I'd like to try and formulate precisely the idea that is only a vague notion in swirling somewhere between my brain and the keyboard at this moment...
First where it came from:
1. In neural theory there is the idea that groups of neurons can communicate best if their firing rate is synchronized to the same frequency. 40 hz (40 spikes per second of the famous neuronal discharge that runs wavelike accross the membrane (axon) of the neuronal cell, from the core to the outer 'dendrites') seems to be a popular 'channel' in the human cortex. When the cells are synchronized, their 'windows for communication are open'. (source > FCDC)
2. According to our idea (Pim, Iris, Roel, Jelle) the brain and the physical environment interact and from this interaction dynamic cognitive structure is formed.
My idea is that the process in 2. is not unlike the process in 1. viz. that succesful cognitive structure can only be formed if the activity in the brain and the coupled activity in the environment (i.e. the physical changes in the environment) are 'synchronized'. Only then can we have a window of opportunity in which a stability (attractor) can be formed. You might also say that when environment and brain have the same rythm, the channel between them is open for communication.
Tuesday, May 08, 2007
EEC and PD
I teach two courses on participatory design. This is the method of involving the end-users in that actual process of designing new products or services.
Theoretically I am interested in embodied, and even more in embedded cognition. Embedded cognition states that thinking is a process that emerges out of the interaction between brain, body and world. Parts of the world get recruited to perform important functions in a cognitive proces. They serve as external memory aids, external representations, visual clue's, they constrain possible behaviors (reducing choice options), present automatic orderings. The physical world is also the medium by which previous behavior of the agent itself, by the traces it leaves in the physical world, gets to influence subsequent patterns of behavior.
Yesterday I read a paper by Hollan, Hutchins and Kirsh. I already knew Hutchins and Kirsh as representatives of an embedded cognition perspective. As it turns out, Holland works in the same dept. in USCD (San Diego) and he is a representative of the participatory design movement (or to be more precise: ethnographic methods, which is in somewhere in the ballpark). The paper presents an argument of why, on the basis of an EEC perspective on cognition, one should do research and design using ethographic methods.
The argument runs as follows: Since parts of the local environment become part of the cognitive strategy that users use in dealing with a technology (think of an airline pilot in a cockpit), their expert knowledge is very 'personal' and the meaning of the interactions that the user engages in, and the function that certain parts of the artefact get to play in this interaction, is highly personal as well. This means that an objective, third-person investigation, especially in a sterile psychological lab, is not going to give you any inside into what is really going on in this user's real-life activities. EEC patterns of behavior grow in an historical process in which chance events and personal histories of users can have big influences on the resulting roles of the interface components in the activity of the user. So, we have to follow an empathic perspective on research and design, doing lot's of observation, interviews 'on site' and perhaps even 'participatory design': letting the user be part of the design team, as an expert of a knowledge domain that other people (not being the user) simply have no access to.
This is a nice article for me because it combines two of my interests that I hadn't really linked so explicitly. Apparently the various activities I engage in have some inner logic that I wasn't aware of yet. I wonder how Salsa dancing is going to fit in the picture...
Theoretically I am interested in embodied, and even more in embedded cognition. Embedded cognition states that thinking is a process that emerges out of the interaction between brain, body and world. Parts of the world get recruited to perform important functions in a cognitive proces. They serve as external memory aids, external representations, visual clue's, they constrain possible behaviors (reducing choice options), present automatic orderings. The physical world is also the medium by which previous behavior of the agent itself, by the traces it leaves in the physical world, gets to influence subsequent patterns of behavior.
Yesterday I read a paper by Hollan, Hutchins and Kirsh. I already knew Hutchins and Kirsh as representatives of an embedded cognition perspective. As it turns out, Holland works in the same dept. in USCD (San Diego) and he is a representative of the participatory design movement (or to be more precise: ethnographic methods, which is in somewhere in the ballpark). The paper presents an argument of why, on the basis of an EEC perspective on cognition, one should do research and design using ethographic methods.
The argument runs as follows: Since parts of the local environment become part of the cognitive strategy that users use in dealing with a technology (think of an airline pilot in a cockpit), their expert knowledge is very 'personal' and the meaning of the interactions that the user engages in, and the function that certain parts of the artefact get to play in this interaction, is highly personal as well. This means that an objective, third-person investigation, especially in a sterile psychological lab, is not going to give you any inside into what is really going on in this user's real-life activities. EEC patterns of behavior grow in an historical process in which chance events and personal histories of users can have big influences on the resulting roles of the interface components in the activity of the user. So, we have to follow an empathic perspective on research and design, doing lot's of observation, interviews 'on site' and perhaps even 'participatory design': letting the user be part of the design team, as an expert of a knowledge domain that other people (not being the user) simply have no access to.
This is a nice article for me because it combines two of my interests that I hadn't really linked so explicitly. Apparently the various activities I engage in have some inner logic that I wasn't aware of yet. I wonder how Salsa dancing is going to fit in the picture...
Thursday, May 03, 2007
Embedded neuromodulation
This post gives a summary of an article I've just read. It is mainly a note for myself.
The article can be downloaded here
The article describes experiments with an autonomous Kephera robot. Sporns et al have modeled a neuromodulatory system, resembling the dopamine reward system in the brain. This dopamine reward system influences the plasticity of the robot. Whenever unexpected reward takes place, the dopamine system get's active, this leads to 'value-dependent learning', both the sensorimotor connections get directly affected (normal stimulus-response associations are formed) and the neuromodulatory system itself get's affected.
QUOTE from a related article
Value signals combine temporal specificity
(they are phasic and short-lasting) with spatial uniformity
(they affect widespread projection regions and act as a
single global signal). Value enters into traditional Hebbiantype
synaptic rules as a third factor, in addition to factors
representing pre- and postsynaptic activity. Because of their
phasic nature, value signals effectively gate plasticity, in
addition to influencing its magnitude and direction (see
below). Value affects plasticity more or less uniformly
throughout the widespread cortical and subcortical regions
to which value systems project.
The interesting thing is that they put this system (which I do not completely grasp at the moment but at any rate resembles something like a sensorimotor system that gets 'laden' with internal, bodily based 'value', depending on reward, which is like Damasio in a way, i.e.: embodiment) in a real environment with objects. The behavior of the robot in the world influenced the subsequent inputs of the robot, because at the beginning, reward giving objects (the red objects) were dispersed quite homogenous in the environment, but the behavior of the robot lead to the effect that clusters of red objects were formed. The result was that at first there was a quite predictable timing/rythm in which the robot would first detect, visually, a red object, then grab it (feeling it with a touch sensor, thereby receiving the reward, which was supposed to model 'tasting/eating' it). But later on, all red objects were clustered, so after an initial delay, suddenly the robot would get massive amounts of reward in short time intervals.
QUOTE from the article:
Our experiments document a progressive alteration of an
environmental variable (the spatial distribution of reward
throughout the environment) due to the behavioral activity
of the robot. This alteration, in turn, has consequences on
synaptic patterns encoding predictions about the
occurrence of future rewards.
It is especially noteworthy that the differences between
early and late phases in experiments with high object
densities are neither the result of purposeful
rearrangements of the environment by either robot or
experimenter, nor are they due to the adjustment of
“internal” variables over time such as learning rates, cell
response functions, or motor variables. Instead they are the
outcome of the coupling between brain, body and
environment. This coupling is strongly reciprocal.
Behavior affects the statistics of reward timings which
drive synaptic plasticity through activation of a
neuromodulatory system. In turn, synaptic changes alter
the coupling between visual and motor units which affects
behavior.
ENDQUOTE
Here they even suggest a possible role for embeddedness (i.e. reshaping your own environment) in the emergence of addiction:
QUOTE from the article
The experiments discussed in this paper may shed light
on the activity and functional role of neuromodulatory
systems (in particular, dopamine) in the course of
“natural”, self-guided behavior. The “attractive force”
exerted by clusters of rewarding objects, resulting in
restricted trajectories of robot movement and navigation as
well as repeated “rapid-fire” sequences of reward
encounters are especially intriguing. Disruptions of the
neurobiological bases of reward processing are thought to
form a major cause for lasting behavioral changes and,
eventually, chronic disease (addiction) in humans. Our
results suggest the hypothesis that a pattern of persistent
reward-seeking behavior may in part be generated as a
result of a progressive reshaping of the environment
coupled with long-lasting synaptic changes in specific
neural structures. Future experiments will investigate this
hypothesis in detail.
