Sat Oct 8 08:16:18 EST 2011
how the exhibition =93The Art of Deceleration. Motion and Rest in Art from =
Caspar David Friedrich to Ai Weiwei=94.
=93The Art of Deceleration=94 distills a theme that touches a nerve with so=
ciety. Since the 19th century, the tempo of life has continuously increased=
up to =93rushing stand still=94 (Paul Virilio). The longing for relaxation=
and contemplation grows at the same time.
The exhibition project in the Kunstmuseum Wolfsburg focuses on the contrapu=
ntal phenomenon of motion and rest in art from the Romantic to classic mode=
rnism and the present day. From the beginning, the fascination for unleashe=
d motion was accompanied by the search for an aesthetic of slowness. The Ku=
nstmuseum Wolfsburg examines this dialectic in a comprehensive exhibition f=
eaturing circa 150 works by 80 artists.
Artists of the exhibition
Josef Albers =96 Giacomo Balla =96 Joseph Beuys =96 Alexander Calder =96 Hu=
ssein Chalayan =96 Francesco Clemente =96 Giorgio de Chirico =96 Robert Del=
aunay =96 Marcel Duchamp =96 Caspar David Friedrich =96 Franz Gertsch =96 D=
ouglas Gordon =96 Andreas Gursky =96 Jeppe Hein =96 Anselm Kiefer =96 Frant=
isek Kupka =96 El Lissitzky =96 Aristide Maillol =96 Kasimir Malewitsch =96=
Christian Marclay =96 Kris Martin =96 Aernout Mik =96 Lazlo Moholy-Nagy =
=96 Giorgio Morandi =96 Bruce Nauman =96 Roman Opalka =96 Julian Opie =96 G=
eorge Osodi =96 Nam June Paik =96 Julius Popp =96 Odilon Redon =96 Gerhard =
Richter =96 Auguste Rodin =96 Mark Rothko =96 Thomas Ruff =96 Jonathan Schi=
pper =96 Jean Tinguely =96 William Turner =96 James Turrell =96 Cy Twombly =
=96 Lee Ufan =96 Fabienne Verdier =96 Bill Viola =96 Andy Warhol =96 Ai Wei=
wei =96 Zhou Xiaohu =96 and others.
The phenomenon of motion and rest in art, from the Romantic Era to the pres=
Modern art used to be primarily equated with acceleration, from William Tur=
ner to Futurism, from the abstract and the kinetic to media-generated art. =
On the other hand, little attention is paid to the fact that the fascinatio=
n with speed has always been combined with a search for the aesthetics of d=
eceleration, something that would explore the dynamics of quiet and the dep=
ths of existences, starting with the images of yearning produced by the Rom=
antics, to the profound =93slow painting=94 by artists such as Mark Rothko =
or Franz Gertsch. This is the first volume to examine this modern dialectic=
, condensing a theme that hits a societal nerve. Well-known authors, such a=
s sociologist Hartmut Rosa and cultural scientist Hartmut B=F6hme, discuss =
the problems of technology- and economy-based acceleration and the increasi=
ng need to slow down.(German edition ISBN 978-3-7757-3242-0)
Exhibition schedule: Kunstmuseum Wolfsburg, November 12, 2011=96April 9, 20=
- - -
AERODYNAMIC BRAKES; DECELERATION; HYPERSONIC SPEED; STABILIZATION; SUPERSON=
IC SPEED; POROSITY; MACH NUMBER; DECELERATION; HYPERSONIC SPEED; HYPERSONIC=
VEHICLES; STABILIZATION; SUPERSONIC SPEED; DYNAMIC STABILITY; DRAG; REENTR=
Book contributor: NASA
Documented aerodynamic deployable decelerator performance data above Mach 1=
. 0 is presented. The state of the art of drag and stability characteristic=
s for reentry and recovery applications is defined for a wide range of dece=
lerator configurations. Structural and material data and other design infor=
mation also are presented. Emphasis is given to presentation of basic aero,=
thermal, and structural design data, which points out basic problem areas =
and voids in existing technology. The basic problems and voids include supe=
rsonic ''buzzing'' of towed porous decelerators in the wake of the forebody=
, the complete lack of dynamic stability data, and the general lack of aero=
thermal data at speeds above Mach 5.
