title: Activation during the Trail Making Test measured with functional near-infrared spectroscopy in healthy elderly subjects.
abstract: Cognitive decline is very common in age and particularly in subjects with neurodegenerative conditions. Besides memory and language, executive functions are very often affected in elderly and patients with Alzheimer's disease or Parkinson's disease. However, the neural alterations associated with these executive deficits are still not fully understood. Therefore, we measured cortical activation using functional near-infrared spectroscopy (fNIRS) in 16 healthy elderly subjects (50-75 years) performing the Trail Making Test (TMT), a widely used neuropsychological instrument measuring executive function. In line with previous studies focusing on younger subjects, the results showed frontal activation during the TMT A and the TMT B in the dorsolateral prefrontal cortex, the frontopolar area and also Broca's area. Furthermore, significant activation in the left motor, somatosensory cortices and somatosensory association cortices was demonstrated. Additionally, after a median split the differences between younger (<58 years) and older (>58 years) subjects were analyzed with the older subjects showing a less focused prefrontal activation. Altogether, fNIRS was found to be suitable to detect cortical activation in elderly subjects during performance of the TMT as well as aging-related differences in prefrontal activation topography. These neural correlates of executive functions should be further investigated as a potential prodromal neural marker of executive deficits and neurodegenerative processes.
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany; German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany; Graduate School of Neural & Behavioural Sciences, Tuebingen, Germany. Electronic address: Katja.Hagen@med.uni-tuebingen.de.
authors.forename: Katja
authors.initials: K
authors.lastname: Hagen
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Ehlis
authors.forename: Florian B
authors.initials: FB
authors.lastname: Haeussinger
authors.forename: Sebastian
authors.initials: S
authors.lastname: Heinzel
authors.forename: Thomas
authors.initials: T
authors.lastname: Dresler
authors.forename: Laura D
authors.initials: LD
authors.lastname: Mueller
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Herrmann
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Fallgatter
authors.forename: Florian G
authors.initials: FG
authors.lastname: Metzger
mesh_terms: D000368:Aged / Q000502:physiology*; D000704:Analysis of Variance; D001931:Brain Mapping; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D002540:Cerebral Cortex / Q000098:blood supply / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D003627:Data Interpretation, Statistical; D056344:Executive Function; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods*; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D014145:Trail Making Test
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate
keywords: Executive function; Functional near-infrared spectroscopy; Trail Making Test