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Monday, January 28, 2019

Learning to Learn Emotional Stability


Educated people know about Pavlov's classical conditioning studies. But few people realize the pervasive implications that apply even today.

The key initial observation made by Pavlov was that when dogs saw objects that looked like (and probably smelled like) food, they salivated. He immediately seized on the concept of ASSOCATION that somehow caused nervous systems to learn. He had no way to know if dogs actually "thought" about the association. It did not matter whether the dogs did or not. The biological adaptiveness of such a learning system was obvious. Pavlov realized he needed to pursue this, instead of digestive physiology, as it was something new and fundamental. He went on to perform experiments that lead to the ideas of UCS/CS and UCR/CR.

The idea he missed was positive reinforcement. In fact, it took some 50 years for others to realize that reinforcement was an underlying mechanism in classical conditioning. This led of course to the idea that you could produce learning by manipulating reinforcement (i.e., operant conditioning).

Pavlov's work, old as it is, is still finding applications today. A couple years ago I got an up-date in the area of PTSD research at a seminar by Gregory Quick from the Department of Psychiatry at the University of Puerto Rico. As Pavlov showed, memory extinction is a basic phenomenon even in simple animals. If you repeatedly flash a light and then stress a rat, it soon learns to become distressed the next time it sees the flash, even after you stop the stress. In the lab, this is manifested by the rat showing freeze behavior. But, if you repeat flash cue enough times without the stress, the conditioned response (CR) (freeze behavior) eventually becomes extinguished.

At first, scientists thought that extinction erases the memory of the CR. But extinction really creates a new memory that competes with memory of the original CR. Both memories co-exist. Over time the extinction memory may be lost, and the CR can return. The implication is that, just as ordinary learning needs rehearsal, so does extinction learning.

Therapy for emotional trauma and PTSD might be more effective if therapy were approached like a conventional learning experience whose memory is affected in all the usual ways. Recall what was said about extinction being a case of new learning. Re-learning of an extinguished response occurs much more readily than it does for initial extinction learning. This is an example of priming. It’s like re-learning a foreign language. It goes easier the second time and the memory might be even more dependable. 

Since memory of an emotional CR learning experience and its extinction can co-exist, these two memories compete for which one is strong enough to survive long-term. Sadly, the CR memory that causes the PTSD is often stronger. Cues are extremely important to both forming and retrieving all kinds of memory. It seems likely there are many more explicit cues for CR memories than for extinction memories. Therapy should be aimed at enriching the number and variety of cues associated with extinction learning. Rehearsal is likewise important. So far, nobody seems to have given that much thought.

There is another aspect to emotional learning: learning to learn. If you have multiple anxieties, they may generalize and "spread" to facilitate learning new anxieties. In other words, the brain is learning to become emotionally dysfunctional. The corollary would be that learning how to promote extinction could also generalize and thus increase the general ability to cope with emotional trauma. Obviously, for one's brain to learn how to do that, one would need to begin with a single relatively easy extinction learning task, and then apply that learning-to-extinguish experience to other situations. Extinction learning needs to be repeated in order to become firmly established.

Sunday, January 13, 2019

Why Lucid Dreams Matter


Lucid dreams are often defined as the ones you know you are having in real time. These are the dreams where you seem to be conscious. You are aware of the story line, and you are often a central character in the story. Sometimes, you may even consciously manipulate the dream content toward a more acceptable outcome.

Scientists have recorded physiological changes during sleep, and there are multiple episodes during sleep, especially early in the morning, that display brain waves similar to those when you are awake accompanied by rapid, jerky eye moves (REM). When people were awakened every time these signs appeared, they invariably said a dream was interrupted.
Source, with permission: Carroll Jones III, Nathaniel Graphics, 2013

Incidentally, I have studied this in animals. It appears that REM sleep is an innate property of the brains of mammals. I discovered REM sleep in ruminants, which at the time were assumed to rest without true sleep. I also discovered a rudimentary form of REM sleep in armadillos, which I studied because they are among the most primitive mammals. However, only people show numerous REM episodes lasting significant times. I have even published a theoretical paper suggesting why people need so much REM sleep.

Some people claim that they don't have lucid dreams, but there are physiological indicators that everybody does dream. It is possible that lucid dreams can occur but are not consolidated in memory. What is the first thing you do when you wake up? You start thinking about something other than what you were dreaming about, such as going to the bathroom, your aching joints, having breakfast, upcoming day's events, and so on. Such distractions interfere with memory consolidation of recent thought.

