Rebecca Pisciotta's blog

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Eye Movement Desensitization and Reprocessing Therapy: The Unseen Role of the Body in Mental Processes

The human brain processes and stores information about experience. It forges links between information currently being processed into memory and other relevant thoughts, ideas, and memories. Shapiro hypothesizes that during a traumatic event normal information processing may be disrupted. This may be due to the strong emotions being felt, or due to dissociation. As a result, information about the event is not fully processed into an adaptive network with other ideas, thoughts, and memories (1). An example of a maladaptive association is a rape survivor knowing that the rapist is the one to blame, and yet acutely feeling as if the rape were their own fault. Shapiro points to these mal-processed experiences as the seat of dysfunction and mental disorder, such as Post Traumatic Stress Disorder (PTSD) and Acute Stress Disorder (ASD), the two main mental disorders that Eye Movement Desensitization and Reprocessing (EMDR) is used to treat (1). The role of EMDR in Shapiro’s hypothesis is to resume and complete the processing of relevant information into adaptive networks. When the incident is recalled, post-therapy, according to Shapiro, the individual should have a new perspective and insight, and is no longer overcome with the excessive emotion and vividness of the incident that plague sufferers of PTSD and ASD.

EMDR therapy occurs in eight stages including assessing the patients readiness for the procedure, the procedure itself, closure, and evaluation of the success of the procedure. The procedure itself also occurs in repeated steps. The patient calls to mind a vivid visual image, negative thought, or bodily stimulus associated with the negative event while following the therapist’s finger as it moves back and forth for approximately 30 seconds (1). These eye movements can be replaced with auditory tones alternating between the left and right ear, or bilateral tactile stimulation of the left and right knees. This is called dual attention stimulus. This step is repeated numerous times until the patient does not report distress at the chosen negative association. The patient then chooses a positive image, thought, or sensation that they would like to replace the negative one and repeats the procedure (1). They follow the therapist’s finger back and forth for 30 seconds until they report that the positive association feels more valid than the negative one. This combination of recall and dual attention stimulus is the key to EMDR.

A number of studies have been done comparing EMDR to no therapy, cognitive behavioral therapy, non-exposure therapy and exposure therapy (without eye movements). EMDR has been shown to be more effective than no treatment and non-exposure treatments, but no more effective than other exposure treatments. This meta-analysis of 34 studies was done by Davidson and Parker (2). Even though EMDR may be no more effective than exposure therapies it still may be preferable. Exposure therapies involve putting the patient in a situation where they must confront the traumatic event or trigger with the therapist while they work through the initial fear to accept that the memory or thing is not truly threatening. This process, though effective, forces the patient to experience anxiety provoking stimuli which may be very distressing. Logistically the process also may be difficult to arrange. EMDR is (typically) not at all distressing, and is a very simple procedure to perform. Multiple other studies have had conflicting results, sometimes showing EMDR to be no more effective than alternative or no therapy.

Even with these inconsistent research results EMDR is still a novel treatment receiving attention by therapists and researchers, and is being used more frequently in PTSD and ASD patients. In 2004 it was approved by the American Psychiatric Association for treatment of PTSD (1). Perhaps the most interesting aspect of EMDR, and the reason it is being given attention, is its utilization of dual attention stimuli in a process that targets memory and emotion. There is something novel and intriguing about a psychological therapy that claims to benefit from the co-occurrence of a seemingly random and unrelated physical stimulus.

It is obvious that our bodies and minds are highly intertwined, that there is a strong psycho-physiological relationship. If EMDR with dual attention stimuli is more effective than without it there is a significant connection between information processing and eye movements (or any bilateral alternating stimulus). We smile when we are happy, we fall asleep when we lie down in bed, we walk to the refrigerator when we are hungry. The direction of interaction is hard to tease out, do we get into bed when we are tired or are we tired because we have gotten into bed? It could be either. These mentioned physical movements are an expression of, or action related to, a specific internal state such as fatigue. These relationships are clearer than the one that exists between dual attention stimuli and memory.

What possible role could eye movement have in the mechanism of information processing? When PTSD sufferers recall their traumatic memories there is increased activity in areas of the right hemisphere responsible for visual images and emotional activity, and decreased activity as compared to normal in Broca’s area (located in the left hemisphere), which is responsible for speech (6). This may explain why PTSD sufferers talk about their trauma in implicit perceptual terms, as opposed to a reflective story telling manner (6). The increase in norepinephrine, which is involved with the hippocampus in long term memory storage, experienced during stressful events may be responsible for the perpetual lifelike vividness of traumatic memories. The alternating bilateral nature of a dual attention stimulus may activate the left and right hemispheres alternatively. This may assist in the integration of the previously right hemisphere isolated traumatic memory into a bilateral network of associations with past memories and current thoughts related to the event (4). This may allow for a reflective interpretation of the event, now mediated by experience. Even if the stimuli does activate the hemispheres alternatively, it is unclear precisely what areas of the hemispheres are being activated and what specific role they play in processing memories. If the eye movements do have a neurobiological function in this treatment, is bilateral hemisphere activation the mechanism of its function or is there something else occurring?

