What Does a Channel Name Identify? Task Transfer Versus Channel Identity Across Neural Recording Sessions

Successful decoding does not establish correct channel identity, and within-session matching need not remain reliable across recording sessions. We separate channel order, acquisition or registration identifiers, functional similarity, and decoder performance. In LINK, matching disjoint samples within a session recovers 88.4% of individual channels after an imposed permutation, but only 1.8% of complete 96-channel maps. These imperfect maps incur a mean $R^2$ loss of 0.0018 for one fixed decoder. Across chronological targets from two other macaques, behavior-conditioned recovery of electrode-channel identities falls from 44.8% in paired within-session controls to 4.7% across sessions. In an exploratory oracle analysis in one macaque, label-fitted reindexing raises mean held-out $R^2$ from 0.06 to 0.38. Across the three macaques, maps fitted on disjoint calibration halves agree on only 5–14% of channels. In 24 mice from the Allen Brain Observatory, repeated-stimulus profiles recover 20.7% of registered cells against a 1.2% random reference. A separate, prospectively frozen four-animal extension tests a locally fitted matcher across sessions. Mean false-match risk against stitched-sorting proxies is 25.66% at 62.55% source coverage, failing the prespecified requirement of at most 10% risk. Together, these experiments show that small decoder losses can coexist with incorrect channel assignments, while local matching competence does not ensure reliable cross-session matching. Identifier recovery, decoder utility, and cross-session matching risk require separate evaluation; acquisition and registered-cell identifiers do not establish biological continuity.