ENDQUOTE
For me this article shows that neuromodulation (embodiment) and embeddedness can be part of a larger perspective in which brain, body and world form a tightly coupled system, where the causal work depends on interaction between both world-events (behavior that reshapes the environment) and internal modulatory signals (reward leading to changes in synaptic connectivity - and hence, in the speed/ease of learning). In this article it is shown how this could work out in practice.
The article can be downloaded here
The article describes experiments with an autonomous Kephera robot. Sporns et al have modeled a neuromodulatory system, resembling the dopamine reward system in the brain. This dopamine reward system influences the plasticity of the robot. Whenever unexpected reward takes place, the dopamine system get's active, this leads to 'value-dependent learning', both the sensorimotor connections get directly affected (normal stimulus-response associations are formed) and the neuromodulatory system itself get's affected.
QUOTE from a related article
Value signals combine temporal specificity
(they are phasic and short-lasting) with spatial uniformity
(they affect widespread projection regions and act as a
single global signal). Value enters into traditional Hebbiantype
synaptic rules as a third factor, in addition to factors
representing pre- and postsynaptic activity. Because of their
phasic nature, value signals effectively gate plasticity, in
addition to influencing its magnitude and direction (see
below). Value affects plasticity more or less uniformly
throughout the widespread cortical and subcortical regions
to which value systems project.
The interesting thing is that they put this system (which I do not completely grasp at the moment but at any rate resembles something like a sensorimotor system that gets 'laden' with internal, bodily based 'value', depending on reward, which is like Damasio in a way, i.e.: embodiment) in a real environment with objects. The behavior of the robot in the world influenced the subsequent inputs of the robot, because at the beginning, reward giving objects (the red objects) were dispersed quite homogenous in the environment, but the behavior of the robot lead to the effect that clusters of red objects were formed. The result was that at first there was a quite predictable timing/rythm in which the robot would first detect, visually, a red object, then grab it (feeling it with a touch sensor, thereby receiving the reward, which was supposed to model 'tasting/eating' it). But later on, all red objects were clustered, so after an initial delay, suddenly the robot would get massive amounts of reward in short time intervals.
QUOTE from the article:
Our experiments document a progressive alteration of an
environmental variable (the spatial distribution of reward
throughout the environment) due to the behavioral activity
of the robot. This alteration, in turn, has consequences on
synaptic patterns encoding predictions about the
occurrence of future rewards.
It is especially noteworthy that the differences between
early and late phases in experiments with high object
densities are neither the result of purposeful
rearrangements of the environment by either robot or
experimenter, nor are they due to the adjustment of
“internal” variables over time such as learning rates, cell
response functions, or motor variables. Instead they are the
outcome of the coupling between brain, body and
environment. This coupling is strongly reciprocal.
Behavior affects the statistics of reward timings which
drive synaptic plasticity through activation of a
neuromodulatory system. In turn, synaptic changes alter
the coupling between visual and motor units which affects
behavior.
ENDQUOTE
Here they even suggest a possible role for embeddedness (i.e. reshaping your own environment) in the emergence of addiction:
QUOTE from the article
The experiments discussed in this paper may shed light
on the activity and functional role of neuromodulatory
systems (in particular, dopamine) in the course of
“natural”, self-guided behavior. The “attractive force”
exerted by clusters of rewarding objects, resulting in
restricted trajectories of robot movement and navigation as
well as repeated “rapid-fire” sequences of reward
encounters are especially intriguing. Disruptions of the
neurobiological bases of reward processing are thought to
form a major cause for lasting behavioral changes and,
eventually, chronic disease (addiction) in humans. Our
results suggest the hypothesis that a pattern of persistent
reward-seeking behavior may in part be generated as a
result of a progressive reshaping of the environment
coupled with long-lasting synaptic changes in specific
neural structures. Future experiments will investigate this
hypothesis in detail.