There are three main hypotheses for the mechanism of action of the dual attention stimuli in EMDR. Kavanaugh posits that the dual attention stimulus serves to interrupt and disrupt the negative associations formed by the traumatic memory. When the existing associations are disrupted new associations can form (1). Because the new associations are formed in the context of therapy they are more adaptive than those formed during the traumatic event. The following two hypotheses are especially intriguing, due to their evolutionary and neurobiological foundations, if not terribly more scientifically provable than the first.

The second hypothesis is posited by MacCulloch, Feldman Barrowcliff, and Van Den Hout. It states that the eye movements are part of an investigatory response, which is part of orienting behavior (4). They seem to propose that when a danger is encountered the first response is fear and a negative physical response and the second step is investigatory behavior, looking for further danger, which can lead to avoidance or approach. Investigatory behavior can result in a positive physical response, relaxation, when it is assessed that there is no further threat (4). If this is the case then the relaxation should occur during EMDR only in trials where the patient is thinking about the traumatic memory. On the trials where the patient is targeting a positive memory no orienting response to danger, and therefore no investigatory response followed by relaxation should occur. Indeed this is supported in a study by a study done by Barrowcliff et al (5).

The third hypothesis is being investigated by Stickgold, Christman, and Garvey. They take a hard neurobiological approach to the problem. They believe that the dual attention stimuli trigger a neurobiological state which is conducive to the conversion of episodic memory to cortical semantic memory. They believe that the eye movements used in therapy mimic the saccades of rapid eye movement (REM) sleep, inducing a similar neurobiological state (4). Many researchers believe that REM sleep is a critical time for integration of stored episodic memory into long term semantic networks. They suggest that the integration of the hippocampally stored target memory into a general semantic network serves to lessen the strength of the memory and its associated amygdally located fear response.

There is still much contention as to the relative efficacy and mechanism of action of eye movement desensitization and reprocessing therapy. Further research with more strictly controlled conditions may elucidate the effects of EMDR as compared to alternative therapies, and serve to further validate its acceptance into common practice. EMDR is still in many ways a mystery. In our attempts to figure out exactly what is occurring inside this black box we are, and can learn a lot about the mechanism of information processing and memory storage, how these processes work, and how they are affected by external variables, such as trauma. Through studying its parallels with other biological processes such as sleep we can learn more about the mechanisms of both, as well as about common patterns underlying varied biological functions.

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Book Commentary on The User Illusion: Cutting Consiousness Down to Size

In his book The User Illusion: Cutting Consciousness Down to Size Danish science journalist Tor Norretranders presents a scientifically sound and intellectually stimulating theory of conscious experience. “The user illusion” refers to a computer users idea of how the computer works based on how they interact with it. The bits and bytes are concealed by a largely metaphorical, extremely simplified, and not necessarily accurate illusion. Norretranders central thesis is that consciousness is our user illusion of ourselves. Consciousness arises after much information has been discarded. Conscious experience is a manageable distillation, essence, of our extremely rich raw experience. The User Illusion is incredibly readable in spite of its plethora of references. Norretranders pulls from innumerable sources, most notably Gödel, Libet, and Shannon. He integrates a wide array of prior research, tying together ideas from information theory, thermodynamics, physics, psychology, and philosophy to substantiate his theory; this is indeed the strongest aspect of the book.

Norretranders builds his theory of consciousness on the tenants of information theory. He makes sure the reader understands the basics before he applies them to his broader claims. The take home message is the notion of information and exformation. Exformation is discarded information. Norretrander uses the example of grocery shopping, among others. At the register the prices of the individual items are summed, it is this number, the total, that we are interested in. The sum is useful to us, it tells us how much money to take out of our wallet, the individual prices are not, they are irrelevant once we obtain the total. The author then extrapolates to consciousness, explaining that a huge amount of information must be discarded along the path from unconscious to conscious experience. While we all realize that our brain performs functions we are not always aware of (converting waves of light into a 3 dimensional picture) the book warns us not to underestimate the unconscious. He explains how the unconscious makes decisions based on information that our conscious does not have access to, and that the role of the conscious self may be solely to decide whether or not to execute the actions decided upon and suggested by the unconscious. An example for this is first impressions, it can take a split second to form an opinion about someone about whom we know next to nothing. Our unconscious may actually be gathering a lot of information about the person based on information (consciously inaccessible) gathered from subtle body language. He shows how the notion of exformation is influential for the individual as well as social experience. He takes the time necessary to clarify these issues which can be difficult to grasp for a reader who has no knowledge of the subject. He shows the breadth of the autonomy exercised by the unconscious with examples familiar to readers with some background knowledge, such as optical illusions.

