Lower P300 Research Articles

Association of GAD1 gene polymorphism rs3749034 with the information processing and cognitive event-related potentials in schizophrenia patients and healthy subjects

ObjectiveGlutamic acid decarboxylase, an enzyme in GABA biosynthesis, is encoded by the GAD1 gene, the transcriptional activity of which is affected by the rs3749034 polymorphism. The aim was to investigate the effects of rs3749034 on cognitive event-related potentials (P300) in healthy subjects and schizophrenic patients. MethodsDetermination of rs3749034 polymorphism was performed in 89 healthy volunteers and 109 schizophrenic patients (males). Two-stimulus oddball task performance and P300 auditory evoked potentials were analyzed and patient symptomatology was assessed using the Positive and Negative Syndrome Scale (PANSS). ResultsAn increased frequency of C allele carriers was disclosed in patients. In controls, superior task performance was observed in cytosine-thymine carriers, while a greater P300 amplitude and shorter latency were found in C/C carriers. Analogous effects were found in patients with a disease onset before 25 years of age. Higher N5 and lower P3 and G5 PANSS scales were revealed in C/C homozygotes. ConclusionsThe findings substantiate an involvement of GABA-ergic mechanisms in maintaining an optimal excitatory-inhibitory balance and an association of rs3749034 with early-onset disorder and negative symptoms of schizophrenia. SignificanceThese results are important for understanding underlying mechanisms and the development of evidence-based methods for assessing the risk of schizophrenia.

Risk Factors for Periprosthetic Femoral Fractures After Cementless Total Hip Arthroplasty

BackgroundThe present study aimed to identify the risk factors of periprosthetic femoral fracture (PFF) after cementless total hip arthroplasty and rank them based on importance. MethodsThe age, sex, body mass index (BMI), osteoporosis, canal flare index (CFI), canal bone ratio (CBR), canal calcar ratio (CCR), stem design, and stem canal fill ratio (P1, P2, P3, and P4) of the proximal femoral medullary cavity of 111 total hip arthroplasty patients who had PFF and 388 who did not have PFF were analyzed. Independent-samples student t-tests were used for continuous variables, and Chi-square tests were used for categorical variables. The importance rankings of influencing factors were assessed using a random forest algorithm. Dimensionally reduced variables were then incorporated into a binary logistic regression model to determine the PFF-related risk factors. ResultsThe mean age, BMI, CBR, CCR, and incidence of osteoporosis were higher in cases of PFF (all P < .001), while the mean CFI, P1, P2, P3, and P4 were lower in cases of PFF (P < .001, P = .033, P = .008, P < .001, and P < .001, respectively). Additionally, the stem design was also statistically associated with PFF (P < .001). Multivariate logistic regression revealed that advanced age, higher BMI, osteoporosis, stem design, lower CFI, higher CBR, higher CCR, lower P1, lower P2, lower P3, and lower P4 were the risk factors of PFF (P < .001, P < .001, P < .001, P < .001, P < .001, P = .010, P < .001, P = .002, P < .001, P < .001, and P = .007, respectively). The ranked importance of the risk factors for PFF was P3, CFI, osteoporosis, CBR, age, P4, P1, stem design, CCR, BMI, and P2. ConclusionsLower P3, lower CFI, osteoporosis, higher CBR, advanced age, lower P4, lower P1, stem design, higher CCR, higher BMI, and lower P2 increased the risk of PFF.

Midfrontal conflict theta and parietal P300 are linked to a latent factor of DSM externalising disorders.

