Re: Categorisation and Prototypes

From: Hooper, Molly (MH395@psy.soton.ac.uk)
Date: Fri May 24 1996 - 17:05:58 BST


What is the classical view of Categorisation?

Categorisation, similarly classed as categorical perception, as John
R. Anderson in his book "Cognitive Psychology and its Implications" of
1995 states, refers to the perception of stimuli as belonging in
distinct, discreet categories, and, the failure to perceive the
graduations among stimuli present within a particular category. This
classical view of Categorisation can be explained further by
exploring investigations conducted in 1969 by Allan Paivio who
studied "Mental Representations" in conjunction with a dual coding
approach and produced some remarkable insights. It appears that
Categorisation occurs when the visual and auditary systems of an
individual is organised by the mind into discreet and completely
distinct categories whose members seem to resemble one another more
so than they would resemble those members present in other
categories. An example of this phenomenon can be found in Stevan
Harnad's book of 1990 "Categorical Perception: The groundwork of
Cognition" where he examines colour categories. Harnad argues that
colours differ, physically , only in their wavelengths, which
gradually become shorter across the spectrum of visible colours.
However, the individual person will perceive qualitative changes from
red to orange to yellow to green, and so on. Such prompt
superordinate classification suggests that abstract information is
stored in organised categories, as it has been proved even in very young
children. Similarly, this process is true of appreciating musical
pitches where slight increasing changes of frequency begin to be heard
as categorical changes from C to C sharp to D to E flat. In each
particular case, discreet specifics are quickly subordinated to
broad categorical criteria , envelopes which subsume constant common
attributes. This conception supposes that related events are grouped
into concept ladders, and maintained with the aid of mnemonic summary
codes. These "perceptual boundaries" have evolved along a physical
continuum, separating it into discrete regions "with qualitative
resemblances within each category and qualitative resemblances
between them." Therefore, this classical view of Categorisation,
incorporating these bounded categories, may indeed provide the
groundwork for our higher-order cognition and language.



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