week 5 - learning behaviour Flashcards

Question

what is the travelling salesman problem?

Answer 1

quickest and most efficient route around an area

Answer 2

when navigating back home and also trying to find new locations for food

Answer 3

radiotracked the bees to see if they gradually optimise their solution. here is a naïve bee. The pink arrows are the prevailing wind direction. The task for this bee is to find all these 5 flowers and link them in a way that is efficient and minimise travelling time and energy. it goes from the nest straight past one flower to 5, then skips the nearest neighbour and goes to 2. so it is just exploring at the moment and figuring out where all the flowers are. this will take some time to make the optimal solution. thats a number of different tracks from the same individual. track 2 is still fairly chaotic but it does find another flower. The first several bouts are random exploration. If ou look at the bee after 24 bouts it is more experienced. this is of a bee on 28th foraging trip, it is an experienced forager and has found an optimal path. From an extremely tortuous path on the first bout it optimises its path and solves the travelling salesman problem. top left is naive bee all others are tracks by experienced bees. Interestingly they never stick to one solution. So what they do is essentially interface exploration with exploitation. Even experienced animals often when they should know where these feeders are, interface a bit of exploration to scout around for future suitable resources and incorporate these into their path if something is found.

Answer 4

an area of the brain that is important in encoding spatial information. Of particular importance in rodents

Answer 5

spatial orientation

Answer 6

explored a neuro equivalent of a physical map in animals brains. cognitive map is the mental equivalent of what you have spatial relationships in the real world, a mental equivalent of a map. It tells you where you are in relation to land marks, moreover like a real map it allows you to travel novel shortcuts on routes you haven’t previously travelled and so on. 1970’s discovered in rodents were so called “place cells”. Cells in the rodent hippocampus that fired reliably and only if that rat was in a particular position in its known environment. So what we have here we have panels and the activity pattern of a single cell whilst the rodent is moving in its environment which has been manipulated into an arena. Where you see blue the cell is inactive and no action potentials are produced. Yellow and red are increasing firing activity. The top left panel shows that while the rat is moving around in a square arena the cell is only active when the rat is in the lower left corner of the arena. Now these various other panels, are the same rat in the exact same arena but varied slightly in its shape. It has been expanded into a rectangle no longer a square. No matter what the shape of the arena it only ever specifies lower left corner, that is only when the cells are fired. Not all cells are that simple some have fairly complex properties. In the lower left group of panels. One rat, one cell, but a different firing pattern. In the original square arena that cells fires when the rat is in the middle of the top edge. That still stays the same when you expand the arena horizontally. But if you expand the cell vertically then the cell fires in a different way, it appears to encode a position relative to that corner. Here on the other hand is a cell which appears to be closer to specifying the middle between two corners. It moves over somewhat in this particular panel. Some cells code specifically for corners of this environment others for relationships with edges and so on. There are hundreds of cells all with individual coding. There ensemble code together encodes where the rat is in a familiar space. in addition to these findings there are also a variety of other types of cells in the hippocampus. For example head direction cells, code for directions rather than places, as in north, south and so on. Provide an overall framework for spatial coordinates. Intention cells in the prefrontal cortex are interesting by recording their physiological activity researchers can see what the rat will do next before it does it. These are cells that fire before the rat moves in a particular direction but will reliably predict that direction. So that the researchers just by monitoring that activity will predict what the rat will do.

Answer 7

caching ability in birds

Answer 8

food storing in birds sometimes have extreme spatial capacity for storing information about where they are storing seeds. these birds store many seeds a day and over a period of month has several thousand caches. They retrieve them often several weeks after caching them. It is in the benefit of trees that they forget some of the seeds. In addition to memorising where they store seeds they remember when they stored them, this is important with how different foods decay at different rates.

Answer 9

Given that the hippocampus has a very central function in spatial memory, the question these researchers asked then is of course is there a correlation with hippocampus and birds lifestyle as many birds cache and others do not.

Answer 10

There are a variety of bird families that were sampled. Relative hippocampus size is divided by the rest of the brain as want to account for variance in body size whereby larger birds will have larger brains. Black points are the ones that cache, the open squares are the ones that are non storers. IN both of these studies you can clearly see that caching species have larger relative hippocampus sizes compared to non storers. So clearly that lifestyle of storing vs non storing lifestyle has an affect on the size of the hippocampus.

Answer 11

Compared in 3 species that are all food storers the relative hippocampal volume depending on the experience of the birds the hippocampal volume. Red is before experienced, 2 groups where one was given experienced with food storing and another group of birds which were prevented from food storing. It turns out that over experience over time has a profound influence on hippocampal volume, in the coal tit there is no change between no experience and pre experience whereas in the experienced bird there is a 1/3 increase in hippocampal size. If the birds have no possibility to store food therefore has no possibility to store spatial memories the hippocampus stays small, only for those birds that are given food to store and so must know where they did it grow their hippocampus.

