Implicit and explicit olfactory memory in people with and without Down syndrome.

Johns et al. (2012) tested how people with Down syndrome remember smells. They used two kinds of memory tests. One test checked if the body remembers a smell without thinking. The other test asked people to name or point to smells they smelled before.

The team compared adults with Down syndrome to typical adults of the same mental age. Everyone smelled odors in a quiet lab room. The study wanted to see which memory system stayed strong and which one struggled.

People with Down syndrome kept the body-based smell memory. They acted like they knew a smell even when they could not say its name. Yet they had a hard time when asked to pick out or name the smells they had smelled earlier.

The gap was big enough that the authors blamed weaker executive skills, not nose problems. In short, the nose worked; the thinking part that labels and recalls did not.

Fyfe et al. (2007) saw the same split in Down syndrome for hand-movement learning. Their group with DS learned motor steps on cue but forgot the order when asked to tell it. Together, the two studies show a pattern: the body can learn while the talking mind lags.

Borella et al. (2013) and Micai et al. (2021) both found wide inhibition trouble in Down syndrome. They say the brain has trouble blocking extra input. Adam’s smell task needed people to block new odors and pick the old one, so the poor smell naming lines up with poor inhibition.

Spriggs et al. (2016) seems to disagree at first. Their group with Down syndrome recalled a staged crime as well as mental-age peers. The key gap is the task: eyewitness recall uses short, clear questions with pictures, while Adam’s task asked people to hold smells in mind without cues. Extra support can mask the deficit; take it away and the gap shows.

When you teach life skills that use smells—cooking, cleaning, fire safety—do not trust that the learner can name or pick the safe odor later. Give extra cues like color tags, picture cards, or a buddy check. Break the task into see-smell-act steps so the executive load stays low. Your prompt becomes the missing label the study says they can’t supply on their own.