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Cognitive style and anxiety as related to the P300 component of the event related potential waveform in eleven and twelve year old males /Kahapi, Ranju M. January 1987 (has links)
No description available.
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The effects of visual-proprioceptive cue conflicts on human tracking performance /Reed, Lawrence Edwin January 1977 (has links)
No description available.
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Design of an Electroencephalography System to Record Transcranial Magnetic Stimulation Evoked PotentialsArchambeault, Mark 08 1900 (has links)
<p> The purpose of this thesis was to design, build and test a prototype artifact suppressing electroencephalogram data acquisition system (AS-EEG-DAQ-S) to collect electroencephalogram (EEG) evoked potential (EP) data during repetitive transcranial magnetic stimulation (rTMS) without the EEG signal being masked by transcranial magnetic stimulation (TMS) artifact. A functional AS-EEG-DAQ-S capable of blocking TMS artifact would provide for the first time a quantitative measurement system to assist in optimal TMS coil positioning during the rTMS treatment of depression, an alternative to electroconvulsive therapy (ECT). This thesis provides the details for an AS-EEGDAQ-S. Preliminary TMS EP results on a human subject were collected. Results showed transcallosal conduction times of 12ms to 31ms, which are consistent with those predicted and collected by other researchers in the TMS field. </p> <p> The first portion of this work provides electrode heating data for modem rTMS Paradigms for the recording ofEEG during rTMS. The concern is that during rTMS EEG electrodes can heat to an unsafe temperature. Seven electrode types were tested: silver/silver chloride, silver cup, gold cup, notched gold cup, notched silver cup, notched gold-plated silver cup, and carbon. All electrodes tested are commercially available, including the carbon electrodes designed for MRI use. The three notched electrodes tested were standard electrodes notched using metal clippers to reduce induced currents. Induced currents are responsible for electrode heating during rTMS and can cause burns to the skin. The results ,of this study show that electrode heating is a concern when collecting BEG during rTMS. However, a number of standard electrodes or slightly modified standard electrodes are suitable for recording BEG during rTMS if certain stimulating parameters are adhered to. </p> <p> The second portion of this work provides the detailed development and design of the AS-EEG-DAQ-S. Four different approaches were tested and their ability to withstand a TMS pulse compared. </p> <p> Short circuiting the input pins of a commercially available EEG amplifier was the first approach tried and yielded only marginal results due to the switches used being designed for digital logic, transistor built, and creating an undesirable offset between input pins. </p> <p> The second approach tested involved continuing to work with a commercially available EEG amplifier and implementing a sample-and-hold circuit between the patient and the EEG machine inputs. This approach had the drawback of requiring that the BEG signal be attenuated back to EEG signal levels, which are near noise amplitude levels. </p> <p> The third approach involved using a high bandwidth amplification circuit to recover quicker from the baseline voltage offset created by the TMS artifact. However, increasing the bandwidth also allows the artifact to saturate the input amplifiers, which then require on the order of 500ms to recover fully. </p> <p> The fourth approach involved combining the second and third approaches to create a high bandwidth amplifier that incorporates a sample-and-hold circuit to prevent amplifier saturation when gain is increased. The fourth approach provide the high bandwidth and artifact blocking behavior desired. </p> / Thesis / Master of Applied Science (MASc)
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Spontaneous and click-evoked otoacoustic emissions from normal hearingyoung adults: a racial comparison陳翠鑫, Chan, Chui-yam, Jenny. January 1998 (has links)
published_or_final_version / Speech and Hearing Sciences / Master / Master of Science in Audiology
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Short latency evoked potentials and intra-individual variability in children.Lord-Maes, Janiece Marie. January 1988 (has links)
Individual differences in learning with a focus on neuropsychologic anomalies underlying learning strategies has been receiving attention in recent years. As a result, interest has increased in quantifying and analyzing cognitive behavior more directly. One of the tools that measures brain activity directly is the evoked potential (EP). This study investigated the EP recorded from the brainstem region, often referred to as brainstem auditory evoked response (BAER). The importance of BAERs in detecting pathology in the brainstem has been well documented. BAERs have also been advocated as an important tool in the electrophysiological assessment of children's brainstem function relative to learning disorders. BAER latencies were recorded, therefore, from a small group of average children and studied in relation to the BAER stability overtime. Intra-individual differences were compared to between-subject differences. So little BAER research has been performed with children that more studies are needed just to clarify normal variability of BAER parameters. The present investigation studied intra-individual differences in the stability of BAER latencies over time in young subjects with normal hearing, for comparing with and contrasting to previous results from a study using an adult sample. BAER latencies were recorded for left, right, and binaural ear presentations. A coefficient of stability (CS) was calculated for each peak, for each ear over time. ANOVA results showed significance for peak and peak by ear interaction. Several BAER parameters were examined within-subjects that may not be revealed in studies between-subjects. Profiles for intra-aural differences over time showed individual differences in the stability of the BAER. Although there appeared to be a trend toward inter-ear differences the differences did not reach significance. The profiles indicated considerable intra-aural pattern replicability, and a trend toward increase in stability over time. The results supported a need for future research on laterality studies, more age specific normative data and correlational studies in relation to individual cognitive differences.
