Table 2.
Results from behavioral experiment in blind and sighted subjects (Cuevas et al., 2010b).
| Subjects | Age (years) | Odor threshold (score/16) | Odor discrimination (score/16) | Multiple choice identification (score/16) | TDI composite score (score/48) | Retronasal testing (score/20) |
|---|---|---|---|---|---|---|
| EB1 | 21 | 7.3 | 15 | 10 | 32.3 | 19 |
| EB3 | 29 | 6.3 | 10 | 16 | 32.3 | 16 |
| EB4 | 40 | 7.0 | 14 | 14 | 35.0 | 17 |
| EB5 | 55 | 15.8 | 15 | 13 | 43.8 | 18 |
| EB8 | 39 | 11.0 | 16 | 11 | 38.0 | 17 |
| EB9 | 51 | 8.0 | 14 | 15 | 37.0 | 17 |
| EB10 | 45 | 15.8 | 13 | 14 | 42.8 | 18 |
| EB11 | 20 | 6.0 | 15 | 12 | 33.0 | 18 |
| Mean (EB) | 37.5 | 9.6 | 14.0 | 13.10 | 36.8 | 17.5 |
| SD (EB) | 13.1 | 4.08 | 1.85 | 2.03 | 4.54 | 0.93 |
| SC1 | 20 | 3.5 | 14 | 16 | 33.5 | 20 |
| SC5 | 53 | 5.0 | 9 | 14 | 28.0 | 19 |
| SC7 | 40 | 6.3 | 9 | 13 | 28.3 | 16 |
| SC8 | 39 | 6.0 | 14 | 11 | 31.0 | 19 |
| SC9 | 50 | 4.8 | 11 | 13 | 28.8 | 17 |
| SC14 | 21 | 4.5 | 14 | 14 | 32.5 | 17 |
| SC15 | 30 | 6.3 | 13 | 14 | 33.3 | 16 |
| SC16 | 39 | 4.0 | 10 | 14 | 28.0 | 18 |
| Mean (SC) | 36.5 | 5.0 | 11.8 | 13.6 | 30.4 | 17.8 |
| SD (SC) | 12.1 | 1.05 | 2.25 | 1.41 | 2.43 | 1.49 |
Note: EB, early blind; SC, sighted control (same numbering as in Table 1); all subjects were right-handed males; sighted subjects were studied blindfolded. Scores were for odor detection threshold (T), odor discrimination (D) and multiple forced-choice identification (I) in the Sniffin’ Stickx test (Hummel et al., 2007). The TDI composite score referred to the sum of individual results obtained for these three subtests (threshold + discrimination + multiple forced choice identification). The retronasal testing (based on the protocol of Heilmann et al., 2002) referred to a multiple forced-choice identification of odorized powders presented via the mouth. For odor detection threshold (ranging from 1 to 16), the closer to 16 corresponded to the higher sensibility to odors (corresponding to a low threshold) and conversely. For all other measures, the score was the sum of correct responses (with a quotation made on a “0: wrong; 1: correct” basis). The EB participants outperformed the SC subjects in the odor detection task (p = 0.007, lower detection threshold in EB) and to a lesser extent, in odor discrimination (p = 0.03) but not in odor multiple forced-choice identification, either orthonasally (p = 0.85), nor retronasally (p = 0.75). The composite TDI score was significantly different between groups (p = 0.0032), mainly due to better scores in EB for odor detection. Data from Cuevas et al. (2010b).