title: Correlation of reaction time in and out of the functional MR unit.
abstract: OBJECTIVE
  The authors performed this study to determine whether reaction times (RTs) recorded in the functional magnetic resonance (MR) imaging environment reflect the performance of the patient outside the imaging room.
  
  
  METHODS
  Fifteen healthy control subjects (mean age, 61.6 years) performed a simple reaction time (SRT) task outside the MR magnet and a visuomotor response time task inside the magnet with use of block-design and event-related paradigms. For both behavioral and functional MR imaging tests, subjects tapped the right index finger upon the appearance of a visual cue. The mean RTs for out-of-magnet and functional MR imaging paradigms were compared. Results. There was a statistically significant difference in RTs between block-design and single-event paradigms (t = 3.458, P < .004). The RT values during functional MR imaging and SRT tasks did not show significant differences (.65 < P < .7, paired t test). However, no correlation was found in RT values between event-related (p = -0.004, P = .15) or block-design (p = 0.03, P = .13) paradigms and SRT data. With the block-design functional MR imaging paradigm, the RT was significantly faster (P < .0003) at the beginning of the session than the end, illustrating the effect of anticipation.
  
  
  CONCLUSIONS
  Functional MR imaging RTs must be used to determine the correlation between subjects' performance and the volume of brain activation in a functional MR imaging experiment. The effect of anticipation should be minimized, which could best be achieved by using event-related paradigms.
authors.forename: Nina
authors.initials: N
authors.lastname: Mikhelashvili-Browner
authors.forename: David M
authors.initials: DM
authors.lastname: Yousem
authors.forename: Allen S
authors.initials: AS
authors.lastname: Mandir
authors.forename: Vince D
authors.initials: VD
authors.lastname: Calhoun
authors.forename: Colin
authors.initials: C
authors.lastname: Wu
authors.forename: Kader Karli
authors.initials: KK
authors.lastname: Oguz
authors.forename: Christina L
authors.initials: CL
authors.lastname: Vaughan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology