The language doesn’t match PCT, but it definitely supports the idea that the internal state of the organism matters much more than whatever stimulus the environment (or some researcher) throws its way.
Some key quotes:
While a dynamical systems approach to neuroscience is hardly new, it’s been difficult to test and model. The way experts think about basic sensory perception tends toward the hierarchical: The cortex builds up and integrates features to form perceptions, sending signals to other layers of the network that integrate still more information until the brain ultimately arrives at a decision or behavior.
Not so in this new work. Instead, the team’s results support a different kind of processing in which “all of this happens at the same time, and … **before the stimulus even arrives,**â€? said Leslie Kay, a neuroscientist at the University of Chicago who focuses on olfaction. “You learn stuff within a cortical area,â€? forming a system of connected clusters to reflect that learning, “and then you influence it [with expectation], and what it knows emerges.â€? [emphasis added by FL]
…
It also highlights the need to move away from focusing on single neurons that respond to particular cues, and toward making internal states and dynamics more explicit in our understanding of sensory networks — evven for the most basic sensory stimuli. “It’s much easier to say that a neuron increases its firing rate,â€? said Anan Moran, a neurobiologist at Tel Aviv University in Israel. But to understand how organisms work, “you cannot account only for the stimulus, but also for the internal state,â€? he added. [emphasis added by FL]
Frank, the language in these quotes sounds to me very like the plan
of the Friston free-energy approach than PCT. The difference between
PCT and Friston is more in that Friston is based in control of
behaviour to fulfil expectation, as opposed to control of input to
fulfil the actors “will”. That may sound like a crucial difference,
but it’s actually more of a difference of interpretation than a
difference in the mathematics of what is proposed, because Friston’s
“control of output” actually maps into the structure of the
reorganized perceptual control hierarchy pretty well. The quote
doesn’t match PCT, but it definitely supports the idea that
the internal state of the organism matters much more than
whatever stimulus the environment (or some researcher)
throws its way.
Â
Some key
quotes:
“* and
then you influence it [with expectation], and what it knows
emerges* .â€? Illustrates the convergence, since “what the
hierarchy knows” is a metaphor for the current state of the
reorganized hierarchy. But it has no “expectation”. It has
“reference values”. An external analyst who knows the current
state of reorganization could have an expectation of the effect of
whatever the hierarchy might do give some change of reference
value due to a disturbance change to a higher-level perception,
but the acting system does not, except as a metaphor.
Metaphors are often useful, but can be, and often are, misleading.
In this case, I think the “expectation” metaphor has led the
Friston followers (and there are many more than there are
followers of PCT) astray.
Martin
Â
While
a dynamical systems approach to neuroscience is hardly new,
it’s been difficult to test and model. The way experts think
about basic sensory perception tends toward the
hierarchical: The cortex builds up and integrates features
to form perceptions, sending signals to other layers of the
network that integrate still more information until the
brain ultimately arrives at a decision or behavior.
Not
so in this new work. Instead, the team’s results support a
different kind of processing in which “all of this happens
at the same time, and … ** before
the stimulus even arrives,**� said Leslie Kay , a
neuroscientist at the University of Chicago who focuses on
olfaction. “You learn stuff within a cortical area,� forming
a system of connected clusters to reflect that learning,
“and then you influence it [with expectation], and what it
knows emerges.� [emphasis added by FL]
…
It
also highlights the need to move away from focusing on
single neurons that respond to particular cues, and toward
making internal states and dynamics more explicit in our
understanding of sensory networks — even for the most bbasic
sensory stimuli. “It’s much easier to say that a neuron
increases its firing rate,� said Anan
Moran ,
a neurobiologist at Tel Aviv University in Israel. But to
understand how organisms work, “you cannot account only for
the stimulus, ** but also
for the internal state**,� he added. [emphasis
added by FL]
From: Warren Mansell wmansell@gmail.com Date: 25 August 2019 at 04:49:17 BST To:mmt-csg@mmtaylor.net Subject:Re: Maybe this puts the S-R psychology to rest
Agreed, and it makes it one of our biggest challenges in arguing for the advantages of PCT…
[Martin Taylor 2019.08.23.14.58]
Frank, the language in these quotes sounds to me very like the plan
of the Friston free-energy approach than PCT. The difference between
PCT and Friston is more in that Friston is based in control of
behaviour to fulfil expectation, as opposed to control of input to
fulfil the actors “will”. That may sound like a crucial difference,
but it’s actually more of a difference of interpretation than a
difference in the mathematics of what is proposed, because Friston’s
“control of output” actually maps into the structure of the
reorganized perceptual control hierarchy pretty well. The quote
doesn’t match PCT, but it definitely supports the idea that
the internal state of the organism matters much more than
whatever stimulus the environment (or some researcher)
throws its way.
Some key
quotes:
“* and
then you influence it [with expectation], and what it knows
emerges* .â€? Illustrates the convergence, since “what the
hierarchy knows” is a metaphor for the current state of the
reorganized hierarchy. But it has no “expectation”. It has
“reference values”. An external analyst who knows the current
state of reorganization could have an expectation of the effect of
whatever the hierarchy might do give some change of reference
value due to a disturbance change to a higher-level perception,
but the acting system does not, except as a metaphor.
Metaphors are often useful, but can be, and often are, misleading.
In this case, I think the “expectation” metaphor has led the
Friston followers (and there are many more than there are
followers of PCT) astray.
Martin
While
a dynamical systems approach to neuroscience is hardly new,
it’s been difficult to test and model. The way experts think
about basic sensory perception tends toward the
hierarchical: The cortex builds up and integrates features
to form perceptions, sending signals to other layers of the
network that integrate still more information until the
brain ultimately arrives at a decision or behavior.
Not
so in this new work. Instead, the team’s results support a
different kind of processing in which “all of this happens
at the same time, and … ** before
the stimulus even arrives,**� said Leslie Kay , a
neuroscientist at the University of Chicago who focuses on
olfaction. “You learn stuff within a cortical area,� forming
a system of connected clusters to reflect that learning,
“and then you influence it [with expectation], and what it
knows emerges.� [emphasis added by FL]
…
It
also highlights the need to move away from focusing on
single neurons that respond to particular cues, and toward
making internal states and dynamics more explicit in our
understanding of sensory networks — even for the most bbasic
sensory stimuli. “It’s much easier to say that a neuron
increases its firing rate,� said Anan
Moran ,
a neurobiologist at Tel Aviv University in Israel. But to
understand how organisms work, “you cannot account only for
the stimulus, ** but also
for the internal state**,� he added. [emphasis
added by FL]