The visuospatial sketchpad holds visual and spatial information

What it is

Alongside the phonological loop, which handles verbal and numeric material, working memory has a separate subsystem dedicated to holding visual appearance and spatial position information — what an object looks like, its color, where several elements are positioned relative to each other, the route of a path — called the visuospatial sketchpad. This content is held here rather than routed through the phonological pathway. It runs in parallel with the phonological loop, not as a substitute for it — the two handle different kinds of information and together make up working memory's storage components.

Why it happens

The visuospatial sketchpad supports the ability to construct and manipulate mental images: it can briefly retain the visual appearance of a scene as well as the spatial relationships between objects or locations, and it supports doing some operations on that internal representation — mentally rotating a shape, or continuing to trace a remembered path. It draws on different processing resources than the phonological loop, which shows up in how selectively different manipulations affect it — an interference task aimed specifically at spatial processing (requiring a concurrent spatial tapping task, for instance) noticeably disrupts this kind of visuospatial retention task, while having little effect on a concurrent verbal retention task.

Studying it

The classic evidence separating the visuospatial sketchpad from the phonological loop comes from crossed dual-task designs: having participants perform a visuospatial retention task (remembering the sequence in which blocks appeared, say) alongside a spatial interference task produces a clear performance drop; swapping in a verbal retention task alongside the same spatial interference task leaves performance almost untouched. Conversely, testing the same set of tasks with a verbal interference manipulation (articulatory suppression) disrupts exactly the verbal task, not the spatial one. This crossed, complementary pattern of disruption is the key evidence that the two subsystems are independent and process different kinds of information.

Where it stops holding

Whether material routes through the visuospatial pathway depends on how it's actually processed, not on the physical form it's presented in: an image whose content is easy to name and describe (a simple symbol, say) may get recoded into a verbal description and stored in the phonological loop rather than staying in the sketchpad. What genuinely relies on this pathway is information that resists being compressed into a verbal label and can only be retained through its own visual-spatial detail.

Applying it

• When a user needs to temporarily remember spatial layout information — where elements were positioned before a screen transition, the respective locations of several objects in a multi-step task — treat it as a visuospatial task in the design, not something a text description of the layout can substitute for.
• If spatial information is going to be interrupted mid-task, prioritize keeping or restoring the relevant visual cues once the interruption ends, rather than expecting the visuospatial sketchpad alone to carry the whole layout through the interruption unaided.
• For multi-step tasks that genuinely depend on users holding spatial memory, keep element positions consistent across steps to reduce the complexity the sketchpad has to maintain.
• Verification: compare accuracy in reconstructing a spatial layout under a "text description of the layout only" condition versus an "actual visual preview" condition. If the visual preview condition performs noticeably better, the content genuinely depends on the visuospatial pathway and shouldn't be substituted with a verbal description.

Related

• Same group: A6.12.1 The phonological loop holds verbal and numeric information · A6.12.3 The two subsystems draw on relatively independent resources, so simultaneous information in different channels doesn't interfere · A6.12.4 The central executive coordinates the subsystems and allocates attention, and has its own capacity limit · A6.12.5 Presenting the same information through both visual and verbal channels can raise working memory's effective capacity
• Nearby: A6.02 Working memory capacity
• Search terms: visuospatial sketchpad · spatial working memory · Corsi block task