Multimodal Distribution of Human Cold Pain Thresholds
Fig 3
Distribution of the cold pain thresholds (CPT) observed in n = 329 subjects pooled from previous studies (Table 1).
The graph displays the data after rescaling for stimulus intensity as SI = 32°C - CPT (Fig 1) and subsequent log transformation as LogSI = ln(SI+1). The density distribution is presented as probability density function (PDF), estimated by means of the Pareto Density Estimation (PDE [21]). A Gaussian mixture model (Eq 1; GMM given as ), was fit to the data, for which the optimum number of mixes was found to be M = 3. Subject distribution among the obtained three Gaussians was n = 155, n = 61 and n = 113 for Gaussian 1–3, respectively, starting from the left.