Ernest 10.1 associates co-occurring sensory stimulations together into bundles. A bundle is a set of sensory stimulations that denotes an object in the world. By constructing bundles, Ernest starts to perform multi-modal sensory integration.
We assume that a bundle can represent a unique kind of object in the world. We drew this assumption from David Hume's bundle theory of objects. This theory postulates that objects consist only of the set (bundle) of their observable properties.
Additionally, Ernest 10.1 constructs a local map of the bundles surrounding him. In this video, the local map is displayed in cell k6 (next to the cycle counter). The local map represents Ernest's awareness of his local surrounding. The top of the map corresponds to the front of Ernest. Ernest's current visual stimulation is represented as a "pie" over the map.
The local map is based on Ernest's somatotopic map. A bundle is learned by associating the tactile stimulation in front of Ernest (the center-top cell in the somatotopic map) with the simultaneous visual stimulation (the "pie"). As he moves, Ernest is then able to follow the newly-created (or recognized) bundle in the somatotopic map.
For example, Ernest creates a bundle for the yellow square on step 27. Then, on step 28, this bundle moves to the center of the map; on step 30, to the center-rear of the map; and, on step 31, to the left-rear corner of the map (the local map is displayed with a delay of one cycle).
When Ernest eats, he associates his gustatory stimulation with the bundle that represents where he is standing, that is, the "fish bundle" that was previously constructed from visual and tactile stimulations. This delicious taste associated with fish then makes Ernest's prefer pursuing fish rather than alga in subsequent activity.
Apart from his still-unexploited local map, and from the fact that his visual field was reduced to a single row of 12 pixels, Ernest 10.1 is the same as poor Ernest 9.3. We now need to investigate how Ernest would use his local map.
Monday, April 25, 2011
Friday, April 8, 2011
Ernest 10.0 has a somatotopic map
Ernest 10.0 is a shark. Sharks are archaic vertebrates whose brain didn't evolve much over the last 450 million years or so. Yet, a shark's brain contains the same set of basic anatomical components as modern vertebrates' brains (Brain, Wikipdia).
In particular, Ernest 10.0 has a somatotopic map—a brain area that represents Ernest's body in an isomorphic way. In humans, this area would correspond to the postcentral gyrus, also known as the primary somatosensory cortex.
In this video, Ernest's somatotopic map is represented as a grayscale grid over Ernest's body. This grid has 9 cells that represent what Ernest touches in the 8 surrounding squares plus the square where he is standing.
Each cell in the somatotopic map can reflect three different kinds of tactile feelings:
- light gray: only water.
- medium gray: something soft, an alga or a fish that Ernest can swim over.
- black: something hard, a wall or the aquarium's side (the central cell is never black because Ernest cannot stand on a wall).
We hypothesize that the somatotopic map will be useful for acquiring a sense of space, although we don't yet know exactly how. We drew this hypothesis from the idea that our sense of space comes from the mere fact that our body occupies space. We, however, could not find much arguments in the literature to support this hypothesis.
Apart from his still-unexploited somatotopic map, and from the fact that he is always hungry for fish, Ernest 10.0 is the same as poor Ernest 9.3. This video shows how miserable he is. He has no sense of space and he is even unable to "simplify" a sequence consisting or turning six times 45° clockwise into a sequence consisting of turning twice 45° counterclockwise (see steps 267 or 279).
In particular, Ernest 10.0 has a somatotopic map—a brain area that represents Ernest's body in an isomorphic way. In humans, this area would correspond to the postcentral gyrus, also known as the primary somatosensory cortex.
In this video, Ernest's somatotopic map is represented as a grayscale grid over Ernest's body. This grid has 9 cells that represent what Ernest touches in the 8 surrounding squares plus the square where he is standing.
Each cell in the somatotopic map can reflect three different kinds of tactile feelings:
- light gray: only water.
- medium gray: something soft, an alga or a fish that Ernest can swim over.
- black: something hard, a wall or the aquarium's side (the central cell is never black because Ernest cannot stand on a wall).
We hypothesize that the somatotopic map will be useful for acquiring a sense of space, although we don't yet know exactly how. We drew this hypothesis from the idea that our sense of space comes from the mere fact that our body occupies space. We, however, could not find much arguments in the literature to support this hypothesis.
Apart from his still-unexploited somatotopic map, and from the fact that he is always hungry for fish, Ernest 10.0 is the same as poor Ernest 9.3. This video shows how miserable he is. He has no sense of space and he is even unable to "simplify" a sequence consisting or turning six times 45° clockwise into a sequence consisting of turning twice 45° counterclockwise (see steps 267 or 279).
