Amygdala response to emotional stimuli without awareness: Facts and interpretations

Over the past two decades, evidence has accumulated that the human amygdala exerts some of its functions also when the observer is not aware of the content, or even presence, of the triggering emotional stimulus. Nevertheless, there is as of yet no consensus on the limits and conditions that affect the extent of amygdala\u2019s response without focused attention or awareness. Here we review past and recent studies on this subject, examining neuroimaging literature on healthy participants as well as brain damaged patients, and we comment on their strengths and limits. We propose a theoretical distinction between processes involved in attentional unawareness, wherein the stimulus is potentially accessible to enter visual awareness but fails to do so because attention is diverted, and in sensory unawareness, wherein the stimulus fails to enter awareness because its normal processing in the visual cortex is suppressed. We argue this distinction, along with data sampling amygdala responses with high temporal resolution, helps to appreciate the multiplicity of functional and anatomical mechanisms centered on the amygdala and supporting its role in non-conscious emotion processing. Separate, but interacting, networks relay visual information to the amygdala exploiting different computational properties of subcortical and cortical routes, thereby supporting amygdala functions at different stages of emotion processing. This view reconciles some apparent contradictions in the literature, as well as seemingly contrasting proposals, such as the dual stage and the dual route model. We conclude that evidence in favor of the amygdala response without awareness is solid, albeit this response originates from different functional mechanisms and is driven by more complex neural networks than commonly assumed. Acknowledging the complexity of such mechanisms can foster new insights on the varieties of amygdala functions without awareness and their impact on human behavior

Human Amygdala in Sensory and Attentional Unawareness: Neural Pathways and Behavioural Outcomes

One of the neural structures more often implicated in the processing of emotional signals in the absence of visual awareness is the amygdala. In this chapter, we review current evidence from human neuroscience in healthy and brain-damaged patients on the role of amygdala during non-conscious (visual) perception of emotional stimuli. Nevertheless, there is as of yet no consensus on the limits and conditions that affect the extent of amygdala’s response without focused attention or awareness. We propose to distinguish between attentional unawareness, a condition wherein the stimulus is potentially accessible to enter visual awareness but fails to do so because attention is diverted, and sensory unawareness, in which the stimulus fails to enter awareness because its normal processing in the visual cortex is suppressed. Within this conceptual framework, some of the apparently contradictory findings seem to gain new coherence and converge on the role of the amygdala in supporting different types of non-conscious emotion processing. Amygdala responses in the absence of awareness are linked to different functional mechanisms and are driven by more complex neural networks than commonly assumed. Acknowledging this complexity can be helpful to foster new studies on amygdala functions without awareness and their impact on human behaviour

Occurrence of microplastics in bivalves: can a systematic literature review support the risk assessment?

