The Jensen Box was developed by University of California, Berkeley

University of California, Berkeley

The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...

 psychologist

Psychologist

Psychologist is a professional or academic title used by individuals who are either:* Clinical professionals who work with patients in a variety of therapeutic contexts .* Scientists conducting psychological research or teaching psychology in a college...

 Arthur Jensen

Arthur Jensen

Arthur Robert Jensen is a Professor Emeritus of educational psychology at the University of California, Berkeley. Jensen is known for his work in psychometrics and differential psychology, which is concerned with how and why individuals differ behaviorally from one another.He is a major proponent...

 as a standard apparatus

Apparatus

Apparatus may refer to:*Technical term for body of the Soviet and post-Soviet governments *Machine*Equipment*Critical apparatus, the critical and primary source material that accompanies an edition of a text-See also:*Fire apparatus...

 for measuring choice reaction time, especially in relationship to differences in intelligence

Intelligence

Intelligence has been defined in different ways, including the abilities for abstract thought, understanding, communication, reasoning, learning, planning, emotional intelligence and problem solving....

.
Since Jensen energized this paradigm

Paradigm

The word paradigm has been used in science to describe distinct concepts. It comes from Greek "παράδειγμα" , "pattern, example, sample" from the verb "παραδείκνυμι" , "exhibit, represent, expose" and that from "παρά" , "beside, beyond" + "δείκνυμι" , "to show, to point out".The original Greek...

, correlations between simple and choice reaction time have been demonstrated in many hundreds of studies. Perhaps the best was reported by Ian Deary

Ian Deary

Ian J. Deary is a Scottish psychologist and Professor of Differential Psychology at the University of Edinburgh. Ian Deary is currently engaged in a 10-year study into the effects of ageing on mental ability using the 1932 Scottish Mental Survey funded by , entitled...

 and colleagues, in a population-based cohort study

Cohort study

A cohort study or panel study is a form of longitudinal study used in medicine, social science, actuarial science, and ecology. It is an analysis of risk factors and follows a group of people who do not have the disease, and uses correlations to determine the absolute risk of subject contraction...

 of 900 individuals, demonstrating correlations between IQ simple and choice reaction time of –0.3 and –0.5 respectively, and of –0.26 with the degree of variation

Variation

- Physics :* Magnetic variation, difference between magnetic north and true north, measured as an angle* Variation , any perturbation of the mean motion or orbit of a planet or satellite, particularly of the moon- Mathematics :* Bounded variation...

 between trials shown by an individual.

The standard box is around 20 inches wide and 12 deep, with a sloping face on which 8 buttons are arrayed in a semicircle, with a 'home' key in the lower center. Above each response button lies a small led

LEd

LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....

 which can be illuminated, and the box contains a speaker

Loudspeaker

A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...

 to play alerting sounds.

Following Hick's law

Hick's law

Hick's Law, named after British psychologist William Edmund Hick, or the Hick–Hyman Law , describes the time it takes for a person to make a decision as a result of the possible choices he or she has. The Hick-Hyman Law assesses cognitive information capacity in choice reaction experiments...

,
reaction times (RTs) slow as a log₂ of the number of choices are presented: Thus when all but one button is covered responses are fastest, and slowest when all 8-responses are available.

Several parameters can be extracted: The mean 1-choice RT gives simple reaction time. The slope of the function across 1,2,4, and 8 lights gives the rate of information processing, an variance

Variance

In probability theory and statistics, the variance is a measure of how far a set of numbers is spread out. It is one of several descriptors of a probability distribution, describing how far the numbers lie from the mean . In particular, the variance is one of the moments of a distribution...

 or standard deviation

Standard deviation

Standard deviation is a widely used measure of variability or diversity used in statistics and probability theory. It shows how much variation or "dispersion" there is from the average...

 in RTs can be extracted to give a measure of response variability within subjects.

Finally, the time to lift off the home button and the time to hit the response button can be measured separately, and these are typically thought of as assessing decision time, and movement time, though in the standard paradigm, subjects can shift decision time into the movement phase by lifting off the home button while the location

Location

Location may refer to:* Location , one of the five geographic themes and a specific position or point in physical space. * Absolute location* Content-location in HTTP headers: a Uniform Resource Identifier...

 computation is still incomplete. Masking the stimulus light can eliminate this artifact.
Simple reaction time correlates with IQ, and there is some evidence that the slope of responding does also, so long as access to the stimulus is controlled.