Cortical feedback depolarization waves: A mechanism of top-down influence on early visual areas
نویسندگان
چکیده
منابع مشابه
Cortical feedback depolarization waves: a mechanism of top-down influence on early visual areas.
Despite the lack of direct evidence, it is generally believed that top-down signals are mediated by the abundant feedback connections from higher- to lower-order sensory areas. Here we provide direct evidence for a top-down mechanism. We stained the visual cortex of the ferret with a voltage-sensitive dye and presented a short-duration contrast square. This elicited an initial feedforward and l...
متن کاملTop-down influence in early visual processing: a Bayesian perspective.
Traditional views of visual processing suggest that early visual neurons are static spatiotemporal filters that extract local features by feedforward computation. The extracted information is then fed forward through a chain of modules to successively higher visual areas for further analysis. Recording from early visual neurons in awake behaving monkeys, we revealed there are many levels of com...
متن کاملA cortical mechanism for triggering top-down facilitation in visual object recognition.
The majority of the research related to visual recognition has so far focused on bottom-up analysis, where the input is processed in a cascade of cortical regions that analyze increasingly complex information. Gradually more studies emphasize the role of top-down facilitation in cortical analysis, but it remains something of a mystery how such processing would be initiated. After all, top-down ...
متن کاملAge-related top-down suppression deficit in the early stages of cortical visual memory processing.
In this study, electroencephalography (EEG) was used to examine the relationship between two leading hypotheses of cognitive aging, the inhibitory deficit and the processing speed hypothesis. We show that older adults exhibit a selective deficit in suppressing task-irrelevant information during visual working memory encoding, but only in the early stages of visual processing. Thus, the employme...
متن کاملthe impact of explicit instruction of top-down reading strategies on reading comprehension of intermediate efl learners
this study investigated (a) the learners’ existing reading strategy repertoire, (b) the effect of instruction in reading strategies on learners’ strategic performance, and (c) the effect of explicit instruction in top-down reading strategies on reading comprehension ability of intermediate learners. the study was conducted with 40 intermediate efl learners in two groups of experimental and cont...
ذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 2006
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.0604925103