Spatial-sequential and spatial-simultaneous working memory in individuals with Williams syndrome.

Lanfranchi et al. (2015) compared two kinds of visual working memory in people with Williams syndrome. They tested spatial-sequential memory (remembering dots that light up one after another) and spatial-simultaneous memory (remembering dots that all appear at once).

Each person with Williams syndrome was matched to a typically developing person of similar mental age. Everyone completed the same dot-span tasks on a computer.

The Williams group scored lower on simultaneous tasks (dots shown together) and on any task that asked them to both store and move information around. They kept up with controls on simple sequential tasks (dots shown one by one).

The trouble showed up only when the brain had to hold several spots in mind at the exact same moment.

Carretti et al. (2013) ran the same two-task design in Down syndrome and saw the same pattern: weak on simultaneous, okay on sequential. The two studies line up like a conceptual replication, showing the deficit is tied to the task format, not the syndrome label.

Morris (2008) had already spotted odd location biases in single cases of Williams syndrome. Silvia’s group data now confirm that those quirks are part of a broader simultaneous-working-memory gap.

Deruelle et al. (2006) found that global visual perception is intact in Williams syndrome. That rules out the idea that kids can’t see the big picture; the bottleneck is in holding multiple spots at once, not in seeing them.

When you test or teach, break spatial info into a short sequence instead of one crowded slide. For example, give three taps in a row rather than three lights at once. This small timing tweak can separate a fail from a pass for learners with Williams syndrome.