Psychiatric illnesses form spectra rather than categories, with symptoms varying continuously across individuals, i.e., there is no clear break between health and disorder. Dimensional measures of behaviour and brain activity are promising targets for studying biological mechanisms that are common across disorders. Here, we assessed the extent to which neural measures of the sensitivity of the three biological systems in the reinforcement sensitivity theory (RST) could account for individual differences in a latent general factor estimated from symptom counts across externalising disorders (EXTs). RST explanatory power was pitted against reduced P300, a reliable indicator of externalising per previous research. We assessed 206 participants for DSM-5 EXTs (antisocial personality disorder, conduct disorder, attention-deficit/hyperactivity disorder, intermittent explosive disorder symptoms, alcohol use disorder, and cannabis use disorder). Of the final sample, 49% met diagnostic criteria for at least one of the EXTs. Electroencephalographic measures of the sensitivities of the behavioural activation system (BAS), the fight/flight/freeze system, and the behavioural inhibition system (BIS), as well as P300 were extracted from the gold bar-lemon and stop-signal tasks. As predicted, we found that low neural BIS sensitivity and low P300 were uniquely and negatively associated with our latent factor of externalising. Contrary to prediction, neural BAS/"dopamine" sensitivity was not associated with externalising. Our results provide empirical support for low BIS sensitivity and P300 as neural mechanisms common to disorders within the externalising spectrum; but, given the low N involved, future studies should seek to assess the replicability of our findings and, in particular, the differential involvement of the three RST systems.

Is it painful? Playing violent video games affects brain responses to painful pictures: An event-related potential study.

Previous research showed mixed evidence on how violent video game exposure (VVGE) may affect empathy for pain in the brain. This study applied an event-related potential (ERPs) approach to improve understanding of how habitual and short-term violent game play may affect top-down and bottom-up empathy for pain brain responses. A total of 58 male participants with different levels of habitual VVGE performed a pain judgment task before and after 40 min of violent game play while their brain responses were recorded. Results showed that only late cognitive-evaluative ERP responses (P3, P625) were sensitive to the pictures’ painfulness, which were also affected by both habitual VVGE and short- term violent game play. As expected, participants with no habitual VVGE showed an ERP pain effect before game play: higher P3 and P625 amplitudes for painful versus nonpainful pictures. In contrast, a similar ERP pain effect was not observed in participants with high VVGE before game play, suggesting habitual desensitization. Short-term violent game play resulted in lower P3 and P625 amplitudes for painful pictures in the no VVGE group, indicating short-term desensitization. We discuss the observed VVGE desensitization effects in terms of top-down regulation of an empathetic response induced by painful stimuli. Though such adaptation could be beneficial in a violent game environment, possible long-term consequences associated with reduced empathic responsiveness in a social context should be further studied. In all, our findings contribute to the debate on the effects of VVGE on the brain by pro- viding first ERP evidence suggesting empathy for pain desensitization.

Reconfiguration of Brain Network Between Resting State and P300 Task

The oddball paradigm is widely applied to the investigation of multiple cognitive functions. Prior studies have explored the cortical oscillation and power spectral differing from the resting-state conduction to oddball paradigm, but whether brain networks existing the significant difference is still unclear. Our study addressed how the brain reconfigures its architecture from a resting-state condition (i.e., baseline) to P300 stimulus task in the visual oddball paradigm. In this study, electroencephalogram (EEG) datasets were collected from 24 postgraduate students, who were required to only mentally count the number of target stimulus; afterwards the functional EEG networks constructed in different frequency bands were compared between baseline and oddball task conditions to evaluate the reconfiguration of functional network in the brain. Compared to the baseline, our results showed the significantly (p < 0.05) enhanced delta/theta EEG connectivity and decreased alpha default mode network in the progress of brain reconfiguration to the P300 task. Furthermore, the reconfigured coupling strengths were demonstrated to relate to P300 amplitudes, which were then regarded as input features to train a classifier to differentiate the high and low P300 amplitudes groups with an accuracy of 77.78%. The findings of our study help us to understand the changes of functional brain connectivity from resting-state to oddball stimulus task, and the reconfigured network pattern has the potential for the selection of good subjects for P300-based brain- computer interface.

