The Subjective Visual Vertical and the Subjective Haptic Vertical Access Different Gravity Estimates

The subjective visual vertical (SVV) and the subjective haptic vertical (SHV) both claim to probe the underlying perception of gravity. However, when the body is roll tilted these two measures evoke different patterns of errors with SVV generally becoming biased towards the body (A-effect, named for its discoverer, Hermann Rudolph Aubert) and SHV remaining accurate or becoming biased away from the body (E-effect, short for Entgegengesetzt-effect, meaning “opposite”, i.e., opposite to the A-effect). We compared the two methods in a series of five experiments and provide evidence that the two measures access two different but related estimates of gravitational vertical. Experiment 1 compared SVV and SHV across three levels of whole-body tilt and found that SVV showed an A-effect at larger tilts while SHV was accurate. Experiment 2 found that tilting either the head or the trunk independently produced an A-effect in SVV while SHV remained accurate when the head was tilted on an upright body but showed an A-effect when the body was tilted below an upright head. Experiment 3 repeated these head/body configurations in the presence of vestibular noise induced by using disruptive galvanic vestibular stimulation (dGVS). dGVS abolished both SVV and SHV A-effects while evoking a massive E-effect in the SHV head tilt condition. Experiments 4 and 5 show that SVV and SHV do not combine in an optimally statistical fashion, but when vibration is applied to the dorsal neck muscles, integration becomes optimal. Overall our results suggest that SVV and SHV access distinct underlying gravity percepts based primarily on head and body position information respectively, consistent with a model proposed by Clemens and colleagues.     

Pulmonary blastomycosis masquerading as metastatic disease in the lung: a case report

We report a case of pulmonary blastomycosis appearing as metastatic laryngeal squamous cell carcinoma. Pulmonary blastomycosis was discovered as right lower lobe subpleural activity consistent with metastatic disease on a positron emission tomographic (PET) scan following total laryngectomy and bilateral neck dissection for locally invasive laryngeal squamous cell carcinoma. A computed tomographic (CT) scan of the chest showed a right lower lobe, subpleural pulmonary nodule. CT-guided fine-needle aspiration of the nodule revealed broad-based budding yeast consistent with blastomycosis. To our knowledge, this is the first case of a PET-positive pulmonary blastomycosis lesion mimicking pulmonary malignancy reported in the literature.