Processing Speed Games: Inspection Time and the Research

Updated 2026-10-25

Written by the Optics Trainer team from published research, with every source linked below.

Processing speed is how quickly you take in information and act on it. Processing speed games and drills, online and in apps for adults and kids, usually ask you to spot, match or tap things under time pressure. This guide explains processing speed as psychologists describe it, the inspection time test and how it differs from reaction time, and what processing speed training studies found, including a 20-year dementia follow-up and the debate about it. It ends with Fast Match, Number Tap and Flower Tap, the Optics Trainer speed games.

What is processing speed?

Psychologists use processing speed to mean how fast a person can carry out simple mental steps, such as noticing, comparing or matching. Timed tasks measure it: matching symbols to digits, scanning for a target, or deciding whether two items are the same.

Timothy Salthouse set out the processing-speed theory of aging in 1996. He proposed that slower processing in older adults impairs thinking in two ways: some steps cannot be finished in the time available, and the results of early steps may be gone by the time later steps finish. He pointed to shared age-related differences across many speed measures as support.

Speed also changes in childhood. Robert Kail pooled 72 studies in 1991 and found that children's response times rose in step with adults' across tasks, and that the gap shrank with age, quickly in childhood and more slowly in adolescence. Standard child tests time this with tasks such as the Coding subtest of the Wechsler intelligence scale.

The inspection time test

Inspection time measures how long you need to see something to judge it correctly, not how fast you respond. Douglas Vickers, Ted Nettelbeck and colleagues introduced the term in 1972. In the standard version, described in a 2020 paper by Eisma and de Winter, two vertical lines of clearly different length, joined at the top, flash on the screen. A mask then covers them. You say which line was longer, taking as long as you like. The display time is shortened until accuracy reaches a set level, such as 90% correct, and that display time is your inspection time.

In 1976, Nettelbeck and Lally tested 10 adults with IQ scores from 47 to 119. Shorter inspection times went with higher scores on the performance subtests of the IQ test, while how fast people pressed the key did not relate to IQ. Eisma and de Winter report that a 2001 meta-analysis of 92 studies by Grudnik and Kranzler estimated the correlation between inspection time and IQ at -0.30, or -0.51 after statistical corrections. Ian Deary's reviews, including one with Con Stough in 1996, discuss what this link means.

Inspection time has also been studied in sport. In 1989, Deary and Mitchell compared the inspection times of 20 club cricketers with their season batting averages and found a correlation of -0.63: batters who needed shorter displays had higher averages.

Inspection time vs reaction time

Reaction time tasks score how quickly you respond, so they include the time to move your finger. Inspection time tasks score how long the display needed to be on screen, and you can answer slowly. Eisma and de Winter note that researchers such as Arthur Jensen valued inspection time because it does not need an immediate motor response. In their own study, participants were told, "This is not a reaction time task."

The two can come apart. In the 1976 Nettelbeck and Lally study, inspection time related to IQ subtests while response speed did not. Our clinic article on visual reaction time testing covers how reaction time is measured clinically.

Inspection time vs reaction time
	Inspection time	Reaction time
What is scored	The shortest display time for accurate judgments	How fast you respond after a signal
Is speed of response scored?	No; answers can be slow	Yes
Typical display	Two lines of different length, then a mask	A light, sound or symbol
Movement time included?	No	Yes

Processing speed training: what studies found

The ACTIVE trial randomized 2,832 older adults, and one of its arms was useful field of view (UFOV) speed training. Our guide to visual brain training covers its design and its 10-year results.

Meta-analyses that pool many trials report results like these:

Lampit and colleagues, 2014, pooled 52 randomized trials of computerized cognitive training with 4,885 healthy older adults. The overall effect was g = 0.22, and on processing speed tests g = 0.31. There was no significant effect on executive function or attention tests, and home-based training was not effective compared with group-based training. The authors pointed out that over half of the participants had trained on speed tasks, and that those gains showed up only on speed tests.
A 2020 Cochrane review by Gates and colleagues pooled 8 trials with 1,183 healthy adults aged 65 and older who trained for at least 12 weeks. It rated the evidence low or very low quality and said the reviewers were very uncertain about effects on speed of processing.
In children, Mackey and colleagues gave children aged 7 to 9 from low-income families 8 weeks of speed games or reasoning games, 2 hours a week. The speed group improved on a standard processing speed test (d = 1.15) but not on a reasoning test, and the reasoning group showed the reverse.
Inspection time can shift with practice: Nettelbeck and Lally reported in 1976 that training did not appear to affect it, but Nettelbeck and colleagues found a practice effect over about 800 trials in 1982, and Eisma and de Winter found that clearer instructions and practice trials raised accuracy.

