Article Figures & Data
Figures
- Figure 1.
The sensory focus of the penis lies lateral to that of the toe. Significant fMRI activations (see Materials and Methods) in the right primary somatosensory cortex after stimulation of the contralateral hallux (red), prepuce or glans (green), penile shaft (blue), and lower abdominal wall (cyan in subjects 5-8) are overlaid onto each individual's anatomical scan. The square depicts the Rolandic template for analysis of primary sensory cortex, and dotted lines mark the central sulcus.
- Figure 2.
Stimulation of the toe and penis leads to contralateral primary somatosensory and bilateral activation in the opercular secondary somatosensory cortex. Random effects group results were significant at p < 0.001 (uncorrected), but activations were thresholded at p < 0.006 for better visibility when projected onto a template-rendered brain. Red and green signify activations related to toe and prepuce. On the single-subject level, most activations reached a significance of p < 0.05, corrected for multiple comparisons within the delineated opercular template volume (dashed lines).
- Figure 3.
A modified version of Penfield and Rasmussen's sensory homunculus.
Tables
Toe Prepuce Penile shaft Lower abdominal wall Single subject Center of gravity (x,y,z) t value Center of gravity (x,y,z) t value Center of gravity (x,y,z) t value Center of gravity (x,y,z) t value 1 22, −35, 68 4.07 28, −31, 70 6.76 28, −31, 70 6.12 2 14, −33, 74 5.12 28, −39, 72 5.6 28, −39, 70 6.29 3 6, −35, 68 7.86 22, −39, 70 5.18 18, −37, 70 6.69 4 14, −33, 75 7.14 — — 20, −34, 68 4.01 5 10, −46, 61 6.03 12, −40, 59 5.65 14, −40, 57 6.2 14, −40, 59 8.26 6 20, −37, 74 5.5 26, −31, 73 5.53 26, −31, 73 8.11 28, −29, 71 8.3 7 10, −41, 70 7.9 12, −40, 65 3.53* 12, −40, 61 4.81 14, −38, 61 7.02 8 6, −37, 74 6.07 32, −41, 70 4.39 34, −39, 70 3.2* 38, −37, 68 3.25* Toe Prepuce Penile shaft Group Center of gravity (x,y,z) t value Center of gravity (x,y,z) t value Center of gravity (x,y,z) t value Region 12, −39, 72 7.38 24, −33, 72 3.43** 24, −35, 68 3.43** SI contralateral 50, −24, 25 11.3 61, −21, 14 8.02 61, −21, 16 5.45 OP1 contralateral 55, 2, 2 5.91 53, 0, 0 7.62 63, −11, 12 3.47** OP4 contralateral −53, −24, 21 5.75 −63, −15, 15 4.77 −63, −22, 34 4.42** OP1 ipsilateral −50, −4, 2 10.83 −55, 6, 2 3.86** −51, −4, 4 5.15 OP4 ipsilateral -
Coordinates indicate the individual local maxima in the x (mediolateral, with positive values indicating right-hemispheric), y (rostrocaudal, with negative values indicating caudal), and z (dorsoventral, with positive values for dorsal) axes in the Talairach space. Individual activations were significant at p < 0.05, corrected for multiple comparisons within the Rolandic template volume (Fig. 1) unless marked otherwise (*p < 0.001, uncorrected). Activations in the group analysis were significant at p < 0.001, uncorrected unless marked otherwise (**p < 0.01, uncorrected). Most of these activations survived thresholds of p < 0.05, corrected for multiple comparisons within the opercular template volume (Fig. 2) on the single-subject level. −, No activation detected.
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