A sleep-lab study in which the EEG was recorded revealed certain physiological signs that are unique to lucid dreams, as opposed to non-lucid dreams. Subjects were trained to generate, recognize, and remember lucid dreams. Subjects who commonly reported having lucid dreams were selected for specific training, which included reminding themselves before going to sleep that they were to recognize when they were having lucid dreams and signal that to sleep monitors by a specific pattern of eye movements (in dream sleep, only the eyes move continuously because a descending motor-inhibition circuit in the brainstem is activated). During early-morning sleep, when lucid dreams were more prevalent, EEG recordings during lucid dreaming revealed REM-like activity in frequency bands δ and θ, and higher-than-usual REM activity in the γ band, the between-states-difference peaking around 40 Hz. 

Voltage power in the 40 Hz band is strongest in the frontal and frontolateral region. Moreover, the 40-Hz activity during REM is more coherent with similar activity in other regions of the cortex. The specific increase in gamma activity and the increased in 40 Hz-band coherence in lucid dreaming suggests that these are this may be the physiological basic of consciousness.
This study is important because the EEG changes are not like those in regular, non-dream sleep but are similar to what occurs in conscious wakefulness. Thus, REM sleep seems to be a form of consciousness. The lucid dreams are special because the content means something, but usually expresses it symbolically or in metaphors. Your brain has escaped the editing shackles of wakefulness and is free to reveal things you might not know about. Sometimes it is things you don't want to know about. However, you brain is trying to tell you something. You don't have to be a Sigmund Freud to figure out some of the meaning.

With my own lucid dreams, when I reflect on the content, I often find they help me to recognize and deal with deeply personal issues. They can point the way to personal insight. If you reflect on the dream content right after awakening, you are likely to remember it. Lucid dream content can change your life, one small step at a time.

Sources:
Klemm, W. R. 2011. Why does REM sleep occur? A wake-up hypothesis. Frontiers in Neuroscience. 5 (73): 1- 12. Doi: 10.3389/fnsys.2011.00073

Voss, Ursula, Holzmann, Romain, Tuin, Inka, and Hobson, Allan, J. (2009). Lucid dreaming: A state of consciousness with features of both waking and non-lucid dreaming. Sleep. 32(9), 1191-1200. https://academic.oup.com/sleep/article/32/9/1191/2454513


Friday, January 04, 2019

Consciousness as Afterthought


I get a lot of questions in Quora about neuroscience, because neuroscience is what I do. A recent question prompts this post. The question was: "Does all thinking originate in subconscious thinking?" This is a provocative question. It gets to the heart of the matter: What is the default mode of brain operation, conscious or subconscious?

Semantic Confusion

Much of the confusion about consciousness arises because words fail us. We have poor definitions for the usual words: conscious, unconscious, subconscious, non-conscious. Before I attempt an answer to my Quora question, let me establish some background about terminology. First, the currency of thought is patterns of nerve impulse activity constrained by flowing in and through defined circuits of linked neurons. The impulse thought patterns that occur in primitive circuitry, like spinal  segments and neuroendocrine circuits are considered nonconscious thoughts because we can never be consciously aware of what those circuits are doing. We can, for example, use instruments to measure our blood pressure, but on its own, the brain can never detect that consciously.

Perhaps the most common kind of thought is that which occurs all the time, even when asleep, that we are not aware of. These days, scholars like to call this "unconscious" thinking.  But coma is clearly an unconscious state, and there often is little electrical activity that reflects thought. That is why a more useful term in this context is "subconscious," a term popularized by Freud. That is probably why the term has fallen into disuse. Too many of Freud's ideas have been discredited. But not his idea of subconsciousness.

Consciousness Is Not the Same as Being Awake

Reflect on your own perceptual experiences. Every time you are consciously aware of something you were attending to it. True, you can be awake without being conscious (see Selective Attention below). This means that we have to make a careful distinction between wakefulness and consciousness. They are not synonymous. You can't be conscious if you are not awake, but being awake does not assure consciousness of non-attended objects.  Wakefulness is generated out of excitatory activity of the brainstem reticular formation acting on neocortex, as I explain in my book, Mental Biology. The mechanisms of consciousness have not been established, but they likely involve coherent nerve impulse activity in distributed circuitry.

The phylogenetic perspective argues for unconsciousness as the default mode of thinking, inasmuch as lower animals are not likely to have conscious thought, yet their behavior clearly indicates that they are awake and their brains are "thinking." Also, we know from studies of infants that behavioral signs of consciousness are rare and only emerge as the brain matures. It is clear that much human thinking occurs below the level of conscious awareness.

