Evidence from many studies conducted over the past century suggests th
at human perception is partitioned into 1-4-s units. More recently, a
similar 1-4-s time constant has been found in non-perceptual phenomena
, i.e. movement patterns, of both human and non-human mammalian specie
s. Based on these findings, it appears that an evolutionarily conserve
d mechanism exists that segments human and non-human mammalian motor a
ctions into 1-4-s units. This being the case, it is believed that the
1-4-s segmentation seen in human perception may also occur in mammalia
n perception. However, it is currently impossible to determine whether
both human and non-human perception is partitioned into 1-4-s units b
ecause the paradigms used to study the 1-4-s unit in human perception
cannot be applied to non-human species. This study hypothesized that v
igilance postures represent a paradigm that will allow such comparativ
e work. This is based on the fact that investigators recently found th
at vigilant postures in humans are partitioned into 1-4-s units, and t
he literature argues strongly that vigilance is largely a perceptual p
henomenon. With this in mind, the current study determined whether sim
ilar vigilant postures occur in non-human mammals and whether such vig
ilant postures are also segmented into 1-4-s units. The study found th
at such postures averaged 2-3.5 s in primates (n = 1 species), carnivo
res (n = 2 species), artiodactyls (n = 3 species), and marsupials (n =
1 species). These findings support the hypothesis that perception in
humans and other mammals is partitioned into units by a conserved mech
anism. It is believed that vigilant postures will be an important quan
tifiable bioassay with which to conduct comparative studies of mammali
an perception.