- - -
Protocols for Deceleration
The exhibition included a performance that begun with a parade through the =
city of Norwich and ended with participants following the protocols and uti=
lising the 'clearing stations'. The performance was filmed and edited into =
a film which was shown at IMT Gallery, London as part of an event for Dead =
Fingers Talk June 12 2010, and at FormContent, London as part of Exitential=
Territories, a Bookworks event, July 17 2010.
The event happened 08 - 21 October 2008.
Seventeen pieces and performance, four monitors playing films, assemblage w=
ith ribbons, display of whips and stopwatch, one glitter drawing under a vi=
trine, one felt banner, nine posters.
The exhibition, presented through the collaboration of Plastique Fantastiqu=
e, was designed as a series of 'clearing' stations to disconnect the viewer=
, wishing to follow a series of protocols, from their attachment to objects=
, commodities and identifications. The exhibition addressed how performance=
art echoes the practices of religions, cults and state institutions concer=
ned with subjectification, control and enlightenment.
- - -
Last minutes of a 8 hours 40 minutes video as part of an art installation. =
Understanding Acceleration and Deceleration
- - -
Stark deceleration of Molecular Beams
Stark deceleration of Molecular Beams
The Stark decelerator for neutral polar molecules is the equivalent of a li=
near accelerator (LINAC) for charged particles, and exploits the interactio=
n of a polar molecule with inhomogeneous time-varying electric fields. The =
deceleration (or acceleration) process can be seen as slicing a packet of m=
olecules with a narrow velocity distribution out of the most intense part o=
f the molecular beam pulse. This packet can then be decelerated or accelera=
ted to any velocity, maintaining the narrow velocity distribution and the p=
article density in the packet.
Apart from being an excellent tool to manipulate molecules in a molecular b=
eam, Stark decelerators also have a high esthetic value!!
- - -
SLOW MOVEMENT OR: Half and Whole =B7 30.01. - 22.03.2009
Adam Avikainen, Becky Beasley, Gerard Byrne, Michaela Fr=FChwirth, Fernanda=
Gomes, Judith Hopf, Guillaume Leblon,Gabriel Lester, Kerry James Marschall=
, Nashashibi/Skaer, Abraham Palatnik, Avery Preesman, Eileen Quinlan, Marku=
s Raetz, Jimmy Robert, Sancho Silva
Movement is the first prerequisite for a story; the second one is the perce=
ption of movement. The exhibition =93Slow Movement or: Half and whole=94 fo=
cuses on stories that arise and are enabled as a process of deceleration se=
ts in =96 in movement itself as well as in its perception.
The term =93deceleration=94 indicates temporality and might consequently su=
ggest an interpretation such as =93the same process unfolds over a longer p=
eriod of time=94. However, as soon as perception is slowed down, other piec=
es of information are introduced and meanings change; the process cannot be=
said to remain the same. The decelerated movement opens up a parallel worl=
The exhibition =93Slow Movement or: Half and whole=94 is dedicated to works=
of art that direct their attention to all that is missed by the quick move=
ment. Thus, they tell completely different stories than a purely functional=
Above all, the idea of =93Slow Movement=94 denotes a space. Not the space o=
f the museum or the physical space of the artworks, but rather the space of=
a movement: decelerated perception grants us the opportunity of entering a=
nd exploring places instead of being spoon-fed preconceived information for=
each second. If the movement is slow, it can encompass many things. In suc=
h a movement, we could spend days and think everything.
