The greater degree to which a persons pupils mirror another predicts a persons greater score on empathy. In disorders such as autism and psychopathy, facial expressions that represent sadness may be subtle, which may show a need for a more non-linguistic situation to affect their level of empathy. Vocal expression
According to DIPR scientist Swati Johar,: VII  sadness is an emotion "identified by current speech dialogue and processing systems". : 12  Measurements to distinguish sadness from other emotions in the human voice include root mean square (RMS) energy, inter-word silence and speaking rate. It is communicated mostly by lowering the mean and variability of the fundamental frequency (f0), besides being associated with lower vocal intensity, and with decreases in f0 over time. Johar argues that, "when someone is sad, slow, low pitched speech with weak high audio frequency energy is produced". Likewise, "low energy state of sadness attributes to slow tempo, lower speech rate and mean pitch". : 10, 13 Sadness is, as stated by Klaus Scherer, one of the "best-recognized emotions in the human voice", although its "generally somewhat lower than that of facial expression". In a study by Scherer, it was found that in Western countries sadness had 79% of accuracy for facial recognition and 71% for vocal, while in Non-Western countries the results were of 74% and 58%, respectively.
Hypertrophic osteoarthropathy is a medical condition combining clubbing and periostitis of the small hand joints, especially the distal interphalangeal joints and the metacarpophalangeal joints. Distal expansion of the long bones as well as painful, swollen joints and synovial villous proliferation are often seen. The condition may occur alone (primary), or it may be secondary to diseases like lung cancer. Among patients with lung cancer, it is most associated with adenocarcinoma and least associated with small cell lung cancer. These patients often get clubbing and increased bone deposition on long bones. Their presenting signs and symptoms are sometimes only clubbing and painful ankles. Cause
Hypertrophic osteoarthropathy is one of many distant effect disorders due to cancer, with lung cancer being the most common cause but also occurring with ovarian or adrenal malignancies. A distant effect disorder, or a paraneoplastic syndrome, affects distant areas and thus is not related to local compression or obstruction effects from the tumor. Other paraneoplastic syndromes include hypercalcemia, SIADH, Cushings syndrome and a variety of neurological disorders. Thought to be due to fibrovascular proliferation caused by accumulation of megakaryocytes in the digital vessels which are normally filtered by the lungs. Diagnosis
People with hypertrophic osteoarthropathy may have bone scans showing parallel lines of activity along the cortex of the shafts and ends of tibiae, femurs and radii; especially around the knees, ankles and wrists. This activity may decrease after treatment of the underlying cause. Treatment
Non-steroidal anti-inflammatory drugs (NSAIDs) can give significant relief of the symptoms.