Selected processing speed and inspection time training studies
Study	Design	Who	Result as reported
Lampit 2014, PLoS Med	Meta-analysis of 52 RCTs	4,885 healthy older adults	g = 0.22 overall; g = 0.31 on speed tests; authors: speed training effects did not generalize beyond speed outcomes
Gates 2020, Cochrane	Systematic review, 8 RCTs	1,183 adults 65+	Very uncertain about effects on processing speed; low or very low quality evidence
Mackey 2011, Dev Sci	Two training groups, 8 weeks	Children aged 7 to 9	Speed group gained on a speed test, not on reasoning
Nettelbeck 1982, Am J Ment Defic	Repeated testing, about 800 trials	20 adults, 10 with intellectual disability	Practice effect in both groups; group gap remained
Eisma 2020, J Cogn	Two experiments	147 and 159 students	Instructions and practice trials raised accuracy

Speed training and dementia: the ACTIVE 20-year follow-up

In 2026, Coe and colleagues linked ACTIVE participants to Medicare claims from 1999 to 2019 (2,021 people). People in the speed training group who had at least one booster session had a lower risk of a diagnosis of Alzheimer's disease or a related dementia (hazard ratio 0.75). Speed-trained people without booster sessions did not (hazard ratio 1.01), and memory and reasoning training showed no effect. The authors concluded that speed training "has the potential to delay the diagnosis" of dementia.

The authors listed limitations: possible selection bias after randomization, the exclusion of about a quarter of the ACTIVE sample, and the fact that a diagnosis depends on access to health care. One author consults for and owns stock in the company that markets the speed training software used in ACTIVE.

A reanalysis by William Dickens in the same journal found that, after correcting for multiple comparisons, none of the results stayed statistically significant, and that the pattern fit a shared effect of all three trainings in the youngest participants. Gross, Rebok and Albert replied that each training arm was a separate pre-specified hypothesis, so they did not see that correction as needed.

Processing speed games online, apps and drills

Online processing speed games and apps borrow these lab tasks and add scores and levels. Their scores have no norms and are not measures. Optics Trainer has three speed games, each modeled on a lab task.

Fast Match is modeled on inspection time. A dot holds your gaze, two rings with one gap each flash, and a mask covers them. You answer whether the gaps pointed the same way. As you progress, the flash gets shorter, from half a second at the start down to a few hundredths of a second, the rings get smaller and farther apart, and the gaps can point eight ways instead of four. Unlike the lab task, the rings appear at different places on the screen and the game scores points in a 60-second round rather than estimating a display time.
Number Tap is modeled on the Schulte table and Trail Making Test Part A: tap numbered tiles in order as fast as you can while new boards turn and recolor the numerals. Our Schulte table guide covers that task.
Flower Tap is modeled on the go/no-go task: tap only the flowers whose C points the target way. Our go/no-go task guide covers it.
All three have an optional binocular mode with red-blue glasses on a phone, tablet or computer, built in on Meta Quest. In Fast Match, one eye sees both rings on each trial.

Where Optics Trainer fits

Optics Trainer is a set of vision and brain training games for iPhone, iPad, Android, web browsers and Meta Quest. Fast Match is modeled on the inspection time task described above, Number Tap on the Schulte table, and Flower Tap on go/no-go. They challenge you to judge brief displays, scan and respond quickly. See the science behind the games for the task behind each game.

None of these games was tested in the studies described here. They are not tests or measures, do not estimate inspection time or processing speed, and are not a treatment or diagnosis. They are not FDA cleared. We make no claim that they change processing speed, attention, IQ, school or sport performance, or dementia risk. For clinical measurement, see our clinic article on visual reaction time testing and Optics Tracker.

Optics Trainer is not a substitute for professional diagnosis or prescribed care. Consult your eye care professional for guidance about your specific condition. The phone and tablet apps start with a 7-day free trial, and a free web account includes 3 plays a day. After that, mobile and web access is $14.99 a month or $149.99 a year, and VR access is $19.99 a month or $199 a year after a 7-day free trial.

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Frequently asked questions

What are processing speed games?

They are timed games built from lab tasks such as symbol matching, visual scanning or brief-display judgments. They practice the task itself; their scores have no norms and are not measures of processing speed.

What is the inspection time test?

Two lines of different length flash and are masked, and you say which was longer, with no rush to answer. The shortest display time at which you are reliably correct is your inspection time. The term dates to 1972.

What is the difference between inspection time and reaction time?

Reaction time scores how fast you respond, including movement. Inspection time scores how long a display must be shown for you to judge it correctly, and answers can be slow. A 1976 study found inspection time related to IQ subtests while response speed did not.

Can processing speed be trained?

People get faster on the speed tasks they practice. The authors of a 2014 meta-analysis noted that speed training gains did not extend beyond speed tests, and a 2020 Cochrane review was very uncertain about effects on processing speed in older adults.

Does speed of processing training lower dementia risk?

A 2026 ACTIVE analysis of Medicare claims found a lower risk of diagnosed dementia only in speed-trained people who had booster sessions. A reanalysis found no significant result after correcting for multiple comparisons and suggested a shared effect of all three trainings in the youngest participants; the original authors disputed that correction.

Are there processing speed games for kids?

Yes. In a 2011 study, children aged 7 to 9 who played speed games for 8 weeks improved on a standard speed test but not on reasoning. Speed games for kids are practice, not a way to test or diagnose a child.

Is there an inspection time game?

Optics Trainer's Fast Match is modeled on inspection time: two gapped rings flash, are masked, and you say whether the gaps match. It was not tested in research and does not make clinical measurements of inspection time.

Sources

Related guides

Try Optics Trainer's speed games

Fast Match, modeled on inspection time, plus Number Tap and Flower Tap challenge you to judge brief displays and respond quickly, with an optional red-blue glasses mode. Play them on phone, tablet, web and Meta Quest. The phone and tablet apps start with a 7-day free trial.

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