Enteritis necroticans (EN), known as pigbel in Papua New Guinea (PNG), may be the important predisposing lesion to mid-gut volvulus, jejunal and ileal ileus and other forms of small bowel strangulation in communities where protein deprivation, poor food hygiene, epochal meat feasting and staple diets containing trypsin inhibitors co-exist. Such human habitats occur in Africa, Central and South America, western Pacific, Asian and south-east Asian cultures. Isolated outbreaks of necrotizing enteritis have been reported from Uganda, Malaysia and Indonesia but as yet no systematic epidemiological study of the prevalence of small bowel strangulations has been described in the surgical literature of 'third world' countries. Now that enteritis necroticans is preventable by vaccination, such studies should be undertaken. This paper outlines the story of pigbel and its control in PNG.
Cross-sensory correspondences can reflect crosstalk between aligned conceptual feature dimensions, though uncertainty remains regarding the identities of all the dimensions involved. It is unclear, for example, if heaviness contributes to correspondences separately from size. Taking steps to dissociate variations in heaviness from variations in size, the question was asked if a heaviness-brightness correspondence will induce a congruity effect during the speeded brightness classification of simple visual stimuli. Participants classified the stimuli according to whether they were brighter or darker than the mid-gray background against which they appeared. They registered their speeded decisions by manipulating (e.g., tapping) the object they were holding in either their left or right hand (e.g., left for bright, right for dark). With these two otherwise identical objects contrasting in their weight, stimuli were classified more quickly when the relative heaviness of the object needing to be manipulated corresponded with the brightness of the stimulus being classified (e.g., the heavier object for a darker stimulus). This novel congruity effect, in the guise of a stimulus-response (S-R) compatibility effect, was induced when heaviness was isolated as an enduring feature of the object needing to be manipulated. It was also undiminished when participants completed a concurrent verbal memory load task, countering claims that the heaviness-brightness correspondence is verbally mediated. Heaviness, alongside size, appears to contribute to cross-sensory correspondences in its own right and in a manner confirming the far-reaching influence of correspondences, extending here to the fluency with which people communicate simple ideas by manipulating a hand-held object.
Everyday language reveals how stimuli encoded in one sensory feature domain can possess qualities normally associated with a different domain (e.g., higher pitch sounds are bright, light in weight, sharp, and thin). Such cross-sensory associations appear to reflect crosstalk among aligned (corresponding) feature dimensions, including brightness, heaviness, and sharpness. Evidence for heaviness being one such dimension is very limited, with heaviness appearing primarily as a verbal associate of other feature contrasts (e.g., darker objects and lower pitch sounds are heavier than their opposites). Given the presumed bidirectionality of the crosstalk between corresponding dimensions, heaviness should itself induce the cross-sensory associations observed elsewhere, including with brightness and pitch. Taking care to dissociate effects arising from the size and mass of an object, this is confirmed. When hidden objects varying independently in size and mass are lifted, objects that feel heavier are judged to be darker and to make lower pitch sounds than objects feeling less heavy. These judgements track the changes in perceived heaviness induced by the size-weight illusion. The potential involvement of language, natural scene statistics, and Bayesian processes in correspondences, and the effects they induce, is considered.
Amodal (redundant) and arbitrary cross-sensory feature associations involve the context-insensitive mapping of absolute feature values across sensory domains. Cross-sensory associations of a different kind, known as correspondences, involve the context-sensitive mapping of relative feature values. Are such correspondences in place at birth (like amodal associations), or are they learned from subsequently experiencing relevant feature co-occurrences in the world (like arbitrary associations)? To decide between these two possibilities, human newborns (median age = 44 hr) watched animations in which two balls alternately rose and fell together in space. The pitch of an accompanying sound rose and fell either congruently with this visual change (pitch rising and falling as the balls moved up and down), or incongruently (pitch rising and falling as the balls moved down and up). Newborns' looking behavior was sensitive to this congruence, providing the strongest indication to date that cross-sensory correspondences can be in place at birth.