Organization of Working Memory— Reconciling Two Different Models Anna Alapatt

Working Memory (WM) Working memory holds information in a rapidly accessible and easily updated state E.g. Getting dressed in the morning Core cognitive ability—predicts intelligence (IQ & scholastic achievement) 3-4 slots for most people (Luck & Vogel, 1997).

What is Visual Short Term Memory (VSTM)? FixationEncodingStorageComparison Previous research has shown that people can maintain 3 to 4 items in VSTM through change detection tasks.

Two hypotheses about how WM is organized General resource model—no matter what is being remembered a single common resource determines memory capacity General resource model—no matter what is being remembered a single common resource determines memory capacity Many resource model—there are multiple types of working memory depending on what type of information is being stored Many resource model—there are multiple types of working memory depending on what type of information is being stored

WM..Many Resources Domain specific slots Domain specific slots Baddeley Model—many resources Baddeley Model—many resources Baddeley’s Model of Memory

WM..One Resource Domain General Slots Cowan Model Focus of attention Activated Portion of LTM Cowan’s Memory Model

General Question Awh, Barton, Vogel (2007), have suggested there might be two distinct abilities within visual working memory: 1) number 2) precision/resolution Awh, Barton, Vogel (2007), have suggested there might be two distinct abilities within visual working memory: 1) number 2) precision/resolution Is it possible one aspect (e.g., number) is domain general, and the other (e.g., precision) domain specific? Is it possible one aspect (e.g., number) is domain general, and the other (e.g., precision) domain specific?

Current Study—2 aspects of memory ability  Used motion & color as examples (both processed in distinct parts of visual cortex)  Reconcile the 2 different models  Predictions :   Cowan’s domain general model may be correct with respect to number   Baddeley’ domain specific model may be correct with respect to the precision of the memory representations.

Experimental Design Sample Array Test ArrayDelay Interval Time 1 second Until Response

The number of motion stimuli that could be stored was reliably correlated with the number of colors. This correlation is consistent with Cowan’s stimulus-general model of capacity in working memory.

These data fall more in line with the hypothesis that color and motion memory are supported by separate resources. These data fall more in line with the hypothesis that color and motion memory are supported by separate resources. Supports Baddeley’s model Supports Baddeley’s model The precision of motion recall did not predict how many colors could be stored in working memory.

Discussion The number of motion patches and the number of colors stored in working memory were correlated. This suggests a common resource mediating how many things can be stored in working memory The number of motion patches and the number of colors stored in working memory were correlated. This suggests a common resource mediating how many things can be stored in working memory The precision of motion memory was not correlated with the number of colors they could store. This suggest that number and precision are different aspects of memory ability, and leaves open the possibility that Baddeley’s multiple resource model is correct with respect to the precision of representations in working memory. The precision of motion memory was not correlated with the number of colors they could store. This suggest that number and precision are different aspects of memory ability, and leaves open the possibility that Baddeley’s multiple resource model is correct with respect to the precision of representations in working memory.

Future Direction This is all a part of a project to look at many different stimuli (orientation, motion, etc.) and see how number and resolution relate across different types of information processed This is all a part of a project to look at many different stimuli (orientation, motion, etc.) and see how number and resolution relate across different types of information processed

Thanks….