The many scholars who claim that humans have no free will use the assumption of subconscious thinking to defend their stance against free will. They came to this conclusion from experiments that say indicate that all willed action is generated subconsciously and only recognized later in consciousness. The experiments and the interpretation are flawed, as I explain in my book on free will. To help defend the stance that free will is an illusion, the proponents go further to argue that consciousness is just an observer, like a movie patron in a theatre. You can just watch what is happening but can't do anything about it. Thus, they construct the specious circular argument that you can’t have free will because free will requires consciousness by definition, and consciousness can’t do anything. How convenient! This absurd notion, held by academics who are not as smart as they think they are, assume that all our consciousness thinking is basically irrelevant. They assume that the neural activity of conscious thought cannot influence neural activity in other parts of the brain, even though they have to admit that the neurons that mediate conscious thought are functionally connected with the other parts of brain. By these connections, conscious thought can, for example, explicitly evaluate the meaning of stimuli, or order certain muscles to contract, or force mental  effort to memorize, or change our emotional state and visceral functions in light of reason or mindfulness meditation, and so on. The circuitry of consciousness is not in a pickle jar outside the brain. It is inextricably bound to other brain circuits.

I certainly don't mean to dignify the anti-free-will position by describing it. However, debunking that position opens the door to reconsider the possible relationship between subconscious and conscious thought. Suppose conscious thought is an afterthought, but not in the restricted sense prescribed by the anti-free-will crowd. Just because subconscious thought can lead to conscious thought does not mean that conscious thought has no action of its own. When we consciously think about what we have recognized in consciousness, all that thinking is, by definition, conscious.  Conscious thought can consider options explicitly. It can reason. It can set goals, plan, command action, evaluate consequences of action, and adjust programming as needed. Subconscious thinking can do that too. Most likely the two modes of thinking work in potentially synergistic ways, though it seems clear that conscious thought can veto subconscious impulses and bad ideas.


Consciousness as Selective Attention

Have you seen the U tube video of a pickup basketball game? The video instructs viewers to count how many times one of the teams pass the ball. Viewers are so focused on the task that many of them fail to see a man in a gorilla suite walk into the game, do a little chest pounding, and then walk off the court. The point is that the eyes and subconscious mind saw the gorilla, but not the conscious mind. The same phenomena has been confirmed in another context. The phenomenon is labeled by psychologists as "inattentional blindness." In other words, we are only conscious of targets of our attention.

Like all biological systems, brains are stimulus-response systems. Humans have unique ways to respond to stimuli and experience, in that their brains selectively identify the information content, evaluate it in terms of available optional responses, and then determines an appropriate response. Both subconscious and conscious thought can be involved, but conscious thought only operates on attended targets.


Scanning for Meaningful Impulse Patterns

While it is clear that conscious brains think, it may be useful to consider that consciousness is also a scanning mechanism. We don't know how such scanning is enabled by wakefulness, but we do know that the awake brain generates more regular oscillations of impulse activity. These oscillations arise in many localized subnetworks throughout the cortex, occurring at varying frequencies and extent of synchrony among other generators. Intracellular recordings of neurons reveal that one or a few spikes are generated each time the membrane depolarizes. Oscillation is a built-in feature of neural circuits which commonly oscillate because impulse output re-enters the circuitry that generates it.  Increasing the frequency of oscillation increases the total impulse discharge because there are more depolarizations per unit of time. This increases the informational throughput in the network. Likewise, the degree to which multiple oscillators synchronize to share data modulates impulse throughput throughout linked circuits.

Perhaps the oscillation itself is the scanning mechanism. As novel or particularly relevant input enters an oscillating circuit, that circuit’s own impulse firing pattern may be disrupted, re-set, change frequency, or alter its time locking to other subnetworks. Enhanced time-locking among circuits could have the magnifying intensity effect that seems to be required in selective conscious attention. The carrying capacity for information is limited, because only subsets of networks in the global workspace synchronously engage at any one moment. This is one way to improve the signal-to-noise ratio of neural circuit processing.

Perhaps conscious thought is the afterthought of this scanning once it latches onto a subconscious thought that compels attention. Such a mechanism has great biological advantage in that it is a way for brain to scan through a noisy stimulus- and thought-world to identify signals that are salient for appropriate and selective processing and response. Once the target is captured in consciousness, conscious neural activity evaluates the salient signals and determines what to do about it and directs useful action. Taken in this light, I answer a tentative yes to my Quora questioner who wanted to know if all thinking originates in subconscious thinking.

Sources

Klemm, W. R. (2014). Mental Biology: The New Science of How the Brain and Mind Relate. New York: Prometheus.

Klemm, W. R. (2016). Making a Scientific Case for Conscious Agency and Free Will. New York: Academic Press.

https://www.youtube.com/watch?v=vJG698U2Mvo   The original basketball game example of the invisible gorilla.

https://www.youtube.com/watch?v=UtKt8YF7dgQ  A confirmation of the invisible gorilla in another context.