Shift of attention to the body location of distracters is mediated by perceptual load in sustained somatosensory attention.
We investigated the impact of task difficulty on neuronal facilitation of to-be-attended somatosensory vibrotactile stimuli and transient tactile distracters during sustained attention. In Experiment 1, we employed an easy detection task and in Experiment 2 a challenging discrimination task. Sustained attention was manipulated by presenting vibrotactile stimuli simultaneously to the index fingers of both hands for a period of 3s. These stimuli elicited the steady-state somatosensory evoked potential (SSSEP). Subjects attended to one body side and had to detect target-stimuli that were embedded in the ongoing vibratory streams. When subjects discriminated target-stimuli we found increased SSSEP amplitudes of the to-be-attended vibrotactile stream and greater N140 amplitudes of the somatosensory evoked potential (SEP). During stimulus detection no such facilitation of the SSSEP was found. Greater N140 amplitudes elicited by to-be-ignored distracters indicated that they pull attention to that body location under conditions of low load.
Adler
Julia
J
Institut für Psychologie I, Universität Leipzig, Seeburgstrasse 14-20, 04103 Leipzig, Germany.
Giabbiconi
Claire-Marie
CM
Müller
Matthias M
MM
D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D004192:Discrimination, Psychological / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000294:innervation; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology; D014110:Touch / Q000502:physiology*; D055815:Young Adult