There may now be a scientific reason for all those silly moments you lose your car keys or say the wrong thing.

Scientists from Johns Hopkins and the University of Nebraska have uncovered an algae virus found in the throat that may have an impact on cognitive function.

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The findings prove that certain microorganisms can lead to subtle physiologic changes without ending in an all-out illness.

In this case, the detected virus was found in the throats of otherwise healthy people and subtly altered cognitive functions like visual processing and spatial orientation.

Forty out of 92 participants involved in the testing were positive for the algae virus and performed worse overall on a set of visual processing tasks.

They also scored, on average, nine points lower on a basic IQ test task than those who did not have the virus.

Researchers say this is a breakthrough in understanding how intelligence can differ from person to person.

“This is a striking example showing that the ‘innocuous’ microorganisms we carry can affect behavior and cognition,” lead investigator Robert Yolken said.

“Many physiological differences between person A and person B are encoded in the set of genes each inherits from parents, yet some of these differences are fuelled by the various microorganisms we harbor and the way they interact with our genes.”