What's New in Neurofeedback

The mind may have no format independent of itself, which is how 0 creeps in at this point. In clinical applied neuroscience we take neural energies and relate them to mental energies and vice versa. We discern patterns of EEG rhythms as predictors of clinical symptoms and vice versa. Different EEG rhythms reflect different inhibitory rates, which in terms of sensorimotor processing reflect different sampling rates of the cortex.

Absolute Threshold is the minimum stimulation needed to detect a stimulus more than half the time. Its complement is the subliminal threshold, the amount of stimulation under which a stimulus is detected less than half the time. Extreme subliminal thresholds were the rage in the 1960s, added a single frame of “SEX” or “Buy refreshments” during a 24-frame-per-second movie to induce consumer action, but its efficacy for inducing action is questionable. However studying subliminal perception is still a useful technique for studying nonconscious states, such as the Defense Mechanism Test which quantifies how unwilling an individual is in perceiving negative information. An illustration of a violence or implied violence is presented in steps of 50 ms increments. The same slide is shown over and over, with longer exposures. Most will not recognize a picture of, say, a mother holding an axe above a baby, when flashed on for only 50 or 100 ms, but will be able to make out the gist of the picture by 250 ms or longer. However individuals who defend constantly against negative information might not make out the gist of the scene until the image is shown for a full second. They might notice a crib at 250 ms, or a baby at 500 ms exposures, and a mother nearby, but the implied violence goes unnoticed until well into conscious perception time. This measure was examined in Air Force pilots by my lab (Eriksen et al., 1996) and those who were slow to perceive threat, who block out signs of danger, an undesirable personality trait of experimental pilots, had higher cortical arousal on average. We need recognition and action at the onset of something going wrong with a plane or space shuttle.

We have a very sensitive absolute threshold for vision, only 3 photons on single receptor across a moment of time will trigger a detection. Our other modalities are sensitive, though chemically we have nothing over sharks which can detect a single drop of blood in thousands of gallons of water whereas we can taste a teaspoon of sugar in only 2 gallons. The absolute threshold of detection depends on a number of factors:

Sensory Adaptation is diminished sensory sensitivity when we get constant stimulation which is why we have tiny muscles in the eye which shift an image from receptor fatigued for that stimulation to an unfatigued receptor hundreds of times a second. A chicken lacks this internal ocular movement and supplies movement with gross movements of its head (e.g., while eating).

Human hearing is most notable for its range of energies it can handle, an astounding ten orders of magnitude, which means we can detect air pressure changes from a bee’s flapping wings to a jet turbo engine, 10 raised to the power of 10, impressive by anyone’s standards.

Human vision is most notable for is iterations, the number of times visual information is re-represented before interpretation, at least 10 times. Its earliest representation occurs in the superior colliculi, the fish’s nonconscious processor of visual information, and the lateral geniculate of the thalamus, the advanced fish CPU, along with cortical and brainstem inputs that help direct the eyes and process the visual information.

The brain is very efficient at detecting change, seeking informative changes in energies, and in sensory processes this is called the Just Noticeable Difference or JND. How much must a stimulus change before becoming noticeably different. Years ago Weber determined that for a difference to be perceived, two stimuli must differ by a relative proportion (not an absolute amount). We are most sensitive to sound frequency, which is why the doppler effect (pitch changes with motion) are part of any train stop or truck passing on the highway. Here are the jnd percentages for common stimulations: Percentage Change

Perception is the process of converting raw sensory information into forms (categories) with differences (identity). It is generally transparent to user until it misfires (e.g., blind spot, illusions) and we failed to appreciate the magnitude of problem of perception until we tried to simulate it (machine vision).

Facts about Perception

Perceptual organization in the visual system follows a hierarchy, starting with edge detection for an object or scene, discerning its depth and whether it’s likely to be stationary or could change (figure-ground distinction). After this comes grouping. Percepts are formed out of the elements by grouping them based on prior knowledge and rules of simplicity and stability, and these principles extend into other psychological domains.

Gestalt Principles of Perceptual Grouping

The final part of perception is our mindset, a mental predisposition to perceive one thing and not another. What you see is influenced by perceptual set, so if you are at Loch Ness in Scotland and expect to see a pleistosaur swimming about, you may convert a riptide into a scaly undulating back. But if you expect no viable dinosaur population to have survived for 65 million years in the cold windy lake in Scotland, you will see waves. Perceptual Set “dangers” are common and addressed by the field of Human Factors. We don’t want to ignore that black splotch and assume it’s a shadow and drive over it and find out it is a person walking by.

-DK

References:

Eriksen HR, Olff M, Mann C, Sterman MB, & Ursin H. (1996). Psychological defense mechanisms and electroencephalographic arousal. Scandinavian Journal of Psychology, 37, 351-61.

