The topography of 4 subtraction ERP-waveforms derived from a 3-tone auditory oddball task in healthy young adults

Introduction: Five components were studied in 4 subtraction waveforms derived from ERPs obtained in passive and active conditions of a 3-tone oddball task (common=70%, C, 0.8 KHz; deviant=15%, D, 2 KHz; 1.4 KHz=15%, t, also used as a target (T)). These waveforms reflect different stimulus-mismatch processes and thus their topography could be revealing of different brain regions mediating them. Methods: The following mismatches were studied: stimulus-mismatch (deviant - common, D/C, rarity and pitch confounded, known as the mismatch negativity, MMN), pitch-mismatch (T - deviant, T/D, rarity not target features controlled, known as processing negativity PN), attention - mismatch (T - t), T/t, controlled for pitch and rarity to show the influence of target features, known as the Negative difference Nd). These are compared with Goodin's procedure (G-wv, (T-common (active) - (t-common (passive)- the "Goodin-waveform"). Results: There were main site effects in normalized data in all cases (not P2 and N2 latency). There were separate frontal and posterior contributions to P1, with the former emphasized where target comparisons were involved. Frontal N1 peaks, largest in D/C (MMN), spread posterior and to the right where target matching was involved. P2 posterior maxima were also less localized where target features were involved in the comparison. N2 topography was similar between waveforms but spread slightly more to each side in the T/t comparison (i.e. Nd). Onset was earlier in the D/C comparison (i.e MMN). Parietal P3 peaks in waves based on target-ERPs showed a left temporal shift (vs D/C), though in T/D P3 was in fact maximal on the right (i.e. PN waveform). Conclusions: Thus an attentional effect(controlled processing) is evident as early as 60 ms. Target features modify the anteroposterior distribution of positivity and negativity for the early components and in the lateralization of P3-like positivity. A comparison of waveforms by latency of potential shift (running t-test) vs. peak identification (MANOVA) is illustrated and discussed. D/C (MMN) and T/t (Nd) waveforms, rather than T/D or G-wv (PN & Goodin waveforms) waveforms are recommended for distinguishing comparator mechanisms for stimulus- and task-relevant features

Development and topography of auditory event-related potentials (ERPs): Mismatch and processing negativity in individuals 8-22 years of age

Introduction: How do ERPs reflecting auditory information processing develop across adolescence? This development is described for the amplitude and latency of five ERP components and four difference-waves in four groups of 11 healthy subjects with mean ages of 10, 14, 17 & 21 years. Methods: Vector normalised data were recorded from 19 sites during diffuse and focused attention in a three-tone oddball. (i.e. in passive, diffuse-attention and active, focussed-attention, discrimination conditions) to see how ERP loci varied with age for tone-type, attention-condition and for four types of difference-wave reflecting nontarget and target comparisons: (mismatch negativity, MMN, an auditory working memory trace; Negative difference, Nd, an attentional trace, but also Processing Negativity, PN and the Goodin-waveform). Results: Age interacted with site for most components. P1 loci sensitive to rare tones moved posteriorly and N1 loci lost their right bias at early puberty. But P2 loci did not move anterior to Cz until adulthood. N2 amplitude, sensitive to attention condition, developed a mature frontal focus by 17 years. Right-biased P3 loci move to the midline with focused attention in young and old alike. Difference-waves reflected three developmental stages (figure 2): In 10 year-olds early deflections (<150 ms) were diffusely distributed; in mid-adolescence the main frontal negative component (150-300 ms) became well-formed and lost an earlier right bias; over 17 years the late positive complex developed a right bias in target-derived waves. Latency decreases for early frontal components were marked in 10-14y olds and for later posterior components in 14-17y olds. MMN topography matured (from a right lateral to bilateral distribution) between 10 and 14 y, while Nd topography matured and became bilateral between 14 and 17y. Conclusions: Major developments of brain function appear at the onset of adolescence (<14y) in early stimulus-selection processes and during adolescence in the differential use of this information (N2- and P3-like latencies

Impaired attention-dependent augmentation of MMN in nonparanoid vs paranoid schizophrenic patients: a comparison with obsessive-compulsive disorder and healthy subjects

Introduction: Mismatch negativity (MMN), in the deviant-minus-standard event-related potential (ERP) difference-waveform, may represent a working memory trace for tone differences (a deviant among a sequence of standards). Most, but not all studies find MMN reduced in patients with schizophrenia. Aims: This report investigates if differences may be attributable to experimental condition (diffuse vs focused attention), component identification (N1-like vs N2-like), topographic distribution and clinical condition (with / without paranoid -hallucinatory symptoms, PH/NP). Comparisons were made for 12 PH and 12 NP schizophrenic patients with 13 obsessive compulsive and 25 normal control subjects. Results: Frontal MMN reduction in schizophrenics largely resulted from an absence of an increase in focused attention conditions as in comparison groups. But there was marked activity recorded from sites over the temporal lobe in NP patients. These features were not reflected in other components except for a visible but nonsignifiant N1-like temporal locus in NP patients. Further, schizophrenic patients did not show an increase in late positivity with focused attention like the comparison groups. Conclusions: The results show that so-called automatic processing deficits in schizophrenia (amount and locus of MMN) are best seen in situations requiring the activation of controlled attentional processes. It is suggested that impaired processing of irrelevant stimuli and reduced frontal MMN in NP patients may reflect reduced dopaminergic responsivity

