Test–retest reliability of concurrently recorded steady-state and somatosensory evoked potentials in somatosensory sustained spatial attention

• Concurrent recording of steady-state and somatosensory evoked potentials.
• Retest reliability during sustained spatial attention.
• Good retest reliability of SSSEP and N140 to target events.
• Attention gain effect in N140 mainly depends on enhanced processing at focused spot.

We investigated the test–retest reliability of sustained spatial attention modulation of steady-state somatosensory evoked potentials (SSSEPs) and the N140 component of the somatosensory evoked potentials (SEPs). Participants attended to one or both hands to perform a target detection task while concurrent mechanical vibrations were presented for 4500 ms to both hands in two recording sessions. Results revealed that the amplitude and the attentional modulation of SSSEPs had high test–retest reliability, while the test–retest reliability for the N140 component was low. SSSEPs for stimuli with focused and divided attention had about the same amplitude. For the N140 component only the stimuli with focused attention were significantly enhanced. We found greater habituation effects for the N140 compared to SSSEP amplitudes but attentional modulation was unaffected in both signals. Given the great test–retest reliability of SSSEP amplitude modulation with attention, SSSEPs serve as an excellent tool for studying sustained spatial attention in somatosensation.