Reviews NEW BOOKS

Calming the Stormy Days with Annie
By M Fattig
-The Annie Books introduce the topic of distractability and ADD to children.
http://www.amazon.com/exec/obidos/ASIN/0979580560

Neuropsychological Assessment of Neuropsychiatric and Neuromedical Disorders 
by Igor Grant M.D. and Kenneth Adams PhD 
-Reviews test batties and other assessment techniques; newly released.
http://www.amazon.com/exec/obidos/ASIN/0195378547

Post-Traumatic Stress Disorder: Basic Science and Clinical Practice 
by Priyattam J. Shiromani, Terence M. Keane, and Joseph E. LeDoux 
-LeDoux and colleagues overview PTSD science.
http://www.amazon.com/exec/obidos/ASIN/160327328X

Compendium of Neuropsychological Tests: Administration, Norms, and Commentary
by O Spreen & E Strauss
-Discussion of neuropsychology tests and clinical techniques helpful in making inferences about integrity of brain regions.  
http://www.amazon.com/exec/obidos/ASIN/0195100190

Our Daily Meds: How the Pharmaceutical Companies...
by Melody Petersen 
-A diatribe against big pharma.
http://www.amazon.com/exec/obidos/ASIN/0312428251

Links to books at http://start.eegspectrum.com/Newsletter/oct2008.htm#section2

Predicting aDHD and oppositional defiant disorder from preschool diagnostic assessments.
-Early manifestations of problem behaviors was predictive of later ADHD diagnosis.
http://www.ncbi.nlm.nih.gov/pubmed/19309194

Adverse events in childhood and chronic widespread pain in adult life
-Childhood road accidents and institutional care were predictive of pain in adult life in this retrospective study.
http://www.ncbi.nlm.nih.gov/pubmed/19304391

Compensatory deficits following rejection: role of social anxiety 
-Rejection was associating with renewed interest in connecting with positive social interactors for those low in social anxiety but not high. 
http://www.ncbi.nlm.nih.gov/pubmed/19319992

High frequency oscillations in EEGs mark epileptogenicity rather than lesion type.
-High frequency ripples (80-250 Hz)occur predominantly in seizure onset zones. 
http://www.ncbi.nlm.nih.gov/pubmed/19297507

Influence of Antisocial and Psychopathic Traits on Decision-Making Biases in Alcoholics.
-Alcohol-dependent males favor risky choices, even those without personality disorders.
http://www.ncbi.nlm.nih.gov/pubmed/19298325

This last week I have been entraining myself with rock songs and Christian rock, notably "How Great is our God" and I came across this piece which even fits chronologically with this newsletter, another spiritual piece written by my late father :

During this past month of February, we celebrated the birthdays of two of the greatest people of all time - Abraham Lincoln and George Washington. And whenever we think of great persons, certain questions inevitably arise: Why are some people great and not others? What are the qualities that make people great? In short, what is greatness?

But before we can answer that question, I think we need to dissociate two ideas which are often linked together: bigness and greatness. In America particularly, we tend to believe that something is a hundred times more important than something else if it is a hundred times as big. And we tend to apply that standard when we evaluate a person's character. So if a person is famous, if he or she is rich, if he or she drives a big car and has a big bank account, if he or she can influence others, we tend to apply the adjective "great" to that person. Historians also are often guilty of applying the word "great" to generals simply because they won several battles or conquered many nations, regardless of their personal attributes. And yet there are truly great people who are neither famous nor rich. There are great individuals in every community, in every church, and in this retirement center, because greatness is a quality of the spirit. There are two essential elements of greatness, and without these characteristics, no life, however famous or rich, is truly great. Each of us has the potentiality to be great if we cultivate these two essential elements. And for my examples this morning, I would like to use the lives of the two great Americans whose birthdays we are celebrating this month and the life of a very familiar Biblical character, Joseph.

The first of these essential qualities is the high soul. The great person's house of life is open to the sky. He or she is guided by his or her faith in God. To a truly great person, faith is not a thing to be analyzed or talked about, but it is something to be lived and lived by. I think Joseph particularly exemplifies this quality. Every single important step in Joseph's life was connected with God. He was always very conscious of God's guidance. Even that decisive moment when his brothers sold him to Midianite slave-traders - a moment which just then he would hardly have connected with God - he later saw as an act of God. "It was not you who sent me here, but God," he said to his brothers long afterwards. What will God think of this? was not an afterthought with him, but entered into his decisions beforehand.

This was as true of Lincoln as of Joseph. On one occasion during the Civil War, a delegation of Northern ministers met with Lincoln, and one of them made the remark that "The Lord is on our side." Lincoln replied, "I don't agree with you." Amid general amazement, Lincoln continued, "I am not at all concerned about that, for we know that the Lord is always on the side of the right. But it is my constant anxiety and prayer that I and this nation should always be on the Lord's side."

That Lincoln was a man of piety and of deep religious conviction is obvious from his life. Noah Brooks, out of his close and continuous friendship with Lincoln, wrote that there was something touching in his childlike and simple reliance upon Divine aid, especially in extremities of fateful events. Brooks wrote that, during the Civil War, "though prayer and reading the Scriptures was Lincoln's constant habit, he more earnestly than ever sought that strength which is promised when mortal help faileth." Throughout !Lincoln's career, he believed that he was an instrument in the hands of God.