In this context, =93Slow Movement=94 functions as a strategy that, through =
the aspect of temporality, always refers to the fragmentary. Beginning and =
end, the limits and margins, are not clearly delineated =96 and they do not=
have to be. Fragments are comprehensible. They can be lived and understood=
like many =93strong=94 experiences in life that are not strong by virtue o=
f their completeness or perfection, but because of their precision. This pr=
ecision does not require localization or =93definition=94, nor does it need=
to be expanded. It exists where it takes place and it persists, not becaus=
e it was made to persist, but because, through this sort of sensory percept=
ion, it has anchored itself in experience.
Many of the works on exhibition are concerned with the manifestations of th=
e coincidental and the ordinary, not by offering a grand-scale atmospheric =
portrayal of the latter as a =93landscape=94, as it were, nor by claiming t=
he ordinary and the coincidental to be universal principles through the way=
they are executed. Rather, they render the manifestations of the coinciden=
tal and the ordinary as occasions for insight, reduced precisely to that po=
int of epiphany. The works of art do not =93create=94 a world; they merely =
refer to an existing world, showing us the =93catch=94 of a process, the fr=
agment that was harnessed and brought forth by a movement.
We digitalize our perception in order to discern the =93whole=94 and to gra=
sp, as quickly as possible, a universal meaning that serves our orientation=
and our further actions. The =93half=94, on the other hand, exhibits the q=
uality of a genuine search for enlightenment, an individual quest for under=
standing. Invariably, this quest for understanding is accompanied by a proc=
ess of deceleration; there are no routine practices that could be used to s=
Therefore, the failed works of art and the amateurish works of art that wil=
l never attain =93completion=94 are of interest too, for they were forced t=
o comprehend something. Just like genius intervenes in an artist=92s activi=
ty, so too can constraints interfere with what he or she is doing. A simple=
movement on our part would suffice.
We like to think of a work of art as an autonomous entity, similar to a per=
son, with which we should make contact and on which we should reflect in a =
patient and careful manner. And just like the flaws and the contradictions =
of a person, the flaws and the contradictions of a work of art can expand o=
ur perspective and broaden our horizon. They allow us to actually get invol=
ved as viewers, to ask ourselves to understand, combine and synthesize and =
to transcend the role of the consumer waiting for a spectacle.
=93Slow Movement or: Half and whole=94 also means: life before art and life=
- - -
Memory and the Aging Brain
(Steven W. Anderson, PhD, Thomas J. Grabowski, Jr. MD
The University of Iowa)
Memory is a complex function, encompassing the encoding, storage, and retri=
eval of diverse types of information. There are multiple memory systems in =
the brain. For example, there are dissociable systems underlying such memor=
y functions as new learning of verbal information, acquisition of a procedu=
ral skill, and retrieval of semantic knowledge from long-term storage. It h=
as been known since the 1950s that epileptic patients who underwent bilater=
al temporal lobectomies developed severe memory impairments (amnesia).
The mesial temporal lobe memory system, including the hippocampus, parahipp=
ocampal gyrus, entorhinal cortex, and perirhinal cortex (Fig. 1), is essent=
ial for the acquisition of new information (anterograde memory). When this =
system is damaged, it becomes difficult or impossible to remember what happ=
ened yesterday or even a few hours or minutes ago. Remote memory for inform=
ation acquired in the distant past remains relatively preserved, as does pr=
ocedural memory (e.g., memory for skills, such as golfing or driving a car)=
. The mesial temporal lobe region is vulnerable to damage from various age-=
related causes, including anoxia /hypoxia that may result from cardiac arre=
st, and head trauma from falls or motor vehicle accidents. This region also=
appears to be selectively affected in the early stages of Alzheimer's dise=
* * *
Age does not affect all domains of cognition equally. For some functions, s=
uch as speed of visual-motor processing, slight decline often can be detect=
ed as people enter their 40s and 50s. However, for most cognitive abilities=
, no measurable decline is evident until age 65 or older. For example, the =
average expected number of words recalled from a 15-word list after a 30-mi=
nute delay is approximately 10 for people aged 55-65, nine for those aged 6=
6- 70, and eight for those up to age 85. These changes, while noticeable, a=
re not disabling. Furthermore, some aspects of cognition, such as one's gen=
eral fund of information, can actually continue to improve throughout one's=
- - -
We carry two brands of Therapeutic Music-
There are at least three neuro-physical healing processes which may be trig=
gered by music.
