Cognitive processes in two-point discrimination: an ERP study.
Clin Neurophysiol
; 115(8): 1875-84, 2004 Aug.
Article
em En
| MEDLINE
| ID: mdl-15261866
ABSTRACT
OBJECTIVE:
To elucidate the temporal features of the cognitive process in two-point discrimination (TPD).METHODS:
We measured somatosensory event-related potentials (ERPs) in 9 subjects during the TPD task, in which we provided a pair of electrical pulses simultaneously, altering the distance between the electrodes. We analyzed the TPD-related ERPs and investigated the relationship between the potentials and the subjects' judgments.RESULTS:
During the TPD task, a negative potential approximately 140 ms after the stimulation (N140) was enhanced as compared to a stimulus counting task. Two late positive components, LPC-1 and LPC-2, whose peak latencies were 300 and 500 ms, respectively, were identified only in the TPD task. The LPC-1 was recorded dominantly in the fronto-central area, while the LPC-2 was detected dominantly in the centro-parietal area. The amplitude of the LPC-2 was significantly modulated by the degree of consistency in the subjects' judgment. On the other hand, these ERP components did not show significant difference between the alternate judgments, i.e. 'one-point' or 'two-point' judgment.CONCLUSIONS:
Our results suggest that the N140 is related to the attention toward the stimulation. The LPC-1 and LPC-2 are likely to correspond to the processes represented by P3a and P3b, based on their temporal and spatial behavior.
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Base de dados:
MEDLINE
Assunto principal:
Cognição
/
Discriminação Psicológica
/
Potenciais Somatossensoriais Evocados
Tipo de estudo:
Prognostic_studies
Limite:
Adult
/
Humans
/
Male
Idioma:
En
Revista:
Clin Neurophysiol
Assunto da revista:
NEUROLOGIA
/
PSICOFISIOLOGIA
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Japão