Microplastics (MPs) are a global environmental issue, particularly affecting the aquatic ecosystem. Due to their small size (<5 mm), MPs can be absorbed or ingested by aquatic organisms, and transferred through food webs. Toxic effects due to the ingestion of MPs, alone or contaminated with additives or pollutants, have been hypothesized. Human exposure is inevitable, also following accumulation in the food chain. Seafood, especially bivalves, being filter feeders and consumed as whole, are an important potential pathway. The scientific interest in the topic is rising, and several narrative reviews on MPs in food, including seafood, have been published since the publication of a statement on the presence of MPs and nanoplastics in food by EFSA in 2016 (1), highlighting a scarcity of data on MPs occurrence. The aim of this review was to systematically revise scientific papers (SPs) to assess the occurrence of MPs in different categories of bivalves (mussels, clams, oysters and scallop) worldwide. A double-step filtration was used, applying increasingly stricter quality criteria. Data on MPs abundance were first discussed focusing on all the investigated species and geographical areas. Then, a subset of SPs selected in the second filtering step was used to calculate the weighted MPs mean abundance and the human exposure per serving size. In the first filtering process 87 SPs, published between 2014 and 2020 in 30 different scientific journals, were retained. Overall, 67 species, 6 genera and 1 family of bivalves were analysed. Mussels were the most analysed (61 SPs), followed by clams (55 SPs), oysters (31 SPs), and scallops (7 SPs). Mytilus edulis and M. galloprovincialis were the most investigated species, followed by P. viridis, Mytilus sp., R. philippinarum and C. gigas. All these are commercial species, globally farmed and distributed. Marine FAO areas 61 and 27 were most investigated. Overall, MPs mean abundance was variably reported, as well as the use of different methods and procedural controls. Therefore, in this study, the weighted MPs mean abundance was calculated only including data from a subset of SPs (n=32; 37%). The overall weighted MPs mean abundance including data from all FAO areas was 1.19 MPs/g ww. The highest value was observed in FAO area 61 (2.33 MPs/g ww), while values <1 MPs/g ww were observed in FAO areas 27 and 57. Among bivalve categories, the highest weighted MPs mean abundance (overall FAO areas) was observed for scallops (1.99 MPs/g ww), followed by mussels (1.71 MPs/g ww), clams (0.84 MPs/g ww) and oysters (0.65 MPs/g ww). Thus, the consumption of standard portions of each bivalve category determines the ingestion of a different number of MPs depending on the FAO area; the highest value (⁓645 MPs) would be ingested with a portion of mussels from FAO area 61. Our findings confirmed the existence of quality issues and the lack of analytical standardization. A disparity among investigated species and geographical areas was observed, and only three studies addressed processed products. These aspects affect the outcome of systematic reviews to support risk assessment; future studies should explore the issue of MPs adopting an interdisciplinary perspective, integrating different technical and scientific competences to collect evidences for risk assessment and management

A deep neural network model of the primate superior colliculus for emotion recognition

Although sensory processing is pivotal to nearly every theory of emotion, the evaluation of the visual input as ‘emotional’ (e.g. a smile as signalling happiness) has been traditionally assumed to take place in supramodal ‘limbic’ brain regions. Accordingly, subcortical structures of ancient evolutionary origin that receive direct input from the retina, such as the superior colliculus (SC), are traditionally conceptualized as passive relay centres. However, mounting evidence suggests that the SC is endowed with the necessary infrastructure and computational capabilities for the innate recognition and initial categorization of emotionally salient features from retinal information. Here, we built a neurobiologically inspired convolutional deep neural network (DNN) model that approximates physiological, anatomical and connectional properties of the retino-collicular circuit. This enabled us to characterize and isolate the initial computations and discriminations that the DNN model of the SC can perform on facial expressions, based uniquely on the information it directly receives from the virtual retina. Trained to discriminate facial expressions of basic emotions, our model matches human error patterns and above chance, yet suboptimal, classification accuracy analogous to that reported in patients with V1 damage, who rely on retino-collicular pathways for non-conscious vision of emotional attributes. When presented with gratings of different spatial frequencies and orientations never ‘seen’ before, the SC model exhibits spontaneous tuning to low spatial frequencies and reduced orientation discrimination, as can be expected from the prevalence of the magnocellular (M) over parvocellular (P) projections. Likewise, face manipulation that biases processing towards the M or P pathway affects expression recognition in the SC model accordingly, an effect that dovetails with variations of activity in the human SC purposely measured with ultra-high field functional magnetic resonance imaging. Lastly, the DNN generates saliency maps and extracts visual features, demonstrating that certain face parts, like the mouth or the eyes, provide higher discriminative information than other parts as a function of emotional expressions like happiness and sadness. The present findings support the contention that the SC possesses the necessary infrastructure to analyse the visual features that define facial emotional stimuli also without additional processing stages in the visual cortex or in ‘limbic’ areas

Convolutional neural networks for vision neuroscience: significance, developments, and outstanding issues

Convolutional Neural Networks (CNN) are a class of machine learning models predominately used in computer vision tasks and can achieve human-like performance through learning from experience. Their striking similarities to the structural and functional principles of the primate visual system allow for comparisons between these artificial networks and their biological counterparts, enabling exploration of how visual functions and neural representations may emerge in the real brain from a limited set of computational principles. After considering the basic features of CNNs, we discuss the opportunities and challenges of endorsing CNNs as in silico models of the primate visual system. Specifically, we highlight several emerging notions about the anatomical and physiological properties of the visual system that still need to be systematically integrated into current CNN models. These tenets include the implementation of parallel processing pathways from the early stages of retinal input and the reconsideration of several assumptions concerning the serial progression of information flow. We suggest design choices and architectural constraints that could facilitate a closer alignment with biology provide causal evidence of the predictive link between the artificial and biological visual systems. Adopting this principled perspective could potentially lead to new research questions and applications of CNNs beyond modeling object recognition

Functional neuroanatomy of racial categorization from visual perception: a meta-analytic study

We effortlessly sort people into different racial groups from their visual appearance and implicitly generate racial bias affecting cognition and behavior. As these mental activities provide the proximate mechanisms for social behaviours, it becomes essential to understand the neural activity underlying differences between own-race and other-race visual categorization. Yet intrinsic limitations of individual neuroimaging studies, owing to reduced sample size, inclusion of multiple races, and interactions between races in the participants and in the displayed visual stimuli, dampens generalizability of results. In the present meta-analytic study, we applied multimodal techniques to partly overcome these hurdles, and we investigated the entire functional neuroimaging literature on race categorization, therefore including more than 2000 Black, White and Asian participants. Our data-driven approach shows that own- and other-race visual categorization involves partly segregated neural networks, with distinct connectivity and functional profiles, and defined hierarchical organization. Categorization of own-race mainly engages areas related to cognitive components of empathy and mentalizing, such as the medial prefrontal cortex and the inferior frontal gyrus. These areas are functionally co-activated with cortical structures involved in auto-biographical memories and social knowledge. Conversely, other-race categorization recruits areas implicated in, and functionally connected with, visuo-attentive processing, like the fusiform gyrus and the inferior parietal lobule, and areas engaged in affective functions, like the amygdala. These results contribute to a better definition of the neural networks involved in the visual parcelling of social categories based on race, and help to situate these processes within a common neural space

La Tubercolosi nel cinghiale cacciato nella Provincia di Crotone: implicazioni alimentari e sanitarie

ABSTRACT ITA La Tubercolosi Bovina è una malattia infettiva contagiosa ad eziologia batterica, sostenuta da Mycobacterium bovis, che determina nell'ospite lesioni nodulari di tipo granulomatoso, localizzati in diverse sedi. La malattia, a carattere zoonotico, è importante per i danni economici che può apportare, potendo colpire un ampio range di ospiti. Tra questi, il cinghiale (Sus scrofa). Questo studio ha preso in considerazione il cinghiale. In questo studio sono stati analizzati i dati derivanti dai controlli ufficiali, degli animali abbattuti durante l’attività venatoria e la caccia di selezione nel territorio della provincia di Crotone (Regione Calabria). Lo scopo del presente studio è stato quello di effettuare un’analisi epidemiologica relativa alla presenza della Tubercolosi nei cinghiali circolanti nel territorio provinciale. Ha inoltre avuto il fine di valutare l’attuale status del controllo ufficiale territoriale anche considerando la trasmissibilità a specie domestiche e all’uomo. Sono stati raccolti i dati riguardanti i cinghiali abbattuti nei due tipi di attività in due archi temporali: dal 2016 al 2021 per l’attività venatoria e dal 2019 al 2021 per la caccia di selezione. Sono stati considerati differenti parametri delle carcasse: sesso degli animali, condizioni generali e cutanee, esito dell’esame anatomo-patologico, tipologia e localizzazione delle lesioni sospette, conferme da parte dell’Istituto Zooprofilattico Sperimentale del Mezzogiorno (I.Z.S. del Mezzogiorno), sezione di Catanzaro, e tipizzazione da parte dell’Istituto Zooprofilattico della Lombardia e dell’Emilia Romagna (IZSLER), sezione di Brescia e territori con più animali sospetti. Dai risultati ottenuti, dopo il processo di selezione, sono stati analizzati i dati relativi a 3093 animali abbattuti. Lesioni sospette sono state descritte a livello delle prime vie orali, con complessi primari incompleti a livello dei linfonodi faringei (90%) e complessi primari completi (10%), nella medesima sede. Oltre a ciò, vi è una localizzazione respiratoria, a livello dei linfonodi bronchiali (40%). Per i visceri, le lesioni si localizzano prevalentemente a livello polmonare (25-30%) e, in minor parte, a livello epatico, sotto forma di complessi primari (3-5%). Le conferme da parte dell’I.Z.S. del Mezzogiorno si attestano al 52% dei campioni inviati (148 carcasse, su 385 sospette). La tipizzazione da parte dell’IZSLER ha riportato come specie predominante M.bovis. I territori maggiormente interessati dai cinghiali sospetti sono risultati Cirò, Umbriatico, Melissa e Crucoli. ABSTRACT EN Bovine Tuberculosis is a contagious infectious disease with bacterial etiology, sustained by Mycobacterium bovis, which causes nodular granulomatous lesions in the host, located in different locations. This zoonotic disease is important for the economic damage it can cause, as it can affect a wide range of guests. Among them, the wild boar (Sus scrofa). This study has took into consideration the wild boar. This study took wild boar into consideration. In this study, the data resulting from official controls of animals killed during hunting and selection hunting in the territory of the province of Crotone (Calabria Region) were analyzed. The purpose is to carry out an epidemiological analysis relating to the presence of Tuberculosis in wild boars circulating in the provincial territory. It also has the purpose of assessing the current status of official territorial control considering the transmissibility to domestic species and to humans. Data regarding wild boars killed in the two types of activity were collected in two time frames: from 2016 to 2021 for hunting and from 2019 to 2021 for selective hunting Different parameters of the carcasses were considered: sex of the animals, general and skin conditions , outcome of the pathological examination, type and location of suspected lesions, confirmations by the Experimental Zooprophylactic Institute of Southern Italy (I.Z.S. del Mezzogiorno), Catanzaro section, and typing by the Zooprophylactic Institute of Lombardy and Emilia Romagna ( IZSLER), Brescia section and territories with more suspected animals. From the obtained results, after the selection process, the data relating to 3093 slaughtered animals were analyzed. Suspected lesions have been described at the level of the first oral routes, with incomplete primary complexes at the level of the pharyngeal lymphnodes (90%) and complete primary complexes (10%), in the same site. In addition to this, there is a respiratory localization, at the level of the bronchial lymphnodes (40%). For the viscera, the lesions are mainly localized in the lungs (25-30%) and, to a lesser extent, in the liver, in the form of primary complexes (3-5%). Confirmations by the I.Z.S. del Mezzogiorno amounted to 52% of the samples sent (148 carcasses, out of 385 suspected). Typing by IZSLER reported M. bovis as the predominant species. The most affected areas by suspected wild boars were Cirò, Umbriatico, Melissa and Crucoli

