Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Methods Inf Med ; 43(1): 36-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15026833

RESUMO

OBJECTIVES: Among the many clinical decisions that psychiatrists must make, assessment of a patient's risk of committing suicide is definitely among the most important, complex and demanding. One of the authors reviewing his clinical experience observed that successful predictions of suicidality were often based on the patient's voice independent of content. The voices of suicidal patients exhibited unique qualities, which distinguished them from non-suicidal patients. In this study we investigated the discriminating power of lower order mel-cepstral coefficients among suicidal, major depressed, and non-suicidal patients. METHODS: Our sample consisted of 10 near-term suicidal patients, 10 major depressed patients, and 10 non-depressed control subjects. Gaussian mixtures were employed to model the class distributions of the extracted features. RESULTS AND CONCLUSIONS: As a result of two-sample ML classification analyses, first four mel-cepstral coefficients yielded exceptional classification performance with correct classification scores of 80% between near-term suicidal patients and non-depressed controls, 75% between depressed patients and non-depressed controls, and 80% between near-term suicidal patients and depressed patients.


Assuntos
Processamento de Sinais Assistido por Computador , Acústica da Fala , Suicídio/psicologia , Qualidade da Voz/fisiologia , Engenharia Biomédica , Depressão/fisiopatologia , Depressão/prevenção & controle , Depressão/psicologia , Humanos , Masculino , Medição de Risco/métodos , Fatores de Risco , Prevenção do Suicídio
2.
Graefes Arch Clin Exp Ophthalmol ; 236(4): 269-73, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9561359

RESUMO

PURPOSE: The purpose of this study was to evaluate the effect of aging on motion detection and perception. METHODS: Forty-six subjects, ages 19-92 years, were asked to view a motion stimulus. Infrared oculography was used to objectively evaluate motion detection by documenting the presence of optokinetic nystagmus as the subjects viewed the stimulus. Subjective responses to motion perception were recorded using a computer joystick. RESULTS: Optokinetic nystagmus was clearly detectable in all 46 subjects. Motion detection and perception thresholds showed age-related deterioration. No relationship was found to gender or age-gender interaction. CONCLUSION: The results indicate motion detection and perception thresholds deteriorate with age. This may reflect a susceptibility to age-related degeneration in specific cortical areas responsible for motion perception as well as neurodegeneration in the retinogeniculate pathway.


Assuntos
Envelhecimento/fisiologia , Percepção de Movimento/fisiologia , Transtornos da Visão/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Nistagmo Optocinético/fisiologia , Estimulação Luminosa , Limiar Sensorial/fisiologia , Testes Visuais , Córtex Visual/fisiologia
3.
J Am Acad Psychoanal ; 23(2): 335-52, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8675453

RESUMO

In this work, we have presented the treatment of a young woman with a psychotic character disorder, and we have described the multilateral transference configuration that derived from the treatment of this disorder. We have described some of the manifestations of this multivalent transference, and have described some aspects of its role in the patient's treatment. The theoretical background has been outlined. Although this transference configuration is relatively unique, we think that the nature of the treatment team that arose in this situation might have treatment implications for others with this disorder.


Assuntos
Terapia Psicanalítica , Regressão Psicológica , Transferência Psicológica , Adulto , Feminino , Humanos , Psicoterapia de Grupo , Transtornos Psicóticos/terapia
4.
Neurology ; 44(10): 1814-8, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7936228

RESUMO

To better understand the damage to the motion pathway that occurs in senile dementia of the Alzheimer type (SDAT), we developed a system to assess separately the conscious perception and unconscious detection of motion in patients with SDAT. Motion perception thresholds were significantly elevated in SDAT (n = 9) compared with controls (n = 12), but motion detection thresholds were normal. This dissociation between the perception and detection of motion in early SDAT parallels histologic evidence of a disconnection between primary and association visual cortices. This disconnection may underlie the severe visual perception deficits seen in SDAT.


Assuntos
Doença de Alzheimer/fisiopatologia , Percepção de Movimento/fisiologia , Eletronistagmografia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Nistagmo Optocinético , Limiar Sensorial
5.
Neurology ; 41(9): 1437-40, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1891094

RESUMO

To determine whether motion sensitivity varies with age, we measured motion discrimination in visual normals 25 to 80 years of age and found that motion thresholds increased linearly with age and were approximately two times higher in those 70 to 80 years old than in participants under thirty. This increase was not attributable to pupil size or retinal image distortion, but probably reflects neurodegeneration in the primary visual pathway. We compared the motion sensitivity of patients with senile dementia of the Alzheimer type (SDAT) with results from a subset of the visual normals of similar age. In SDAT patients, there were significant threshold elevations, which were more pronounced in the patients with more severe dementia. These findings confirm previous reports of visual system involvement in SDAT and indicate motion testing may reveal preclinical visual system involvement in SDAT.


