Medical Devices; Neurological Devices; Classification of the Evoked Photon Image Capture Device. Final order.

The Food and Drug Administration (FDA) is classifying the Evoked Photon Image Capture Device into class I (general controls). The Agency is classifying the device into class I (general controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

Actividad electrofisiológica durante el procesamiento de sílabas y prefijos / Electrophysiological activity during the processing of syllables and prefixes

Muchos prefijos coinciden con la primera sílaba de la palabra en español. En esta investigación se llevó a cabo un experimento con la técnica de ERPs (Potenciales evento-relacionados) para comparar un priming de prefijo (ej. infeliz–I"CAPAZ) con un priming silábico (ej. caliza-CACHETE). Los resultados mostraron una activación temprana (100-200ms) para las palabras prefijadas, mientras que el priming silábico no llegó a alcanzar diferencias significativas en esta ventana. Entre los 400 y los 600 ms la activación morfológica produjo valores más positivos que la línea base como resultado de una más fácil integración entre prime y target. Por el contrario, en esta ventana, se observó un pico más negativo que la línea base en la condición silábica. En definitiva, los resultados de este experimento parecen mostrar un curso de procesamiento distinto dependiendo de la relación morfológica o fonolólgico-silábica existente entre el prime y target(AU)

Many prefixes in Spanish agree with the first syllable boundary of the words. This research carried out a ERPs (Event Related Potentials) experiment comparing a prefix priming (e.g. infeliz-I"CAPAZ –unhappyunable) with a syllabic priming (e.g. caliza-CACHETE –limestone-slap). The results showed an early activation (100-200ms) for prefixed words category. However, the syllabic priming did not reach significant differences at this component. Between 400 and 600ms morphologically related pairs evoked more positive values than the base-line as a consequence of an easier integration between prime and target. On the contrary, syllabically related pairs showed a larger negativity at this window. These contrasting results show a different course of processing depending on the relationship: morphological or phonological, existing between prime and target(AU)

Local classifiers for evoked potentials recorded from behaving rats.

Dynamic states of the brain determine the way information is processed in local neural networks. We have applied classical conditioning paradigm in order to study whether habituated and aroused states can be differentiated in single barrel column of rat's somatosensory cortex by means of analysis of field potentials evoked by stimulation of a single vibrissa. A new method using local classifiers is presented which allows for reliable and meaningful classification of single evoked potentials which might be consequently attributed to different functional states of the cortical column.

Un modelo neurocognitivo de la actividad sensoriomotora de carácter preparatorio en humanos / A neurocognitive model for short-term sensory and motor preparatory activity in humans

The purpose of this review is to present information from different experiments that supports the proposal that brain systems are able to predict, in a short-term interval, certain characteristics about the next incoming stimuli. This ability allows the subject to be ready for the stimuli and be more efficient in completing the required task. Evidence is presented from different sensory-motor experiments, such as the central cueing Posner paradigm; Contingent Negative Variation (E1-E2), spectral modulationduring expectancy and Lateralized Readiness Potential during the first-order sequential effect. Some cases from motor experiments are also presented, such as express saccades, the manual gap paradigm and ocular smooth pursuit movements. All these data support a neurocognitive model that canbe related to neuroanatomical structures whose connections have been wellestablished. In the final section, a possible algorithm that explains the selection of a preparatory set among the alternatives is discussed (AU)

Electrophysiological aberrations in borderline personality disorder: state of the evidence.

Electrophysiological technology is noninvasive and relatively inexpensive. In order to assess the usefulness of this technology in probing the pathophysiology of borderline personality disorder (BPD), we reviewed the literature in which an electrophysiological modality was used to examine BPD. Twenty-two articles were identified, from which diagnostic criteria and data on comorbidity and control groups were extracted. Although the majority of studies pointed to a high prevalence of electrophysiological aberrations in patients, very few studies had adequate control groups and adequate evaluation of comorbidity. We conclude that although the existing literature reflects a preliminary stage of the field, it suggests that electrophysiological investigations may be useful in investigating BPD.

