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Oddball Task (oddball + task)
Selected AbstractsCombining fMRI and SNP data to investigate connections between brain function and genetics using parallel ICA,HUMAN BRAIN MAPPING, Issue 1 2009Jingyu Liu Abstract There is current interest in understanding genetic influences on both healthy and disordered brain function. We assessed brain function with functional magnetic resonance imaging (fMRI) data collected during an auditory oddball task,detecting an infrequent sound within a series of frequent sounds. Then, task-related imaging findings were utilized as potential intermediate phenotypes (endophenotypes) to investigate genomic factors derived from a single nucleotide polymorphism (SNP) array. Our target is the linkage of these genomic factors to normal/abnormal brain functionality. We explored parallel independent component analysis (paraICA) as a new method for analyzing multimodal data. The method was aimed to identify simultaneously independent components of each modality and the relationships between them. When 43 healthy controls and 20 schizophrenia patients, all Caucasian, were studied, we found a correlation of 0.38 between one fMRI component and one SNP component. This fMRI component consisted mainly of parietal lobe activations. The relevant SNP component was contributed to significantly by 10 SNPs located in genes, including those coding for the nicotinic ,-7cholinergic receptor, aromatic amino acid decarboxylase, disrupted in schizophrenia 1, among others. Both fMRI and SNP components showed significant differences in loading parameters between the schizophrenia and control groups (P = 0.0006 for the fMRI component; P = 0.001 for the SNP component). In summary, we constructed a framework to identify interactions between brain functional and genetic information; our findings provide a proof-of-concept that genomic SNP factors can be investigated by using endophenotypic imaging findings in a multivariate format. Hum Brain Mapp, 2009. © 2007 Wiley-Liss, Inc. [source] Inhibitory control and spatial working memory in Parkinson's diseaseMOVEMENT DISORDERS, Issue 10 2007Caroline Gurvich DPsych (Clin Neuro) Abstract Patients with Parkinson's disease (PD) have difficulty performing tasks relying on inhibitory control and working memory, functions of the prefrontal cortex. Eye movement paradigms can be used to investigate basic sensorimotor functions and higher order cognitive aspects of motor control. This study investigated inhibitory control and spatial working memory in the saccadic system of 13 individuals with mild-moderate PD and 13 age-matched controls. Tasks explored suppression of reflexive saccades during qualitatively different tasks, generation of express and anticipatory saccades, and the ability to respond to occasional, unpredictable ("oddball") targets that occurred during a sequence of well-learned, reciprocating saccades between horizontal targets. Spatial working memory was assessed using single and two-step (involving a visually guided saccade during the delay period) memory-guided tasks. Results for the PD group indicated an increased percentage of response selection errors during an oddball task, reduced suppression of inappropriate reflexive saccades during memory-guided tasks (but not during fixation or saccade-engagement tasks), and an increased percentage of express and anticipatory saccades. Spatial working memory was preserved in the PD group during single and two-step memory-guided tasks. These findings are consistent with dysfunction within fronto-striatal and prefrontal-collicular pathways influencing suppression and selection of eye movements. © 2007 Movement Disorder Society [source] Evidence for a new late positive ERP component in an attended novelty oddball taskPSYCHOPHYSIOLOGY, Issue 5 2010Craig G. McDonald Abstract In attended novelty oddball tasks, rare nontarget stimuli can elicit two late positive ERP components: P3a and P300. In passive oddball tasks, P300 is not elicited by these stimuli. In passive tasks, however, P3a is accompanied by another positive component, termed eP3a, which may have evaded detection in attended oddball tasks because of its spatiotemporal overlap with P300. To address this, temporal-spatial principal components analysis was used to quantify ERPs recorded in attended three-tone and novelty oddball tasks. As expected, novel stimuli elicited both P3a and P300. The analysis also identified a third component, evident in novelty ERPs as an inflection on the leading edge of P3a. This component has the same antecedent conditions as P3a, but is earlier and more centrally distributed. Its spatiotemporal characteristics suggest that it may be the eP3a component recently described in passive oddball tasks. [source] To PE or not to PE: A P3-like ERP component reflecting the processing of response errorsPSYCHOPHYSIOLOGY, Issue 3 2009K. Richard Ridderinkhof Abstract ERP studies have highlighted several electrocortical components that can be observed when people make errors. We propose that the PE reflects processes functionally similar to those reflected in the P3 and that the PE and P3 should covary. We speculate that these processes refer to the motivational significance of rare target