Biomedical subjects

K A Scholey

Publications and source records attributed to K A Scholey.

4 recordsLinked to original sources

PubMed1996

Serial order in spatial immediate memory.

Serial order effects in spatial memory are investigated in three experiments. In the first an analysis of errors in recall data suggested that immediate transpositions were the most common error and that order errors over 2 or 3 adjacent items accounted for the majority of errors in recall. The first and last serial positions are less error-prone than is the middle position in sets of six and seven items. A second experiment investigated recognition of transpositions and found that immediate transpositions were hardest to recognize but that a traditional serial position effect was not found. This may be due to the difficulty of maintaining one set of spatial items when another set is presented for comparison. A probe experiment, in which subjects were asked to recognize whether a single item came from a memory set and then to assign it to its position in the set indicated that the first and last positions were remembered more accurately than were central positions. The combination of serial order data in recall and position data suggests that there are similarities between serial order and position effects in the verbal and spatial domains and that serial order in spatial sequences is position-based.

Adult↗

PubMed1996

The relationship between articulation time and memory performance in verbal and visuospatial tasks.

The number of verbal items which can be recalled immediately is related to the rate at which an individual can speak. Subvocal rehearsal, or articulatory recoding in working memory, has been assumed to mediate this relation. For spatial items recalled in order there is also a relationship with articulation rate, which is not related to verbal rehearsal of the items. One reason for this might be that the relationship is mediated by speed of memory scanning for serial position tags in a memory set, which is related to processing speed. Subjects were asked to perform visuospatial memory tasks which involved serial position and visuospatial memory tasks in which serial position was not involved. They also performed a digit span task. The results indicated that the visuospatial memory tasks were highly related, that they were only weakly related to digit span, and that articulation rate was correlated with every measure of memory performance used, whether serial position was involved or not. There is no support for the hypothesis that speed of scanning for serial position information in immediate spatial memory leads to a relationship with articulation rate, nor is there any support for the view that memory span tasks in different domains share resources for dealing with serial order. The results are discussed in relation to Cowan, Keller, Hulme, Roodenrys, McDougall & Rack's (1994) suggestion that the relationship between articulation rate and memory span may be mediated by general processing speed.

Adult↗

PubMed1994

Characteristics of spatial memory span: is there an analogy to the word length effect, based on movement time?

In studies of verbal short-term memory it has been shown that the length of words to be remembered affects the size of memory span. This word-length effect is attributed to relationships between the rate of rehearsal of verbal material and the time it takes to speak the words being rehearsed. For spatial memory span there may also be an internal rehearsal system linked to overt responding, and if there is a strong analogy to be drawn between the verbal and spatial domains then movement time between spatial targets should predict the number of spatial locations that can be recalled. In the experiments reported here the time taken to move between spatial targets is varied by altering the size of targets and the distance between them. No difference between span performance on a nine-block spatial span task were found, either on immediate recall or on recall after an interval. When recall is of items from an array of 27, grouped in nine sets of three, with only one location in any set being presented on any trial, there is an effect of display size. This effect is consonant with the argument that movement time is related to spatial rehearsal, but other explanations are also possible. However, if recall in this task is scored over the nine sets rather than over the 27 items, then there is no difference between the displays. The results indicate that performance on the normal nine-block spatial-span task cannot be predicted by movement time.

Adult↗

PubMed1994

Interference in immediate spatial memory.

It has been suggested that maintenance in visuospatial immediate memory involves implicit motor processes that are analogous to the articulatory loop in verbal memory. An alternative account, which is explored here, is that maintenance is based on shifts of spatial attention. In four experiments, subjects recalled spatial memory span items after an interval, and in a fifth experiment, digit span was recalled after an interval. The tasks carried out during the interval included touching visual targets, repeating heard words, listening to tones from spatially separated locations, pointing to these tones, pointing to visual targets, and categorizing spatial targets as being from the left or right. Spatial span recall was impaired if subjects saw visual targets or heard tones, and this impairment was increased if either a motor response or a categorical response was made. Repeating words heard in different spatial locations did not impair recall, but reading visually presented words did interfere. For digit span only, the tasks involving a verbal response impaired recall. The results are interpreted within a framework in which active spatial attention is involved in maintaining spatial items in order in memory, and is interfered with by any task (visual, auditory, perceptual, motor) that also makes demands on spatial attention.

Acoustic Stimulation↗