The death of Aylan Kurdi did affect people's attitude to the migration crisis – but not for long, according to an academic study.

The photograph of the body of the three-year-old Syrian boy washed up on a Greek beach shocked the world in September 2015 and gave a human face to the crisis that had already cost thousands of lives.

Now a report from Decision Research in Oregon has found the picture made a measurable difference to the international response.

It says: "The data show that the world was basically asleep as the body count in the Syrian war rose steadily into the hundreds of thousands.

"The iconic image of a young Syrian child, lying face-down on a beach, woke the world for a brief time, bringing much-needed attention to the war and the plight of its many victims."

However, it adds that "this empathic response was short-lived".

The researchers tracked Google searches for the terms "Aylan," "refugees," and "Syria" after the photo was shared and found a big increase. They also obtained data on donations to the Swedish Red Cross and found the number of daily donations during the week after the publication of the photo was more than 100 times what it had been the week before.

While the effect was sustained until five weeks after the photo's appearance, the number then declined to a level no different from that in the week before publication.

It said the findings showed that "an iconic photo of a single child was worth more than hundreds of thousands of statistical lives. People who were unmoved by the relentlessly rising death toll in Syria appeared to care much more about the crisis there after having seen Aylan's photograph."

However, it also notes the phenomenon of "compassion fade", in which the more people who were in need the less the public's emotional response seemed to be.

The authors say that while empathy was an important driving force when it came to action in humanitarian crises, it need to be harnessed to strong international institutions and well thought through principles for intervention.

They conclude: "Surely, for decisions as difficult and emotionally charged as those highlighted by the photograph of Aylan Kurdi, we should require nothing less."