Semantically Congruent Bimodal Presentation with Divided-Modality Attention Accelerates Unisensory Working Memory Retrieval

Although previous studies have shown that semantic multisensory integration can be differentially modulated by attention focus, it remains unclear whether attentionally mediated multisensory perceptual facilitation could impact further cognitive performance. Using a delayed matching-to-sample paradigm, the present study investigated the effect of semantically congruent bimodal presentation on subsequent unisensory working memory (WM) performance by manipulating attention focus. The results showed that unisensory WM retrieval was faster in the semantically congruent condition than in the incongruent multisensory encoding condition. However, such a result was only found in the divided-modality attention condition. This result indicates that a robust multisensory representation was constructed during semantically congruent multisensory encoding with divided-modality attention; this representation then accelerated unisensory WM performance, especially auditory WM retrieval. Additionally, an overall faster unisensory WM retrieval was observed under the modality-specific selective attention condition compared with the divided-modality condition, indicating that the division of attention to address two modalities demanded more central executive resources to encode and integrate crossmodal information and to maintain a constructed multisensory representation, leaving few resources for WM retrieval. Additionally, the present finding may support the amodal view that WM has an amodal central storage component that is used to maintain modal-based attention-optimized multisensory representations.

Peripersonal and reaching space differ: Evidence from their spatial extent and multisensory facilitation pattern

Peripersonal space (PPS) is a multisensory representation of the space near body parts facilitating interactions with the close environment. Studies on non-human and human primates agree in showing that PPS is a body part-centered representation that guides actions. Because of these characteristics, growing confusion surrounds peripersonal and arm-reaching space (ARS), that is the space one’s arm can reach. Despite neuroanatomical evidence favoring their distinction, no study has contrasted directly their respective extent and behavioral features. Here, in five experiments (N = 140) we found that PPS differs from ARS, as evidenced both by participants’ spatial and temporal performance and by its modeling. We mapped PPS and ARS using both their respective gold standard tasks and a novel multisensory facilitation paradigm. Results show that: (1) PPS is smaller than ARS; (2) multivariate analyses of spatial patterns of multisensory facilitation predict participants’ hand locations within ARS; and (3) the multisensory facilitation map shifts isomorphically following hand positions, revealing hand-centered coding of PPS, therefore pointing to a functional similarity to the receptive fields of monkeys’ multisensory neurons. A control experiment further corroborated these results and additionally ruled out the orienting of attention as the driving mechanism for the increased multisensory facilitation near the hand. In sharp contrast, ARS mapping results in a larger spatial extent, with undistinguishable patterns across hand positions, cross-validating the conclusion that PPS and ARS are distinct spatial representations. These findings show a need for refinement of theoretical models of PPS, which is relevant to constructs as diverse as self-representation, social interpersonal distance, and motor control.

Multisensory Configural Learning of a Home Refuge in the Whip Spider Phrynus marginemaculatus

ABSTRACTWhip spiders (Amblypygi) reside in structurally complex habitats and are nocturnally active yet display notable navigational abilities. From the theory that uncertainty in sensory inputs should promote multisensory representations to guide behavior, we hypothesized that their navigation is supported by a configural, multisensory representation of navigational inputs, an ability documented in a few insects and never reported in arachnids. We trained Phrynus marginemaculatus to recognize a home shelter characterized by both discriminative olfactory and tactile stimuli. In tests, subjects readily discriminated between shelters based on the paired stimuli. However, subjects failed to recognize the shelter in tests with either of the component stimuli alone. This result is consistent with the hypothesis that the terminal phase of their navigational behavior, shelter recognition, can be supported by the integration of multisensory stimuli as a configural representation. We hypothesize that multisensory configural learning occurs in the whip spiders’ extraordinarily large mushroom bodies, which may functionally resemble the hippocampus of vertebrates.

Desenvolvimento e evidências de validade da Bateria de Autoconsciência Corporal e Saúde Ergonômica para Músicos/Development and validity evidence of a Battery of Evaluation of Body Self-awareness and Ergonomic Health in Musicians

Introdução: Considerando evidências de estudos anteriores que indicam uma relação entre a representação multisensorial do corpo e a percepção da dor, sugere-se que a autoconsciência corporal seja uma variável relevante na avaliação da saúde desses indivíduos. Objetivo: desenvolver e levantar evidências de validade de uma bateria de escalas psicométricas que avaliam a autoconsciência corporal relacionada aos aspectos ergonômicos e saúde da atividade musical. Método: 415 estudantes universitários de música participaram da pesquisa. A partir de um estudo transversal com delineamento de survey foram levantadas evidências da validade do tipo conceitual, dos itens e construto. Resultados: a versão final da bateria apresenta três escalas: 1) Escala de Autoconsciência Corporal de Músicos; 2) Escala de Autopercepção de Dor e Performance e; 3) Escala de Aspectos Preventivos. Aspectos relacionados à teorização do construto autoconsciência corporal com foco nas possibilidades de avaliação dos fatores psicossociais, associados à prevenção da dor são discutidos. Conclusão: a estruturação das três escalas desenvolvidas fornecem evidências de que os aspectos ergonômicos em saúde do músico, incluindo as dimensões física, cognitiva e organizacional devem fazer parte de medidas psicométricas destinadas às avaliações clínicas dessa população. Abstract Introduction: Considering the evidence of the relationship between the multisensory representation of the body and the perception of pain, it is suggested that body self-consciousness is a relevant variable in the evaluation of the health of musicians. Objective: to develop and to raise evidences of the conceptual, item and construct validity of a psychometric scale that evaluates the body self-consciousness and the ergonomic / health aspects of the musicians. Method: A crosssectional quantitative study with a survey design for the development of a psychometric instrument. 415 university students of music participated. The data were analyzed with the aid of the Statistical Package for the Social Sciences, R software and by factor analysis. Results: the final version of the instrument presents three scales: 1) Body Self-Awereness Scale of Musicians; 2) Self-perception of Pain and Performance Scale; 3) Scale of Preventive Aspects. The structuring of the three scales reinforces the hypothesis that the ergonomic aspects of the musician's health, including the physical, cognitive and organizational dimensions, should be part of the psychometric measures for this occupational task. Conclusion: the Body Self-Consciousness and Musician's Health Battery proved to be a suitable psychometric measure for the clinical evaluation of this population. Keywords: ergonomics; body self-consciousness; musculoskeletal pain; health of the musician.

Maternal brain gain: enlarged representation of the peripersonal space in pregnancy

Our ability to maintain a coherent bodily self despite continuous changes within and outside our body relies on the highly flexible multisensory representation of the body, and of the space surrounding it: the peripersonal space (PPS). The aim of our study was to investigate whether during pregnancy - when extremely rapid changes in body size and shape occur - a likewise rapid plastic reorganization of the neural representation of the PPS occurs. We used an audio-tactile integration task to measure the PPS boundary at different stages of pregnancy. We found that in the second trimester of pregnancy and postpartum women did not show differences in their PPS size as compared to the control group (non-pregnant women). However, in the third trimester the PPS was larger than the controls' PPS and the shift between representation of near and far space was more gradual. We therefore conclude that during pregnancy the brain adapts to the sudden bodily changes, by expanding the representation of the space around the body. This may represent a mechanism to protect the vulnerable abdomen from injury from surrounding objects.