Neural activity during response inhibition associated with improvement of dysphoric symptoms of PTSD after trauma-focused psychotherapy\u2014an EEG-fMRI study

Although trauma-focused cognitive behavioural therapy (TF-CBT) is the frontline treatment for posttraumatic stress disorder (PTSD), up to one half of patients do not respond optimally to this treatment. Inhibitory functions are important for successful management of PTSD, yet there is a dearth of knowledge regarding the extent to which neural mechanisms unpinning response inhibition are associated with TF-CBT response. Treatment-seeking PTSD patients (n = 40) were assessed during a response inhibition task (the Go/No-Go task) while undergoing functional magnetic imaging (fMRI) and event-related potentials (ERP) in separate sessions. PTSD symptom severity was assessed with the Clinician-Administered PTSD Scale, before undergoing nine sessions of TF-CBT. They were then reassessed post-treatment to estimate reduction in fear and dysphoric symptoms of PTSD. Although neural responses during the inhibitory task did not predict overall symptom change, reduced activation in the left precuneus and the right superior parietal cortex predicted greater improvement in dysphoric symptoms. ERP responses during response inhibition indicated that lower P3 peak latency predicted greater reduction of dysphoric symptoms. There were no significant predictors of changes of fear symptoms. These findings indicate that neural activity associated with response inhibition can act as a predictive biomarker of TF-CBT response for PTSD symptoms. This pattern of findings underscores the importance of delineating the role of biomarkers to predict remission of subtypes of PTSD.

First sirenian remains from the Palaeogene of Crimea

ABSTRACT Fragmentary remains, including two anterior premolars, axis fragment, a phalanx, and rib fragments from the Middle Eocene (late Bartonian) Ak-Kaya locality represent the first sirenian fossils from the Paleogene of Crimea. The lower p3 shows some similarity with p3 in the dugongid Eotheroides sp. from the Eocene of North America. The axis is similar in proportions to the axis of the stem sirenian Sobrarbesiren from the Middle Eocene of Spain. The manual(?) phalanx suggests a semiaquatic adaptation of the Crimean sirenian. These remains are identified as Sirenia indet. with possible affinities with the Dugongidae.

1921. Otto Zdansky discovers the Peking Man Fossil

It is common to praise archaeologists for their major discoveries, this is how the name of Otto Zdansky (1894-1988) is linked to that of the Peking Man he discovered at the end of the summer of 1921 in China, 48 km from Beijing (Peking). Less often mentioned is the interest given by the inventor to research undertaken on the fossil isolated teeth of this Homo erectus from China that he unearthed on the Zhoukoudian site (formerly Chou-kou-tien). These teeth of Sinanthropus pekinensis, which he had sent to Uppsala University of Sweden, had also become important in 1980 for me who was then trying to understand how ancient men lived. The three original isolated teeth discovered and described by Otto Zdansky, held at Uppsala in the ZKD (Zhoukoudian) collection since 1923 : Right upper M3 (1921) Left lower P3 (shipped in1923) Right lower P4 (1952), are reflecting the expanding interest of the1920s in the traces of the “peripheral” human evolution in China [Black 1926; Zdansky 1927, 1952]. In January 1980 I contacted Otto Zdansky (figure 1) to include their study; using a method I had started in 1976 to carry out an analysis of the wear of teeth examined under the microscope of populations in order to deduce the different food choices. This and excerpts from Otto Zdansky’s letters reproduced in bold italics bring to life this story of the discovery of the first fossilized remains of Peking Man.

Insecurity primes influence attentional processing of infant emotions: the role of attachment styles

Insecure attachment is associated with an insensitive attentional processing of infant emotions, whereas secure attachment is more sensitive to perceiving infant signals. Regardless, whether exposure to reminders of insecure attachment can influence the attention processing of infant faces in securely and insecurely attached women remains unclear. The present study investigated the electrophysiological mechanism involved in attention function when preceded by insecurity primes. By means of ECR, we selected 21 nulliparous women with a secure attachment, 20 with an avoidant attachment, and 20 with an anxious attachment. Our results suggested that securely attached women allocated more attention resources to infant emotions, which was reflected by increased N1 and P2 amplitudes under insecurity primes. In contrast, insecurity primes led to the suppression of early selective attention (lower N1 amplitude) and later controlled attention (lower P3 amplitude) to infant emotions in both anxiously and avoidantly attached women. Furthermore, we also observed the inhibition of attentional processing (reflected by the P2 amplitude) in avoidantly attached women, who attended infant emotions under neutral primes but avoided them under insecurity primes. In conclusion, the present study implies that insecurity primes may push insecurely attached women to exhibit an insensitive attentional processing while elevating the allocation of attention resources to infant emotions in securely attached women.

