Biomedical subjects

Steve Pettifer

Publications and source records attributed to Steve Pettifer.

3 recordsLinked to original sources

PubMed2003

Transfer of route learning from virtual to real environments.

The authors investigated the extent to which route learning in a virtual environment (VE) transfers to the real world. In Experiment 1, active VE exploration, on its own or with a map, produced better transfer of training than either no VE training at all or passive VE training; however, transfer was achieved after shorter training times with the map. Experiment 2 demonstrated that VE + map training was not superior to training with a map alone, and Experiment 3 demonstrated that the poorer performances observed after passive VE training were not simply due to a lack of attention but to the lack of active navigational decisions. The authors concluded that the present VE technology does not provide better route learning than studying a map.

Adolescent↗

PubMed2002

Performance of a skilled motor task in virtual and real environments.

Three experiments compared the performances of adult participants (three groups of 10) on a perceptuo-motor task in both real world (RW) and virtual environments (VEs). The task involved passing a hoop over a bent wire course, and three versions of the task were used: a 3-D wire course with no background, a flattened version of the 3-D course (2(1/2)-D course) with no background, and the 2(1/2)-D course with added background to provide spatial context. In all three experiments the participants had to prevent the hoop from touching the wire as they moved it. In the first experiment, the VE condition produced about 18 times more errors than the RW task. The VE 2(1/2)-D task was found to be as difficult as the 3-D, and the 2(1/2)-D with the added background produced more errors than the other two experiments. Taken together, the experiments demonstrate the difficulty of performing fine motor tasks in VEs, a phenomenon that has not been given due attention in many previous studies of motor control in VEs.

Adolescent↗

PubMedDate not supplied

A network architecture supporting consistent rich behavior in collaborative interactive applications.

Network architectures for collaborative virtual reality have traditionally been dominated by client-server and peer-to-peer approaches, with peer-to-peer strategies typically being favored where minimizing latency is a priority, and client-server where consistency is key. With increasingly sophisticated behavior models and the demand for better support for haptics, we argue that neither approach provides sufficient support for these scenarios and, thus, a hybrid architecture is required. We discuss the relative performance of different distribution strategies in the face of real network conditions and illustrate the problems they face. Finally, we present an architecture that successfully meets many of these challenges and demonstrate its use in a distributed virtual prototyping application which supports simultaneous collaboration for assembly, maintenance, and training applications utilizing haptics.

Communication↗