Seeing the image of a newscaster on a television set causes us to think that the sound coming from the loudspeaker is actually coming from the screen. How images capture sounds is mysterious because the brain uses different methods for determining the locations of visual versus auditory stimuli. The retina senses the locations of visual objects with respect to the eyes, whereas differences in sound characteristics across the ears indicate the locations of sound sources referenced to the head. Here, we tested which reference frame (RF) is used when vision recalibrates perceived sound locations. Visually guided biases in sound localization were induced in seven humans and two monkeys who made eye movements to auditory or audiovisual stimuli. On audiovisual (training) trials, the visual component of the targets was displaced laterally by 5-6°. Interleaved auditory-only (probe) trials served to evaluate the effect of experience with mismatched visual stimuli on auditory localization. We found that the displaced visual stimuli induced ventriloquism aftereffect in both humans (ϳ50% of the displacement size) and monkeys (ϳ25%), but only for locations around the trained spatial region, showing that audiovisual recalibration can be spatially specific. We tested the reference frame in which the recalibration occurs. On probe trials, we varied eye position relative to the head to dissociate head-from eye-centered RFs. Results indicate that both humans and monkeys use a mixture of the two RFs, suggesting that the neural mechanisms involved in ventriloquism occur in brain region(s) using a hybrid RF for encoding spatial information.

Visual calibration of auditory space requires re-alignment of representations differing in (1) format (auditory hemispheric channels vs visual maps) and (2) reference frames (head-centered vs eye-centered). Here, a ventriloquism paradigm from Kopčo, Lin, Shinn-Cunningham, and Groh [J. Neurosci. 29, 13809–13814 (2009)] was used to examine these processes in humans for ventriloquism induced within one spatial hemifield. Results show that (1) the auditory representation can be adapted even by aligned audio-visual stimuli, and (2) the spatial reference frame is primarily head-centered, with a weak eye-centered modulation. These results support the view that the ventriloquism aftereffect is driven by multiple spatially non-uniform, hemisphere-specific processes.

Individuals with autism spectrum disorder often have difficulty acquiring relevant auditory and visual information in daily environments, despite not being diagnosed as hearing impaired or having low vision. Resent psychophysical and neurophysiological studies have shown that autistic individuals have highly specific individual differences at various levels of information processing, including feature extraction, automatic grouping and top-down modulation in auditory and visual scene analysis. Comparison of the characteristics of scene analysis between auditory and visual modalities reveals some essential commonalities, which could provide clues about the underlying neural mechanisms. Further progress in this line of research may suggest effective methods for diagnosing and supporting autistic individuals. This article is part of the themed issue ‘Auditory and visual scene analysis'.

Methanolic extracts from the seagrass Zostera japonica were extracted successively using n-hexane (n-C(6)H(14)), dichloromethane (CH(2)Cl(2)), ethyl acetate (EtOAc), and water to give the n-C(6)H(14) (16.8%), CH(2)Cl(2) (40.6%), EtOAc (34.1%), and H(2)O (8.5%) soluble fractions, respectively. We have demonstrated that the hexane fraction has the highest capacity to inhibit proIL-1beta expression as compared to other fractions in lipopolysaccharides (LPS)-stimulated J774A.1 murine macrophages. Further analysis of the composition and antiinflammatory activity of the subfraction H5 from hexane fraction showed that it had the best antiinflammatory capacity and that it's major constituents were fatty acids, including palmitic acid methyl ester (21.5%), palmitic acid (24.02%), linoleic acid methyl ester (13.09%), oleic acid methyl ester (8.41%), and linoleic acid (7.93%), respectively. H5 inhibited LPS-induced TNFalpha, IL-1beta, and IL-6 in a dose-dependent manner, suggesting that H5 is bioactive in antiinflammation in vitro. This study is the first to report the antiinflammatory activity of extracts obtained from the seagrass Z. japonica.