Social distance modulates the process of uncertain decision-making: evidence from event-related potentials.

PurposeSocial distance affects risk perception in uncertain decision-making, but how this effect works and the mechanism of how social distance influences the early processing stages of uncertain decision-making are still unclear. This investigation aimed to explore how social distance influences risk-taking during uncertain decision-making using the Iowa Gambling Task with recording of event-related potentials.MethodsA total of 57 healthy subjects (36 female) participated in the modified single-choice Iowa Gambling Task when they gambled based on three quantified social distances (self, friend, and stranger). The social distance between participant and beneficiary was quantified on a scale of 0–100 points, with 0 representing self, 5 representing a close friend, and 100 representing a stranger.ResultsThree stages of uncertain decision-making were analyzed. Behavioral results showed that social distance worked interactively with choice frame, and high social distance made people choose a more advantageous deck and a less disadvantageous deck than low social distance. The P300 in the choice-evaluation stage, which reflects stimulus discrimination, directly proved this result by showing that gambling for a stranger caused higher P300 when evaluating an advantageous deck and lower P300 when evaluating a disadvantageous deck than for others. Decision preceding negativity in the response-selection stage represents the anticipation of risky choices: this was larger with high social distance when choosing a disadvantageous deck. Feedback-related negativity and feedback-related P300 had motivational significance, showing smaller amplitudes when gambling for a stranger than for oneself.ConclusionThese results provide evidence that social distance works interactively with choice frames of uncertain decision-making. People at high social distance are more risk-taking in an advantageous frame and more risk-avoid ant in a disadvantageous frame.

The auditory P300 component of ERPs elicited during the oddball paradigm in type 2 diabetic patients

Background: There is increasing interest in the impact of diabetes mellitus on cognitive functioning. Several studies found evidence of decreased cognitive performance in type 2 diabetics (T2DM). Since the P300 component of event-related potentials (ERPs) provides valuable information concerning cognition, we studied this component of ERPs in T2DM. Methods: Auditory P300 event-related potentials (P300) were elicited in 43 T2DM patients and 29 age and sex-matched healthy volunteers by use of the auditory oddball paradigm, taking into account the age of the subjects, disease duration and the metabolic control. Results: Compared with controls, diabetics had significantly longer P300 latencies (F= 5.05, p= 0.026) and lower P300 amplitudes both in Cz and Pz electrode positions (F= 8.01, p= 0.005 and F= 13.67, p= 0.000 respectively). In addition, a significant inverse correlation between P300 latency and amplitude was observed in diabetics both in Cz and Pz electrode positions (r= -0.43, p= 0.003 and r= -0.39, p= 0.01 respectively), whereas essentially no relationship between amplitude and latency was observed for the control group. N200 and P300 latencies and the reduction in their amplitudes in Cz and Pz leads were not related to either disease duration or metabolic control. Conclusions: The observed electrophysiological abnormalities may reflect impairment of information processing and working memory, possibly associated with an accelerated ageing process. Our findings suggest that surface-recorded ERPs may be useful for detecting and monitoring the changes in brain function associated with diabetes mellitus.

Structural MRI Correlates of Cognitive Event-Related Potentials in Multiple Sclerosis.

