PMID- 12901714
OWN - NLM
STAT- MEDLINE
DCOM- 20031013
LR  - 20101118
IS  - 1534-7362 (Electronic)
IS  - 1534-7362 (Linking)
VI  - 3
IP  - 6
DP  - 2003
TI  - Pattern-onset stimulation boosts central multifocal VEP responses.
PG  - 432-9
AB  - Multifocal visual evoked potentials (VEP) allow one to assess whether stimulation 
      at specific visual field locations elicits cortical activity; it might therefore 
      enable us to conduct objective visual field perimetry. However, due to the 
      cortical folding, which differs markedly between subjects, a particular 
      electroencephalogram generator may fail to project signal on some recording 
      electrodes. This may lead to false alarms for potential scotomata. Here we 
      compare pattern-reversal and pattern-onset stimulation in their efficacy to 
      activate the visual cortex and recorded mfVEPs to 60 locations comprising a 
      visual field of 44 degrees diameter. We report three main findings: (1) 
      Pattern-onset compared to pattern-reversal enhances the amplitude by 30% for 
      stimulation of the central visual field (<10 degrees radius), while evoking 30% 
      less response in the periphery (>15 degrees ). (2) Although pattern-onset and 
      pattern-reversal responses differ markedly in their eccentricity dependence, they 
      have a similar topographical distribution. (3) By combining both stimuli, the 
      number of false positives was reduced to less than 1.5% of the visual field 
      locations tested. We conclude that pattern-onset and pattern-reversal activate 
      identical visual cortical areas but target different neural mechanisms within 
      these areas. Furthermore, pattern-onset stimulation greatly increases the 
      sensitivity of the mfVEP to assess the cortical representation of the central 10 
      degrees of the visual field.
FAU - Hoffmann, Michael B
AU  - Hoffmann MB
AD  - Visual Processing Lab, Universitats-Augenklinik, Freiburg, Germany. 
      hoffmann@aug.ukl.uni-freiburg.de
FAU - Straube, Sirko
AU  - Straube S
FAU - Bach, Michael
AU  - Bach M
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Vis
JT  - Journal of vision
JID - 101147197
SB  - IM
MH  - Adult
MH  - Evoked Potentials, Visual/*physiology
MH  - Humans
MH  - Pattern Recognition, Visual
MH  - Visual Cortex/*physiology
MH  - Visual Field Tests
MH  - Visual Fields/*physiology
EDAT- 2003/08/07 05:00
MHDA- 2003/10/14 05:00
CRDT- 2003/08/07 05:00
PHST- 2003/01/14 00:00 [received]
PHST- 2003/08/07 05:00 [pubmed]
PHST- 2003/10/14 05:00 [medline]
PHST- 2003/08/07 05:00 [entrez]
AID - 3/6/4 [pii]
AID - 10.1167/3.6.4 [doi]
PST - ppublish
SO  - J Vis. 2003;3(6):432-9. doi: 10.1167/3.6.4.