How does visual language affect crossmodal plasticity and cochlear implant success?

Cochlear implants (CI) are the most successful intervention for ameliorating hearing loss in severely or profoundly deaf children. Despite this, educational performance in children with CI continues to lag behind their hearing peers. From animal models and human neuroimaging studies it has been proposed the integrative functions of auditory cortex are compromised by crossmodal plasticity. This has been argued to result partly from the use of a visual language. Here we argue that 'cochlear implant sensitive periods' comprise both auditory and language sensitive periods, and thus cannot be fully described with animal models. Despite prevailing assumptions, there is no evidence to link the use of a visual language to poorer CI outcome. Crossmodal reorganisation of auditory cortex occurs regardless of compensatory strategies, such as sign language, used by the deaf person. In contrast, language deprivation during early sensitive periods has been repeatedly linked to poor language outcomes. Language sensitive periods have largely been ignored when considering variation in CI outcome, leading to ill-founded recommendations concerning visual language in CI habilitation.

Navigating the auditory scene: an expert role for the hippocampus.

Over a typical career piano tuners spend tens of thousands of hours exploring a specialized acoustic environment. Tuning requires accurate perception and adjustment of beats in two-note chords that serve as a navigational device to move between points in previously learned acoustic scenes. It is a two-stage process that depends on the following: first, selective listening to beats within frequency windows, and, second, the subsequent use of those beats to navigate through a complex soundscape. The neuroanatomical substrates underlying brain specialization for such fundamental organization of sound scenes are unknown. Here, we demonstrate that professional piano tuners are significantly better than controls matched for age and musical ability on a psychophysical task simulating active listening to beats within frequency windows that is based on amplitude modulation rate discrimination. Tuners show a categorical increase in gray matter volume in the right frontal operculum and right superior temporal lobe. Tuners also show a striking enhancement of gray matter volume in the anterior hippocampus, parahippocampal gyrus, and superior temporal gyrus, and an increase in white matter volume in the posterior hippocampus as a function of years of tuning experience. The relationship with gray matter volume is sensitive to years of tuning experience and starting age but not actual age or level of musicality. Our findings support a role for a core set of regions in the hippocampus and superior temporal cortex in skilled exploration of complex sound scenes in which precise sound "templates" are encoded and consolidated into memory over time in an experience-dependent manner.

Avulsion of the gallbladder following trivial injury.

Traumatic cholecystectomy is a rare condition that has always been described in the context of major trauma and associated liver or biliary injuries. We present a case of isolated traumatic cholecystectomy following a trivial injury which resulted in both a delayed presentation and a difficult diagnosis.

The STA2 and MEL1 genes of Saccharomyces cerevisiae are idiomorphic.

The STA2 (glucoamylase) gene of Saccharomyces cerevisiae has been mapped close to the end of the left arm of chromosome II. Meiotic analysis of a cross between a haploid strain containing STA2, and another strain carrying the melibiase gene MEL1 (which is known to be at the end of the left arm of chromosome II) produced parental ditype tetrads only. Since there is no significant DNA sequence similarity between the STA2 and MEL1 genes, or their respective flanking regions, we conclude that these two genes are carried by separate non-hybridizing sequences of chromosomal DNA, either of which can reside at the end of the left arm of chromosome II. By analogy with the mating-type locus of Neurospora crassa, we suggest that the STA2 and MEL1 genes are idiomorphs with respect to one another.