Cognitive impairment in multiple sclerosis has been associated with cognitive event-related potentials and MRI abnormalities. This study aims to explore for the first time the association between P300 and MRI in multiple sclerosis. Fifty-eight relapsing-remitting patients (41.5 ± 10.5 years old, 41 women, disease duration 139.7 ± 84.9 months) and 51 healthy controls were used. Visual P300 responses and a set of 2- or 3-dimensional MRI indices were obtained. Neuropsychological testing and psychological evaluations were also performed. Multiple sclerosis patients had significantly lower P300 amplitude and more prolonged P300 latencies and reaction times than healthy controls. In total, 67.2% of patients were identified with abnormal P300 response. These patients had greater disability and physical fatigue and had lower visuospatial memory scores than those with normal P300 response. Abnormally low P300 amplitude was associated with lower peripheral gray matter volume and was correlated only with normalized frontal horn width and normalized brain volume, after adjusting for age and education. The moderating role of brain reserve was also documented. P300 event-related potential was related to both linear and volumetric MRI markers. Future studies should expand these results in other disease types and longitudinally. Event-related potentials could serve as an ancillary tool for cognitive assessment in multiple sclerosis.

Abnormalities of P300 before and after antidepressant treatment in depression: an ERP-sLORETA study.

Despite a wide range of reports on depression-induced P300 changes, it is still debatable whether P300 can return to a pattern characteristic of healthy individuals following antidepressant treatment. Thus, the present study aims to compare P300 and its underlying neural activation in depressed patients before and after antidepressant treatment to explore the brain regions related to pathogenesis and to evaluate the prognosis after treatment. P300 was evoked by the oddball auditory paradigm and collected from 14 sex-matched, age-matched, and education level-matched patients and controls. P300 was also collected in the same patients after treatment. sLORETA was used to explore the source activation of P300 components. Depressed patients before and after antidepressant treatment tended to show lower P300 amplitudes compared with healthy controls, and their P300 amplitudes of F3 electrodes were correlated negatively to their scores on the 24-item Hamilton Depression Rating Scale, the Snaith-Hamilton Pleasure Scale, and the nine-item Patient Health Questionnaire. P300 amplitudes of P4 electrodes were correlated negatively with their scores on the Dysfunctional Attitude Scale. P300 source activation of depressed patients before antidepressant treatment was reduced in the left superior parietal lobule and the precuneus compared with healthy controls and depressed patients after treatment. No difference was found between healthy controls and depressed patients after treatment. The left superior parietal lobule and the precuneus might be therapeutic targets of depression.

Anterior premolar variability in Pleistocene cave and brown bears and its significance in species determination

The current study deals with the anterior premolar pattern in the cave and brown bear lineage, and its significance in species determination. The occurrence of single premolars and its combinations in skulls and mandibles is recorded for various chronological and regional groups. Both lineages stay more “conservative” in the upper than in the lower dentition, but show contrasting reduction tendencies. Brown bears tend to retain the first premolar, while in the cave bear lineage, third premolars prevail. Exclusively diagnostic for brown bears is the occurrence of a single P1, as well as a complete dentition in skulls. With caution, the combination of P1 and P3 is characteristic for the Deninger bear/cave bear lineage. This pattern was not observed in the current brown bear sample, but has been mentioned in literature. In mandibles, evidence of a single p1 (and its combinations) and a complete dentition is exclusively found in brown bears. A single lower p3 is diagnostic for Deninger bears in completely preserved diastema. The absence of all three anterior premolars as typical for the cave bear lineage is occasionally reported for brown bears in literature, but was not observed in the studied material. Other premolar combinations stay scarce in both lineages, and may partly be influenced by early or pathological tooth loss. Brown bears reveal no evolutionary trend in premolar reduction. All possible patterns and a similar frequency of complete dentition is found in modern and fossil representatives. No evidence was found for high variability in the premolar pattern of U. deningeri, as is suggested in literature. The already moderate presence of anterior premolars declines further in Late Pleistocene cave bears. Nonetheless, already the bears of the Cromerian Forest-Bed lack all anterior premolars in mandibles, and hence imply partly evolutionary tendencies in the cave bear lineage, but also populational differences in the occurrence of premolars anterior the P4/p4.

