Figure 1
From: V1 neurons respond to luminance changes faster than contrast changes
Visual stimulation and responses of V1 neurons to luminance changes and contrast changes.
(a) Stimulus presentation. Each stimulus was presented for 20 ms (50 Hz) and all stimuli were presented randomly and consecutively. The dark, small ring inside the left-most panel represents the RF of a visual neuron in V1. (b) Examples of PSTHs. The PSTHs were calculated with a 1 ms bin and smoothed using a window of 11 ms. The 4 × 4 matrix of panels show PSTHs of the neuron in Fig. 2a to partial combinations of stimulus parameters (luminance: 4, 10, 34 and 58 cd/m2 and contrast: 0%, 30%, 60% and 90% of a 10 × 10 matrix of stimuli with luminance at 10 levels (4–58 cd/m2 in 6 cd/m2 steps) and contrast at 10 levels (0–90% in 10% steps)). Each panel shows responses (spike rates) to a stimulus from 50 ms prior to the stimulus onset until 100 ms after the onset. The dark horizontal bar (=20 ms) indicates the duration of stimulus presentation. Shadows indicate the s.e.m. The background luminance of the CRT monitor screen was 31 cd/m2, which was the mean luminance of all stimuli.
