Could an Unshielded EEG Cable Corrupt Signals?

[JCD]

Hi I have just received a high density electrocap for recording eeg -signals and discovered that the cable that leads to the electrodes is not shielded.
Does this probably corrupt the signal?

 

[somasimple]

Hi,

It is possible that the unit uses a differential measure that lowers the noise.
And I saw many pretty cables that were well grounded but look like they weren't.