Article Figures & Data
Figures
- Figure 1.
Perceptual tasks. A, Simple vibrotactile. B, Amplitude discrimination. C, Backward masking, target–masker delay, 100 ms. D, Backward masking, target–masker delay, 50 ms. E, Forward masking, masker–target delay, 100 ms. F, Forward masking, masker–target delay, 50 ms. In all tasks except amplitude discrimination, the participant's goal was to detect which interval contained the target tap (a 20 Hz sinusoidal pulse, 25 ms in duration, with amplitude ranging from 1 to 100 μm). In amplitude discrimination, the goal was to select the interval with the stronger tap. A and C–F show only the interval containing the tap.
- Figure 2.
Adaptive psychophysical procedure. A, Performance of a participant (∘, correct; x, incorrect) on the simple vibrotactile detection task. The participant reported the perceived target interval by pressing one of two response keys. Target amplitude for each trial was selected using the modified ψ method. B, Most probable psychometric function, given the participant's performance. The dashed vertical line shows the stimulus level corresponding to 76% correct response probability. C, Posterior PDF for the participant's vibrotactile detection threshold. The mean of the PDF was taken as the best estimate of the participant's threshold.
- Figure 3.
Posterior PDFs for thresholds of a single CBPR participant (top panels) and a single sighted participant (bottom panels) on all six tasks. Left, SV (solid lines) and AD (dashed lines). Middle, BM. Right, FM. In middle and right panels, the solid line indicates 100 ms target–masker delay, and the dashed line indicates 50 ms target–masker delay. Note that the estimated target detection thresholds at 50 ms delay are higher than those that at 100 ms delay; target detection thresholds under forward masking are higher than under backward masking; and the thresholds of the sighted participant on each task are higher than those of the CBPR participant.
- Figure 4.
Mean performance of the five participant groups on the nonmasking tasks. A, SV. B, AD. Error bars indicate ±1 SE. S, Sighted.
- Figure 5.
Mean masking performance metric of the five participant groups. A–D, Backward masking, 100 ms, 50 ms; forward masking, 100 ms, 50 ms. Error bars indicate ±1 SE. For masked target detection thresholds in micrometers, see supplemental Figure 3 (available at www.jneurosci.org as supplemental material).
- Figure 6.
Mean masking decay time constants of the five participant groups. A, Backward masking decay time constant. B, Forward masking decay time constant. Error bars indicate ±1 SE.
- Figure 7.
Mean time taken to read the Braille test passage for each of the proficient Braille reader groups. Error bars indicate ±1 SE.
- Figure 8.
Masking task performance metric of proficient Braille readers plotted against time required to read the Braille test passage. A–D, Backward masking, 100 ms, 50 ms; forward masking, 100 ms, 50 ms.
- Figure 9.
Estimated COA during Braille reading plotted against masking decay time constants. A, Backward masking decay time constant. B, Forward masking decay time constant. For breakdown by proficient reader group, see supplemental Figure 5 (available at www.jneurosci.org as supplemental material).
Tables
Age (years) Blind (N = 57) Sighted (N = 89) 19–30 26.3 (15) 21.3 (19) 30–40 5.3 (3) 9.0 (8) 40–50 14.0 (8) 15.7 (14) 50–60 31.6 (18) 24.7 (22) 60–70 17.5 (10) 19.1 (17) 70–80 5.3 (3) 10.1 (9) -
Percentages (and numbers) of participants are shown in each group, for each age decade.
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CBPR (N = 22) EBPR (N = 11) LBPR (N = 10) LBNR (N = 14) Sighted (S) (N = 89) Median age (years) 52.5 49.6 47.7 59.0 53.5 Age range (years) 20.2–74.2 23.1–71.0 21.2–65.7 19.5–72.0 20.0–78.1 Women, men 17, 5 5, 6 4, 6 6, 8 50, 39 NLP, LP 15, 7 10, 1 2, 8 3, 11 — OHR, THR 12, 10 5, 6 6, 4 — — -
NLP, No light perception; LP, residual light perception; OHR, one-hand reader; THR, two-hand reader. The bottom three rows list numbers of participants.
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Supplemental Material
Files in this Data Supplement:
- supplemental material - Supplemental Material