ENDQUOTE
For me this article shows that neuromodulation (embodiment) and embeddedness can be part of a larger perspective in which brain, body and world form a tightly coupled system, where the causal work depends on interaction between both world-events (behavior that reshapes the environment) and internal modulatory signals (reward leading to changes in synaptic connectivity - and hence, in the speed/ease of learning). In this article it is shown how this could work out in practice.
Tuesday, May 01, 2007
Time
As of this week I am in a philosophy group at work. I get one day per week to write philosophical papers - to be published in professional journals.
The first paper will have to be a follow up on the paper that Iris, Pim, Roel and me wrote (and will be published in Theory and Psychology). This paper deals with the question of what the new 'role' of the brain is when one starts thinking about intelligent behavior as being emergent out of an interplay between brain, body and environment. In contrast, of course, stands the cognitivist idea of the brain as being a sort of computer that takes in sense data, deciphers from these sense data a message in the language of thought (i.e.: 'meaning'), and then, on the basis of internally stored knowledge of the world, produces a response in the form of a behavior/act. The new way of seeing the brain, we venture, is that whenever the brain comes into action, *there is already behavior going on*. Lot's of behavior emerges out of the interplay between our body and the world. On a low level, parts of our nervous system help in forming structural couplings between the organism and its environment, leading to adaptive behaviors. This is not based on representing the environment internally, but based on forming a stable 'relation' between brain and aspects of the environment. Once such a low-level sensorimotor relation has been formed, higher parts of the brain can (but don't always) put a *bias* onto this lower level system. This bias works as an internal control parameter in a dynamical system. Increasing the value of the bias gradually can lead to dramatic qualitative changes in behavior. But the bias itself did not cause the behavior, it is just a bias. You need a fully operational sensorimotor loop for the higher brain activation to be able to effect it's causal work. Just like you cannot steer by just having a steering wheel in your hands, you also need to have a car that the steering wheel is attached to. But perhaps this is a bad analogy.
The next step is to take this starting point and write a new paper which has to involve, in some way, the subject of TIME, since time is the main theme of our philosophy group. I proposed that 'timing' is essential for the formation of structural couplings between organism and environment. I will be working out this idea in the coming weeks here in this weblog.
The first paper will have to be a follow up on the paper that Iris, Pim, Roel and me wrote (and will be published in Theory and Psychology). This paper deals with the question of what the new 'role' of the brain is when one starts thinking about intelligent behavior as being emergent out of an interplay between brain, body and environment. In contrast, of course, stands the cognitivist idea of the brain as being a sort of computer that takes in sense data, deciphers from these sense data a message in the language of thought (i.e.: 'meaning'), and then, on the basis of internally stored knowledge of the world, produces a response in the form of a behavior/act. The new way of seeing the brain, we venture, is that whenever the brain comes into action, *there is already behavior going on*. Lot's of behavior emerges out of the interplay between our body and the world. On a low level, parts of our nervous system help in forming structural couplings between the organism and its environment, leading to adaptive behaviors. This is not based on representing the environment internally, but based on forming a stable 'relation' between brain and aspects of the environment. Once such a low-level sensorimotor relation has been formed, higher parts of the brain can (but don't always) put a *bias* onto this lower level system. This bias works as an internal control parameter in a dynamical system. Increasing the value of the bias gradually can lead to dramatic qualitative changes in behavior. But the bias itself did not cause the behavior, it is just a bias. You need a fully operational sensorimotor loop for the higher brain activation to be able to effect it's causal work. Just like you cannot steer by just having a steering wheel in your hands, you also need to have a car that the steering wheel is attached to. But perhaps this is a bad analogy.
The next step is to take this starting point and write a new paper which has to involve, in some way, the subject of TIME, since time is the main theme of our philosophy group. I proposed that 'timing' is essential for the formation of structural couplings between organism and environment. I will be working out this idea in the coming weeks here in this weblog.
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