The counterpart sign (patibhaga nimitta)

Recognise when the mental image transforms into a luminous, purified counterpart — this marks the threshold of access concentration.

Why it works

The patibhaga nimitta is phenomenologically distinct from the uggaha: it appears more brilliant, clear, and uniform than the original physical object, and arises spontaneously rather than being willed. This transformation appears to correspond to a shift from attentional maintenance in working memory to a more autonomous, absorbed mode of processing — what Theravada tradition calls access concentration (upacara samadhi).

How to do it

1. Continue stable practice with the uggaha nimitta without forcing anything new.
2. When the image spontaneously brightens, clarifies, or shifts appearance, allow it without grasping or analysis.
3. Do not poke at it mentally — any evaluative thought tends to dissolve the patibhaga.
4. Rest in the image's presence and allow it to stabilise on its own terms.

Evidence

The phenomenological shift described as patibhaga is reported consistently across classical and contemporary practitioner accounts. No neuroimaging study has tracked the nimitta transformation specifically, though access concentration as a distinct attentional threshold is discussed in contemporary contemplative science. (anecdotal)

The patibhaga stage is entirely practitioner-reported; its neurological correlate is unknown. Some teachers question whether reports are consistent across traditions.

Common mistake

Treating any brightening as the patibhaga and immediately trying to enter jhana — the nimitta needs time to stabilise fully before it can sustain absorption.