Tuesday, April 5, 2011
Poor Ernest 9.3
On step 406, we removed the yellow-green landmark that Ernest was using to find his way towards the southeast field. This leaves poor Ernest spinning in place, miserably goalless.
To explore space in the absence of landmarks, Ernest will need some skills to construct a spatial representation of the environment. Such skills are exhibited by most vertebrates and are believed to involve some basic components of the vertebrate's brain. We now need to explore the role of these components.
To explore space in the absence of landmarks, Ernest will need some skills to construct a spatial representation of the environment. Such skills are exhibited by most vertebrates and are believed to involve some basic components of the vertebrate's brain. We now need to explore the role of these components.
Friday, April 1, 2011
Ernest 9.3
The colliculus activation algorithm has been improved. This gives Ernest 9.3 a smoother behavior than Ernest 9.2 (e.g., see the elegant curve taken on the way back to the hive on steps 356-388).
In addition, Ernest's thorax now takes the color of the most motivating landmark in the visual field—the landmark that raises the most activation in the colliculus. This landmark is the object of Ernest's current attention and drives Ernest's homing tendency.
At the beginning, Ernest is seeking to gather pollen but he does not know how to distinguish flowers from other landmarks. The highest activation is only given by the largest landmark in the visual field (i.e., the closest landmark). This causes Ernest to visit all landmarks randomly. When a landmark is visited, this landmark's activation is lowered for some time, meaning that Ernest temporarily looses interest in this landmark. This causes Ernest to move on to another landmark.
On step 38, Ernest finds a landmark from which he can gather the pollen (the blue flower). This switches his motivation to make him seek for the hive. In the hive-seeking motivational mode, landmarks raise an additional activation that is proportional to their proximity to the hive (or to Ernest's place of birth) as much as Ernest remembers from his way out. This activation mechanism causes Ernest to go back to the yellow square by traveling from known landmarks to known landmarks. After reaching the yellow square (step 83) he finds no more motivating landmarks and starts a random exploration again until he finds the hive for the first time on step 94.
When on the hive, Ernest drops the pollen and switches back to the pollen-seeking motivational mode. Now, the highest activation is generated by landmarks that Ernest remembers as being the closest to the pollen. This leads Ernest back to the northeast flower field. On the second way back, Ernest is now able to recognize the hive, which causes him to turn directly towards the hive on step 159 (by-passing the yellow square).
When the northeast flower field is empty, Ernest fumbles again until he sees new landmarks to explore (green landmarks in the southeast field on step 311). From then on, he starts exploiting the southeast field the same way he exploited the northeast field.
In addition, Ernest's thorax now takes the color of the most motivating landmark in the visual field—the landmark that raises the most activation in the colliculus. This landmark is the object of Ernest's current attention and drives Ernest's homing tendency.
At the beginning, Ernest is seeking to gather pollen but he does not know how to distinguish flowers from other landmarks. The highest activation is only given by the largest landmark in the visual field (i.e., the closest landmark). This causes Ernest to visit all landmarks randomly. When a landmark is visited, this landmark's activation is lowered for some time, meaning that Ernest temporarily looses interest in this landmark. This causes Ernest to move on to another landmark.
On step 38, Ernest finds a landmark from which he can gather the pollen (the blue flower). This switches his motivation to make him seek for the hive. In the hive-seeking motivational mode, landmarks raise an additional activation that is proportional to their proximity to the hive (or to Ernest's place of birth) as much as Ernest remembers from his way out. This activation mechanism causes Ernest to go back to the yellow square by traveling from known landmarks to known landmarks. After reaching the yellow square (step 83) he finds no more motivating landmarks and starts a random exploration again until he finds the hive for the first time on step 94.
When on the hive, Ernest drops the pollen and switches back to the pollen-seeking motivational mode. Now, the highest activation is generated by landmarks that Ernest remembers as being the closest to the pollen. This leads Ernest back to the northeast flower field. On the second way back, Ernest is now able to recognize the hive, which causes him to turn directly towards the hive on step 159 (by-passing the yellow square).
When the northeast flower field is empty, Ernest fumbles again until he sees new landmarks to explore (green landmarks in the southeast field on step 311). From then on, he starts exploiting the southeast field the same way he exploited the northeast field.
Monday, March 28, 2011
Ernest 9.2 has a superior colliculus
Ernest 9.2 has a visual resolution of 2 rows of 12 pixels. As before, Ernest can see above colored landmarks. The closest landmarks are seen in the first row, and possible landmarks behind these are seen above in the second row. Ernest 9.2's visual angular span equals 180°. As before, Ernest 9.2 cannot see through walls.
