Metallic Taste from Electrical and Chemical Stimulation

Abstract

A series of three experiments investigated the nature of metallic taste reports after stimulation with solutions of metal salts and after stimulation with metals and electric currents. To stimulate with electricity, a device was fabricated consisting of a small battery affixed to a plastic handle with the anode side exposed for placement on the tongue or oral tissues. Intensity of taste from metals and batteries was dependent upon the voltage and was more robust in areas dense in fungiform papillae. Metallic taste was reported from stimulation with ferrous sulfate solutions, from metals and from electric stimuli. However, reports of metallic taste were more frequent when the word 'metallic' was presented embedded in a list of choices, as opposed to simple free-choice labeling. Intensity decreased for ferrous sulfate when the nose was occluded, consistent with a decrease in retronasal smell, as previously reported. Intensity of taste evoked by copper metal, bimetallic stimuli (zinc/copper) or small batteries (1.5-3 V) was not affected by nasal occlusion. This difference suggests two distinct mechanisms for evocation of metallic taste reports, one dependent upon retronasal smell and a second mediated by oral chemoreceptors.

The use of standard electrode potentials to predict the taste of solid metals

“…The results in the present study complement, from a materials science perspective, the 292 work by Lawless et al (2005) by comparing other solid metals (silver, tin, chromium and 293 gold, some of which are used in modern cutlery) to those known to produce metallic tastes 294 directly in the oral cavity (e.g. zinc and copper).…”

Visual task performance in the blind with the BrainPort V100 Vision Aid

“…These events included three reports of metallic taste, one report of a tingling sensation in the mouth, and one report of tongue sensitivity. The metallic taste can be explained by the finding that electrical stimulation can induce metallic sensations [37]. All these adverse events were considered to be mild in severity [19].…”

Selecting and Training a Panel to Evaluate the Metallic Sensation of Meat

“…If this value exceeds the upper -α critical to the Neweel and Macfarlane (1987) table, we can conclude that significant differences exist among the samples. The data showed that the sample cooked formed (Gonzalez et al, 1998;Shiffmann, 2000;Zacarias et al, 2001;Lawless et al, 2005;Hoehl et al, 2010). The results of the study by Hoel et al (2010) indicate that there is a difference in the identification of basic tastes and metallic sensations, and corresponding thresholds depending on the water in which substances are diluted.…”

“…Therefore, investigators should direct attention to water quality, especially when analysis of metallic sensation is important. Deionized or distilled water has been suggested because it ensures constant composition (Lawless et al, 2005). However, the pH of the deionized water is below neutral and therefore generates a bitter taste or metallic sensation (Whelton et al, 2007).…”