Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: What takes the brain so long: Object recognition at the level of minimal
  images develops for up to seconds of presentation time   Rich empirical evidence has shown that visual object recognition in the brain
is fast and effortless, with relevant brain signals reported to start as early
as 80 ms. Here we study the time trajectory of the recognition process at the
level of minimal recognizable images (termed MIRC). These are images that can
be recognized reliably, but in which a minute change of the image (reduction by
either size or resolution) has a drastic effect on recognition. Subjects were
assigned to one of nine exposure conditions: 200, 500, 1000, 2000 ms with or
without masking, as well as unlimited time. The subjects were not limited in
time to respond after presentation. The results show that in the masked
conditions, recognition rates develop gradually over an extended period, e.g.
average of 18% for 200 ms exposure and 45% for 500 ms, increasing significantly
with longer exposure even above 2 secs. When presented for unlimited time
(until response), MIRC recognition rates were equivalent to the rates of
full-object images presented for 50 ms followed by masking. What takes the
brain so long to recognize such images? We discuss why processes involving
eye-movements, perceptual decision-making and pattern completion are unlikely
explanations. Alternatively, we hypothesize that MIRC recognition requires an
extended top-down process complementing the feed-forward phase.

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The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph