Isolating the proper neural correlates of visual awareness from its neural consequences

One of the major challenges in the neuroscience of consciousness is to disclose the timing and neural mechanisms underlying visual awareness, the subjective experience of seeing. Electroencephalography (EEG) studies investigating the time course of consciousness-related neural processes have found two potential correlates of visual awareness: the N2 and the P3 ERP components. However, recent works have suggested that only N2 correlates to visual awareness, whereas later neural activity expressed by the P3 component reflects post-perceptual processes related to subjects\u2019 report or to accumulation of sensory evidence leading to decision-making. Building upon this observation, the objective of this study was to provide further evidence that the P3 component reflects a post-perceptual process. To this end, we designed two EEG experiments in which we directly manipulated decision making processes and visual awareness while keeping constant the physical property of visual stimuli. This experimental manipulation allowed us to identify the possible influences of post-perceptual processing over the time course of neural responses and determine the temporal window at which such influence occurs. In Experiment 1, we manipulated participant\u2019s decision criterion by inducing, respectively, a liberal and a conservative decision bias in two different experimental sessions. The aim of this first Experiment was to determine whether our manipulation of the decision processes would produce a modulation of P3 ERP component. Experiment 2 was identical to Experiment 1 except that participants were not requested to adjust their decision criterion (own criterion session). The aim of this experiment was to examine whether in a condition in which there was no manipulation of post-perceptual processes, N2 and P3 ERP component would distribute differently. Electrophysiological and Behavioral results of Experiment 2 were then compared with those of Experiment 1. If the amplitude of the P3 reflects post-perceptual processes related to decision making processes, one would expect to find some differences in the topography or in the time-course of the P3 between the condition in which a decision criterion was imposed (Experiment 1) and the condition in which there was not a decision bias induced (Experiment 2). ERP results of Experiment 1 revealed that the amplitude of the N2 and the P3 components were enhanced for those trials were subjects reported to have seen the stimulus as compared to unaware trials. Importantly, the amplitude of the P3 was modulated by the decision criterion: it was enhanced when participants adopted the liberal criterion compared to the conservative criterion, suggesting that P3 reflects brain processes related to decision making that occurs after that awareness has emerged. ERP data of Experiment 2 confirmed that aware responses were associated with enhanced N2 and P3 amplitude than unaware responses. Interestingly, the decision criterion manipulation had an effect on P3 component revealing that the own and the liberal criteria were associated with an increased positivity over central areas if compared to the conservative criterion. In addition, we found that the amplitude of the N2 was enhanced for the own session if compared to conservative and liberal sessions. Overall these results suggest that when sensory information was relevant for the task (own session) a bigger N2 was observed. On the contrary, P3 amplitude was sensitive to the manipulation of the decision criterion, suggesting a critical role of neural activity expressed by the P3 component in decision making processes. These findings support the hypothesis that P3 might reflect post-perceptual processes that occur after that awareness has emerged while the N2 component reflects a proper correlate of visual awareness

Late positivity does not meet the criteria to be considered a proper neural correlate of perceptual awareness

Contrastive analysis has been widely employed in the search for the electrophysiological neural correlates of consciousness. However, despite its clear logic, it has been argued that it may not succeed in isolating neural processes solely involved in the emergence of perceptual awareness. In fact, data from contrastive analysis would be contaminated by potential confounding factors reflecting distinct, though related, processes either preceding or following the conscious perception. At present, the ERP components representing the proper correlates of perceptual awareness still remain to be identified among those correlating with awareness (i.e., Visual Awareness Negativity, VAN and Late Positivity, LP). In order to dissociate visual awareness from post-perceptual confounds specifically related to decision making, we manipulated the response criterion, which affects how a percept is translated into a decision. In particular, while performing an orientation discrimination task, participants were asked to shift their response criterion across sessions. As a consequence, the resulting modulation should concern the ERP component(s) not exclusively reflecting mechanisms regulating the subjective conscious experience itself but rather the processes accompanying it. Electrophysiological results showed that N1 and P3 were sensitive to the response criterion adopted by participants. Additionally, the more the participants shifted their response criterion, the bigger the ERP modulation was; this was consequently indicative of the critical role of these components in the decision-making processes regardless of awareness level. When considering data independently from the response criterion, the aware vs. unaware contrast showed that both VAN and LP were significant. Crucially, the LP component was also modulated by the interaction of awareness and response criterion, while VAN results to be unaffected. In agreement with previous literature, these findings provide evidence supporting the hypothesis that VAN tracks the emergence of visual awareness by encoding the conscious percept, whereas LP reflects the contribution from post-perceptual processes related to response requirements. This excludes a direct functional role of this later component in giving rise to perceptual awareness

Markers of TMS-evoked visual conscious experience in a patient with altitudinal hemianopia

