Young people with autism may find it difficult to multi-task because they stick rigidly to the order in which tasks are given to them, according to new research led by Strathclyde University.
Difficulty with "prospective memory" (remembering to carry out their intentions) may also contribute to the challenges they face, says the report on multitasking in high-functioning adolescents with autistic spectrum disorders (ASD).
The researchers presented 18 adolescents with ASD and 18 who were developing normally with a series of tasks, such as collecting and delivering a book and making a cup of hot chocolate, to be performed within eight minutes.
The activities were carried out in a virtual environment of a school building with three floors and two stairwells. A virtual environment could be useful for future teaching and training of young people with ASD, say the researchers.
They found that the ASD pupils did not appear to deviate from the order in which the tasks were listed, although it would have been more efficient to cluster errands on the same floor and complete them at the same time.
They also broke several rules for the tasks, such as those which specified they were only allowed to go up one staircase and down another.
"A possible reason why ASD participants made more stairwell journeys might be that they adhered more closely to the order that tasks were presented on the list, rather than re-ordering them efficiently," said the researchers, who were led by Gnanathusharan Rajendran, a psychology lecturer at Strathclyde.
When tasks were given singly, they were achieved by the ASD group. But when several had to be "interleaved", the ASD participants completed fewer of them and made more errors in the allocated time.
The ASD group did not appear to find the three-step tasks any more difficult than the TD (typically developing) group; it was the lack of completion of two-step and one-step tasks that brought down their scores.
The findings will offer the basis for further investigation into the causes of multi-tasking impairments associated with ASD, such as planning, prospective and retrospective memory, time-pressure anxiety, inhibitory control and socio-communication, said Dr Rajendran.
Step by step
Three of the six errands allocated to the young people had only one step to them; two had two steps and one had three.
The researchers found that the ASD (autistic spectrum disorder) group completed 63 per cent of one-step activities, 56 per cent of two-step activities, and 72 per cent of three-step activities.
The figures for the TD (typically developing) group were 85 per cent, 92 per cent and 72 per cent respectively.