Brain training

What it measures: Simple reaction time: how quickly your brain detects a signal and triggers a movement.

Why it's valuable: Processing speed is one of the most studied markers of cognitive ageing. In large population studies, slower and more variable reaction times track with lower cognitive ability and older age.

1. Deary IJ, Der G. Reaction time, age, and cognitive ability: longitudinal findings from age 16 to 63 years in representative population samples. Aging, Neuropsychology, and Cognition. 2005;12(2):187–215.

What it measures: Speed of visual processing and how much you can take in at a glance, in the centre and at the edges of your vision.

Why it's valuable: This is based on the useful-field-of-view task. In the ACTIVE trial, older adults who trained on it improved processing speed, and a 10-year follow-up linked speed training to a lower risk of dementia. The practice tasks here are a simplified version and have not been tested themselves.

1. Ball K, Berch DB, Helmers KF, et al. Effects of cognitive training interventions with older adults: a randomized controlled trial. JAMA. 2002;288(18):2271–2281.
2. Edwards JD, Xu H, Clark DO, et al. Speed of processing training results in lower risk of dementia. Alzheimer's & Dementia: Translational Research & Clinical Interventions. 2017;3(4):603–611.

What it measures: Sustained attention and alertness over two minutes, including lapses (responses slower than 500 ms).

Why it's valuable: The Psychomotor Vigilance Task is a standard research tool for measuring the effects of sleep loss and fatigue. A quick daily check can show how sleep and recovery affect your alertness.

1. Dinges DF, Powell JW. Microcomputer analyses of performance on a portable, simple visual RT task during sustained operations. Behavior Research Methods, Instruments, & Computers. 1985;17(6):652–655.
2. Basner M, Dinges DF. Maximizing sensitivity of the Psychomotor Vigilance Test (PVT) to sleep loss. Sleep. 2011;34(5):581–591.

What it measures: Divided attention: how many moving objects you can follow at the same time.

Why it's valuable: Multiple object tracking shows people can follow several independently moving targets at once, usually around four. It reflects the kind of attention used when driving, playing sport or moving through a crowd.

1. Pylyshyn ZW, Storm RW. Tracking multiple independent targets: evidence for a parallel tracking mechanism. Spatial Vision. 1988;3(3):179–197.

What it measures: Digit span: how many items you can hold in short-term (working) memory at once.

Why it's valuable: Working memory underpins reasoning, learning and following conversations. Digit span is part of standard clinical cognitive batteries; most adults hold about seven digits.

1. Miller GA. The magical number seven, plus or minus two: some limits on our capacity for processing information. Psychological Review. 1956;63(2):81–97.

What it measures: Working memory updating: holding recent items in mind and constantly replacing them.

Why it's valuable: The n-back task was first used to study age differences in short-term memory and is now one of the most widely used working-memory tasks in research.

1. Kirchner WK. Age differences in short-term retention of rapidly changing information. Journal of Experimental Psychology. 1958;55(4):352–358.

What it measures: Selective attention and interference control: ignoring the word to name the ink color.

Why it's valuable: The Stroop effect is one of the most replicated findings in psychology. It measures executive control — the ability to override an automatic response, which supports focus under distraction.

1. Stroop JR. Studies of interference in serial verbal reactions. Journal of Experimental Psychology. 1935;18(6):643–662.
2. MacLeod CM. Half a century of research on the Stroop effect: an integrative review. Psychological Bulletin. 1991;109(2):163–203.

What it measures: Response inhibition: acting quickly on one signal while holding back on another.

Why it's valuable: Stopping an impulse is a core executive function. Go/No-Go tasks engage frontal brain networks involved in self-control and are widely used in attention research.

1. Simmonds DJ, Pekar JJ, Mostofsky SH. Meta-analysis of Go/No-go tasks demonstrating that fMRI activation associated with response inhibition is task-dependent. Neuropsychologia. 2008;46(1):224–232.

What it measures: Visuomotor speed and accuracy: how quickly and precisely you move to a target.

Why it's valuable: Fitts's law describes the speed–accuracy trade-off in aimed movement. Hand–eye coordination reflects how well vision, attention and motor control work together.

1. Fitts PM. The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology. 1954;47(6):381–391.

What it measures: Self-rated calm before and after one minute of slow breathing.

Why it's valuable: Slow, controlled breathing is linked to greater parasympathetic (rest-and-digest) activity and improved mood. Short daily practice is an easy micro-habit to track.

1. Zaccaro A, et al. How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Frontiers in Human Neuroscience. 2018;12:353.
2. Balban MY, et al. Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine. 2023;4(1):100895.