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Archive for April, 2012

Taking strides toward understanding how the brain processes stimuli to recognise images, researchers have figured out how to project neural activity on to a TV screen.

How do they do it?
UC Berkeley professor Jack Gallant and his team use MRI to track blood-flow changes in a subject’s primary visual cortex – the brain’s largest visual processing centre – as he or she watches a movie. The researchers then create a model of the visual cortex that matches the blood-flow pattern with the images the subject is viewing.

Algorithms are applied to compare the brain signals with a catalogue of about 5.000 hours of YouTube video. The images that most accurately correspond to the brain activity are compiled into a composite video that resembles the YouTube footage.

In this video, Gallant explains how they succeeded in decoding and reconstructing people’s dynamic visual experiences…

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by Dr. Friedemann Schaub

An iceberg is a great analogy that describes the connection between the conscious and the subconscious mind– with a small, visible part above the surface and a huge part below. The conscious mind is responsible for our awareness in the waking state. Thinking analytically, creating logical order, wondering about cause and effect and asking “why” are all characteristics of the conscious mind. The conscious mind is the place of cognitive learning and understanding and uses the intellect to come up with logical solutions for problems. It makes choices based on facts and moves the body deliberately.

The subconscious or unconscious mind (terms which can be used interchangeably), is the part of our mind, which operates usually below the level of our normal consciousness. Like in the iceberg analogy, the subconscious mind is the vaster and more substantial part of our mind. Out of the 2 Million bits of information which approach us every second, the conscious mind can only register 7+/- bits, whereas the subconscious mind computes 140+/-. The subconscious mind is in charge of our emotions, which explains why we can feel a certain way without really knowing why – for example waking up grumpy one day and completely happy the next. The subconscious mind also stores memories from any events of our past. Just take a moment and think about the house you grew up in. Before you visited this place in your conscious mind, you had to access this information from its subconscious storage space. However, not all memory is accessible to us; one so called “prime directions” of the subconscious mind, is to seal off traumatic events, which we are not ready to deal with. In addition, our deepest core beliefs, values and imprints are “anchored” and programmed into our subconscious mind.

The subconscious mind is also responsible for all physiological functions of the body; we don’t regulate our heart rate, breathing, kidney function or digestion with our conscious mind. If we would, the collection of trillions of cells that comprise our body, would not work together as effectively and harmoniously as it usually does. And even “deliberate” movement, such as walking, requires the precise coordination of many different muscles, a challenge that we would not able to master consciously. Along those lines, have you ever noticed that you can’t really recall, how you drove yourself to work or how you were eating that sandwich, while watching TV. The subconscious mind takes control of all these automatic movements and patterns, without our conscious awareness. In fact, studies suggest that more than 75% of our daily activities are regulated by the subconscious mind.

Considering the vast responsibilities of the subconscious mind, its power and enormous  potential become very obvious. With the right leverage we can move mountains. Working directly with the subconscious mind provides this leverage, to effectively create profound and long-lasting changes on the mental, emotional and physical level.

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Proprioception

 
Proprioception (play /ˌprpri.ɵˈsɛpʃən/ PRO-pree-o-SEP-shən), from Latin proprius, meaning “one’s own” and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement.[1] It is distinguished from exteroception, by which we perceive the outside world, and interoception, by which we perceive pain, hunger, etc., and the movement of internal organs.

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Epinephrine (also known as adrenaline) is a hormone and a neurotransmitter.[1] It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system.[2] In chemical terms, adrenaline is one of a group of monoamines called the catecholamines. It is produced in some neurons of the central nervous system, and in the chromaffin cells of the adrenal medulla from the amino acids phenylalanine and tyrosine.[3]

Extracts of the adrenal gland were first obtained by Polish physiologist Napoleon Cybulski in 1895. These extracts, which he called nadnerczyna, contained adrenaline and other catecholamines.[4] Japanese chemist Jokichi Takamine and his assistant Keizo Uenaka independently discovered adrenaline in 1900.[5][6] In 1901, Takamine successfully isolated and purified the hormone from the adrenal glands of sheep and oxen.[7] Adrenaline was first synthesized in the laboratory by Friedrich Stolz and Henry Drysdale Dakin, independently, in 1904.[6]

Adrenaline is used to treat a number of conditions including: cardiac arrest, anaphylaxis, and superficial bleeding.[8] It has been used historically for bronchospasm and hypoglycemia, but newer treatments for these, such as salbutamol, a synthetic epinephrine derivative, and dextrose, respectively, are currently preferred.[8]

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The James–Lange theory refers to a hypothesis on the origin and nature of emotions and is one of the earliest theories of emotion, developed independently by two 19th-century scholars, William James and Carl Lange.