Answer 12

to see whether it is just the hippocampus that grows or the whole brain. So what she did is to look at another area of the brain to show that it is not the whole brain that increases in size only the hippocampal region which is associated with memory.

Answer 13

how birds can learn from observation by success in mate choices. female bird experienced with male bird 1 (phenotype 1) and that hasn’t been particularly successful and only produced 1 egg. Encounters another male bird of same species looking slightly different, colour pattern on head, with that guy she produced 4 eggs and so remembers how the helpful male looked compared to non helpful males. She will in the future chose males based on the particular success shes had in the past and focus on having mates looking at phenotype number 2.

Answer 14

recognise each other

Answer 15

scent markings | individual recognition of faces

Answer 16

individuals. The very bare bones level of society all you need to remember is some cues which identify all members of the society and which don’t identify others that are not part of the society.

Answer 17

honey bees have guard bees at the entrance of their nest which identify every animal that enters the hive by smelling them to identify whether its scent is from this hive or an intruder that would have a different scent. In this case the identification is not by individual recognition its learning who is part of your group by common features, and this case a scent.

Answer 18

Three portraits of particular wasps in the bottom left. These are 3 wasps from the same colony and their facial features are distinguishable, the three wasps from the same colony and same species. They have highly distinct visual facial markings. It turns out that these wasps have linear hierarchy in their colony. There is an alpha female at the top who gets to immobilise all the egg laying, if she is to die then the next individual moves up. That linear hierachy is supported by individual fights, duals which can be costly, lots of energy or sometimes death of an individual. Establish hierarchy once the individual duals and after that don’t fight as they know where they belong in the hierarchy. They avoid these costly fights. The reasons the wasps can identify each other by these individual facial markings. It is an adaptive benefit they help avoid future confrontations where an individual would definitely lose and is costly. This has been demonstrated by Chittka. Who explored individual recognition. associated some faces with mild electric shocks and the wasps turn out to rapidly learn such facial features and retain them in memory for some period of time. They go to the ‘friend’ wasp not the ‘foe’ wasp which gave them an electric shock. Good at learning these faces and retaining them in memory. Colonies are small so the memory capacity does not have to be that large, but of course this is a distincition in memory capacity where by we have to remember thousands of faces and them only a dozen. But remember that this is a difference in capacity not quality of that memory.

Answer 19

Researchers made the fish associated a light signal with the appearance of another fish that could potentially be an aggressive threat. That is the green curve. As a result of that over a period of multiple weeks the fish became more aggressive just as a result of being expose to that light without actually being exposed to aggression. The red line shows the opposite. The light source is a condition stimulus which predicts the risk of an aggressive encounter.

Answer 20

males will remember the outcome of contests. Which in turn influences the outcome of future contests. Individuals which have one confrontation and win carry a lot of confidence and will win again. In this case it was shown in fighting fish the probability of a fish that has won its first envcounter, whether it will win its second encounter; ‘win win’ which is pretty much 100% and then lose to win will often be 0%. SO fish has lost past contest will not win the next one either. They were careful in matching the fish with same size competitors etc. So memory seems to play a strong role in the fishes chance of winning the next outcome. This is the proportion of losses and whether you will lose again. Shows the exact same relationship as before.

Answer 21

depends what environment these animals operate in

Answer 22

First tested bees in lab conditions where they learned that Blue is non reward and yellow reward.Then took these same bees and tested their natural foraging success in the field. What we found is there are profound reliable differences between learning speed in different individuals and different colonies. What is plotted here is 2 learning curves. Plotting number of errors as a function of experience. as you move from left to right it is increasing experience, and as a function of that percent errors. This is a slow learning bee which starts at 50% errors which is normal as has no experience, takes 80 visits to have a low percent error. Fast learner starts at 50% but after 20 visits is at a low percent error. Very big differences in learning speed between these 2 animals. Can quantify each individuals learning speed by fitting a learning curve to it. Using a specific formula. T is essentially indicating how fast individuals learn, perhaps quietly counter intuitively when T is small. And not learning as fast when T is relatively low???

Answer 23

now looking at T values for various colonies. Each dot is one colony. There are some variation within each colony. Learning speed as symbolised by T value on the x axis, small T values mean rapid learning, large T values mean slow learning. there is huge variation between colonies, some learn extremely rapidly others slowly. This is under natural conditions, testing their foraging success by measuring how much nectar they bring home. Turns out there is a good correlation between how fast they learn in lab conditions nad how good they are at foraging in natures economy. colonies with fast learners had the highest foraging success. The slowest learning colony had the worst foraging success. Learning in tightly controlled lab conditions is a good indicator at how good they will be at foraging in the wild.

week 5 - learning behaviour Flashcards

(47 cards)