1. Music is nonverbal so can move through the brain's auditory cortex direc=
tly to the center of the limbic system. This system governs emotional exper=
iences and basic metabolic responses such as body temperature, blood pressu=
re and heart rate. It can help create new neuropathways in the brain, as we=
2. Music can activate the flow of stored memory and imagined material acros=
s the corpus collosum (bridge between left and right hemispheres of the bra=
in) helping the two work in harmony. This stimulates the immune system.
3. Music can excite peptides in the brain and stimulate the production of e=
ndorphins, which are natural opiates secreted by the hypothalamus, which pr=
oduces a feeling of natural euphoria, shifting mood and emotion.
Psychoacoustics is essentially the study of the perception of sound. This i=
ncludes how we listen, our psychological responses, and the physiological i=
mpact of music and sound on the human nervous system. In the realm of psych=
oacoustics, the terms music, sound, frequency, and vibration are interchang=
eable. The study of psychoacoustics dissects the listening experience.
An important distinction is the difference between a psychological and a ne=
urological perception. Slightly detuned tones can cause brain waves to spee=
d up or slow down, for instance. Additionally, soundtracks that are filtere=
d and gated (this is a sophisticated engineering process) create a random s=
onic event. It triggers an active listening response and thus tonifies the =
auditory mechanism, including the tiny muscles of the middle ear. As a resu=
lt, sounds are perceived more accurately, and speech and communication skil=
ls improve. While a psychological response may occur with filtered and gate=
d sounds, or detuned tones, the primary effect is physiological, or neurolo=
gical, in nature.
Research on the neurological component of sound is currently attracting man=
y to the field of psychoacoustics. A growing school of thought - based on t=
he teachings of the French doctor Alfred Tomatis - values the examination o=
f both neurological and psychological effects of resonance and frequencies =
on the human body.
Dr. Alfred Tomatis is considered the Father of Psychoacoustics. Joshua Leed=
s expands and confirms the theories of Dr. Tomatis with the modern addition=
of computerized measurement of brainwaves, heart rates, and other body pul=
ses. Researchers like Joshua can now document specific uses and benefits of=
music for the body, mind, and psyche through neuro-feedback and other comp=
uter programs. With the ability to measure comes specificity; and then the =
employment of sound and music can become more precise=85 Music can now be s=
ymptom-specific, application-specific, and environment-specific.
In the realm of application-specific music and sound, psychoacoustically-de=
signed soundtracks revolve around the following concepts and techniques:
=95 Resonance (tone)
=95 Entrainment (rhythm)
=95 Sonic Neurotechnologies (highly specialized sound processing)
=95 Intentionality (focused application for specific benefit).
RESONANCE & ENTRAINMENT
=95 All atomic matter vibrates.
=95 Frequency is the speed at which matter vibrates.
=95 The frequency of vibration creates sound (sometimes inaudible).
=95 Sounds can be molded into music.
Resonance can be broadly defined as "the impact of one vibration on another=
." Literally, it means "to send again, to echo." To resonate is to "re-soun=
d." Something external sets something else into motion, or changes its vibr=
atory rate. This can have many different effects some subtle and some not s=
Another fascinating and important aspect of resonance is the process of ent=
rainment. Entrainment, in the context of psychoacoustics, concerns changing=
the rate of brain waves, breaths, or heartbeats from one speed to another =
through exposure to external, periodic rhythms.
The most common example of entrainment is tapping your feet to the external=
rhythm of music. Just try keeping your foot or your head still when you ar=
e around fun, up-tempo rhythms. You will see that it is almost an involunta=
ry motor response. However, tapping your feet or bopping your head to exter=
nal rhythms is just the tip of the iceberg. While your feet might be jitter=
bugging, your nervous system may be getting a terrible case of the jitters!
