An activation map showing a focal activation would appear as which analogy?

An activation map showing a focal activation would appear as which analogy?

• A. Pebble in a pond
• B. River delta
• C. Spiral wave
• D. Patchwork pattern

Answer: (A)

Activation maps show when and where electrical activity starts and how it sweeps through tissue. A focal activation begins at a single, localized point and then spreads outward in all directions. This outward propagation from a single center is like ripples from a pebble dropped in a pond: a bright center appears first, and waves radiate outward with time. In a uniform tissue, the wavefront travels roughly as expanding circles from the origin, making the central spot the source of activation. The other analogies imply different patterns: a river delta suggests many branching sources, a spiral wave indicates rotating reentry around a core, and a patchwork pattern points to multiple, irregular regions rather than a single origin. So the pebble in a pond best captures a focal activation.

Activation maps show when and where electrical activity starts and how it sweeps through tissue. A focal activation begins at a single, localized point and then spreads outward in all directions. This outward propagation from a single center is like ripples from a pebble dropped in a pond: a bright center appears first, and waves radiate outward with time. In a uniform tissue, the wavefront travels roughly as expanding circles from the origin, making the central spot the source of activation. The other analogies imply different patterns: a river delta suggests many branching sources, a spiral wave indicates rotating reentry around a core, and a patchwork pattern points to multiple, irregular regions rather than a single origin. So the pebble in a pond best captures a focal activation.