Mind, Body, World- Foundations of Cognitive Science, 2013a

hypothesis (Dawson, 1998), is used to explain information devices by performing
analyses at three different levels: computational, algorithmic, and implementational.
The approach that has been developed in this chapter agrees with this view,
but adds to it an additional level of analysis: the architectural. We will see throughout
this book that an information processing architecture has properties that separate
it from both algorithm and implementation, and that treating it as an independent
level is advantageous.
The view that information processing devices must be explained by multiple
levels of analysis has important consequences for cognitive science, because the
general view in cognitive science is that cognition is also the result of information
processing. This implies that a full explanation of human or animal cognition also
requires multiple levels of analysis.
Not surprisingly, it is easy to find evidence of all levels of investigation being
explored as cognitive scientists probe a variety of phenomena. For example, consider
how classical cognitive scientists explore the general phenomenon of human memory.
At the computational level, researchers interested in the formal characterization
of cognitive processes (such as those who study cognitive informatics
[Wang, 2003, 2007]), provide abstract descriptions of what it means to memorize,
including attempts to mathematically characterize the capacity of human memory
(Lopez, Nunez, & Pelayo, 2007; Wang, 2009; Wang, Liu, & Wang, 2003).
At the algorithmic level of investigation, the performance of human subjects in
a wide variety of memory experiments has been used to reverse engineer “memory”
into an organized system of more specialized functions (Baddeley, 1990) including
working memory (Baddeley, 1986, 2003), declarative and nondeclarative memory
(Squire, 1992), semantic and episodic memory (Tulving, 1983), and verbal and
imagery stores (Paivio, 1971, 1986). For instance, the behaviour of the serial position
curve obtained in free recall experiments under different experimental conditions
was used to pioneer cognitive psychology’s proposal of the modal memory model,
in which memory was divided into a limited-capacity, short-term store and a much
larger-capacity, long-term store (Waugh & Norman, 1965). The algorithmic level is
also the focus of the art of memory (Yates, 1966), in which individuals are taught
mnemonic techniques to improve their ability to remember (Lorayne, 1998, 2007;
Lorayne & Lucas, 1974).
That memory can be reverse engineered into an organized system of subfunctions
leads cognitive scientists to determine the architecture of memory. For
instance, what kinds of encodings are used in each memory system, and what
primitive processes are used to manipulate stored information? Richard Conrad’s
(1964a, 1964b) famous studies of confusion in short-term memory indicated that
it represented information using an acoustic code. One of the most controversial
topics in classical cognitive science, the “imagery debate,” concerns whether the
52 Chapter 2