In this video, Ernest's half-circular head represents what Ernest sees. The first row is represented inside the half circle. The second row is represented on the half circle's crown. For example, on step 34, the inside of the half circle takes a light-green color because Ernest sees the square where it is standing, and the crown reflects the flower and the other squares that Ernest sees over the light-green square.
The environment is the same as with Ernest 9.1. The hive and the flowers are now represented as icons but Ernest distinguishes them only by their color and taste as before.
The most significant improvement is that Ernest 9.2 has a superior colliculus—a brain region also known as the tectum in the invertebrate. The superior colliculus maintains an internal retinotopic representation of the animal's surrounding environment. The superior colliculus is used to orient motivation and behavior towards a specific direction in the animal's egocentric referential (in some rudimentary vertebrates, like the hagfish, the superior colliculus constitutes the biggest brain region).
The effects of Ernest's colliculus are first seen on step 110. At this point, Ernest was heading toward the light-green square that was already known as leading to the flower field. On step 110, a flower appeared in the right side of the visual field. Because the flower was more motivating than the light-green square, the flower generated more activation in the colliculus's right side than that generated by the light-green square in the colliculus's center. This activation triggered a signal sent to the sequential system that caused Ernest to turn to the right towards the flower.
Ernest 9.2's initial phase of sensorymotor contigency learning lasts longer than before because of the increased complexity of the visual system. In this video, this initial learning phase roughly goes up to step 100. Once sensorymotor contingencies are learned, the pollen gathering is faster and steadier than with Ernest 9.1. Ernest 9.2 finishes gathering the five flowers on step 414, whereas Ernest 9.1 took 598 steps in the previous example run.
In this video, Ernest's half-circular head represents what Ernest sees. The first row is represented inside the half circle. The second row is represented on the half circle's crown. For example, on step 34, the inside of the half circle takes a light-green color because Ernest sees the square where it is standing, and the crown reflects the flower and the other squares that Ernest sees over the light-green square.
The environment is the same as with Ernest 9.1. The hive and the flowers are now represented as icons but Ernest distinguishes them only by their color and taste as before.
The most significant improvement is that Ernest 9.2 has a superior colliculus—a brain region also known as the tectum in the invertebrate. The superior colliculus maintains an internal retinotopic representation of the animal's surrounding environment. The superior colliculus is used to orient motivation and behavior towards a specific direction in the animal's egocentric referential (in some rudimentary vertebrates, like the hagfish, the superior colliculus constitutes the biggest brain region).
The effects of Ernest's colliculus are first seen on step 110. At this point, Ernest was heading toward the light-green square that was already known as leading to the flower field. On step 110, a flower appeared in the right side of the visual field. Because the flower was more motivating than the light-green square, the flower generated more activation in the colliculus's right side than that generated by the light-green square in the colliculus's center. This activation triggered a signal sent to the sequential system that caused Ernest to turn to the right towards the flower.
Ernest 9.2's initial phase of sensorymotor contigency learning lasts longer than before because of the increased complexity of the visual system. In this video, this initial learning phase roughly goes up to step 100. Once sensorymotor contingencies are learned, the pollen gathering is faster and steadier than with Ernest 9.1. Ernest 9.2 finishes gathering the five flowers on step 414, whereas Ernest 9.1 took 598 steps in the previous example run.
Tuesday, March 1, 2011
Ernest 9.1 gathers pollen into the hive
Ernest 9.1 is similar to Ernest 9.0 but the bee has some new ways to interact with singularities in the environment. As before, she must visit a singularity to know what possibilities of interaction this singularity offers to her.
The violet square now represents the nest where she would gather the pollen. Colored squares are low landmarks that she can fly over, except the turquoise square that is the wall corner into which she would bump. As before, blue squares are flowers from which she can collect pollen.
Steps 0-60: initial phase of sensorymotor contingencies learning (as discussed before). She finds the nest on step 17, then continues exploring.
Step 98: she finds the first pollen.
Steps 99-163: she fumbles back to the nest.
Steps 163: she drops the pollen into the nest.
Steps 165-275: a second gathering cycle where she is still fumbling on her way back to the nest.
Steps 278-363: the third gathering cycle. This time, she finds the direct way back to the nest.
Steps 364-600: she explores the second flower field and adapts her way back to the nest.
The violet square now represents the nest where she would gather the pollen. Colored squares are low landmarks that she can fly over, except the turquoise square that is the wall corner into which she would bump. As before, blue squares are flowers from which she can collect pollen.
Steps 0-60: initial phase of sensorymotor contingencies learning (as discussed before). She finds the nest on step 17, then continues exploring.
Step 98: she finds the first pollen.
