Biomedical subjects

Nigel Foreman

Publications and source records attributed to Nigel Foreman.

7 recordsLinked to original sources

PubMed2005

Assessment of visual-spatial deficits in patients with Parkinson's disease and closed head injuries using virtual environments.

Cognitive spatial deficits have been reliably reported in patients with Closed Head Injury (CHI), though in patients with Parkinson's disease (PD) the phenomenon is disputed. CHI and non-demented PD patients were tested using a Judgement of Line Orientation Test, and two spatial tests using virtual environments (VEs). Performance on the Line Orientation and one VE test was worse in the CHI group than controls, but PD patients showed no apparent spatial deficits. However, performance on the second VE test (virtual tray of objects task) did reveal a deficit, both CHI and PD groups being significantly impaired. The data illustrate that particular spatial deficits can be differentiated using appropriate VE-based tasks, and that non-demented PD patients show a paradigm-specific visual-spatial impairment.

Adult↗

PubMed2004

Distance underestimation in virtual space is sensitive to gender but not activity-passivity or mode of interaction.

Four groups of undergraduates (half of each gender) experienced a movement along a corridor containing three distinctive objects, in a virtual environment (VE) with wide-screen projection. One group simulated walking along the virtual corridor using a proprietary step-exercise device. A second group moved along the corridor in conventional flying mode, depressing a keyboard key to initiate continuous forward motion. Two further groups observed the walking and flying participants, by viewing their progress on the screen. Participants then had to walk along a real equivalent but empty corridor, and indicate the positions of the three objects. All groups underestimated distances in the real corridor, the greatest underestimates occurring for the middle distance object. Males' underestimations were significantly lower than females' at all distances. However, there was no difference between the active participants and passive observers, nor between walking and flying conditions.

Adolescent↗

PubMed2004

Memory for targets in a multi-level simulated-environment: a comparison between able-bodied and physically disabled children.

Two groups of children, one able-bodied and the other with physical disabilities, explored a symmetrical three-tiered virtual building that contained six distinctive target objects, two on each story. In a subsequent test, the target objects were removed and participants were asked to make judgments of the directions to the former target locations from each floor in turn. At each test site, judgments were required for targets that were formerly on the same floor and for those on higher and lower floors. Relative tilt error scores suggested a bias for both groups, in that targets that were higher than the test location were judged as consistently lower than their actual position, whereas targets that were lower than the test location were judged as higher than their actual position. Absolute tilt errors revealed an asymmetry in both groups, with more accurate tilt errors for judgments directed to lower than higher floors. The relevance of these results for the source of the asymmetry is discussed.

Child↗

PubMed2004

Memory for targets in a multilevel simulated environment: evidence for vertical asymmetry in spatial memory.

In two experiments, adult participants explored a symmetrical three-tiered computer-simulated building that contained six distinctive objects, two on each floor. Following exploration, the objects were removed, and the participants were asked to make direction judgments from each floor, indicating the former positions of the objects on that floor and on higher and lower floors. Relative tilt error scores indicated a bias, in that targets that were higher than the test location were judged as consistently lower than their actual positions and targets that were lower than the test location were judged as consistently higher than their actual positions. Absolute tilt errors revealed an asymmetry, with more accurate and less variable tilt errors for judgments directed to lower floors than for judgments directed to higher floors. Experiment 3 ruled out an account of the findings that does not relate them to spatial memory. The results suggest that the superiority of downward over upward spatial judgments, previously reported in two-dimensional visual-spatial tasks, extends to navigational spatial memory.

Adolescent↗

PubMed2003

Improving spatial functioning in children with cerebral palsy using computerized and traditional game tasks.

PURPOSE: To examine the effectiveness of combining virtual environment (VE) instruction with additional desk-top tasks, based on the Luria-Vygotsky methodology, for spatial remediation in children having complex motor disabilities restricting movement. METHODS: In Experiment 1, from among children attending for residential rehabilitation, an experimental subgroup had additional spatial training using a VE and corresponding desk-top models. All children were tested at the start and end of training, using four spatial tests. In Experiment 2, larger groups of children (pair-matched for initial performance) were given the same training as in Experiment 1, but experimentals received both VE-based training and supporting tasks designed to improve executive functions and verbal regulation of spatial functioning. Assessment involved a wider range of tests than in Experiment 1. RESULTS: In Experiment 1, both groups showed improvement at retest, but experimentals showed greater improvement. Children beginning with the lowest level of cognitive performance failed to benefit from the additional training. In Experiment 2 the experimental group made significantly greater improvement than controls, irrespective of initial performance level. CONCLUSIONS: VE-based spatial training is effective for children with complex disabilities, particularly when combined with training that remediates cognitive weaknesses.

Adolescent↗

PubMed2003

Spatial knowledge of a real school environment acquired from virtual or physical models by able-bodied children and children with physical disabilities.

In Experiment 1, 2 groups of able-bodied children were exposed to both a complex single-tier virtual environment (VE) and a physical model of a different environment. For 1 group, the VE accurately modeled a real school, and for the other group the physical model did so. In transfer testing in the real school, orientation accuracy was greater in the group exposed to the VE of the real school. In Experiment 2, children with physical disabilities explored the VE model of the real school and were tested as in the 1st experiment. Measures of orientation accuracy and map-placing were significantly better in this group than in the guessing adult control group. The results illustrate the potential for VEs as useful spatial training media.

Adolescent↗

PubMed2002

Effects of early mobility on shortcut performance in a simulated maze.

This experiment compared the shortcut choices of able-bodied teenagers with those of physically disabled teenagers who had varying histories of mobility impairment. In a computer-simulated kite-shaped maze, participants were allowed to explore three arms that connected four rooms. Subsequently they were offered a choice between paths connecting two rooms, one of which was a novel shortcut. Disabled teenagers chose correctly on fewer occasions than their able-bodied counterparts. Despite equivalent current levels of mobility, disabled participants whose mobility was more limited early in development were poorer at the task than those whose mobility had deteriorated with age. The results suggest that early independent exploration is important in the development of spatial knowledge, and suggest that the detrimental effects of limited early exploratory experience may persist into the teenage years.

Adolescent↗