Serial memory processing: Difference between revisions

Revision as of 19:24, 9 April 2012

Revision as of 19:54, 9 April 2012

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;Primacy and recency effects

In serial memory processing, [[Primacy effect]] and [[Recency effect]] effects for accuracy of recall are commonly found. These effects are found for both visual <ref name=Parmentier>Parmentier, F. B., Andres, P., Elford, G., & Jones, D. M. (2006). Organization of visuo-spatial serial memory: Interaction of temporal order with spatial and temporal grouping. ''Psychological Research, 70''(1).</ref> and auditory <ref name=Avons>Avons, S. E. (1998). Serial report and item recognition of novel visual patterns. ''British Journal of Psychology, 89''(1).</ref> stimuli in memory tasks. This means that of the many items in a memory set during serial memory processing, the first item and the last seem to be recalled faster and more accurately than the other items. These effects may exist if recall errors are due to serial position. ThereIt is theorized that items are mistaken for other items from a nearby position in the memory set (e.g. the 5th item is mistaken for the 4th item or the 6th item). Since there are more nearby serial positions to middle items in a set, andthere are therefore more opportunities for mixmixing-up items. On the other hand, there are very few serial positions nearby to the first and last position, and therefore these positions may be remembered more accurately (or mistaken less). The first and last position may be less error-prone positions and more easily recalled. <ref name=Naire>Nairne, J. S. (1992). The loss of positional certainty in long-term memory.''Psychological Science, 3''(3).</ref>

The suffix effect, is an effect that removes the recency effect, simply by adding in a meaningless item at the end of the original memory set. The belief is that this meaningless item will be remembered instead of the second-to-last item which was originally remembered due to the recency effect. However, the suffix effect varies based on the similarity of the item to the set. For visual stimuli, adding in the meaningless item, whether or not it is visually similar to the original memory set, will remove the recency effect. For auditory stimuli, adding in the meaningless item will only remove the recency effect if it is phonologically similar. Adding an item that is phonologically different (e.g. A, Q) will not have this effect. <ref name=Parmienterr>Parmentier, F. B., Tremblay, S., & Jones, D. M. (2004). Exploring the suffix effect in serial visuospatial short-term memory. ''Psychonomic Bulletin and Review, 11''(2).</ref>

;Stimuli grouping effects

Items in a serial memory can be presented in ways that promote grouping. Individuals can group the memoryset of items spatially and temporally. <ref name=Parmentier />

Spatial grouping refers to the items in the original memory set being grouped by their spatial characteristics. An example of this would be presenting the first three items in the top right corner, and the remaining three items in the bottom left corner. These items are now grouped into two groups of three based on their spatial attributes. As well, itIt has been found that the longer the spatial pathways from item to item, the slower the recall time and the lower the accuracy of recall. Therefore, item’s that have a small spatial pathway between them, are remembered better and faster. In this case, the fourth item would be remembered less easily, because the spatial pathway from the top right corner (where the third item was) to the bottom left corner (where the fourth item will be) is longer than most. <ref name=Parmentier />

Temporal grouping refers to the items in the original memory set being grouped by their temporal characteristics. An example of this would be presenting the first three items simultaneously, then waiting five seconds, and then presenting the remaining three items. These items are now grouped into two groups of three based on their temporal attributes. It has been found that when item’s are grouped temporally, the accuracy of recall is higher than when they are not. As well, there is evidence that participants may create their own temporal groupings. In a memory task where items were not temporally grouped, the reaction times of recall for the 1st, 4th and 7th (out of 9) items were significantly faster. ShowingThis finding shows evidence forthat participants may be creating their own temporal group of three, since the first item of each group (the 1st, 4th and 7th) are recalled faster than the rest of the items in their "group". <ref name=Parmentier />

;Other errors

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;Processing in atypical individuals

It has been found that when mental age is equated, there is no difference in performance on serial memory tasks for children with [[autism]]. This is an important finding as serial memory processing is a cognitive ability that may not be related to other cognitive abilities that are hindered by autism spectrum disorders. <ref name=Prior>Prior, M. R., & Chen, C. S. (1976). Short-term and serial memory in autistic, retarded, and normal children. ''Journal of Autism and Childhood Schizophrenia, 6''(2).</ref>

;Neuro-perspective

Serial memory processing has been studied neurologically, and certain brain regions have been found to be associated to this processing. There is evidence that both the [[prefrontal cortex]] and the [[hippocampus|hippocampal region]] are related to serial memory processing. This is because lesions in these areas tend to be related to impaired ability in remembering serial order. <ref name=Chiba>Chiba, A., Kesner, R., & Reynolds, A. (1994). Memory for spatial ___location as a function of temporal lag in rats: Role of hippocampus and medial prefrontal cortex. ''Behavioral and Neural Biology 61''(1).</ref> Rat studies have shown that lesions in the prefrontal cortex cause an inability to remember the 2nd of two items in a set. As well, the rats showed increased [[corticosterone]] while experiencing stress during a serial memory task. On the other hand, rat studies have also shown that lesions in the hippocampal regions cause an inability to remember the 1st of two items. Furthermore, these rats do not show an increase in their corticosterone while experiencing stress, demonstrating differing effects for differing brain regions. As well it shows that the different brain regions differentially activate corticosterone, a hormone related to memory effects. <ref name=Chauveau>Chauveau, F., et al. (2009). The hippocampus and prefrontal cortex are differentially involved in serial memory retrieval in non-stress and stress conditions. ''Neurobiology of Learning and Memory, 91''(1).</ref>

Generally, it has been found that the [[left hemisphere]] is better at serial processing and serial memory comparisons than the [[right hemisphere]]. These processes may be more related to the lateralization of left hemispheric functions rather than right hemispheric ones.