List Memory and Alphabetic Retrieval

[Danielle S. McNamara]

John,
Perhaps I have misunderstood, but when you said that we cannot retrieve
positional pointers, I was reminded of some Estes data in STM serial
recall. He looked at intrusions between lists and showed that if an item
from a previous listed intruded into the recall of a subsequent list, the
item retained its position in the list (or within 1 position).  So, this
indicates that the position of the item is not necessarily generated on
line but is intrinsic to the encoding of the item.  If I remember
correctly, you and Mike simulated this type of data (i.e., item/order
recall) -- would it have or did it predict these types of intrusions across
lists?  If so, how?
Danielle

>
>The model with Mike Matessa did step through the list, first by groups
>and then by items within a group, as Todd describes and as the Klahr
>model did.  My view, again such as it is, is an elaboration of the
>answer above.  This is that one cannot really retrieve positional
>pointers but rather has to generate them.  Thus, the only way to know
>what position an item occupies is to count up positional pointers until
>one gets to it.  Indeed, I think we would concede we can only retrieve
>the position of m in its group by generating (abcd) (efg) (hijk) (lmnop)
>and saying second.
>
>Both points illustrate the fact that a significant piece of the ACT-R
>theory of serial memory does not come from the ACT-R architecture but
>rather assumptions about the position-based representation which are
>motivated by the data.



Danielle S. McNamara
  Asst. Professor
  Department of Psychology
  Old Dominion University
  Norfolk, Virginia 23529-0267

email: dmcnamar at odu.edu
phone: (757) 683-4446
fax: (757) 683-5087