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Slow cortical auditory evoked potentials and auditory steady-state evoked responses in adults exposed to occupational noiseBiagio, Leigh. January 2009 (has links)
Thesis (M. Communication Pathology)--University of Pretoria, 2009. / Includes bibliographical references.
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Crossmodal interactions in stimulus-driven spatial attention and inhibition of return: evidence from behavioural and electrophysiological measuresMacDonald, John J. 05 1900 (has links)
Ten experiments examined the interactions between vision and audition in stimulusdriven
spatial attention orienting and inhibition of return (IOR). IOR is the demonstration that
subjects are slower to respond to stimuli that are presented at a previously stimulated location. In
each experiment, subjects made go/no-go responses to peripheral targets but not to central
targets. On every trial, a target was preceded by a sensory event, called a "cue," either in the
same modality (intramodal conditions) or in a different modality (crossmodal conditions). The
cue did not predict the location of the target stimulus in any experiment. In some experiments,
the cue and target modalities were fixed and different. Under these conditions, response times to
a visual target were shorter when it appeared at the same location as an auditory cue than when it
appeared on the opposite side of fixation, particularly at short (100 ms) cue-target stimulus onset
asynchronies (Experiments 1A and IB). Similarly, response times to an auditory target were
shorter when it appeared at the same location as a visual cue than when it appeared at a location
on the opposite side of fixation (Experiments 2A and 2B). These crossmodal effects indicate that
stimulus-driven spatial attention orienting might arise from a single supramodal brain
mechanism. IOR was not observed in either crossmodal experiment indicating that it might arise
from modality specific mechanisms. However, for many subjects, IOR did occur between
auditory cues and visual targets (Experiments 3A and 3B) and between visual cues and auditory
targets (Experiment 4A and 4B) when the target could appear in the same modality as the cue on
half of the trials. Finally, the crossmodal effects of stimulus-driven spatial attention orienting on
auditory and visual event-related brain potentials (ERPs) were examined in the final two
experiments. Auditory cues modulated the ERPs to visual targets and visual cues modulated the
ERPs to auditory targets, demonstrating that the mechanisms for spatial attention orienting
cannot be completely modality specific. However, these crossmodal ERP effects were very
different from each other indicating that the mechanisms for spatial attention orienting cannot be
completely shared.
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A comparison of ocular and cervical vestibular evoked myogenic potentials in the evaluation of different stages of clinically certain Ménière’s disease.McElhinney, Sarah-Anne January 2009 (has links)
Cervical vestibular evoked myogenic potential (cVEMP) testing is widely used in the
assessment of vestibular disorders in clinical practice (Welgampola & Colebatch, 2003).
Ocular vestibular evoked myogenic potentials (oVEMPs) are similar to the cervical VEMPs in
that the vestibular system is also stimulated by a loud sound. The difference is that the
response is measured on the inferior oblique muscle of the eye as opposed to the
sternocleidomastoid muscle (SCM) of the neck (Chihara, Iwasaki, Ushio, & Murofushi,
2007). The current study compares the standard cervical VEMP to the ocular VEMP in both
control subjects and participants with “clinically certain” Ménière’s disease. By investigating
cervical VEMPs in comparison to ocular VEMPs we aimed to improve the ability to stage and
diagnose Ménière’s disease using the ocular VEMP.