This theory states that within human beings, there is a response to experiences in the world and that the autonomic nervous system creates physiological events such as muscular tension, a rise in heart rate, perspiration, and dryness of the mouth. Emotions, then, are feelings which come about as a result of these physiological changes, rather than being their cause. James and Lange arrived at the theory independently. Lange specifically stated that vasomotor changes are emotions. (Ex. A person rationalizes that because he/she is crying, he/she must be sad.) James elucidated his concept as:

My theory … is that the bodily changes follow directly the perception of the exciting fact, and that our feeling of the same changes as they occur is the emotion. Common sense says, we lose our fortune, are sorry and weep; we meet a bear, are frightened and run; we are insulted by a rival, are angry and strike. The hypothesis here to be defended says that this order of sequence is incorrect … and that the more rational statement is that we feel sorry because we cry, angry because we strike, afraid because we tremble … Without the bodily states following on the perception, the latter would be purely cognitive in form, pale, colorless, destitute of emotional warmth. We might then see the bear, and judge it best to run, receive the insult and deem it right to strike, but we should not actually feel afraid or angry.
This order of causality is a difficult one. The theory has been largely disfavored in modern times. Some evidence to support it, however, may come from the fact that sufferers of various psychological challenges such as panic disorders often experience psychoemotional trauma after physiological responses arise in the body, responses which individuals are conditioned to associate with a particular emotional state but which can, via therapy, be dissociated.

This theory was challenged in the 1920s by psychologists such as Walter Cannon and Philip Bard, who theorized that physiological changes are caused by emotions, collectively known as the Cannon-Bard theory of emotion.

Cannon–Bard theory

Walter Bradford Cannon (1871-1945) was a physiologist at Harvard University, who is perhaps best known for his classic treatise on homeostasis.[1] Philip Bard (1898-1977) was a doctoral student of Cannon’s, and together they developed a model of emotion called the Cannon-Bard Theory.[2] Cannon was an ardent experimenter who relied on studies of animal physiology. Through these studies, Cannon and Bard highlighted the role of the brain in generating physiological responses and feelings; a role that is important in their explanation of emotion experience and production.[3]

The Cannon-Bard Theory, also known as the thalamic theory, suggests that individuals experience emotions and physiologically react simultaneously. These actions include changes in muscular tension, perspiration, etc. This theory challenges the James-Lange theory of emotion introduced in the late 19th century, which suggests that emotion results from one’s “bodily change,” rather than the other way around.[4]

The theory sparked much controversy in cognitive circles due to its suggestion that emotion lacks a mechanism, and many theorists attempted to provide explanations of emotion that suggested a mechanism. One such theory was provided by Schachter & Singer’s two factor theory of emotion, in which they posited that emotion is the cognitive interpretation of a physiological response. For many, this remains the best formulation of emotion.

I see a man outside my window. I am afraid. I begin to perspire.

The Cannon-Bard Theory of Emotion is based on the premise that one reacts to a specific stimulus and experiences the corresponding emotion simultaneously. Therefore, if one is afraid of heights and is traveling to the top of a skyscraper, they are likely to experience the emotion of fear. Subsequently, the perception of this emotion (fear) influences the person’s reaction to the stimulus (heights). Cannon and Bard posited that one is able to react to a stimulus only after experiencing the related emotion and experience.[6]

The third theory of emotion is Schachter & Singer’s two factor theory of emotion. This theory states that cognitions are used to interpret the meaning of physiological reactions to outside events.

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Neural Cell Adhesion Molecule (NCAM, also the cluster of differentiation CD56) is a homophilic binding glycoprotein expressed on the surface of neurons, glia, skeletal muscle and natural killer cells. NCAM has been implicated as having a role in cell–cell adhesion,neurite outgrowth, synaptic plasticity, and learning and memory.

NCAM is a glycoprotein of Immunoglobulin(Ig)superfamily. At least 27 alternatively spliced NCAM mRNAs are produced, giving a wide diversity of NCAM isoforms. The three main isoforms of NCAM vary only in their cytoplasmic domain:

  • NCAM-120kDa (GPI anchored)
  • NCAM-140kDa (short cytoplasmic domain)
  • NCAM-180kDa (long cytoplasmic domain)

The extracellular domain of NCAM consists of five immunoglobulin-like (Ig) domains followed by two fibronectin type III (FNIII) domains. The different domains of NCAM have been shown to have different roles, with the Ig domains being involved in homophilic binding to NCAM, and the FNIII domains being involved signaling leading to neurite outgrowth.

Homophilic binding occurs between NCAM molecules on opposing surfaces (trans-) and NCAM molecules on the same surface (cis-)1. There is much controversy as to how exactly NCAM homophilic binding is arranged both in trans- and cis-. Current models suggest trans- homophilic binding occurs between two NCAM molecules binding antiparallel between all five Ig domains or just IgI and IgII. cis- homophilic binding is thought to occur by interactions between both IgI and IgII, and IgI and IgIII, forming a higher order NCAM multimer. Both cis- and trans- NCAM homophilic binding have been shown to be important in NCAM “activation” leading to neurite outgrowth.

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