Reorganization of thalamocortical connections in congenitally blind humans.

Cross-modal plasticity in blind individuals has been reported over the past decades showing that nonvisual information is carried and processed by "visual" brain structures. However, despite multiple efforts, the structural underpinnings of cross-modal plasticity in congenitally blind individuals remain unclear. We mapped thalamocortical connectivity and assessed the integrity of white matter of 10 congenitally blind individuals and 10 sighted controls. We hypothesized an aberrant thalamocortical pattern of connectivity taking place in the absence of visual stimuli from birth as a potential mechanism of cross-modal plasticity. In addition to the impaired microstructure of visual white matter bundles, we observed structural connectivity changes between the thalamus and occipital and temporal cortices. Specifically, the thalamic territory dedicated to connections with the occipital cortex was smaller and displayed weaker connectivity in congenitally blind individuals, whereas those connecting with the temporal cortex showed greater volume and increased connectivity. The abnormal pattern of thalamocortical connectivity included the lateral and medial geniculate nuclei and the pulvinar nucleus. For the first time in humans, a remapping of structural thalamocortical connections involving both unimodal and multimodal thalamic nuclei has been demonstrated, shedding light on the possible mechanisms of cross-modal plasticity in humans. The present findings may help understand the functional adaptations commonly observed in congenitally blind individuals.

Honey bees respond to multimodal stimuli following the principle of inverse effectiveness.

Multisensory integration is assumed to entail benefits for receivers across multiple ecological contexts. However, signal integration effectiveness is constrained by features of the spatiotemporal and intensity domains. How sensory modalities are integrated during tasks facilitated by learning and memory, such as pollination, remains unsolved. Honey bees use olfactory and visual cues during foraging, making them a good model to study the use of multimodal signals. Here, we examined the effect of stimulus intensity on both learning and memory performance of bees trained using unimodal or bimodal stimuli. We measured the performance and the latency response across planned discrete levels of stimulus intensity. We employed the conditioning of the proboscis extension response protocol in honey bees using an electromechanical setup allowing us to control simultaneously and precisely olfactory and visual stimuli at different intensities. Our results show that the bimodal enhancement during learning and memory was higher as the intensity decreased when the separate individual components were least effective. Still, this effect was not detectable for the latency of response. Remarkably, these results support the principle of inverse effectiveness, traditionally studied in vertebrates, predicting that multisensory stimuli are more effectively integrated when the best unisensory response is relatively weak. Thus, we argue that the performance of the bees while using a bimodal stimulus depends on the interaction and intensity of its individual components. We further hold that the inclusion of findings across all levels of analysis enriches the traditional understanding of the mechanics and reliance of complex signals in honey bees.

Development of tropical mixed juice with low added-sugar content: Sensory and nutritional aspects.

The aim of the present study was to develop a mixed tropical fruit juice of cashew apple, acerola and melon with low added-sugar content considering sensory and nutritional aspects. Five formulations were developed varying the concentration of the different fruits. A total of 172 consumers rated their overall liking using a 9-point hedonic scale and described their sensory characteristics using a Check-all-that-apply question. In addition, the functional properties of the juices were evaluated by analyzing vitamin C, total phenolic compounds and antioxidant capacity. Results showed that the addition of sugar and fruit composition affected the sensory characteristics and consumer liking of the formulations. Samples without added sugar and with higher melon concentration showed lower liking scores (p < 0.05). In addition, the highest concentration of acerola had a positive effect on nutritional characteristics. The formulation with 50% of fruit pulp (60% of cashew apple, 30% of acerola and 10% of melon), 47% of water, and 3% of added sugar achieved the best results. The effect of aroma on sweetness perception was investigated by adding identical to natural aromas of melon, apple and pineapple to the selected formulation. However, aroma did not significantly modify sweetness perception, evaluated using a rate-all-that-apply question.

Blending Emotions and Cross-Modality in Sonic Seasoning: Towards Greater Applicability in the Design of Multisensory Food Experiences.