Steps 99-163: she fumbles back to the nest.
Steps 163: she drops the pollen into the nest.
Steps 165-275: a second gathering cycle where she is still fumbling on her way back to the nest.
Steps 278-363: the third gathering cycle. This time, she finds the direct way back to the nest.
Steps 364-600: she explores the second flower field and adapts her way back to the nest.
Monday, February 21, 2011
Ernest 9.0 can roam in flower fields
Ernest 9.0 is a honey-bee. She likes roaming toward flashy colors in her environment and she uses colored spots as landmarks for navigation.
She is alternatively in two different states: hungry or thirsty. When she is hungry, she has a violet thorax; when she is thirsty, she has a blue thorax. She does not know a priori what landmark can be eaten or drunk so she tries them all.
In this experiment, we can see a first learning phase (steps 0-150) where she learns sensorymotor contingencies by following her intrinsic motivation to visit landmarks (as before and discussed here). While doing so, she also learns that only blue landmarks can be drunk. She has an additional taste sense that informs her if the place where she is standing can be eaten or drunk. After step 150, she begins roaming more efficiently from landmarks to landmarks until she ends up on the violet landmarks and discovers that this can be eaten (steps 150-380).
She associates landmarks with the fulfillment of specific needs. For example, when she is thirsty, she memorizes roughly how long she travels from each specific landmark to a place where she drinks. When she gets thirsty again, she navigates preferably toward the landmarks that are the closest to the drinking area as she remembers.
This prompts her to go back to the drinking area event though the blue square is hidden behind the wall (steps 380-430). Similarly, she goes back to the eating area after drinking. Distance values are updated overtime so the navigation improves based on experience and on environmental regularities (if we introduce blue and violet squares without respecting a drinking and an eating area, she only finds them through random browsing).
To obtain these behaviors, we improved both the visual system and the motivational system in a tightly intertwined way, as we will report next.
She is alternatively in two different states: hungry or thirsty. When she is hungry, she has a violet thorax; when she is thirsty, she has a blue thorax. She does not know a priori what landmark can be eaten or drunk so she tries them all.
In this experiment, we can see a first learning phase (steps 0-150) where she learns sensorymotor contingencies by following her intrinsic motivation to visit landmarks (as before and discussed here). While doing so, she also learns that only blue landmarks can be drunk. She has an additional taste sense that informs her if the place where she is standing can be eaten or drunk. After step 150, she begins roaming more efficiently from landmarks to landmarks until she ends up on the violet landmarks and discovers that this can be eaten (steps 150-380).
She associates landmarks with the fulfillment of specific needs. For example, when she is thirsty, she memorizes roughly how long she travels from each specific landmark to a place where she drinks. When she gets thirsty again, she navigates preferably toward the landmarks that are the closest to the drinking area as she remembers.
This prompts her to go back to the drinking area event though the blue square is hidden behind the wall (steps 380-430). Similarly, she goes back to the eating area after drinking. Distance values are updated overtime so the navigation improves based on experience and on environmental regularities (if we introduce blue and violet squares without respecting a drinking and an eating area, she only finds them through random browsing).
To obtain these behaviors, we improved both the visual system and the motivational system in a tightly intertwined way, as we will report next.
Thursday, February 10, 2011
Ernest 8.4
Ernest 8.4 is the same as Ernest 8.3 except that Ernest 8.4's eyes can distinguish between various colors. Particularly, Ernest 8.4 can distinguish between two kinds of targets: blue targets and violet targets.
Ernest 8.4's eyes can also distinguish between singularities in the constitution of walls: orange bricks and yellow bricks. So far, however, Ernest's motivational system does not exploit these distinctions. Bricks leave Ernest 8.4 totally indifferent.
The next step will consist of making Ernest's motivations depend on internal states. For example, Ernest would pursue blue targets when he is "thirsty" and violet targets when he is "hungry". Moreover, we would like Ernest to learn to use environmental singularities as landmarks to navigate toward the desired target. Our idea is to make Ernest autonomously acquire new motivations to navigate toward landmarks that he has associated with desired targets.
Ernest 8.4's eyes can also distinguish between singularities in the constitution of walls: orange bricks and yellow bricks. So far, however, Ernest's motivational system does not exploit these distinctions. Bricks leave Ernest 8.4 totally indifferent.
The next step will consist of making Ernest's motivations depend on internal states. For example, Ernest would pursue blue targets when he is "thirsty" and violet targets when he is "hungry". Moreover, we would like Ernest to learn to use environmental singularities as landmarks to navigate toward the desired target. Our idea is to make Ernest autonomously acquire new motivations to navigate toward landmarks that he has associated with desired targets.
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