22 control participants and 19 participants with confirmed unilateral Ménière’s disease
took part in the study. The peak latency and amplitudes of the ocular and cervical VEMP tests
were recorded and analysed. In addition, the background electromyographic (EMG) activity
of both the inferior oblique and sternocleidomastoid muscles was recorded throughout testing.
A questionnaire was also distributed to all participants to compare the relative difficulty of the
VEMP tests. Statistical analysis using the paired t-test, standard t-test and the one-way
ANOVA on ranks test was applied to determine a difference between the control and patient
groups for both the ocular and cervical VEMP tests.
Overall, the threshold and IAD ratio measures did not produce any significant results
when sound was presented to the affected ear for the cervical and ocular VEMP tests. A
significant reduction in amplitude of the VEMPs from the Ménière’s groups was found
compared to the control groups for the ocular the cervical VEMPs. Overall, an increase in P2
and N3 latency of the ocular VEMP response in Ménière’s patients was determined. Results
from the questionnaire suggest that the ocular VEMP test was more tolerable to the cervical
VEMP test in this current study. Furthermore, statistical analyses revealed no significant
differences in EMG level between the control and Ménière’s group for both the ocular and
cervical VEMP data.
Overall, results suggest that both the cervical and ocular VEMP tests provide information
regarding the integrity of the saccule, owing to the abnormal VEMP findings in the
participants with Ménière’s disease. In addition, this study provides evidence that the ocular
VEMP is as useful a tool in diagnosing Ménière’s disease as the cervical VEMP.
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A comparison of ocular and cervical vestibular evoked myogenic potentials in the evaluation of different stages of clinically certain Ménière’s disease.McElhinney, Sarah-Anne January 2009 (has links)
Cervical vestibular evoked myogenic potential (cVEMP) testing is widely used in the assessment of vestibular disorders in clinical practice (Welgampola & Colebatch, 2003). Ocular vestibular evoked myogenic potentials (oVEMPs) are similar to the cervical VEMPs in that the vestibular system is also stimulated by a loud sound. The difference is that the response is measured on the inferior oblique muscle of the eye as opposed to the sternocleidomastoid muscle (SCM) of the neck (Chihara, Iwasaki, Ushio, & Murofushi, 2007). The current study compares the standard cervical VEMP to the ocular VEMP in both control subjects and participants with “clinically certain” Ménière’s disease. By investigating cervical VEMPs in comparison to ocular VEMPs we aimed to improve the ability to stage and diagnose Ménière’s disease using the ocular VEMP. 22 control participants and 19 participants with confirmed unilateral Ménière’s disease took part in the study. The peak latency and amplitudes of the ocular and cervical VEMP tests were recorded and analysed. In addition, the background electromyographic (EMG) activity of both the inferior oblique and sternocleidomastoid muscles was recorded throughout testing. A questionnaire was also distributed to all participants to compare the relative difficulty of the VEMP tests. Statistical analysis using the paired t-test, standard t-test and the one-way ANOVA on ranks test was applied to determine a difference between the control and patient groups for both the ocular and cervical VEMP tests. Overall, the threshold and IAD ratio measures did not produce any significant results when sound was presented to the affected ear for the cervical and ocular VEMP tests. A significant reduction in amplitude of the VEMPs from the Ménière’s groups was found compared to the control groups for the ocular the cervical VEMPs. Overall, an increase in P2 and N3 latency of the ocular VEMP response in Ménière’s patients was determined. Results from the questionnaire suggest that the ocular VEMP test was more tolerable to the cervical VEMP test in this current study. Furthermore, statistical analyses revealed no significant differences in EMG level between the control and Ménière’s group for both the ocular and cervical VEMP data. Overall, results suggest that both the cervical and ocular VEMP tests provide information regarding the integrity of the saccule, owing to the abnormal VEMP findings in the participants with Ménière’s disease. In addition, this study provides evidence that the ocular VEMP is as useful a tool in diagnosing Ménière’s disease as the cervical VEMP.
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The prediction of both short and long term outcomes follwing severe brain injury using somatosensory evoked potentialsCarter, Bradley Graham. January 2006 (has links)
Thesis (PhD) - Swinburne University of Technology, 2006. / Submitted for the degree of Doctor of Philosophy, Swinburne University of Technology - 2006. Typescript. Bibliography: p. 191-223.
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