Fig. 5: Numerosity-selective responses are modality-specific.
a Neural responses driven by visual and haptic numerosity stimuli largely overlap. Colors in each data point represent which type of sensory input produced numerosity-selective neural response (as captured by the pRF model with variance explained >30%). b Maps of preferred visual numerosities with the outlines of the visual and haptic numerosity maps shown in blue and black/white lines respectively. The topographic numerosity maps of the two modalities only partially overlap. c Percentage of overlap between the visual and haptic numerosity maps relative to the map sizes averaged across participants, hemispheres, and modalities (i.e., visual and haptic numerosity maps). Error bars show the standard deviation of the mean. n indicates the number of maps that were averaged together. d No systematic relationship between the two modalities was found between participants or maps. A box-plot diagram shows the distribution of correlation coefficient values (r) that were obtained from the analyses of correlation between the two haptic stimulus configurations, the visual test–retest and the correlation between preferred haptic and visual numerosities in their shared areas (right). Stars show significant differences between groups in post hoc test for multiple comparisons (Bonferroni correction; * indicates padj = 2 × 10−5; ** indicates padj = 1.9 × 10−9). The average of the correlation coefficients of each part of the data was significantly higher than zero (one-sample t test: two haptic stimulus configurations: t(61) = 14, p = 9.8 × 10−21; visual test–retest: t(63) = 9.75, p = 3.2 × 10−14; haptic and visual: t(50) = 3.18, p = 0.0025). In the box-plot diagram, the central mark indicates the median, and the bottom and top edges of the box indicate the 25th and 75th percentiles, respectively. The whiskers extend to the most extreme data points not considered outliers, and the outliers are plotted individually using the “+” symbol. n indicates the number of maps that were grouped together.
