Seminar in Beach
Room, 3rd floor Tolman hall, UC Berkeley April 18 2014 2pm
Seán O
Nualláin of universityofireland.com
The great
neuroscientist Karl Pribram and equally great physicist David Bohm
collaborated a generation ago with, among others, Jiddah Krishnamrti
to produce a completely new worldview. It provided a narrative, based
on cutting-edge science on how the evolutionary process allowed
nature to express itself as the “implicate” becoming “explicate”
and presenting itself to consciousness manifest in us.This beautiful
paradigm eventually failed to overcome resistance centering on the
neurophysiological plausibility and lack of detail.
In 1999, after having met Seán O
Nualláin at a conference on Gurdjieff organized by Seán’s
close friend Jacob Needleman, Karl Pribram spent a week at the O
Nualláin lab in Dublin. There, for the first time, a detailed
computational implementation of the Pribram / Bohm work was done. Far
from being merely a beautiful theoretical framework, it was found
that the view of dendrodendritic connections between neurons as the
critical computational operation in the brain explained many
heretofore intractable problems about sense perception. Moreover, it
was consistent with Stapp's work on quantum neural activity qua
harmonic oscillators.
Henry Stapp will open the session at
2pm with a discussion of quantum mechanics and the possible
relation to neuroscience
This seminar will
provide an overview of all this work as a prelude to a new course on
consciousness studies as described at http://foundationsofmind.org/courses.html
The full workshop schedule is as below
How does simulation of a
single neuron in ones visual system produce the richness of
subjective color perception? This is the topic of connecting qualia
to neural activity. The capability for achieving that connection has
only become available in the past six months, because of a new
instrument developed at UC Berkeley. But before getting to the recent
experiments some context is appropriate in the context of this 20th
anniversary of the Tucson "Toward a Science of Consciousness"
(TSC) meetings. Who can forget Chalmer's presentation of the "Hard
Problem" at TSCII in 1996. The 764 page book of papers from that
meeting is a treasure and is unequaled in capturing the state of the
field at that point. The challenge of connecting the hard problem of
qualia to the neural correlates of the brain is still with us and
I'll argue that advances in technology may enable substantial
progress. My article in the Vision and Consciousness section of
the TSCII book was titled "Double Judgment Psychophysics for
Research on Consciousness: Applications to Blindsight"
(cornea.berkeley.edu/pubs/120.pdf).
My present title could have been the same as the old title but
replacing "Double" to "Triple", and "Blindsight"
to "color" as I now discuss.
A new instrument that enables single neuron brain stimulation has been developed by Austin Roorda of UC Berkeley. The new technology that combines adaptive optics and super precise image stabilization enables one to do careful psychophysics on individual cones and ganglion cells. Retinal ganglion cells (RGC) are special since they are the bottleneck for vision, carrying information to the brain along the optic nerve. Roorda's lab is next to mine and we have been developing new approaches for single and double RGC stimulation. One of the big surprises is that activation of single retinal neurons can produce a wide variety of color percepts. It had previously been thought that single RGC stimulation would produce limited color percepts (red, green, yellow, blue) based on the opponent color mechanisms found in RGCs and the brain's lateral geniculate nucleus (LGN). But a much greater diversity of colors were found. In our experiments for every single RGC stimulation we make a triple judgment on the perceived hue, saturation and intensity of the stimulus. We also do that with different background colors. Several competing hypotheses regarding the mechanisms that produce the surprisingly diverse color percepts are now being tested and will be discussed. We are especially interested in the neural basis for what is called "unique hues". There is, for example, surprising general agreement on "unique yellow" a color that is neither reddish nor greenish. Unfortunately the wavelength of unique yellow differs from what would be predicted from the tuning of RGCs and LGN cells. By paired stimulation of adjacent reddish and greenish RGCs we hope to gain an understanding of what causes the agreement on the unique hues. The new instrument opens up a great variety of experiments linking neural activity to perception.
While it is universally accepted that several types of cells in the
retina, including rods, do not spike, little investigation has been
done to ask how sense-data can be processed without neural firing.
Moreover, the fact that timing of afferent impulses to a neuron shapes
its firing has not received enough attention. This talk argues that
firing is actually a limit case of a more general mode of neural
functioning in which subthreshold oscillations have a critical causal
role. A harmonic oscillator model of the neuron is sketched, beginning
from a compartmental Hodgkin-Huxley model, and it is shown how the
emergent principles operate equally for tactile, auditory, and visual
input.
The full workshop schedule is as below
Workshop in Beach Room, 3rd
floor Tolman hall, UC Berkeley April 18 2014 2pm
2-10
pm Introductory remarks Seán O Nualláin
2-15pm
Henry Stapp on “Quantum Mechanics and neuroscience ”
3-15
pm Stan Klein “Connecting visual qualia to their neural
correlates”
A new instrument that enables single neuron brain stimulation has been developed by Austin Roorda of UC Berkeley. The new technology that combines adaptive optics and super precise image stabilization enables one to do careful psychophysics on individual cones and ganglion cells. Retinal ganglion cells (RGC) are special since they are the bottleneck for vision, carrying information to the brain along the optic nerve. Roorda's lab is next to mine and we have been developing new approaches for single and double RGC stimulation. One of the big surprises is that activation of single retinal neurons can produce a wide variety of color percepts. It had previously been thought that single RGC stimulation would produce limited color percepts (red, green, yellow, blue) based on the opponent color mechanisms found in RGCs and the brain's lateral geniculate nucleus (LGN). But a much greater diversity of colors were found. In our experiments for every single RGC stimulation we make a triple judgment on the perceived hue, saturation and intensity of the stimulus. We also do that with different background colors. Several competing hypotheses regarding the mechanisms that produce the surprisingly diverse color percepts are now being tested and will be discussed. We are especially interested in the neural basis for what is called "unique hues". There is, for example, surprising general agreement on "unique yellow" a color that is neither reddish nor greenish. Unfortunately the wavelength of unique yellow differs from what would be predicted from the tuning of RGCs and LGN cells. By paired stimulation of adjacent reddish and greenish RGCs we hope to gain an understanding of what causes the agreement on the unique hues. The new instrument opens up a great variety of experiments linking neural activity to perception.
4pm
Gautam Agarwal, et al.
“The
emergence of information in mesoscopic measures of brain activity”
“Resonate and fire; how non-spiking
neurons process sensory data”
While it is universally accepted that several types of cells in the
retina, including rods, do not spike, little investigation has been
done to ask how sense-data can be processed without neural firing.
Moreover, the fact that timing of afferent impulses to a neuron shapes
its firing has not received enough attention. This talk argues that
firing is actually a limit case of a more general mode of neural
functioning in which subthreshold oscillations have a critical causal
role. A harmonic oscillator model of the neuron is sketched, beginning
from a compartmental Hodgkin-Huxley model, and it is shown how the
emergent principles operate equally for tactile, auditory, and visual
input.
The
talk ends with speculation on the role of attention and
consciousness.
