Cognitive Domains

What Keel Measures — and Why

Cognition is not one thing. Each domain — processing speed, working memory, spatial reasoning, semantic fluency, executive function — changes differently with age, is affected by different conditions, and signals different things when it declines. These guides explain each domain, what changes are normal, and what Keel tracks.

Processing Speed

Processing Speed: What It Is and Why It Changes With Age

Processing speed is the rate at which your brain performs mental operations. It is one of the first cognitive abilities to show age-related change — and one of the most measurable.

6 min read
Working Memory

Working Memory: What It Is and Why It Changes With Age

Working memory is the brain's mental scratch pad — the system that holds and manipulates information in real time. It is central to reasoning, learning, and following complex instructions.

6 min read
Spatial Reasoning

Spatial Reasoning: What It Is and Why It Changes With Age

Spatial reasoning is the ability to perceive, manipulate, and navigate spatial relationships. It is one of the most evolutionarily ancient cognitive abilities — and one that shows consistent age-related change.

6 min read
Semantic Fluency

Semantic Fluency: What It Is and Why It Changes With Age

Semantic fluency is the brain's ability to rapidly search and retrieve organized conceptual knowledge — words, categories, names, and facts. It is a window into how efficiently your language and memory networks are communicating.

6 min read
Executive Function

Executive Function: What It Is and Why It Changes With Age

Executive function is the brain's management system — the set of cognitive controls that govern planning, decision-making, impulse control, and mental flexibility. It is the most distinctly human of our cognitive abilities.

6 min read
Episodic Memory

Episodic Memory: What It Is and Why It Changes With Age

Episodic memory is memory for personal experiences — what happened, when it happened, and where. It is the memory system most commonly affected by both normal aging and early Alzheimer's disease.

6 min read
Attention

Attention: What It Is and Why It Changes With Age

Attention is not a single ability but a family of cognitive controls that govern what your brain processes and what it ignores. Its changes with age are subtle but have cascading effects on nearly every other cognitive domain.

6 min read
Verbal Recall

Verbal Recall: What It Is and Why It Changes With Age

Verbal recall is the ability to retrieve previously heard or read information. It is one of the most practical cognitive abilities in daily life — and one of the most sensitive to the changes of both normal aging and early cognitive impairment.

6 min read
Reaction Time

Reaction Time: What It Is and Why It Changes With Age

Reaction time is a direct measure of neural processing speed — how long it takes your nervous system to detect, process, and respond to a stimulus. It is one of the most objective and reliable windows into cognitive aging.

6 min read
Visuospatial Ability

Visuospatial Ability: What It Is and Why It Changes With Age

Visuospatial ability is how well your brain perceives, processes, and acts on visual-spatial information. It governs everything from reading a map to parking a car — and it changes in characteristic ways that are both detectable and informative.

6 min read

See all your domains in one trend line

Keel tests five domains in four minutes a day. Over weeks, you build a multi-domain picture of your cognitive baseline — and can see which domains are stable, which are varying, and which might be shifting.

Free to start. No account required. Not a diagnostic tool.