Neuroscience 2002 Abstract
| Presentation Number: | 761.16 |
|---|---|
| Abstract Title: | FUNCTIONAL MAGNETIC RESONANCE IMAGING OF THE HUMAN LGN. |
| Authors: |
Fukui, M.*1
; O'Connor, D. H.1
; Herwig, U.1
; Pinsk, M. A.1
; Kastner, S.1
1Dept Psych & Ctr Study Brain, Mind & Behav, Princeton Univ, Princeton, NJ |
| Primary Theme and Topics |
Sensory Systems - Vision -- Subcortical visual pathways |
| Session: |
761. Vision: subcortical vision II Poster |
| Presentation Time: | Wednesday, November 6, 2002 4:00 PM-5:00 PM |
| Location: | Hall A2-B3 F-61 |
| Keywords: | contrast, temporal frequency |
The lateral geniculate nucleus (LGN) is the thalamic station in the retinocortical projection and has been studied extensively using single-cell recordings in nonhuman primates. It has proven difficult to activate the human LGN using fMRI due to its small size and deep location. We developed an fMRI paradigm that reliably activated the LGN to study its functions at the neural population level. Seven subjects were scanned in a 3 T head scanner using gradient echo EPI (TR=2s, TE = 30 ms, flip angle = 90 deg.). Checkerboard stimuli that were modulated in temporal frequency (0.5, 7.5, 20 Hz) or contrast (3 to 100%) were presented in alternation to the left or right hemifield in blocks of 16 seconds while subjects passively viewed a central fixation cross. Contrast response functions (CRFs) and temporal frequency functions (TRFs) were obtained in the LGN and in visual areas V1, V2, V3/VP, V3A, MT/MST and V4/TEO. CRFs increased approximately monotonically in the LGN and in visual cortex with a more rapid saturation in dorsal stream areas. CRFs of the LGN correlated best with V1. TRFs increased with increasing temporal frequency in the LGN and in visual cortex. TRFs of the LGN correlated with V1 and V2 but not with higher extrastriate visual areas. In conclusion, fMRI activity of the human LGN depended both on stimulus contrast and temporal frequency, correlating best with early visual areas.
Supported by NIH, Whitehall Foundation and NSF.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2002 Neuroscience Meeting Planner. Orlando, FL: Society for Neuroscience, 2002. Online.
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