Bilateralidade, simetria e correlaçäo clínico-eletrofisiológica na retinose pigmentar / Bilaterality, symmetry and clinical-electrophysiological correlation in retinitis pigmentosa

Objetivo: estudar a simetria e a correlaçäo entre achados psicofísicos e eletrofisiológicos em pacientes com retinose pigmentar (RP). Método: 58 pacientes com RP (média de idade de 34,4 ñ 16,8 anos), sendo 32 homens e 26 mulheres, foram examinados, realizando-se acuidade visual (AV), campo visual (CV), eletrorretinograma (ERG) e eletro-oculograma (EOG). Foram realizados os testes de Student para amostras dependentes e a correlaçäo de Pearson. Resultados: a AV média, em logMAR, foi de 0,35 (equivalente Snellen 20/47) para o olho esquerdo (OE). O campo visual foi de 20º em média para ambos os olhos (AO). O índice inter-ocular de correlaçäo de Pearson calculado para a AV e o CV foi de, respectivamente, r=0,722 e r=0,967 (p=0,05)

Avaliaçao da eficácia dos monofilamentos de Semmes-Weinstein no diagnóstico e evoluçao da neuropatia diabética através da análise comparativa com o estudo eletrofisiológico dos nervos e da correlaçao com o exame clínico / Evaluation of the efficacy of Semmes-Weinstein monofilaments in the diagnosis and evolution of diabetic neuropathy through comparative analysis with the electrophysiological study of nerves and correlation with clinical examination

O objetivo do presente trabalho foi aferir a eficácia dos monofilamentos de Semmes-Weinstein como instrumento de avaliaçao da sensibilidade dos pés de pacientes portadores de diabete mellitus. Realizou-se uma análise comparativa entre o método de Semmes-Weinstein e o exame eletrofisiológico dos nervos em pacientes diabéticos. Foram estabelecidas, também, correlaçaes entre os achados clínicos dos pacientes e os graus de comprometimento dos nervos periféricos detectados pelo exame com os monofilamentos. Foram avaliados 35 pacientes diabéticos nao insulino dependentes, sendo 16 do sexo feminino e 19 do sexo masculino, com idades entre 39 e 72 anos, médiade idade 35 amos, e a duraçao da doença variando entre 2 e 30 anos, com média de 11 anos

Optimal detection, classification, and superposition resolution in neural waveform recordings.

The effects of noise autocorrelation on neural waveform recognition (detection, classification, and superposition resolution) are investigated in this study using microelectrode recordings from the cortex of a monkey. Optimal waveform recognition is accomplished by passing the data through a whitening filter before matched filtering for detection or template matching for classification and superposition resolution. Template matching without whitening requires about 40% higher signal-to-noise ratio than template matching with whitening for comparable classification and superposition resolution. The comparable difference for detection is 15%.

The value of catheter mapping during sinus rhythm to localize site of origin of ventricular tachycardia.

We assessed the value of endocardial catheter mapping in 52 patients in sinus rhythm and with 102 morphologically distinct ventricular tachycardias. The local bipolar electrograms from various regions of the left ventricle were assessed and quantitatively classified with respect to the characteristics of amplitude and duration. With the use of this assessment we found that electrograms from the site of origin were of significantly lower amplitude and longer duration; however, because such an overlap occurred with electrograms that were not from sites of origin, this does not serve as a useful clinical marker. Various types of electrograms, including normal, abnormal, fractionated, abnormal late, fractionated late, and longest, were evaluated with respect to sensitivity, specificity, and positive predictive value. None of these types possessed the ability to reliably localize the site of origin of ventricular tachycardia. We therefore conclude that endocardial catheter mapping during sinus rhythm is not useful as a guide in localized surgical therapy of ventricular tachycardia. Surgery guided only by the results of mapping during sinus rhythm would result in a more extensive excision than that directed by maps obtained during ventricular tachycardia and in some cases would result in the exclusion of the area considered to be the site of origin of the tachycardia.