Sonic seasoning refers to the way in which music can influence multisensory tasting experiences. To date, the majority of the research on sonic seasoning has been conducted in Europe or the USA, typically in a within-participants experimental context. In the present study, we assessed the applicability of sonic seasoning in a large-scale between-participants setting in Asia. A sample of 1611 participants tasted one sample of chocolate while listening to a song that evoked a specific combination of cross-modal and emotional consequences. The results revealed that the music's emotional character had a more prominent effect than its cross-modally corresponding attributes on the multisensory tasting experience. Participants expressed a higher buying intention for the chocolate and rated it as having a softer texture when listening to mainly positive (as compared to mainly negative) music. The chocolates were rated as having a more intense flavor amongst those participants listening to 'softer' as compared to 'harder' music. Therefore, the present study demonstrates that music is capable of triggering a combination of specific cross-modal and emotional effects in the multisensory tasting experience of a chocolate.

Electrophysiological Dynamics of Visual Speech Processing and the Role of Orofacial Effectors for Cross-Modal Predictions.

The human brain generates predictions about future events. During face-to-face conversations, visemic information is used to predict upcoming auditory input. Recent studies suggest that the speech motor system plays a role in these cross-modal predictions, however, usually only audio-visual paradigms are employed. Here we tested whether speech sounds can be predicted on the basis of visemic information only, and to what extent interfering with orofacial articulatory effectors can affect these predictions. We registered EEG and employed N400 as an index of such predictions. Our results show that N400's amplitude was strongly modulated by visemic salience, coherent with cross-modal speech predictions. Additionally, N400 ceased to be evoked when syllables' visemes were presented backwards, suggesting that predictions occur only when the observed viseme matched an existing articuleme in the observer's speech motor system (i.e., the articulatory neural sequence required to produce a particular phoneme/viseme). Importantly, we found that interfering with the motor articulatory system strongly disrupted cross-modal predictions. We also observed a late P1000 that was evoked only for syllable-related visual stimuli, but whose amplitude was not modulated by interfering with the motor system. The present study provides further evidence of the importance of the speech production system for speech sounds predictions based on visemic information at the pre-lexical level. The implications of these results are discussed in the context of a hypothesized trimodal repertoire for speech, in which speech perception is conceived as a highly interactive process that involves not only your ears but also your eyes, lips and tongue.

Cross-modal correspondences in sine wave: Speech versus non-speech modes.

The present study aimed to investigate whether or not the so-called "bouba-kiki" effect is mediated by speech-specific representations. Sine-wave versions of naturally produced pseudowords were used as auditory stimuli in an implicit association task (IAT) and an explicit cross-modal matching (CMM) task to examine cross-modal shape-sound correspondences. A group of participants trained to hear the sine-wave stimuli as speech was compared to a group that heard them as non-speech sounds. Sound-shape correspondence effects were observed in both groups and tasks, indicating that speech-specific processing is not fundamental to the "bouba-kiki" phenomenon. Effects were similar across groups in the IAT, while in the CMM task the speech-mode group showed a stronger effect compared with the non-speech group. This indicates that, while both tasks reflect auditory-visual associations, only the CMM task is additionally sensitive to associations involving speech-specific representations.

Non-visual exploration of novel objects increases the levels of plasticity factors in the rat primary visual cortex.

BACKGROUND: Historically, the primary sensory areas of the cerebral cortex have been exclusively associated with the processing of a single sensory modality. Yet the presence of tactile responses in the primary visual (V1) cortex has challenged this view, leading to the notion that primary sensory areas engage in cross-modal processing, and that the associated circuitry is modifiable by such activity. To explore this notion, here we assessed whether the exploration of novel objects in the dark induces the activation of plasticity markers in the V1 cortex of rats. METHODS: Adult rats were allowed to freely explore for 20 min a completely dark box with four novel objects of different shapes and textures. Animals were euthanized either 1 (n = 5) or 3 h (n = 5) after exploration. A control group (n = 5) was placed for 20 min in the same environment, but without the objects. Frontal sections of the brains were submitted to immunohistochemistry to measure protein levels of egr-1 and c-fos, and phosphorylated calcium-dependent kinase (pCaKMII) in V1 cortex. RESULTS: The amount of neurons labeled with monoclonal antibodies against c-fos, egr-1 or pCaKMII increased significantly in V1 cortex after one hour of exploration in the dark. Three hours after exploration, the number of labeled neurons decreased to basal levels. CONCLUSIONS: Our results suggest that non-visual exploration induces the activation of immediate-early genes in V1 cortex, which is suggestive of cross-modal processing in this area. Besides, the increase in the number of neurons labeled with pCaKMII may signal a condition promoting synaptic plasticity.

