Effects of visual contrast on visual evoked potentials and Doppler signal

We studied visually evoked cerebral blood flow responses (VEFR) and visual evoked potentials (VEP) to different visual contrasts and analysed the relationship between them. The records were made from 35 healthy volunteers aged 38.6 ± 10.1 years. The stimulus was a black‐and‐white checkerboard with visual contrasts (VC) of 1%, 10% and 100%. The VEFR were measured in the posterior cerebral artery using transcranial Doppler, and the VEP were recorded from the occipital leads. We found the relationship between visual contrast and VEFR (r = 0.79, P < 0.01) as well as between visual contrast and VEP (r = 0.71, P < 0.01). We also found moderate association between the VEP and the VEFR (r = 0.69, P < 0.01). The analysis of the regression slopes between two different age subgroups (P < 0.01) did not show a significant difference (P = 0.020). We concluded that a simultaneous recording of VEFR and VEP to visual contrasts could allow an assessment of neurovascular coupling in humans.

[1]  A. Ngai,et al.  Frequency-dependent changes in cerebral blood flow and evoked potentials during somatosensory stimulation in the rat , 1999, Brain Research.

[2]  A. M. Dale,et al.  Spatiotemporal Brain Imaging of Visual-Evoked Activity Using Interleaved EEG and fMRI Recordings , 2001, NeuroImage.

[3]  R. Aaslid,et al.  Visually evoked dynamic blood flow response of the human cerebral circulation. , 1987, Stroke.

[4]  L. Palmer,et al.  Response to Contrast of Electrophysiologically Defined Cell Classes in Primary Visual Cortex , 2003, The Journal of Neuroscience.

[5]  David J Heeger,et al.  Linking visual perception with human brain activity , 1999, Current Opinion in Neurobiology.

[6]  S. Hillyard,et al.  Cortical sources of the early components of the visual evoked potential , 2002, Human brain mapping.

[7]  H. Spekreijse,et al.  Standard for Visual Evoked Potentials 1995 , 1996, Vision Research.

[8]  T. Carpenter,et al.  Linear coupling between functional magnetic resonance imaging and evoked potential amplitude in human somatosensory cortex , 2000, Neuroscience.

[9]  D. Heeger,et al.  Neuronal activity in human primary visual cortex correlates with perception during binocular rivalry , 2000, Nature Neuroscience.

[10]  D. G. Albrecht,et al.  Spikes versus BOLD: what does neuroimaging tell us about neuronal activity? , 2000, Nature Neuroscience.

[11]  Hellmuth Obrig,et al.  Habituation of the Visually Evoked Potential and Its Vascular Response: Implications for Neurovascular Coupling in the Healthy Adult , 2002, NeuroImage.

[12]  M. Hennerici,et al.  Age and stimulus dependency of visually evoked cerebral blood flow responses. , 1999, Stroke.

[13]  S. Glantz.  Primer of applied regression and analysis of variance / Stanton A. Glantz, Bryan K. Slinker , 1990 .

[14]  H. Spekreijse,et al.  Standard for visual evoked potentials 1995. The International Society for Clinical Electrophysiology of Vision. , 1996, Vision research.

[15]  D. G. Albrecht,et al.  Striate cortex of monkey and cat: contrast response function. , 1982, Journal of neurophysiology.

[16]  M. Lauritzen,et al.  Coupling and uncoupling of activity‐dependent increases of neuronal activity and blood flow in rat somatosensory cortex , 2001, The Journal of physiology.

[17]  M. Štrucl,et al.  The influence of brightness, colour and complexity on visual evoked doppler flow responses. , 2002, Ultrasound in medicine & biology.

[18]  B. Rosengarten,et al.  Neurovascular coupling in terms of a control system: validation of a second-order linear system model. , 2001, Ultrasound in medicine & biology.