Assuntos
Envelhecimento , Doença de Alzheimer/fisiopatologia , Percepção de Movimento , Percepção Visual , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Limiar Sensorial
6.
Invest Ophthalmol Vis Sci ; 31(9): 1895-902, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2211035

RESUMO

Most hypotheses of acquired dyschromatopsia invoke the mechanism of selective damage to specific components of the afferent visual system to explain the predominance of red-green and blue-yellow hue-discrimination defects found in neural and retinal disorders, respectively. However, this pattern of hue-discrimination disturbance in ocular disease may vary. There are frequent exceptions which are inadequately explained by existing hypotheses. In an effort to explain the pattern and pathogenesis of acquired dyschromatopsias better, the authors examined patients with nonproliferative diabetic retinopathy (DR) and late-stage retrobulbar neuritis (RBN) using age-corrected Farnsworth-Munsell 100-hue testing and threshold static perimetry. As expected, most DR eyes showed some degree of relative blue-yellow dyschromatopsia (89%) with few showing a greater weighting towards red-green dyschromatopsia (11%). However, an approximately equal number of RBN eyes had a relative blue-yellow (48%) versus red-green dyschromatopsia (52%). For RBN, the authors found a strong association between the spatial distribution of field defect and the type of relative hue-discrimination disturbance. Eyes with greater field depression at the fovea relative to the perifovea showed a relative preponderance of red-green dyschromatopsia (68%) as opposed to blue-yellow dyschromatopsia (32%), whereas eyes with greater relative perifoveal impairment showed a relative preponderance of blue-yellow dyschromatopsia (100%). This relationship between the relative spatial distribution of visual field damage and the relative hue-discrimination deficit in RBN was statistically significant (P = 0.002). Such an association was not found for DR.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Defeitos da Visão Cromática/fisiopatologia , Fóvea Central/fisiopatologia , Neurite Óptica/fisiopatologia , Campos Visuais , Adolescente , Adulto , Idoso , Testes de Percepção de Cores , Defeitos da Visão Cromática/etiologia , Retinopatia Diabética/complicações , Retinopatia Diabética/fisiopatologia , Humanos , Pessoa de Meia-Idade , Neurite Óptica/complicações , Testes de Campo Visual
7.
Invest Ophthalmol Vis Sci ; 31(4): 722-9, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2335439

RESUMO

Several lines of evidence suggest that the large optic nerve fibers, which form the magnocellular retinocortical pathway, are preferentially susceptible to early glaucomatous damage. It is evident from studies of the functional architecture of the visual system that the magnocellular pathway underlies the global perception of motion. Therefore, we have developed a psychophysical technique for assessing motion detection thresholds in patients with ocular hypertension (OHT) and primary open-angle glaucoma (POAG). For this purpose we employed a dynamic random dot display that contained varying degrees of a coherent motion signal embedded within a background of random motion noise. We used this technique to measure motion thresholds in POAG patients (n = 37), OHT patients (n = 14), and age-matched controls (n = 39). Motion thresholds were elevated by 70% for the POAG group and 44% for the OHT group relative to controls. In the same patients, no significant deficit in form discrimination was found as measured by Pelli-Robson charts. Our results demonstrate that significant motion perception deficits are evident in POAG and OHT. These findings support the suggestion that significant and selective damage to the magnocellular pathway occurs in OHT and POAG and indicate that motion threshold testing may reveal preclinical optic nerve disease in early POAG.


Assuntos
Glaucoma de Ângulo Aberto/fisiopatologia , Percepção de Movimento/fisiologia , Hipertensão Ocular/fisiopatologia , Sensibilidades de Contraste , Humanos , Pessoa de Meia-Idade , Limiar Sensorial , Campos Visuais
8.
Invest Ophthalmol Vis Sci ; 31(2): 359-67, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2303333

RESUMO

Using a modified Humphrey perimeter, we evaluated 16 eyes with primary open-angle glaucoma and visual field loss (defects 0.5-3.0 log units in depth), and 14 normal eyes. Each eye was tested twice in random order with conventional luminance-increment static perimetry and with the perimeter modified to produce a high-luminance yellow adapting background and a blue test stimulus. The background was a broad-spectrum light of 500 nm and above (yellow), while the stimulus was a broad-spectrum light of 500 nm and below (blue). Paired comparisons were made between conventional and blue/yellow sensitivities for every point examined (1184 points in 16 diseased eyes and 1036 points in 14 normal eyes). Defect depths were determined by using the age-corrected norms distributed in the Humphrey Statpac software. In glaucomatous eyes, blue/yellow sensitivity showed greater impairment than did conventional perimetric sensitivity, in which defect depths were less than 1.0 log unit. However, for defects greater than 1.0 log unit in depth, conventional perimetric sensitivity and blue/yellow sensitivity showed equivalent degrees of damage. Receiver operating characteristic (ROC) analysis was used to compare the ability of blue/yellow and of conventional perimetry in distinguishing between glaucomatous and normal eyes. Results indicated that although blue/yellow color-contrast perimetry may be more sensitive for the detection of incipient glaucomatous damage, in the manifest stages of visual field damage blue/yellow color-contrast perimetry is no more sensitive than is conventional (luminance-increment) perimetry for defining the extent of glaucomatous visual field defects.


Assuntos
Percepção de Cores , Sensibilidades de Contraste , Glaucoma de Ângulo Aberto/fisiopatologia , Campos Visuais , Adulto , Idoso , Idoso de 80 Anos ou mais , Glaucoma de Ângulo Aberto/diagnóstico , Humanos , Pessoa de Meia-Idade , Distribuição Aleatória , Testes de Campo Visual/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...