Relationship Between Auditory Context and Visual Distance Perception: Effect of Musical Expertise in the Ability to Translate Reverberation Cues Into Room-Size Perception.

In a recently published work by our group [ Scientific Reports, 7, 7189 (2017)], we performed experiments of visual distance perception in two dark rooms with extremely different reverberation times: one anechoic ( T ∼ 0.12 s) and the other reverberant ( T ∼ 4 s). The perceived distance of the targets was systematically greater in the reverberant room when contrasted to the anechoic chamber. Participants also provided auditorily perceived room-size ratings which were greater for the reverberant room. Our hypothesis was that distance estimates are affected by room size, resulting in farther responses for the room perceived larger. Of much importance to the task was the subjects' ability to infer room size from reverberation. In this article, we report a postanalysis showing that participants having musical expertise were better able to extract and translate reverberation cues into room-size information than nonmusicians. However, the degree to which musical expertise affects visual distance estimates remains unclear.

Direct-location versus verbal report methods for measuring auditory distance perception in the far field.

In this study we evaluated whether a method of direct location is an appropriate response method for measuring auditory distance perception of far-field sound sources. We designed an experimental set-up that allows participants to indicate the distance at which they perceive the sound source by moving a visual marker. We termed this method Cross-Modal Direct Location (CMDL) since the response procedure involves the visual modality while the stimulus is presented through the auditory modality. Three experiments were conducted with sound sources located from 1 to 6 m. The first one compared the perceived distances obtained using either the CMDL device or verbal report (VR), which is the response method more frequently used for reporting auditory distance in the far field, and found differences on response compression and bias. In Experiment 2, participants reported visual distance estimates to the visual marker that were found highly accurate. Then, we asked the same group of participants to report VR estimates of auditory distance and found that the spatial visual information, obtained from the previous task, did not influence their reports. Finally, Experiment 3 compared the same responses that Experiment 1 but interleaving the methods, showing a weak, but complex, mutual influence. However, the estimates obtained with each method remained statistically different. Our results show that the auditory distance psychophysical functions obtained with the CMDL method are less susceptible to previously reported underestimation for distances over 2 m.

The strength of weak embodiment.

While popular within some cognitive science approaches, the embodiment approach has still found resistance, particularly in light of evidence arguing against strong forms of embodiment. Among other things, the embodiment approach breaks away from the Cartesian ontology of the modulatory system. We claim that the advantages of the embodiment approach are: a) it grounds cognition into modal experience, b) it is harmonious with a materialist philosophy of mind (emergent materialism), and c) it is supported by experimental research in various fields. However, embodiment must still address abstractions, theoretical misunderstandings (representations vs non-representations) and neuroscientific findings that challenge the extension and relevance of sensorimotor properties into cognitive processes. While the strong version of embodiment is seriously challenged by conceptual and physiological setbacks, its weak version is supported by compelling evidence. We suggest future research focus on the psychophysiological bases of grounded cognition and redirect efforts towards the field of cross-modal correspondence.

La teoría de la cognición corporeizada se separa de una ontología cartesiana basada en el sistema modular. Las ventajas del enfoque de la corporeización son: a) enraiza la cognición en la experiencia modal, b) está en armonía con una filosofía materialista de la mente (materialismo emergente), y c) está respaldada por la investigación experimental en varios campos. Sin embargo, la corporeización todavía debe dar cuenta de las abstracciones, los malentendidos teóricos (representación vs. no representación) y los hallazgos neurocientíficos que desafían la relevancia de las propiedades sensoriomotoras en los procesos cognitivos. Mientras que la versión fuerte de la corporeización se ve seriamente desafiada por los retos conceptuales y fisiológicos, su versión débil es respaldada por evidencia convincente. Sugerimos que la investigación futura se centre en las bases psicofisiológicas de la cognición corporeizada y redirija los esfuerzos hacia el campo de la correspondencia intermodal.

Dogs recognize dog and human emotions.