A flaw presents itself in part two (of four), in which Norretranders dives into the body of evidence that forms the base of his theory. The evidence, he concludes, states that out of the eleven million bits of information that enter through our sensory modalities every second, only sixteen bits ever enter our consciousness. His confidently definitive manner of writing, as well as his lack of acknowledgment of any opposition adds to the startling nature of this claim. While it is true that only a fraction of the information we receive is ever available to our consciousness the numbers to which Norretranders continually refers back are misleading. The eleven million bits is arrived at by calculating the number of neurons leading from our sensory organs to our brain, which represents the maximum amount of information we can receive from the outside. The number sixteen is calculated from various experiments that determine the information transmitting capacity of different cognitive functions. This is determined for example by attributing a bit value to a letter (based on the fact that it is one of a possible 26) and calculating how many words (therefore letters) a person can read per second. Both methods of determining bit capacity are valid, but to compare them is to compare apples and oranges. To make a valid comparison between sensory and conscious capacities Norretranders would need to be able to either compute the number of neurons involved in conscious brain activity, or the total informational bit capacity of our sensory experience. The flaw is methodological, and does not weaken his theory as a whole. But his obscurity in this matter is disappointing when he is able to be so lucid throughout the rest of the book.

There is, astonishingly, only one other area in which The User Illusion is noticeably sub par. Once Norretranders introduces the reader to his theory of consciousness he attempts to integrate it into an (over) abundance of ideas, just to mention a few: the Gaia theory, communism, market theory, straight lines, constructionism, emergence, chaos, computation, boundaries, nuclear weapons, paradoxes, and length. Each of these ideas are introduced, and skimmed over, in part four. The last section of the book is scattered, the topics addressed lack coherence and depth, and it is difficult to see how some are even relevant (such as his Gaia theory tangent). Part four contrasts parts two and three in which Norretranders stretches to apply his theory to unanticipated topics with a rewarding result.

One intriguing idea that I found particularly notable is a surprisingly insightful connection the author draws between the unconscious-conscious dynamic, and the central doctrines of Judaism and Christianity in chapter nine. Judaism chastises and rewards individuals based on their actions, whereas Christianity judges the individual based on their actions as well as their thoughts and urges. If the unconscious is responsible for producing the urge to action, and we are consciously only able to decide whether or not to follow through on the urges, then Christianity is judging the individual based on thoughts/urges over which they have no voluntary control. This is another example of Norretranders ability to pull ideas from various fields of thought, synthesize them, and come up with a novel and thought provoking conclusion. By breaking the book up into four parts Norretranders is able to set up, explain, and elaborate on his theory in a segmented yet sequential manner; which is useful to the reader when tackling a book of this size. Though it is slightly out of date, having been written in 1991, his ideas fit well with current research, and the discussions of this semester, on the nature of sensory perception, such as vision and pain. The User Illusion presents a worthwhile theory of conscious experience that is exceptionally integrative, thoughtful, and well supported

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The Subjective Nature of Reality and its Pervasiveness in the Human Experience: Contributions from Diverse Fields of Thought.

The relationship between the subjective and the objective is something that superimposes on every aspect of life, whether realized or not. No two individuals are identical, and the simple fact that we are isolated non-identical beings implies that we must lead non-identical lives. That may sound like an obvious statement but the pervasiveness of this “different-ness” is not so obvious. It exists on many levels, some more tangible than others. It is one thing to say that person A and person B see different things when looking at a Picasso, it is another to say that reality as person A experiences it, and reality as person B experiences it are fundamentally different things. If this question is to be approached, if we are to attempt to understand the relationship between the subjective and the objective, the relationship between ourselves, others, and the world, it is valuable to look at the various levels at which this relationship is defined.

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Free Will and the Readiness Potential

All healthy humans feel like they have some degree of free will, the ability to discern and consciously choose one of a number of possible options. Free will is here defined as a conscious and deliberate process by which an individual comes to choose between multiple options, absent of any involuntary causal determination. But how does free will fit in with neurophysiology and what we know about the brain?

We know that neurons form networks. The particular connections in and between networks are a result of genetics, biology, environment, and every past experience, action, and thought. We know that our brain is governed by physical law, neurons spontaneously fire when the intra and extra cellular concentrations of NaCl change. All the molecular occurrences in our brains are results of previous ones, and cause future ones. So we can imagine that every thought we have, every action potential, is actually the result of every molecular occurrence since (and including) the Big Bang. Newtonian physics supports the idea that once the initial conditions of the universe were set, the rest of history follows inevitably. This is the central idea of the theory of determinism. If we adopt strict determinism, and imagine a thought experiment in which we possess complete knowledge, of every occurrence, every motion of every particle, every value held by every person, everything they have experienced and thought, we would be able to perfectly predict the outcome of any situation. If we are physical systems subject to determinism, there may not be room for free will in the picture.

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