Rhythmic entrainment is contagious: If the brain doesn't resonate with a rh=
ythm, neither will the breath or heart rate. In this context, rhythm takes =
on new meanings. Not only is it entertaining, but rhythmic entrainment is a=
potent sonic tool as well - be it for motor function or other autonomic pr=
ocesses such as brainwave, heart, and breath rates. Alter one pulse (such a=
s brain waves) with music, and the other major pulses (heart and breath) wi=
ll dutifully follow.
Music alters the performance of the nervous system primarily because of ent=
rainment. Entrainment is the rhythmic manifestation of resonance. With entr=
ainment, a stronger external pulse does not just activate another pulse but=
actually causes the latter to move out of its own resonant frequency to ma=
Understanding the interlocking concepts of resonance and entrainment enable=
s us to grasp the way external tone and rhythm can heal or create havoc. So=
und affects glass and concrete as well as brain waves, motor response, and =
Support chemical balance in the brain with BALANCE FORMULA 1
Representing two distinct approaches to therapeutic sound, filtration/gatin=
g (F/G) and binaural beat frequencies (BBFs) currently define the growing f=
ield of "sonic neurotechnologies." This phrase was coined by Joshua Leeds t=
o describe the arena of sound work that depends on the precise mechanical m=
anipulation of sound waves to bring about desired changes in the psyche and=
Filtration/gating (F/G) techniques have been honed in Tomatis clinics world=
wide. By gradually gating and filtering out the lower range of music (somet=
imes up to 8000 Hz), and then adding the frequencies back in, a retraining =
of the auditory processing system occurs. The effects of filtration and gat=
ing are felt on a psychological, neurodevelopmental, and physical level. Th=
e application of sound stimulation has been effective in the remediation of=
many neurodevelopmental issues. Children and adults with learning/attentio=
n difficulties, developmental delays, auditory processing problems, sensory=
integration and perceptual challenges have experienced profound improvemen=
t. F/G is used in our The Listening Program.
Another approach to sound processing is the field of binaural beat frequenc=
ies (BBFs). By listening through stereo headphones to slightly detuned tone=
s (i.e., sound frequencies that differ by a prescribed number of Hz), sonic=
brainwave entrainment takes place. Facilitating a specific range of brainw=
ave states may assist in arenas such as pain reduction, enhanced creativity=
, or accelerated learning. BBFs are used in our light and sound unit as wel=
l as our Hemi-Sync music.
These two sonic neurotechnologies - used separately - have roots in neurolo=
gy, physiology, and psychology. They must be used carefully and wisely. BBF=
S and F/G soundtracks can be powerful tools. Consequently, proper considera=
tion must always be afforded.
Detailed information about sonic neurotechnologies can be found in the book=
, The Power of Sound, by Joshua Leeds. It's available through our link to A=
mazon.com on the home page.
SOUND STIMULATION WITH FILTRATION/GATING
In the broadest definition, sound stimulation can be defined as the excitem=
ent of the nervous system by auditory information. Sound stimulation audito=
ry retraining narrows the focus. In this context, a precise application of =
electronically processed sound, through headphones, can have the effect of =
retraining the auditory mechanism to take in a wider spectrum of sound freq=
uencies. An ear that cannot process tone properly is a problem of great mag=
nitude. As discussed in previous chapters, sufficient auditory tonal proces=
sing is a prerequisite to normal auditory sequential processing.
=95 Auditory tonal processing (ATP) may be defined as the ability to differ=
entiate between the tones utilized in language.
=95 Auditory sequential processing (ASP) is the ability to link pieces of a=
uditory information together.
Auditory tonal processing is a basis for more complex levels of auditory se=
quential processing. ASP is the ability to receive, hold, process, and util=
ize auditory information using our short-term memory. As the foundation for=
short-term memory, ASP is one of the building blocks of thinking.