The perception of emotional expressions allows animals to evaluate the social intentions and motivations of each other. This usually takes place within species; however, in the case of domestic dogs, it might be advantageous to recognize the emotions of humans as well as other dogs. In this sense, the combination of visual and auditory cues to categorize others' emotions facilitates the information processing and indicates high-level cognitive representations. Using a cross-modal preferential looking paradigm, we presented dogs with either human or dog faces with different emotional valences (happy/playful versus angry/aggressive) paired with a single vocalization from the same individual with either a positive or negative valence or Brownian noise. Dogs looked significantly longer at the face whose expression was congruent to the valence of vocalization, for both conspecifics and heterospecifics, an ability previously known only in humans. These results demonstrate that dogs can extract and integrate bimodal sensory emotional information, and discriminate between positive and negative emotions from both humans and dogs.

Synesthesia and music perception / Sinestesia e percepção musical

The present review examined the cross-modal association of sensations and their relationship to musical perception. Initially, the study focuses on synesthesia, its definition, incidence, forms, and genetic and developmentalfactors. The theories of the neural basis of synesthesia were also addressed by comparing theories emphasizing the anatomical aspect against others reinforcing the importance of physiological processes. Secondly, cross-modal sensory associations, their role in perception, and relationship to synesthesia were analyzed. We propose the existence of a lower, unconscious degree of synesthesia in non-synesthetes. This latent synesthesia (without explicit sensory manifestations) would be functional, aiding the construction of abstract associations between different perceptual s. Musical meaningmight be constructed largely by synesthetic processes, where the sensory associations from sound activate memories, images, and emotions.

No presente trabalho de revisão, investigamos o cruzamento de sensações e sua relação com a percepção musical. Inicialmente, nos debruçamos sobre o estudos da sinestesia, sua definição, incidência, formas, fatores genéticos e de desenvolvimento. Abordamos ainda as teorias sobre as bases neurais da sinestesia, comparando teorias que enfatizam os aspectos anatômicos a outras que reforçam a importância de processos fisiológicos. Numa segunda seção tratamos dos cruzamentos de modos sensoriais, seu papel na percepção e sua relação com a sinestesia. Cogitamos haver um grau desinestesia mais baixo e inconsciente em não sinestetas, esta sinestesia latente (sem manifestações sensoriais explícitas) seria funcional, auxiliando na construção de associações abstratas entre campos perceptivos diferentes. A significação musical talvez seja construída, em grande parte, por processos sinestésicos, em que as associações sensoriais a partir do sonoro ativam memórias, imagens e emoções.

Sugar reduction in probiotic chocolate-flavored milk: Impact on dynamic sensory profile and liking.

Reducing the sugar content of processed products has been claimed to be one of the most efficient strategies for decreasing sugar intake. The present work aimed at studying the influence of sugar reduction on the dynamic sensory profile and consumers' liking of probiotic chocolate-flavored milks using a novel temporal methodology, and to evaluate two alternatives (vanilla flavor and thaumatin) to attenuate the sensory changes caused by sugar reduction. Probiotic chocolate-flavored milks were formulated with different reductions in added sugar (0, 20, 40 and 60%). Vanilla flavor and thaumatin were added to the sugar-reduced samples at two concentrations. Samples were evaluated by trained assessors using Temporal check-all-that-apply (TCATA). Additionally, consumers evaluated the dynamic sensory profile of a subset of the samples using TCATA and indicated their overall liking using a 9-point hedonic scale. Results from the present work showed that the main effect of sugar reduction on the dynamic sensory profile of the probiotic chocolate-flavored milks was related to changes in sweetness, bitterness and thickness. A reduction in added sugar of 20% led to changes in sweetness intensity, which were perceived by both trained assessors and consumers. However, consumers' liking was not significantly affected by sugar reduction up to 40%. The addition of vanilla flavor at suprathreshold concentrations was not efficient in increasing sweetness perception in chocolate-flavored milks with the lowest sugar reduction percentage, suggesting that it may not be a feasible alternative for reducing sugar in this product category. These results suggest that in many situations sugar content of food products could be decreased without a relevant impact on consumers' sensory and hedonic perception.

Synesthesia and music perception.

