearly shows forward planning

monkeys: decrease in accuracy on switch trials - increase in latency

pigeons: no change in accuracy - increase in latency for switch trials

Evidence for Planning in Animals: Mask Trials

when subject presses A, the following stimuli are masked and the subject must remember the place of the remaining stimuli

how could an animal be beating the task? computer monitor leaves a residual on a white mask, so could be able to see the number - researchers may be using only a few number arrangements instead of randomly creating new arrangements every trial

pigeon study: 3 stimuli instead of 9 - pigeon is able to select the stimuli in the correct order, however this is likely not a case of collective search strategy - this is because they only have to remember A and B, not C - they are only planning one step ahead - select first one, remember where second one is and then select the remaining rectangle

Planning Strategy (Collective Search)

animals encode each item’s spatial position and then plan a sequence of motor responses

constrained by working memory

information about each item must be encoded separately

Eidetic Strategy (Photographic Memory)

animals are encoding an image of the item display before the items are masked and then use that image to guide responses

not constrained by working memory

items encoded together in a single image