stimuli in case of the P3 and of salient performance errors in case of the PE. Here we investigated whether PE amplitude after errors in a Simon task is correlated specifically to varying target,target intervals in a visual oddball task, a factor known to parametrically affect P3 amplitude. The amplitude of the PE, but not the NE, was observed to covary with the effect of target,target interval on P3 amplitude. The specificity of this novel finding supports the notion that the PE and P3 reflect similar neurocognitive processes as possibly involved in the conscious processing of motivationally significant events. [source] Gender differences in behavioral inhibitory control: ERP evidence from a two-choice oddball taskPSYCHOPHYSIOLOGY, Issue 6 2008Jiajin Yuan Abstract The inhibition of inappropriate behaviors is important for adaptive living in changing environments. The present study investigated gender-related behavioral inhibitory control by recording event-related potentials for standard and deviant stimuli while subjects performed a standard/deviant distinction task by accurately pressing different keys within 1000 ms. The results showed faster reaction times (RTs) for deviant stimuli in women than in men, although RTs for standard stimuli were similar across genders. There were significant gender and stimulus interaction effects on mean amplitudes during each of the 170,230-ms, 250,330-ms, and 350,600-ms intervals, and women exhibited shorter latencies and larger amplitudes than men at deviant-related P2, N2, and P3 components. As an accurate, fast response to the rare deviant stimuli involves behavioral inhibitory control on the prepotent response whereas the response to the standard stimuli does not, it is clear that there is a general gender difference in behavioral control for human adults. This may relate to differential inhibitory demands by each gender during evolution. [source] Visual novel stimuli in an ERP novelty oddball paradigm: Effects of familiarity on repetition and recognition memoryPSYCHOPHYSIOLOGY, Issue 1 2007Yael M. Cycowicz Abstract The orienting response, the brain's reaction to novel and/or out of context familiar events, is reflected by the novelty P3 of the ERP. Contextually novel events also engender high rates of recognition memory. We examined, under incidental and intentional conditions, the effects of visual symbol familiarity on the novelty P3 recorded during an oddball task and on the parietal episodic memory (EM) effect, an index of recollection. Repetition of familiar, but not unfamiliar, symbols elicited a reduction in the novelty P3. Better recognition performance for the familiar symbols was associated with a robust parietal EM effect, which was absent for the unfamiliar symbols in the incidental task. These data demonstrate that processing of novel events depends on expectation and whether stimuli have preexisting representations in long-term semantic memory. [source] Target-to-target interval versus probability effects on P300 in one- and two-tone tasksPSYCHOPHYSIOLOGY, Issue 3 2003R. J. Croft Abstract The P3(00) is an electrophysiological index of neural processing that varies with such stimulus parameters as interstimulus interval (ISI) and target probability, with a common view being that it reflects an endogenous form of memory update. Building on previous research, we argue that relations between P3 amplitude and both ISI and probability may be attributable to the target-to-target interval (TTI). Employing between-subject (Experiment 1; N=24) and within-subject (Experiment 2; N=10) designs, the present paper addresses this by testing subjects on a standard two-tone auditory oddball task as well as a one-tone task. In both studies, P3 amplitude increased and latency decreased linearly with TTI, and these relations were relatively unaffected by ISI or probability. This suggests that ISI and probability per se do not independently affect P3 amplitude, and that TTI offers a strong explanation of the reported relations between P3 amplitude and both ISI and probability. [source] Spatiotemporal analysis of experimental differences in event-related potential data with partial least squaresPSYCHOPHYSIOLOGY, Issue 3 2001Nancy J. Lobaugh One challenge in the analysis of event-related potentials (ERPs) is to identify task-related differences in scalp topography. The multivariate Partial Least Squares (PLS) analysis was used to identify the spatiotemporal distribution of ERP differences related to experimental manipulations. Two simulations included latency shifts and amplitude changes at peaks with temporal overlap. PLS identified effects only at modeled timepoints and electrodes. In contrast, principal components analysis identified differences at most timepoints. We also demonstrated that PLS identified combinations of waveform differences, not isolated sources. ERP components in an auditory oddball task were also assessed with PLS. The primary distinction was between ERPs on hit and correct rejection trials, expressed at multiple timepoints and electrodes. PLS provides a mechanism to describe experimental differences in ERP waveforms, simultaneously across the head. [source] Auditory P300 Event-Related Potentials and Neurocognitive Functions in Opioid Dependent