Cognitive dysfunction and event-related potentials in patients with chronic fatigue syndrome

Cognitive dysfunction, as a common symptom among patients with chronic fatigue syndrome(CFS) and patients with fibromyalgia(FM), impacts on life quality, occupation and study of these patients. However, the neural correlates to the cognitive impairment are unknown. Event related potentials, which reflect the information processing objectively and constantly, provide possibility for taking a insight into and estimating the dysfunction. By summarizing and analyzing studies in event related potentials about chronic fatigue syndrome, fibromyalgia, we found that CFS patients were characterized with prolonged latency of N200 and P300 accompanied by decreased P300 amplitude when they performed on Oddball paradigm, fibromyalgia patients were characterized with lower P300 amplitude when they concentrated on Oddball task, meanwhile, fibromyalgia patients also showed decreased P100/N100, P200, P300, LPC in emotional word decision task and somatic pictures decision task. It's suggests that the cognitive dysfunction in CFS is mainly caused by slowed speed of information identification and classification, whereas in FM it's dysregulation in attention control system results in the cognitive dysfunction. Limitations in current studies and prospects on researches about cognitive dysfunction in CFS for future were also discussed. Key words: Chronic fatigue syndrome; Fibromyalgia; Cognitive dysfunction; Event related potentials

Visuospatial information processing load and the ratio between parietal cue and target P3 amplitudes in the Attentional Network Test

In ERP studies of cognitive processes during attentional tasks, the cue signals containing information about the target can increase the amplitude of the parietal cue P3 in relation to the ‘neutral’ temporal cue, and reduce the subsequent target P3 when this information is valid, i.e. corresponds to the target's attributes. The present study compared the cue-to-target P3 ratios in neutral and visuospatial cueing, in order to estimate the contribution of valid visuospatial information from the cue to target stages of the task performance, in terms of cognitive load. The P3 characteristics were also correlated with the results of individuals’ performance of the visuospatial tasks, in order to estimate the relationship of the observed ERP with spatial reasoning.In 20 typically developing boys, aged 10–13 years (11.3±0.86), the intelligence quotient (I.Q.) was estimated by the Block Design and Vocabulary subtests from the WISC-III. The subjects performed the Attentional Network Test (ANT) accompanied by EEG recording. The cued two-choice task had three equiprobable cue conditions: No cue, with no information about the target; Neutral (temporal) cue, with an asterisk in the center of the visual field, predicting the target onset; and Spatial cues, with an asterisk in the upper or lower hemifield, predicting the onset and corresponding location of the target. The ERPs were estimated for the mid-frontal (Fz) and mid-parietal (Pz) scalp derivations.In the Pz, the Neutral cue P3 had a lower amplitude than the Spatial cue P3; whereas for the target ERPs, the P3 of the Neutral cue condition was larger than that of the Spatial cue condition. However, the sums of the magnitudes of the cue and target P3 were equal in the spatial and neutral cueing, probably indicating that in both cases the equivalent information processing load is included in either the cue or the target reaction, respectively. Meantime, in the Fz, the analog ERP components for both the cue and target stimuli did not depend on the cue condition. The results show that, in the parietal site, the spatial cue P3 reflects the processing of visuospatial information regarding the target position. This contributes to the subsequent “decision-making”, thus reducing the information processing load on the target response, which is probably reflected in the lower P3. This finding is consistent with the positive correlation of parietal cue P3 with the individual's ability to perform spatial tasks as scored by the Block Design subtest.

Longitudinal predictors of cannabis use and dependence in offspring from families at ultra high risk for alcohol dependence and in control families.

