* Visual cortical gamma-band activity during free viewing of natural images.
- Gamma-band activity in visual cortex has been implicated in several cognitive operations, like perceptual grouping and attentional selection. So far, it has been studied primarily under well-controlled visual fixation conditions and using well-controlled stimuli, like isolated bars or patches of grating. If gamma-band activity is to subserve its purported functions outside of the laboratory, it should be present during natural viewing conditions. We recorded neuronal activity with a 252-channel electrocorticographic (ECoG) grid covering large parts of the left hemisphere of 2 macaque monkeys, while they freely viewed natural images. We found that natural viewing led to pronounced gamma-band activity in the visual cortex. In area V1, gamma-band activity during natural viewing showed a clear spectral peak indicative of oscillatory activity between 50 and 80 Hz and was highly significant for each of 65 natural images. Across the ECoG grid, gamma-band activity during natural viewing was present over most of the recorded visual cortex and absent over most remaining cortex. After saccades, the gamma peak frequency slid down to 30-40 Hz at around 80 ms postsaccade, after which the sustained 50- to 80-Hz gamma-band activity resumed. We propose that gamma-band activity plays an important role during natural viewing.
=>出席している, そこにある, 現在の, 今の, 当面の, いあわせている, 考慮している, 現在, を人に贈る,
進呈する, を与える, を渡す, を紹介する, を公開する, を見せる, 示す, 贈り物, 【文法】現在時制の,
プレゼント, 贈る, ある, 現在形の
Overview of noun present
The noun present has 3 senses (first 2 from tagged texts)
1. (17) present, nowadays -- (the period of time that is happening now; any continuous stretch of
time including the moment of speech; "that is enough for the present"; "he lives in the present with
no thought of tomorrow")
2. (4) present -- (something presented as a gift; "his tie was a present from his wife")
3. present, present tense -- (a verb tense that expresses actions or states at the time of speaking)
Overview of verb present
The verb present has 13 senses (first 10 from tagged texts)
1. (40) show, demo, exhibit, present, demonstrate -- (give an exhibition of to an interested
audience; "She shows her dogs frequently"; "We will demo the new software in Washington")
2. (28) present, represent, lay out -- (bring forward and present to the mind; "We presented the
arguments to him"; "We cannot represent this knowledge to our formal reason")
3. (14) stage, present, represent -- (perform (a play), especially on a stage; "we are going to
stage `Othello'")
4. (13) present, submit -- (hand over formally)
5. (7) present, pose -- (introduce; "This poses an interesting question")
6. (3) award, present -- (give, especially as an honor or reward; "bestow honors and prizes at
graduation")
7. (3) give, gift, present -- (give as a present; make a gift of; "What will you give her for her
birthday?")
8. (3) deliver, present -- (deliver (a speech, oration, or idea); "The commencement speaker
presented a forceful speech that impressed the students")
9. (2) introduce, present, acquaint -- (cause to come to know personally; "permit me to acquaint you
with my son"; "introduce the new neighbors to the community")
10. (1) portray, present -- (represent abstractly, for example in a painting, drawing, or sculpture;
"The father is portrayed as a good-looking man in this painting")
11. confront, face, present -- (present somebody with something, usually to accuse or criticize; "We
confronted him with the evidence"; "He was faced with all the evidence and could no longer deny his
actions"; "An enormous dilemma faces us")
12. present -- (formally present a debutante, a representative of a country, etc.)
13. salute, present -- (recognize with a gesture prescribed by a military regulation; assume a
prescribed position; "When the officers show up, the soldiers have to salute")
Overview of adj present
The adj present has 2 senses (first 2 from tagged texts)
1. (60) present -- (temporal sense; intermediate between past and future; now existing or happening
or in consideration; "the present leader"; "articles for present use"; "the present topic"; "the
present system"; "present observations")
2. (39) present -- (being or existing in a specified place; "the murderer is present in this room";
"present at the wedding"; "present at the creation")
--- WordNet end ---