This study conducts a psycholinguistic experiment using the concept-formation paradigm to probe perception of tones across different syllable types. Native-speaking subjects were trained to perceive tonal identities in Taipei Taiwanese and then tested with novel tokens comprising checked versus non-checked pairs to see if comparable tonal values across distinct syllable types are categorized as 'having the same tone'. The results of our experiment indicate that 'tonal identity', like other concepts formed by human categorization, has its fuzzy edges. Extracting and establishing tonal identity becomes increasingly difficult as syllable structures become more different.