Coherence between fMRI time-series distinguishes two spatial working memory networks.
Neuroimage
; 26(1): 177-83, 2005 May 15.
Article
em En
| MEDLINE
| ID: mdl-15862217
ABSTRACT
Widespread and distributed brain regions are thought to form networks that together support working memory. We recently demonstrated that different cortical areas maintain relatively different codes across a memory delay (Curtis et. al., J Neurosci, 2004; 243944-3952). The frontal eye fields (FEF), for example, were more active during the delay when the direction of the memory-guided saccade was known compared to when it was not known throughout the delay. Other areas showed the opposite pattern. Despite these task-dependent differences in regional activity, we could only assume but not address the functional interactions between the identified nodes of the putative network. Here, we use a bivariate technique, coherence, to formally characterize functional interactions between a seed region and other brain areas. We find that the type of representational codes that are being maintained in working memory biases frontal-parietal interactions. For example, coherence between FEF and other oculomotor areas was greater when a motor representation was an efficient strategy to bridge the delay period. However, coherence between the FEF and higher-order heteromodal areas, e.g., dorsolateral prefrontal cortex, was greater when a sensory representation must be maintained in working memory.
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Base de dados:
MEDLINE
Assunto principal:
Percepção Espacial
/
Memória de Curto Prazo
/
Rede Nervosa
Limite:
Adolescent
/
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article