Nelson Cowan University of Missouri, Columbia 2008572071 Jeon Young- joo

1. HUMAN FACTORS ENGINEERINGIMS621 Evolving Conceptions of Memory Storage, Selective Attention, and Their Mutual Constraints Within the Human Information-Processing System Nelson CowanUniversity of Missouri, Columbia 2008572071 Jeon Young-joo

2. Contents • Introduction • Characteristics of Memory Storage • Central Processor or Executive • Mechanisms of Selective Attention • Derived Components of Processing • Revised Graphic Representation of Processing • Appraisal of Alternative to the Present Approach • Research Issues • Conclusion

3. Introduction • Pipeline-model(Broadbent’s, 1958) • Information is conveyed in a fixed serial order from one storage structure to the next • "filter" • Flaw of the model • Its characterization of the subject as a passive recipient of information • massive "top-down“ influences in perception • the inability to represent processing strategies and flexibility in a plausible manner • logical flaws in methods • Alternative model • "Maltese cross" • allowed increased flexibility in the sequence of information transfer. • this model may have too many unnecessary degrees of freedom. • Parallel process (McClelland, and Hinton, 1986) • Organization of the Article • Memory storage will be reviewed • “Central Executive“ • Alternative Models 

4. Characteristics of Memory Storage • Broadbent's model (1958) • Atkinson and Shiffrin‘s(1968) Broadbent (1958)

5. Characteristics of Memory Storage • Problem of the Order of Stores • Multistore model • Episodic vs. Samantic(Anderson and Bower, 1973) • Short- Term Storage as an Active State • Properties of Short-Term (Activated) Versus Long-Term Memory • Timing of memory activation • Coding & Control property • Ex. IBMCIAFBIRCASOS • Storage capacity limits Stimulation Sensory memory Sort-term store Long-term store Norman (1968)

6. Characteristics of Memory Storage • Distinctions Between Sensory and Short-Term Stores • Overview. • Sensory: A brief phase providing continued sensation for up to several 100 msec. & a second phase retaining more processed sensory information for some seconds. • Perceptual coding and the concept of sensory storage.  • Modality specific • continuous information • Two phases of sensory storage. • Echoic memory (several sec.) • Kallman & Massaro(1979) : standard-mask-target, standard-target-mask • Efron(1970) : estimate the time of onset or time of offset • Eriksen and Johnson (1964) • Iconic memory (100 msec.)

7. Characteristics of Memory Storage • Sensory vs. Short-term storage • Duration • sensory memory : 10 to 20 s. • the duration of short-term storage require at least four requirements • one must prevent or assess the contribution of sensory memory • one must not interfere with the non-sensory memory that is being studied • one must prevent rehearsal processes that would extend the period of activation • one must prevent or assess the effects of other factors that encourage attentive processing • Capacity limits • there is no evidence of the unlimited capacity of sensory storage across some seconds. • Awareness • Both would be memory in an activated state serving as a data base accessible to attentive processing • Coding • coding characteristics do not provide sufficient grounds to propose the functional separation between the second phase of sensory memory and short-term storage any more than do the concepts of duration, capacity, or access to awareness

8. Characteristics of Memory Storage • Concept of Multifaceted Short-Term Store • All forms of short-term storage may consist of temporarily activated memory elements, and all may enter awareness when attentional processes are focused on them. It is thesecommon features that appear to be most important when one is attempting to understand the overall organization of the processing system.

9. Central Processor or Executive • Clarification of Central Executive Concept • The central executive may be a conglomeration of different processes rather than a unified structure, but these processes at least are highly related. • the selection of information channels from short-term memory • scanning short-term memory to select among items recently entered from the stimulus or from long-term memory • the maintenance of information in short-term memory through various types of rehearsal • long-term memory searches leading to the more elaborate storage of short-term memory information in long-term memory • problem-solving activities including principled long-term memory retrieval and a recombination of short-term memory units to form new associations. • Short-Term Storage With and Without Central Executive • A concept in memory can be automatically activated by a stimulus, or attentive processes can be directed to the concept. • effortful activation of memory categories corresponding to relevant stimuli or concepts also improves the subject's resistance to the involuntary capturing of attention by irrelevant stimuli. • Long-Term Storage With and Without Central Executive

10. Mechanisms of Selective Attention • Overview • a careful definition of an attentional filter • Assumptions about the chronology of the transfer of information from store to store • a definition of perception • a justifiable set of assumptions about the mechanism of filtering or selection.  • Selective filter. • A filter must mean more than just a point of selectivity in processing; some investigators have pointed out the likelihood that selectivity occurs at many different levels of processing  Information Information Sensory Storage Perception of selective memory Broadbent (1957)

11. Mechanisms of Selective Attention • Locus of Selective Attention • Delineation of theoretical position • Partial coading and activation in a system with an intermediate-level filter • Implications of learned automaticity for attentional filtering • Habituation Hypothesis of Selective Attention • Effects of habituation to unattended stimuli • Effects of orienting to changes in unattended stimuli • Formation of a neural model • Active attentional focus • Cautionary note

12. Derived Components of Processing • The strength of the present conception of information processing depends upon the identification of a small repertoire of basic components • sensory storage across several 100 msec. • long-term memory • a short-term store consisting of the activated subset of long-term memory • effortful, active processes or a central executive, which selects a subset of information in short-term storage as the focus of attention.  • Articulatory loop(Baddeley,1986) • Complex mental functions such as reasoning, learning, and problem solving presumably also rely upon passive storage and active processing together, but these types of function a depend upon at least two major aspects of the cognitive system that fall outside of the scope of this review: • the structure of knowledge within long-term memory and • the structure and function of the central executive

13. Revised Graphic Representation of Processing

14. Appraisal of Alternatives to the Present Approach • Single-Store Approach (Wickelgren, 1973) • Levels of Processing: Another Single-Store Approach? • Parallel-Stores Approach (Shallice and Warrington, 1970) • Flexible-Order Multistore Approach (Broadbent, 1984) • Computer Model of Memory Storage and Activation (Anderson, 1983)

15. Research Issues • Short and Long Sensory Store • Short-Term Activation and Focus of Attention • Selective Attention and Habituation • Working memory System as Derived Components

16. Conclusion • Sensory storage may be functionally distinct from other forms of short-term storage only in the first few hundred milliseconds. • Short-term storage should be viewed as an activated subset of long-term memory. • Selective attention involves habituation rather than filtering as it is usually conceived.