Trial by trial dependencies in multisensory perception and their correlates in dynamic brain activity

A well-known effect in multisensory perception is that congruent information received by different senses usually leads to faster and more accurate responses. Less well understood are trial-by-trial interactions, whereby the multisensory composition of stimuli experienced during previous trials shapes performance during a subsequent trial. We here exploit the analogy of multisensory paradigms with classical flanker tasks to investigate the neural correlates underlying trial-by-trial interactions of multisensory congruency. Studying an audio-visual motion task, we demonstrate that congruency benefits for accuracy and reaction times are reduced following an audio-visual incongruent compared to a congruent preceding trial. Using single trial analysis of motion-sensitive EEG components we then localize current-trial and serial interaction effects within distinct brain regions: while the multisensory congruency experienced during the current trial influences the encoding of task-relevant information in sensory-specific brain regions, the serial interaction arises from task-relevant processes within the inferior frontal lobe. These results highlight parallels between multisensory paradigms and classical flanker tasks and demonstrate a role of amodal association cortices in shaping perception based on the history of multisensory congruency

Conserved extended haplotypes of the major histocompatibility complex: further characterization

Since the complete sequencing of a human major histocompatibility complex (MHC) haplotype, interest in non-human leucocyte antigen (HLA) genes encoded in the MHC has been growing. Non-HLA genes, which outnumber the HLA genes, may contribute to or account for HLA and disease associations. Most information on non-HLA genes has been obtained in separate studies of individual loci. To comprehensively address polymorphisms of relevant non-HLA genes in 'conserved extended haplotypes' (CEH), we investigated 101 International Histocompatibility Workshop reference cell lines and nine additional anonymous samples representing all 37 unambiguously characterized CEHs at MICA, NFKBIL1, LTA, NCR3, AIF1, HSPA1A, HSPA1B, BF, NOTCH4 and a single nucleotide polymorphism (SNP) at HLA-DQA1 as well as MICA, NOTCH4, HSPA1B and all five tumour necrosis factor short tandem repeat (STR) polymorphisms. This work (1) provides an extensive catalogue of MHC polymorphisms in all CEHs, (2) unravels interrelationships between HLA and non-HLA haplotypical lineages, (3) resolves reported typing ambiguities and (4) describes haplospecific markers for a number of CEHs. Analysis also identified a DQA1 SNP and segments containing MHC class III polymorphisms that corresponded with class II (DRB3 and DRB4) lineages. These results portray the MHC where lineages containing non-HLA and HLA variants in linkage disequilibrium may operate in concert and can guide more thorough design and interpretation of HLA-disease relationships

Intersensory binding across space and time: A tutorial review

Spatial ventriloquism refers to the phenomenon that a visual stimulus such as a flash can attract the perceived location of a spatially discordant but temporally synchronous sound. An analogous example of mutual attraction between audition and vision has been found in the temporal domain, where temporal aspects of a visual event, such as its onset, frequency, or duration, can be biased by a slightly asynchronous sound. In this review, we examine various manifestations of spatial and temporal attraction between the senses (both direct effects and aftereffects), and we discuss important constraints on the occurrence of these effects. Factors that potentially modulate ventriloquism—such as attention, synesthetic correspondence, and other cognitive factors—are described. We trace theories and models of spatial and temporal ventriloquism, from the traditional unity assumption and modality appropriateness hypothesis to more recent Bayesian and neural network approaches. Finally, we summarize recent evidence probing the underlying neural mechanisms of spatial and temporal ventriloquism. Keywords: Multisensory, Processing, Temporal processing, Spatial localizatio