Sequential processing functions are fundamental to speech, language, learni=
ng, and other perceptual skills. The ability to interpret sound efficiently=
provides the neurological foundation for these sequential functions. Per n=
eurodevelopmental specialist Robert J. Doman Jr., "many people who have exp=
erienced auditory processing deficits have seen their sequential functions =
return and/or improve when proper tonal processing is restored."
The primary sound application used in the remediation of impaired tonal pro=
cessing was created by Alfred Tomatis. Further discussions cannot take plac=
e without absolute acknowledgment of his pioneering research. The current f=
ield of sound stimulation auditory retraining evolves from Tomatis's discov=
eries of the powerful effect of filtration and gating of sound.
In the context of auditory retraining, let's summarize these terms:
=95 Filtration means the removal of specific frequencies from an existing s=
ound recording, be that the music of Mozart or a recording of a voice. Thro=
ugh the use of sound processing equipment, it is possible to isolate and mu=
te certain frequency bandwidths. With filtration, any part of the low, mid,=
or high end of a recording can be withdrawn and reintroduced at will. On a=
visual level, imagine erasing the bottom part of a picture and then eventu=
ally drawing it back in. This is filtration.
=95 Gating refers to the creation of a random sonic event. This is accompli=
shed by electronically processing a soundtrack so it unexpectedly jumps bet=
ween the high and low frequencies. While not always pretty to listen to, th=
e net effect of this sound treatment is an extensive exercising of the musc=
les of the middle ear. The combined process of filtration and gating create=
s a powerful auditory workout. And for good reason! The middle ear mechanis=
m must work very hard to translate the complexity of the "treated" incoming=
Music is one of many things that can help those with attentional difficulti=
es. There are several good interventions, ranging from medications to non-m=
edication treatments. We provide the best of the alternative treatments. Th=
ey have been heavily researched and have a consistent record of accomplishm=
ent in aiding their users in obtaining optimum performance. Click on the Ho=
me page button to find out the benefits of our programs.
Parts of "Psychoacoustics" is excerpted from The Power of Sound, published =
by Healing Arts Press. (c) 2001 Joshua Leeds.
Processing Speed, More Than Memory, Impacts Communication In Normal Aging.
In a five-year Language Across the Life Span Project funded by the National=
Institute on Aging, University of Kansas Distinguished Professor Susan Kem=
per has identified the aging brain's slower processing speed as the prime c=
andidate in typical communication problems of healthy older adults.
Kemper devised a dual-task procedure that precisely measured and analyzed t=
he ability of young and older adults to do two things at once keep a cursor=
on a moving target on a computer screen while responding to questions to m=
easure how aging affects communication abilities.
The dual-task procedure allowed the researchers to track the moment-by-mome=
nt fluctuations in individuals' tracking performances as a function of what=
they were saying. While it was not surprising that younger adults did bett=
er at dual-tasking, both young and older adults hit a "functional ceiling" =
when the target was moving rapidly or when the questions required thoughtfu=
l and complex responses.
Producing long, complex sentences with lots of nouns and verbs was costly t=
o tracking performance, so young and older adults used short, simple senten=
ces when tracking to avoid hitting that functional ceiling, Kemper said.
But another pattern also emerged: Young adults often limited what they were=
saying to stay with the rapidly moving target, while older adults sacrific=
ed target tracking to provide complex, thoughtful responses.
The researchers were also interested what determined the "height" of the fu=
"We didn't find much evidence that working memory or long-term memory play =
a role in dual-tasking, but we think that processing speed does," said Kemp=
er. "What I think is going on is that you have to rapidly switch your atten=
tion from tracking to talking, going back and forth pretty rapidly, and tha=
t's where the processing speed really comes in. Older adults seem to be slo=
wer at switching between tasks so their functional ceiling is lower."
Further, a close analysis of the responses investigated whether the demands=
of planning what to say, actually saying it or recovering from what had ju=
st been said was costly in terms of tracking performance.
"We could look at tracking performance as reflecting the difficulty of the =
next sentence individuals were going to say, the one they were actually pro=
ducing or the one they just said," Kemper said.
