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Dear Dario, The term “window” may be inappropriate in
this
context, as it implies a “brick wall” type of temporal filter. A more
appropriate metaphor may be “time constant” with an exponential decay
function.
The precise function depends on the nature of the sensory input and the
purpose
to which it’s put. Erickson’s visual integration study of
ca. 1965 suggests
that eidetic imagery (a form of visual memory) may persist up to ca. 1.5
seconds. He used quasi-random dot patterns, which when presented
concurrently to
both visual fields, formed tri-gram letter sequences. By varying the
time delay
between the two dot patterns, the decay function (for this task) could
be
deduced. Experiments on tonal fission and fusion
(by van
Noorden, Bregman and others) can be interpreted similarly (translating
frequency distance into appropriate spatial coordinates). In speech, the average duration of a
“turn” in
spontaneous dialogue is ca. 2 seconds (it varies somewhat, depending on
speaking
style, topic and communication medium). Integration of linguistic
elements of
variable scale (phonetic feature, segment, syllable, word, phrase) into
“meaning” is likely to conform to comparable limits as those cited
above. Cowan and others have estimated the span
of
short-term memory to be ca. 4 seconds, an interval close to the typical
upper limit
of a talker’s “turn” in spontaneous (true) dialogues. The sensory systems are closely
intertwined with
the memory systems, which in turn are intimately associated with
communication,
emotion and action. This is one reason why estimates of time
constants/windows
vary somewhat across modality, task and subject. Best wishes, and good luck with your
research. |