I notice that you do not use the symmetrical expression “respond with negative valence”. Is that because there is no antagonistic “negative valence” neurotransmitter? I know that there are neurotransmitters for stress but it seems that antagonistic learning works differently in the brain than dopamine reward, or?
OK, the more complete version would be
If, when lots of people think of Person X, their brains tend to respond with positive valence, then that fact is related to X having high social status / prestige (as above);
If, when lots of people think of Person X, their brains tend to respond with negative valence, then that fact is related to X having low social status / prestige (as above);
If, when lots of people think of Person X, their brains tend to respond with fear of them (or awe, or something in that vicinity) then that fact is related to X having high dominance.
If, when lots of people think of Person X, their brains tend to respond with lack-of-fear of them (or lack-of-awe, or feeling-of-safety, or feeling-of-the-stakes-being-low, or something in that vicinity) then that fact is related to X having low dominance.
I’m thinking of valence as a signal that can swing both positive and negative, as opposed to a positive-valence signal in the brain and a separate negative-valence signal in the brain. I acknowledge that there are areas in the brain where positive and negative contributions get calculated separately, but I think those pathways mostly get merged back together (positive minus negative) into a final all-things-considered valence signal.
Wait, do you mean this abstractly, or in the sense that there is a signal in the brain (a neurotransmitter etc.) that can be both positive and negative? How would that work biophysically?
A neuron can have a normal baseline of activity, and then be more-active-than-baseline sometimes and less-active-than-baseline other times. Phasic dopamine is the famous example that I especially have in mind here (cf. “dopamine pause” versus “dopamine burst”). I presume there are other examples too, but that’s something of a guess.
Here’s another option: If Signal X inhibits Neuron Group Z, and Signal Y excites Neuron Group Z, then we can abstractly subtract Signal X from Signal Y to get an abstract signal that can swing both positive and negative, and have coherent effects in the brain of either sign, even if there isn’t any one physical signal corresponding to that.
Do I understand correctly that the baseline of tonic dopamine sets the zero point and the bursts or absence of bursts indicate the positive/negative signal around that zero point?
The second option also makes general sense to me. It would more reliably result in absolute reward signals as the zero point is indeed the absence of either signal. I wonder if there are such neuron groups that do have such inhibition properties as you propose.
Do I understand correctly that the baseline of tonic dopamine sets the zero point and the bursts or absence of bursts indicate the positive/negative signal around that zero point?
Yes, that is what I was saying, except “pause” is different from “absence of burst”. E.g.
Electrical activity of midbrain DA neurons in vivo is characterized by tonic background activity in a narrow frequency range (ca. 1-8Hz) interrupted by either transient (i.e. phasic, <500ms) sequences of high-frequency firing (>15Hz), so called “bursts”, or transient pauses of electrical activity, where DA neurons generate no action potentials.
So 1-8Hz is the baseline / zero point, a “burst” is more activity than baseline, and a “pause” is less activity than baseline.
There’s a beginner-friendly discussion of dopamine neurons in Brian Christian’s Alignment Problem book, if memory serves.
I wonder if there are such neuron groups that do have such inhibition properties as you propose.
There are inhibitory synapses all over the brain—probably a comparable number to excitatory synapses (I don’t know the exact ratio offhand). Inhibitory synapses often (maybe “usually”) use GABA as the neurotransmitter, while excitatory synapses often use glutamate as the neurotransmitter.
1-8Hz is quite a range. I guess the base rate is not stable even within an individual. That would imply that the zero point is not actually fix. Given that tge brain can also achieve the effect with inhibitory synapses, I wonder whether there is a reason for this.
I also wonder what would happen if existing neuronal networks were trained with varying zero points. Would that improve learning like dropout is improving generalization?
OK, the more complete version would be
If, when lots of people think of Person X, their brains tend to respond with positive valence, then that fact is related to X having high social status / prestige (as above);
If, when lots of people think of Person X, their brains tend to respond with negative valence, then that fact is related to X having low social status / prestige (as above);
If, when lots of people think of Person X, their brains tend to respond with fear of them (or awe, or something in that vicinity) then that fact is related to X having high dominance.
If, when lots of people think of Person X, their brains tend to respond with lack-of-fear of them (or lack-of-awe, or feeling-of-safety, or feeling-of-the-stakes-being-low, or something in that vicinity) then that fact is related to X having low dominance.
I’m thinking of valence as a signal that can swing both positive and negative, as opposed to a positive-valence signal in the brain and a separate negative-valence signal in the brain. I acknowledge that there are areas in the brain where positive and negative contributions get calculated separately, but I think those pathways mostly get merged back together (positive minus negative) into a final all-things-considered valence signal.
Wait, do you mean this abstractly, or in the sense that there is a signal in the brain (a neurotransmitter etc.) that can be both positive and negative? How would that work biophysically?
A neuron can have a normal baseline of activity, and then be more-active-than-baseline sometimes and less-active-than-baseline other times. Phasic dopamine is the famous example that I especially have in mind here (cf. “dopamine pause” versus “dopamine burst”). I presume there are other examples too, but that’s something of a guess.
Here’s another option: If Signal X inhibits Neuron Group Z, and Signal Y excites Neuron Group Z, then we can abstractly subtract Signal X from Signal Y to get an abstract signal that can swing both positive and negative, and have coherent effects in the brain of either sign, even if there isn’t any one physical signal corresponding to that.
Do I understand correctly that the baseline of tonic dopamine sets the zero point and the bursts or absence of bursts indicate the positive/negative signal around that zero point?
The second option also makes general sense to me. It would more reliably result in absolute reward signals as the zero point is indeed the absence of either signal. I wonder if there are such neuron groups that do have such inhibition properties as you propose.
Yes, that is what I was saying, except “pause” is different from “absence of burst”. E.g.
So 1-8Hz is the baseline / zero point, a “burst” is more activity than baseline, and a “pause” is less activity than baseline.
There’s a beginner-friendly discussion of dopamine neurons in Brian Christian’s Alignment Problem book, if memory serves.
There are inhibitory synapses all over the brain—probably a comparable number to excitatory synapses (I don’t know the exact ratio offhand). Inhibitory synapses often (maybe “usually”) use GABA as the neurotransmitter, while excitatory synapses often use glutamate as the neurotransmitter.
Thanks for the primer.
1-8Hz is quite a range. I guess the base rate is not stable even within an individual. That would imply that the zero point is not actually fix. Given that tge brain can also achieve the effect with inhibitory synapses, I wonder whether there is a reason for this.
I also wonder what would happen if existing neuronal networks were trained with varying zero points. Would that improve learning like dropout is improving generalization?