Men and Their BrothersTHE AMERICAN JOURNAL ON ADDICTIONS, Issue 3 2009Shubh Mohan Singh MD Event-related-potentials (especially P300) and cognitive functioning as potential endophenotypes have not been studied in opioid dependence. We compared auditory P300 and cognitive functions in opioid-dependent men, their brothers and normal controls in an exploratory study with a view to find shared genetic factors in the development of opioid dependence. Twenty abstinent opioid-dependent males, their brothers and twenty matched controls were administered Wisconsin card sorting test (WCST), digit span test, trail making test-B, and auditory event-related potentials (P300) from an oddball task were recorded. The opioid dependent group performed the worst, the brothers group was intermediate, and the control group performed the best on tests of WCST, digit span and trail making test-B. The opioid dependent group had the smallest amplitudes and longest latencies of P300, and was followed by the brothers group who had an intermediate position and the control group who had the largest amplitudes and the shortest latencies. P300 and executive neurocognitive functions can be considered endophenotypes for the genetic study of vulnerability to opioid dependence. These are reflective of executive dysfunction and disrupted behavioral inhibition and the intermediate position of brothers suggests a common genetic substrate as a component of the etiology. [source] Evidence for a new late positive ERP component in an attended novelty oddball taskPSYCHOPHYSIOLOGY, Issue 5 2010Craig G. McDonald Abstract In attended novelty oddball tasks, rare nontarget stimuli can elicit two late positive ERP components: P3a and P300. In passive oddball tasks, P300 is not elicited by these stimuli. In passive tasks, however, P3a is accompanied by another positive component, termed eP3a, which may have evaded detection in attended oddball tasks because of its spatiotemporal overlap with P300. To address this, temporal-spatial principal components analysis was used to quantify ERPs recorded in attended three-tone and novelty oddball tasks. As expected, novel stimuli elicited both P3a and P300. The analysis also identified a third component, evident in novelty ERPs as an inflection on the leading edge of P3a. This component has the same antecedent conditions as P3a, but is earlier and more centrally distributed. Its spatiotemporal characteristics suggest that it may be the eP3a component recently described in passive oddball tasks. [source] The sensitivity of human event-related potentials and reaction time to mobile phone emitted electromagnetic fieldsBIOELECTROMAGNETICS, Issue 4 2006D.L. Hamblin Abstract There is some evidence to suggest that exposure to mobile phones (MPs) can affect neural activity, particularly in response to auditory stimuli. The current investigation (n,=,120) aimed to test recent findings in this area, namely that N100 amplitude and latency would decrease, and that P300 latency and reaction time (RT) would increase under active relative to sham exposure during an auditory task. Visual measures were also explored. A double blind, counterbalanced, crossover design was employed where subjects attended two sessions 1 week apart. In both sessions participants (1) performed auditory and visual oddball tasks while electroencephalogram (EEG) was recorded with a MP set to sham exposure mounted over the temporal region, and (2) performed the same tasks while the handset was set to active/sham. When active, the MP transmitted for 30 min at 895 MHz (average power 250 mW, pulse modulated at 217 Hz, average SAR 0.11 W/kg). Paired t -tests compared difference scores from the sham/sham session to those from the sham/active condition. The study was designed to detect differences of of a standard deviation with a power of 0.80. There was no significant difference between exposure conditions for any auditory or visual event related potential (ERP) component or RT. As previous positive findings were not replicated, it was concluded that there is currently no evidence that acute MP exposure affects these indices of brain activity. Bioelectromagnetics 27:265,273, 2006. © 2006 Wiley-Liss, Inc. [source] Event-related potentials and white matter lesions in bipolar disorderACTA NEUROPSYCHIATRICA, Issue 1 2002E. F. P. M. Vuurman Objectives: To investigate neurophysiological parameters which possibly distinguish subtypes I and II of patients with a bipolar disorder, and contrast the findings with observations from a group of schizophrenic patients and a group of healthy controls. Methods: Sixty-six volunteers underwent a MRI scan to determine the number and location of white matter lesions (WSL). A electrophysiological registration was made while all volunteers performed a auditory ,oddball' task, and the amplitude of the resulting P300 wave was compared. Results: Earlier reports of higher numbers of WSL in bipolar disorder were not replicated in this study. Subtypes I and II showed a different P300 amplitude and subtype I resembled the results of the schizophrenia group. Conclusion: Bipolar patients in remission have a functional brain disorder that is expressed by a change in physiological response to external stimuli. [source] | |||||||||||||