Cannabis use is common among adolescents. Identification of the factors associated with continued heavy use into young adulthood and development of cannabis abuse and dependence is of considerable importance. The role of familial risk for addiction and an associated endophenotype, P300 amplitude, has not previously been related to cannabis use and dependence. A prospective longitudinal study spanning childhood and young adulthood provided the opportunity for exploring these factors, along with genetic variation, in the cannabis use behaviors of 338 young adult offspring from high and low familial risk for alcohol dependence families (ages 19-30). P300 data were collected multiple times in childhood. The association between young adult patterns of cannabis use or cannabis abuse/dependence was tested with genetic variation in the cannabinoid gene, CNR1, the ANKK1-DRD2 gene, and childhood developmental trajectories of P300. Young adult patterns of cannabis use was characterized by three patterns: (i) no use throughout; (ii) declining use from adolescence through young adulthood; and (iii) frequent use throughout. Following the low P300 trajectory in childhood predicted cannabis abuse and dependence by young adulthood. A four SNP ANKK1-DRD2 haplotype (G-G-G-C) was found to be significantly associated with the frequency of use patterns (P = 0.0008). Although CNR1 variation overall was not significantly associated with these patterns, among individuals with cannabis abuse/dependence the presence of one or both copies of the rs806368 A > G minor allele conferred a 5.4-fold increase (P = 0.003) in the likelihood that they would be in the frequent and persistent use group rather than the declining use group.

Epigenetically downregulated Semaphorin 3E contributes to gastric cancer.

Axon guidance protein Semaphorin 3E (Sema3E) promotes tumor metastasis and suppresses tumor cell death. Here, we demonstrated that Sema3E was decreased in gastric cancer. Its levels were inversely associated with tumor progression. Levels of Sema3E were associated with low p300 and high class I histone deacetylase (class I HDAC). Ectopic expression of Sema3E inhibited proliferation and colony formation of gastric cancer cell lines in vitro and xenografts in vivo. Sema3E overexpression inhibited migration and invasion of gastric cancer cells, which was associated with induction of E-cadherin and reduction of Akt and ERK1/2 phosphorylation. We suggest that silencing of Sema3E contributes to the pathogenesis of gastric cancer.

Effects of the Interaction Between the Level of Anxiety and the Val66Met Polymorphism of the Brain-Derived Neurotrophic Factor Gene on Attention in Patients with Schizophrenia Spectrum Disorders

The effects of the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene and levels of trait anxiety (negative emotionality) on attention were studied in 90 patients with schizophrenia and schizoaffective psychosis. Attention was evaluated using auditory event-related potentials (ERP) and neuropsychological testing. Genotype was found to have a significant effect (anxiety was not) on the efficiency of performing the neuropsychological test on attention and the amplitude of the ERP P300 wave in the frontal and temporal leads. Carriers of the Met allele has poorer performance of the attention task than subjects with the ValVal genotype, and also showed a lower P300 wave amplitude. Genotype combined with the level of anxiety was found to affect the N100 wave in response to the non-significant stimulus, significant differences being seen only in the group with a low level of anxiety: the Met allele was associated with lower N100 amplitudes. Among patients with high levels of anxiety, N100 wave amplitude was independent of the BDNF gene variant present. It is suggested that people with high levels of anxiety expend more effort to solve the task correctly at the early stages of signal recognition, the amplitudedecreasing effect of the “risk allele” being eliminated.

Is cognitive processing affected in adults with hypospadias?: P300 study.

BackgroundHypospadias is a common urogenital system disorder. The frenulum, which is the most sensitive area of the glans penis, is not present in patients with hypospadias. This may lead to a failure in sexual and ejaculatory function, and cause emotional problems affecting cognitive processes.AimWe aimed to study auditory Event Related Potentials (ERP) in patients with hypospadias to understand the status of cognitive function.Materials and MethodsSeventeen patients with hypospadias who presented to the Urology Outpatient Clinic of Çanakkale Military Hospital, and 11 healthy individuals of similar age were chosen. The auditory oddball paradigm with ERP from the Cz and Fz head regions were studied. The latency and amplitude of the P300 wave were measured.ResultsBoth, the study and control groups consisted of young males. Although the study group had a longer P300 latency and lower P300 amplitude when compared to control group, the results were not statistically significant (p: 0.059 and 0.346 respectively).ConclusionAlthough the results are not statistically significant, our findings indicate that there may be cognitive changes in patients with hypospadias. Further studies of larger sample size and older patient cohorts are needed.