The team behind the study from the university's department for cognitive neuroscience are hoping to recruit around 90 people aged 18 to 35 to take part in the study.
Researchers are offering 120 Swiss francs to participants and had initially hoped to present their results by the middle of this year.
But an ad designed to attract people suffering from fear of snakes has so managed to draw in just 30 people or so over several months.
Now efforts to draw people to the study – which involves contact with a live but non-venomous snake – have been ramped up, with ads being placed on trams in the Swiss city.
An obvious first conclusion might be that people are too afraid of snakes to even consider taking part in the study. The real answer, however, is more surprising.
“Fear of snakes is about as common as fear of spiders,” Nathalie Schicktanz of Basel University's department for cognitive neuroscience told regional daily the Basler Zeitung.
But the scientist said the problem with recruiting people for the study was that “there are hardly any snakes here and people hardly ever come into contact with the animals”.
She explained that potential study recruits were often seeing real live snakes for the first time and that many people actually realised at that moment that they weren't afraid of them.
Schicktanz now hopes the end of the summer holidays will mean a rise in numbers and a full complement of participants will be on board by spring 2019.
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