While planning and producing complex sentences cost both younger and older =
adults tracking precision, planning seemed to be most costly for both older=
and younger adults. Older adults also needed recovery time after producing=
a complex sentence.
Kemper said that the study marks a milestone in methodology and in the prec=
ise measurement of language and communication problems.
She also stressed that language and communication problems, especially thos=
e that arise during dual-tasking, may be indicators of the onset of dementi=
as like Alzheimer's disease. This approach may also be useful for evaluatin=
g the efficacy of treatments for neuropathologies, she said.
"We know that there are brain markers even for people in their 40s who may =
be on the verge of developing dementia," Kemper said. "But those are reveal=
ed by very expensive tests that are not widely available. So perhaps langua=
ge and communication might provide early warning signs that might be picked=
up and also serve as an access point for trying to develop interventions."=
Results of the study have been most recently reported in Journal of Geront=
ology: Psychological Sciences, March 2011, volume 66:2, and Psychology and =
Aging, December 2010, volume 25:4.
Source: University of Kansas, Life Span Institute
- - -
[From Wikipedia, the free encyclopedia]
For Ian Lowe's book, see Reaction Time (book).
"Reaction time" redirects here. For the biological mechanism, see Reflex.
Mental chronometry is the use of response time in perceptual-motor tasks to=
infer the content, duration, and temporal sequencing of cognitive operatio=
ns. Mental chronometry is one of the core paradigms of experimental and cog=
nitive psychology, and has found application in various disciplines includi=
ng cognitive psychophysiology/cognitive neuroscience and behavioral neurosc=
ience to elucidate mechanisms underlying cognitive processing.
Mental chronometry is studied using the measurements of reaction time (RT).=
Reaction time is the elapsed time between the presentation of a sensory st=
imulus and the subsequent behavioral response. In psychometric psychology i=
t is considered to be an index of speed of processing. That is, it indic=
ates how fast the thinker can execute the mental operations needed by the t=
ask at hand. In turn, speed of processing is considered an index of process=
ing efficiency. The behavioral response is typically a button press but can=
also be an eye movement, a vocal response, or some other observable behavi=
Response time is the sum of reaction time plus movement time.
Usually the focus in research is on reaction time. There are four basic mea=
ns of measuring RT given different operational conditions during which a su=
bject is to provide a desired response:
Simple reaction time is the time required for an observer to respond to the=
presence of a stimulus. For example, a subject might be asked to press a b=
utton as soon as a light or sound appears. Mean RT for college-age individu=
als is about 160 milliseconds to detect an auditory stimulus, and approxima=
tely 190 milliseconds to detect visual stimulus.
Recognition or Go/No-Go reaction time tasks require that the subject press =
a button when one stimulus type appears and withhold a response when anothe=
r stimulus type appears. For example, the subject may have to press the but=
ton when a green light appears and not respond when a blue light appears.
Choice reaction time (CRT) tasks require distinct responses for each possib=
le class of stimulus. For example, the subject might be asked to press one =
button if a red light appears and a different button if a yellow light appe=
ars. The Jensen Box is an example of an instrument designed to measure choi=
ce reaction time.
Discrimination reaction time involves comparing pairs of simultaneously pre=
sented visual displays and then pressing one of two buttons according to wh=
ich display appears brighter, longer, heavier, or greater in magnitude on s=
ome dimension of interest.
Due to momentary attentional lapses, there is a considerable amount of vari=
ability in an individual's response time, which does not tend to follow a n=
ormal (Gaussian) distribution. To control for this, researchers typically r=
equire a subject to perform multiple trials, from which a measure of the 't=
ypical' response time can be calculated. Taking the mean of the raw respons=
e time is rarely an effective method of characterizing the typical response=
time, and alternative approaches (such as modeling the entire response tim=
e distribution) are often more appropriate.
- - -
The Brain What Is the Speed of Thought?
Faster than a bird and slower than sound. But that may be besides the point=
: Efficiency and timing seem to be more important anyway.
by Carl Zimmer
More information about the empyre