The present review examined the cross-modal association of sensations and their relationship to musical perception. Initially, the study focuses on synesthesia, its definition, incidence, forms, and genetic and developmental factors. The theories of the neural basis of synesthesia were also addressed by comparing theories emphasizing the anatomical aspect against others reinforcing the importance of physiological processes. Secondly, cross-modal sensory associations, their role in perception, and relationship to synesthesia were analyzed. We propose the existence of a lower, unconscious degree of synesthesia in non-synesthetes. This latent synesthesia (without explicit sensory manifestations) would be functional, aiding the construction of abstract associations between different perceptual fields. Musical meaning might be constructed largely by synesthetic processes, where the sensory associations from sound activate memories, images, and emotions.

No presente trabalho de revisão, investigamos o cruzamento de sensações e sua relação com a percepção musical. Inicialmente, nos debruçamos sobre o estudos da sinestesia, sua definição, incidência, formas, fatores genéticos e de desenvolvimento. Abordamos ainda as teorias sobre as bases neurais da sinestesia, comparando teorias que enfatizam os aspectos anatômicos a outras que reforçam a importância de processos fisiológicos. Numa segunda seção tratamos dos cruzamentos de modos sensoriais, seu papel na percepção e sua relação com a sinestesia. Cogitamos haver um grau de sinestesia mais baixo e inconsciente em não sinestetas, esta sinestesia latente (sem manifestações sensoriais explícitas) seria funcional, auxiliando na construção de associações abstratas entre campos perceptivos diferentes. A significação musical talvez seja construída, em grande parte, por processos sinestésicos, em que as associações sensoriais a partir do sonoro ativam memórias, imagens e emoções.

Connectional subdivision of the claustrum: two visuotopic subdivisions in the macaque.

The claustrum is a surprisingly large, sheet-like neuronal structure hidden beneath the inner surface of the neocortex. We found that the portions of the claustrum connected with V4 appear to overlap considerably with those portions connected with other cortical visual areas, including V1, V2, MT, MST and FST, TEO and TE. We found extensive reciprocal connections between V4 and the ventral portion of the claustrum (vCl), which extended through at least half of the rostrocaudal extent of the structure. Additionally, in approximately 75% of the cases, we found reciprocal connections between V4 and a more restricted region located farther dorsal, near the middle of the structure (mCl). Both vCl and mCl appear to have at least a crude topographic organization. Based on the projection of these claustrum subdivisions to the amygdala, we propose that vCl and mCl are gateways for the transmission of visual information to the memory system. In addition to these crude visuotopically organized regions, there are other parts of the claustrum that obey the topographical proximity principle, with considerable overlap of their connections. There is only an overall segregation of claustrum regions reciprocally connected to the occipital, parietal, temporal and frontal lobes. The portion of the claustrum connected to the visual cortex is located ventral and posterior; the one connected to the auditory cortex is located dorsal and posterior; the one connected to the somatosensory cortex is located dorsal and medial; the one connected to the frontal premotor and motor cortices is located dorsal and anterior; while the one connected to the temporal cortex is located ventral and anterior. The extensive reciprocal connections of the claustrum with almost the entire neocortex and its projections to the hippocampus, amygdala and basal ganglia prompt us to propose its role as a gateway for perceptual information to the memory system.

Reconhecimento de emoções em cães domésticos (Canis familiaris): percepção de pistas faciais e auditivas na comunicação intra e interespecífica / Emotion recognition in domestic dogs (Canis familiaris): perception of facial and auditory cues in intra and interspecific communication