A RESPONSABILIDADE CIVIL DO EMPREGADOR EM FACE DO ASSÉDIO MORAL NO TRABALHO

A pesquisa realizada tem por escopo analisar a responsabilidade civil do empregador pelos danos causados em razão do assédio moral no trabalho, tanto por atos praticados por ele próprio quanto por atos praticados por seus empregados ou prepostos. Examina-se, para tanto, o assédio moral no trabalho, conceito, modalidades e danos causados. Em seguida, atenta-se para a teoria da responsabilidade civil, conceituando-a, analisando seus pressupostos. Por fim, analisa-se a responsabilidade civil do empregador em face do assédio moral no trabalho. A fim de viabilizar a presente pesquisa, utilizou-se o método dedutivo, buscando amparo nas fontes bibliográficas que versam sobre o tema, coletando informações em doutrinas, jurisprudências e no texto do ordenamento jurídico vigente. Como conclusão da pesquisa,  pode-se afirmar que o empregador, qualquer que seja a hipótese de assédio moral praticado no trabalho, será responsabilizado, seja diretamente, quando responde por atos próprios, seja indiretamente, quando responde por atos praticados por seus empregados, incidindo a  esponsabilidade civil objetiva

Novelty-elicited mismatch negativity in patients with schizophrenia on admission and discharge

Introduction: MMN, an electrophysiological measure of auditory working memory, is usually recorded as the difference in the event-related potential (ERP) elicited by a rare deviant and a common standard sound. The amplitude is usually reduced in patients with schizophrenia (refs below). Here we looked at the response in the extreme and most simple case of the deviant being always a novel, different tone on every presentation. We compared the novelty-MMN with clinical symptoms expressed - both measures being made soon after admission and again 2-3 months later just before discharge. Methods: We compared 20 patients (mean age 26y) with a first, second or third episode of schizophrenia on admission with 21 healthy controls (mean age 26y) and were able to repeat the measures with 12 patients at discharge and with 15 controls. An early MMN component (80-140 ms), a later component (140-300 ms) and the P3a were recorded and topography examined after min-max norming from 19 sites. Symptoms were assessed with the positive and negative syndrome scale (PANSS). Results: a) Novelty-elicited MMN was not significantly reduced on admission. b) The early component remained unaltered, but the amplitude of the later component decreased significantly during inpatient treatment. While the decrease appeared significant over the left hemisphere in the raw data, the lateral difference was lost after normalizing the data. c) Improved positive symptom ratings were associated with increases of the early component latency, but decreases of the late component latency. d) P3a at Fz showed an increased latency between sessions in the patients but there were no group differences in amplitude. Conclusions: Our results are partially consistent with two other studies using a conventional MMN that showed a lack of MMN normalization where symptoms improved (Schall et al., 1998; Umbricht et al., 1998) - in the present study MMN deteriorated. While trait features have been attributed to conventional MMN reductions in schizophrenia, our results suggest that if novelty responses are impaired in patients with schizophrenia then the differences may be sensitive to state

Bariatric Surgery Closure During COVID-19 Lockdown in Italy: The Perspective of Waiting List Candidates

Background: From the beginning of March 2020, lockdown regimens prevented patients with obesity from receiving bariatric surgery. Surgical emergencies and oncological procedures were the only operations allowed in public hospitals. Consequently, patients with morbid obesity were put in a standby situation. With the aim at exploring the viewpoint of our future bariatric surgery patients, we built a questionnaire concerning obesity and COVID-19.Method: A total of 116 bariatric surgery candidates were approached using a telephonic interview during the Italian lockdown.Results: Of the total sample, 73.8% were favorable to regular bariatric surgery execution. Forty percent were concerned about their own health status due to the COVID-19 emergency, and 61.1% were troubled by the temporary closure of the bariatric unit. The majority of the sample were eating more. Forty-five percent and the 27.5% of patients reported a worsening of the emotional state and physical health, respectively. Most of the patients (52.2%) considered themselves more vulnerable to COVID-19, especially individuals with class III obesity. Patients who reported an increased consumption of food were younger (43.44 +/- 12.16 vs. 49.18 +/- 12.66; F = 4.28, p = 0.042). No gender difference emerged.Conclusion: The lockdown had a negative result on Italian patients' psychological well-being and eating habits. The majority of patients would have proceeded with the surgery even during the COVID-19 emergency. Effective management and bariatric surgery should be restarted as soon as possible

Event-related potentials during an auditory discrimination with prepulse inhibition in patients with schizophrenia, obsessive-compulsive disorder and healthy subjects

Introduction: Prepulse inhibition (PPI) is a measure of the influence of a stimulus (S1) on the response elicited by a second stimulus (S2) occurring shortly afterwards. Most S1/S2 measures of gating have used behavioral startle and the P50 event-related potential (ERP) amplitudes to detect PPI in a simple paired stimulus paradigm. Aims: Here we report on two behavioral (EOG and reaction time, RT) and 5 ERP measures of PPI where S2 was the target or standard in an oddball discrimination. Subjects were 21 healthy controls (CON), 11 obsessive-compulsive (OCD) and 9 schizophrenic patients (SCH). Results: The prepulse 100ms before S2 induced fewer omission errors and longer RTs compared to a 500ms S1-S2 interval in all subjects. PPI was also evident in EOG, P50, N1, P3 but not P2 or N2 amplitudes of CON subjects. SCH patients showed attenuation of PPI on the same measures. OCD patients were characterized only by their slow RT and a marginal attenuation of EOG-PPI. Discussion: A correlational analysis implied separate relationships of ERP indices of PPI to the cognitive and psychomotor consequences of the prepulse on behavioral and discrimination responses. However SCH patients showed a general rather than a specific impairment of these indices