Why a few minutes a day
beats an hour on Sunday.

Brisk is built on four design choices: it is short, it is daily, it mixes three kinds of puzzle, and it explains every answer. None of these were guesses. Each rests on a finding that has been replicated many times in the learning and ageing literature. This page sets them out, and is careful about what they do and do not prove.

1. Spaced practice beats massed practice

The spacing effect is one of the oldest and most robust findings in psychology. A 2006 meta-analysis of 839 assessments across 317 experiments found that spreading practice over separate sessions produced better retention than the same amount of practice in one sitting, at every retention interval tested.^[1] The optimal gap grew with how long you wanted to remember something. For skills you want to keep indefinitely, a little practice every day is close to ideal.

This is why Brisk offers six puzzles a day rather than sixty at the weekend. The habit is easier to keep, and the practice is better distributed.

2. Retrieving beats rereading

Roediger and Karpicke showed that students who were tested on material remembered it far better a week later than students who spent the same time rereading it, even though the rereaders felt more confident.^[2] The act of pulling an answer out of memory strengthens it in a way that passive review does not. Every Brisk question is a retrieval: a sum you compute, a word you reconstruct, a rule you infer. The explanation afterwards is feedback, which retrieval practice needs to work well.

3. Timing matters, especially later in life

In a classic 1993 study, older and younger adults were tested on memory tasks in the morning and late afternoon.^[3] Older adults, most of whom were morning types, performed as well as younger adults in the morning and markedly worse in the afternoon. The effect, called synchrony, has been replicated in most studies of fluid cognition in older adults. A daily puzzle that resets at a fixed time and takes two minutes fits easily into whatever hour you are sharpest.

4. Variety appears to matter more than intensity

In a cohort followed by Carlson and colleagues, older adults who took part in a wider variety of activities had lower risk of cognitive impairment, regardless of how demanding each activity was.^[4] The Synapse Project, a randomised trial in which older adults spent fourteen weeks learning quilting, digital photography or both, found memory gains in the groups that learned something new and demanding, and none in groups that did familiar, low-demand activities.^[5] The common thread is novelty and breadth. Brisk’s mix of arithmetic, anagrams, word meanings and number patterns is a small nod to that: six different demands rather than one repeated.

What this does not show

None of these studies tested a two-minute puzzle game. The spacing and testing effects are about learning and remembering specific material. The variety findings are observational or about far more intensive engagement. It would be dishonest to string them together into a claim that Brisk makes you smarter or protects your brain, and we do not. What they support is narrower and still worth having: if you are going to do puzzles, short, daily, varied and self-checking is the sensible way to do them. For the broader question, read do brain games work?