Washington also possessed the quality of the high soul. Many of his public addresses indicate his faith. For example, he concluded an address to his troops on July 2, 1776, with these words: "Let us rely on the goodness of the cause and the aid of the Supreme Being, in Whose hands victory is, to animate and encourage us to great and noble actions." Certainly Washington was one of the most dedicated men who ever served the cause of freedom. His faith and courage remained constant in the face of overwhelming odds, and there is the never-to-be-forgotten scene of his praying at Valley Forge when American fortunes were at their lowest ebb.

When we scan history and count the conquering generals who put crowns upon their heads or observe the current world scene in which generals often glide into the role of dictators, Washington's idealism and faith are outstanding. He rebuked his officers who suggested that he make himself a king. When the states fell to wrangling after the Revolution, a disaster that would have offered a personally ambitious man another chance for a crown, Washington met with the governors in Alexandria, Virginia, and initiated action that gave the nation the Constitution. He accepted the Presidency only because of his devotion to duty. Truly, all three of these men - Joseph, Lincoln, Washington - possessed a high soul, a faith in God and a devotion to duty that is as open to us as it was to them.

The second essential quality of greatness is a wide heart. Joseph again had this quality of spirit. His treatment of his brothers, who had so grievously wronged him, showed that he had a heart willing to forget the past, a heart willing to return good for evil. To men who had been as mean to him as they could possibly be, he was as good and generous as he could possibly be. Most of us think we are pretty virtuous if in return for a dirty deal we do just a tiny, grudging act of kindness, and of course, that is better than revenge, but the truly great person is far above measuring what he or she gives by what has been given him or her. True greatness includes more than justice; it also includes forgiveness and mercy.

Lincoln also had this quality. During the War, he once sent a personal message to the Secretary of War, Edwin M. Stanton. In a very few minutes, the messenger returned to the White House, bursting with indignation. The President looked up in surprise. "Did you give the message to Stanton?" he asked. The other man nodded. "What did he do?" Lincoln asked. "He tore it up," exclaimed the messenger, "and what's more, sir, he said you are a fool."

The President rose slowly from the desk and looked at the messenger quizzically. "Did Stanton call me that?" he asked. "He did, sir, and he repeated it," was the reply. "Well," said the President, "I reckon it must be true then because Stanton is generally right." The messenger waited for the storm to break, but Lincoln returned to his work, and as he lay in death, the same Stanton was to say, "There lies the most perfect ruler of men the world has ever known." This was not the only time that Lincoln showed this quality of the wide heart. In the early months of the war when every message brought bad news, Lincoln went to call on General George B. McClellan, the commander of the Army of the Potomac, taking a member of his Cabinet with him. Official etiquette prescribes that the President shall not visit a private citizen, but the times were too tense for etiquette; Lincoln wanted First-hand news from the only man who could give it.

The general was out, and for an hour Lincoln and the Cabinet member waited in the parlor. They heard his voice at last in the hall, but McClellan brushed by without so much as a word of greeting and proceeded on his way upstairs. Ten minutes passed, fifteen, half an hour, and finally, Lincoln sent a servant to remind the General that he was still waiting. The man soon returned, shocked and embarrassed. The general had said he was too tired for a conference, so he had undressed and gone to bed!

The Cabinet member restrained himself until he and Lincoln reached the sidewalk. Then he demanded that McClellan be relieved from his command because of insubordination. Lincoln laid a soothing hand on the man's shoulder. "I will hold McClellan's horse if only he will bring us victories."

Washington had a similar spirit. He had a sharp temper, but he usually kept it under control. However, he lost it one day as a young man in the course of an argument at a Virginia polling booth. William Payne, a much smaller man, finally hit Washington with a club and knocked him down. To Virginians of the eighteenth century, that kind of incident meant just one thing - a duel. Washington, who was then colonel of the Colonial Regiment, would be expected to show his physical courage. For twenty-four hours, he remained in seclusion. After a while, he cooled off sufficiently to weigh the incident with a certain amount of impartiality. Finally he wrote Payne, asking him for a meeting the next day in the spot where the blow had been struck. A large crowd assembled because fireworks were expected. But before the whole assembly, Washington acknowledged to Payne that his conduct had been wrong and asked to be his friend. Now some people may feel that it is a mark of high breeding never to overlook a slight or an injury, but the truly great persons have been superior to personal resentments and small annoyances. Pettiness brings its own punishment, and persons who return evil for evil hurt themselves more than anyone else. Now you may say that you cannot possibly emulate persons such as Washington, Lincoln, or Joseph, and perhaps you cannot, so far as ability is concerned. But all of us can emulate their spirit. As Gilbert Knight once remarked, "It is one of the highest uses of history to remind individuals and nations that greatness is always possible." Henry Wadsworth Longfellow put it well when he wrote in "The Psalm of Life":

            "Lives of great men all remind us 
            We can make our lives sublime 
            And departing, leave behind us 
            Footprints on the sands of time."

All of us have the seeds of greatness in our own lives, and insofar as we cultivate a high soul. and a wide heart, we will be great persons in our own right.

-Rev Frank Kaiser, Feb 22, 1959; revised Feb 18, 1973