Biomedical subjects

Mary M Smyth

Publications and source records attributed to Mary M Smyth.

6 recordsLinked to original sources

PubMed2005

Verbal coding and the storage of form-position associations in visual-spatial short-term memory.

Short-term memory for form-position associations was assessed using an object relocation task. Participants attempted to remember the positions of either three or five Japanese Kanji characters, presented on a computer monitor. Following a short blank interval, participants were presented with 2 alternative Kanji, only 1 of which was present in the initial stimulus, and the set of locations occupied in the initial stimulus. They attempted to select the correct item and relocate it back to its original position. The proportion of correct item selections showed effects of both articulatory suppression and memory load. In contrast, the conditional probability of location given a correct item selection showed an effect of load but no effect of suppression. These results are consistent with the proposal that access to visual memory is aided by verbal recoding, but that there is no verbal contribution to memory for the association between form and position.

Adult↗

PubMed2005

Serial position memory in the visual-spatial domain: reconstructing sequences of unfamiliar faces.

In two studies we presented pictures of unfamiliar faces one at a time, then presented the complete set at test and asked for serial reconstruction of the order of presentation. Serial position functions were similar to those found with verbal materials, with considerable primacy and one item recency, position errors that were mainly to the adjacent serial position, a visual similarity effect, and effects of articulatory suppression that did not interact with the serial position effect or with the similarity effect. Serial position effects were found when faces had been seen for as little as 300 ms and after a 6-s retention interval filled with articulatory suppression. Serial position effects found with unfamiliar faces are not based on verbal encoding strategies, and important elements of serial memory may be general across modalities.

Adolescent↗

PubMed2004

The role of sight of the hand in the development of prehension in childhood.

In two studies, children between 5 and 10 years of age were asked to reach to grasp an object without sight of the hand during the movement. The oldest children and adults were faster when they could see the hand and increased maximum grip aperture when they could not see the hand. The 10-year-olds were less able to integrate grasp and lift than adults when they could see their hands. Children aged 5 and 6 showed no increase in movement time when they could not see the hand and did not adapt maximum grip aperture to lack of sight. These effects remained when children were encouraged to reach for and lift the target as quickly as possible. The results indicate that younger children did not give preference to vision in the control of prehension, while older children used visual feedback to improve efficiency. Dependence on sight of the hand for the control of prehension does not simply decrease with age, but it may be integrated into an anticipatory control strategy where it contributes to the efficiency of control.

Child↗

PubMed2004

Development of prehension between 5 and 10 years of age: distance scaling, grip aperture, and sight of the hand.

The authors investigated whether 5- to 10-year-old children (N = 75) differ from adults (N = 12) in the developmental course of distance scaling and the adaptations to the inability to see the hand during prehension movements. The children reached under a surface and grasped and lifted an object suspended through it. All children scaled velocity appropriately for movement distance, both with and without sight of the hand. However, 5- to 6-year-old children did not increase grip aperture with increased distance, whereas older children and adults did. The older children and adults spent longer after peak deceleration when they could not see the hand, and maximum grip aperture (MGA) was larger, providing an increased safety margin. Children aged 5 to 6 spent the same amount of time between peak deceleration and grasp, whether or not they could see the hand, and they failed to increase MGA when they could not see the hand. Prehension in the younger children differed from that of older children in two ways: The younger children did not integrate reach and grasp over different distances and did not use visual information about hand position to optimize accuracy.

Adolescent↗

PubMed2003

Two distinct pathways for developmental coordination disorder: persistence and resolution.

This article describes the perceptual motor, educational and social outcome of early motor delay in a group of 17-18 year old Finnish adolescents who were originally evaluated at age 5. The study group consisted of 65 adolescents: 22 with significant motor problems (or developmental coordination disorder, DCD), 23 with minor motor problems (intermediate group) and 20 controls. The goal of this study was to reassess the results obtained when they were age 15 and to determine whether the variables used earlier could still discriminate the adolescents at age 17. The results showed that at age 17 all perceptual motor tasks differentiated the three groups. The DCD group performed less well than the control group on all tasks, with the intermediate group situated between these two. Discriminant function analyses showed that more classification errors occurred between the control and intermediate groups at age 17 than at age 15, suggesting that the distinction between these groups becomes more difficult with age. In the educational domain, similar to the findings at age 15, the adolescents with DCD had the lowest WAIS scores and shortest school careers of the three groups. In the social domain, as found two years earlier, the DCD group had the lowest perceptions of athletic and scholastic competence while the intermediate and control groups did not differ. In addition, the interview results indicated that the three groups were in different stages of identity development. In sum, the outcome at age 17 was a replication of the results obtained at age 15 and suggests two developmental paths for those with early perceptual motor problems: 'persistence' and 'catching up'.

Adolescent↗

PubMed2003

Developmental coordination impairments in adulthood.

The aim of this study was to extend the understanding of Developmental Coordination Disorder (DCD) into adulthood. We recruited 19 adults aged between 18 and 65 who had received diagnoses of DCD or dyspraxia or who self-reported as having motor impairments consistent with a history of DCD, together with age- and gender-matched controls. Participants were given tests of manual dexterity, handwriting, construction, obstacle avoidance, dynamic balance, static balance, dual task performance, ball skills, reaction time, movement time and sequencing. As a group, adults with DCD performed more poorly than controls across all tasks. Slowness and variability of movement was a pervasive feature of their performance and many individuals had considerable problems with sequencing and with dual task performance. A discriminant function analysis conducted using six performance measures correctly classified participants as car drivers or non-drivers. Adults do retain motor difficulties and these can exclude them from important activities of daily living.

Adolescent↗