Cães domésticos (Canis familiaris) são animais sociais que apresentam uma série de habilidades cognitivas para interagir com outros cães e com pessoas. Apesar de muitos estudos com cães terem investigado o uso de pistas comunicativas, a sensibilidade a estados de atenção, a capacidade de discriminação de faces e de vocalizações e até o processamento de expressões faciais, ainda não existem evidências de que esses animais são capazes de obter e utilizar simultaneamente informações emocionais de expressões faciais e auditivas. O reconhecimento de estados emocionais pode ser entendido como uma característica adaptativa, uma vez que possui um papel muito importante no contexto social e pode ser crucial para o estabelecimento e manutenção de relacionamentos em longo prazo. Interessados em investigar as habilidades de leitura e compreensão de emoções, utilizamos um paradigma de preferência de olhar para testar cães de família de várias raças em sua habilidade de reconhecer emoções de maneira cross-modal. Analisamos o comportamento visual espontâneo dos sujeitos frente a dois estímulos visuais (mesmo indivíduo, expressão facial diferente) e um som (vocalização) congruente a uma das duas imagens. Utilizamos estímulos caninos e humanos, de fêmeas e machos, com valência positiva e negativa, apresentados do lado esquerdo e do lado direito, e avaliamos seus possíveis efeitos sobre o desempenho dos animais. A variável utilizada para as análises foi o índice de congruência: a proporção de tempo de olhar para a imagem congruente em relação ao tempo total de olhar para as telas. Os cães demonstraram ser capazes de associar informações das faces (fotografias) e das vocalizações (playbacks) e integrá-las em uma única representação mental, independente da espécie, do sexo, da valência e do lado de apresentação do estímulo.(AU)

Domestic dogs (Canis familiaris) are social animals that show a series of cognitive abilities to interact with other dogs and people. Although many studies have investigated the use of communicative cues, the sensitivity to attentional states, the capacity of discriminating faces and vocalizations and even the processing involved in facial expressions exploration, there are no evidences that these animals are capable of obtaining and using emotional information from facial and auditory expressions. The recognition of emotional states may be understood as an adaptive feature, since it plays a very important role in social context and might be crucial to the establishment and maintenance of long term relationship. Interested in investigating the abilities of reading and understanding emotions, we used a preferential looking paradigm to test family dogs of various breeds for their ability to cross-modally recognize emotions. We analysed the spontaneous looking behaviour of subjects when facing two visual stimuli (same individual, different facial expression) and hearing a sound (vocalization) which was congruent to one of the images. We used dogs and humans, females and males, positive valence and negative valence and left-presented and right-presented stimuli to assess their possible effects on the animals performance. The variable used for the analysis was congruence index: the proportion of time looking at the congruent images over the total looking time to the screens. Dogs demonstrated being capable of associating information from faces (photographs) and vocalizations (playbacks) and integrating them in a single mental representation, independent of species, sex, valence or side of stimulus presentation.(AU)

Music-color associations are mediated by emotion.

Experimental evidence demonstrates robust cross-modal matches between music and colors that are mediated by emotional associations. US and Mexican participants chose colors that were most/least consistent with 18 selections of classical orchestral music by Bach, Mozart, and Brahms. In both cultures, faster music in the major mode produced color choices that were more saturated, lighter, and yellower whereas slower, minor music produced the opposite pattern (choices that were desaturated, darker, and bluer). There were strong correlations (0.89 < r < 0.99) between the emotional associations of the music and those of the colors chosen to go with the music, supporting an emotional mediation hypothesis in both cultures. Additional experiments showed similarly robust cross-modal matches from emotionally expressive faces to colors and from music to emotionally expressive faces. These results provide further support that music-to-color associations are mediated by common emotional associations.

A composition algorithm based on crossmodal taste-music correspondences.

While there is broad consensus about the structural similarities between language and music, comparably less attention has been devoted to semantic correspondences between these two ubiquitous manifestations of human culture. We have investigated the relations between music and a narrow and bounded domain of semantics: the words and concepts referring to taste sensations. In a recent work, we found that taste words were consistently mapped to musical parameters. Bitter is associated with low-pitched and continuous music (legato), salty is characterized by silences between notes (staccato), sour is high pitched, dissonant and fast and sweet is consonant, slow and soft (Mesz et al., 2011). Here we extended these ideas, in a synergistic dialog between music and science, investigating whether music can be algorithmically generated from taste-words. We developed and implemented an algorithm that exploits a large corpus of classic and popular songs. New musical pieces were produced by choosing fragments from the corpus and modifying them to minimize their distance to the region in musical space that characterizes each taste. In order to test the capability of the produced music to elicit significant associations with the different tastes, musical pieces were produced and judged by a group of non-musicians. Results showed that participants could decode well above chance the taste-word of the composition. We also discuss how our findings can be expressed in a performance bridging music and cognitive science.