Microplastiche nei Molluschi Bivalvi: revisione sistematica della Letteratura

Le Microplastiche (MP) sono microscopiche particelle di dimensioni inferiori ai 5 mm, potenzialmente capaci di introdursi nella catena trofica. I Molluschi Bivalvi (MB), in quanto organismi filtratori, sono particolarmente soggetti all’accumulo di tali particelle. Inoltre, considerando anche il fatto che vengono consumati interi, risultano un alimento potenzialmente a rischio per l’uomo. Lo scopo del presente lavoro di tesi è stato quello di effettuare una revisione della letteratura relativa agli studi effettuati per la ricerca di MP nei MB al fine di ottenere uno stato dell’arte della problematica. La ricerca è stata svolta su tre differenti database, indagando 4 categorie di MB: cozze, vongole, ostriche e cappesante. Sono stati selezionati 61 studi, sulla base di alcuni criteri di inclusione minimi. Qualora presenti, sono state anche analizzate diverse informazioni aggiuntive. La maggior parte degli studi è stata pubblicata su riviste trattanti tematiche ecologico-ambientali (n= 41; 67%). La categoria più indagata negli studi è quella delle vongole. La maggior parte dei campioni analizzati proveniva da acque europee (46%) o asiatiche (33%). In Europa, i campioni sono stati raccolti prevalentemente nelle acque italiane, francesi ed olandesi, mentre in Asia, nelle acque cinesi. Nella categoria “cozza”, il genere Mytilus spp. è risultato essere il più analizzato in Europa (97%). Per la categoria ostriche, C. gigas è stata quella maggiormente analizzata in Europa (86%), in America del Nord (80%) e in Asia (37.5%). Riguardo alla quantificazione di MP nei tessuti, non è stato possibile fornire un valore medio, in quanto il numero di MP non veniva espresso mediante un valore standard. Inoltre, si evince anche una enorme difformità nella descrizione morfologica delle MP. Infine, un aspetto molto importante è l’estrema varietà nei protocolli analitici utilizzati che spesso non tengono conto delle possibili vie di contaminazione durante la processazione dei campioni. Quanto detto mette in evidenza come ad oggi il problema non venga affrontato nell’ottica di effettuare una raccolta dati mirata alla valutazione del rischio per l’uomo. Infatti, nonostante questo venga ad oggi considerato trascurabile, molti aspetti relativi all’interazione delle MP con l’organismo umano così come la possibilità che esse veicolino altre sostanze tossiche sono ancora poco investigati. In particolare non esiste ancora una normativa volta alla gestione delle MP negli alimenti in generale e nei MB nello specifico, né tantomeno la definizione di una dose giornaliera raccomandata

Basic Emotions in Human Neuroscience: Neuroimaging and Beyond

The existence of so-called ‘basic emotions’ and their defining attributes represents a long lasting and yet unsettled issue in psychology. Recently, neuroimaging evidence, especially related to the advent of neuroimaging meta-analytic methods, has revitalized this debate in the endeavor of systems and human neuroscience. The core theme focuses on the existence of unique neural bases that are specific and characteristic for each instance of basic emotion. Here we review this evidence, outlining contradictory findings, strengths and limits of different approaches. Constructionism dismisses the existence of dedicated neural structures for basic emotions, considering that the assumption of a one-to-one relationship between neural structures and their functions is central to basic emotion theories. While these critiques are useful to pinpoint current limitations of basic emotions theories, we argue that they do not always appear equally generative in fostering new testable accounts on how the brain relates to affective functions. We then consider evidence beyond PET and fMRI, including results concerning the relation between basic emotions and awareness and data from neuropsychology on patients with focal brain damage. Evidence from lesion studies are indeed particularly informative, as they are able to bring correlational evidence typical of neuroimaging studies to causation, thereby characterizing which brain structures are necessary for, rather than simply related to, basic emotion processing. These other studies shed light on attributes often ascribed to basic emotions, such as automaticity of perception, quick onset, and brief duration. Overall, we consider that evidence in favor of the neurobiological underpinnings of basic emotions outweighs dismissive approaches. In fact, the concept of basic emotions can still be fruitful, if updated to current neurobiological knowledge that overcomes traditional one-to-one localization of functions in the brain. In particular, we propose that the structure-function relationship between brain and emotions is better described in terms of pluripotentiality, which refers to the fact that one neural structure can fulfill multiple functions, depending on the functional network and pattern of co-activations displayed at any given moment