Abstract Transcranial magnetic stimulation (TMS) of the occipital and parietal cortices can induce phosphenes, i.e. visual sensations of light without light entering the eyes. In this paper, we adopted a TMS-EEG interactive co-registration approach with a patient (AM) showing altitudinal hemianopia. Occipital and parietal cortices in both hemispheres were stimulated while concurrently recording EEG signal. Results showed that, for all sites, neural activity differentially encoding for the presence vs. absence of a conscious experience could be found in a cluster of electrodes close to the stimulation site at an early (70 ms) time-period after TMS. The present data indicate that both occipital and parietal sites are independent early gatekeepers of perceptual awareness, thus, in line with evidence in favor of early correlates of perceptual awareness. Moreover, these data support the valuable contribution of the TMS-EEG approach in patients with visual field defects to investigate the neural processes responsible for perceptual awareness

Reliability in reporting perceptual experience: behaviour and electrophysiology in hemianopic patients

Patients with hemianopia can present with the so called blindsight phenomenon: the ability to perform above chance in the absence of acknowledged awareness. Proper awareness reports are, thus, crucial to distinguish pure forms of blindsight from forms of conscious, yet degraded, vision. It has in fact been recently shown that 1) dichotomous and graded measures to assess awareness can lead to different behavioural results in patients with hemianopia and that 2) different grades of perceptual clarity show different electrophysiological correlates in healthy participants. Here, in hemianopic patients, we assessed awareness by means of the four-point Perceptual Awareness Scale (PAS) and investigated its neural correlates with Event Related Potentials (ERPs). Results showed that patients, in most of the cases, can rate the clarity of their perceptual experience in a graded manner. Moreover, graded perceptual experiences correlated with the amplitude of deflections in ERPs. These results call for the need to assess perceptual awareness with graded measures and for the importance to use electrophysiological data to correlate behaviour with neural processing

The core curriculum in the university training of the teacher of physical education in Italy

Structural, organizational and normative developments in the school setting in Italy, in the last fifty years, suggest that teachers role should be considered throughout the social, cultural and scientific innovations that lead these changes. Based on this theoretical proposition, the purpose of the present study was to identify some key elements of Physical Education Teacher Training Core Curriculum in Italy. The study takes a documental-based approach to the development of teaching skills and lists action supported by Italian Ministry of Education in the last decades to foster adequate teacher training programs, with particular reference to Physical Education teacher training in the low and high school, since the earlier courses in 18th century till now. The results revealed that teacher training programs in Italy sometimes lacked of adequate methods and significant contents, so it is very important to underline the value of a new approach in teacher training that aim to ensure the acquisition of key competence, according to Recommendation of the European Parliament and to create a cooperation between University and the Italian Olympic Committee. In conclusion, a new approach in teacher training could foster a broad advance in specialization and professional development of physical education teacher, adjusting our educational path to the European best practices

A Secure Cloud-Based SCADA Application: the Use Case of a Water Supply Network

Cloud computing paradigm is gaining more and more momentum, to the extent that it is no more confined to its initial application domains, i.e. use by enterprises and businesses willing to lower costs or to increase computing capacity in a flexible manner. In particular, increasing interest is recently being paid to the huge potentials - in terms of benefits for the society at large - that might result from the adoption of cloud computing technology by critical infrastructure (CI) operators. This is of course putting special emphasis on the need for dependable and trustworthy security mechanisms in cloud technology based services, since a critical infrastructure is vital for essential functioning of a country. Incidental or deliberate damages to a CI have serious impacts on the economy, and possibly make essential services unavailable to the communities it serves. In this paper we present the proof-of concept of a cloud-based Water Supply Network Monitoring (WSNM) application, named RiskBuster (RB), that ensures the confidentiality and integrity of SCADA monitoring data collected from dam sensors and stored in the cloud by using the innovative Intel Software Guard eXtension (SGX) technology

Personalized modeling of Alzheimer's disease progression estimates neurodegeneration severity from EEG recordings

Introduction: Early identification of Alzheimer's disease (AD) is necessary for a timely onset of therapeutic care. However, cortical structural alterations associated with AD are difficult to discern. Methods: We developed a cortical model of AD-related neurodegeneration accounting for slowing of local dynamics and global connectivity degradation. In a monocentric study we collected electroencephalography (EEG) recordings at rest from participants in healthy (HC, n = 17), subjective cognitive decline (SCD, n = 58), and mild cognitive impairment (MCI, n = 44) conditions. For each patient, we estimated neurodegeneration model parameters based on individual EEG recordings. Results: Our model outperformed standard EEG analysis not only in discriminating between HC and MCI conditions (F1 score 0.95 vs 0.75) but also in identifying SCD patients with biological hallmarks of AD in the cerebrospinal fluid (recall 0.87 vs 0.50). Discussion: Personalized models could (1) support classification of MCI, (2) assess the presence of AD pathology, and (3) estimate the risk of cognitive decline progression, based only on economical and non-invasive EEG recordings. Highlights: Personalized cortical model estimating structural alterations from EEG recordings.Discrimination of Mild Cognitive Impairment (MCI) and Healthy (HC) subjects (95%)Prediction of biological markers of Alzheimer's in Subjective Decline (SCD) Subjects (87%)Transition correctly predicted for 3/3 subjects that converted from SCD to MCI after 1y

How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons

COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients