We measured the vector strength and phase differences for responses to opposite-polarity stimuli.
We also measured the vector strength and poststimulus oscillation amplitude following the second pulse in the pair.
Vector strength (VS) and Rayleigh statistics (RS) were used to quantify cortical temporal fidelity (see [27]).
Polar maps were computed by vectorially summing up the responses to each stimulus condition and normalizing to the sum vector length, thus providing (for each pixel) a preference angle and a vector strength (VS) value between 0 and 1, for minimal and maximal modulation, respectively.
The average vector of the period histogram has length defined as the vector strength (VS, [ Goldberg and Brown, 1969]) and angle defined as the BP.
Importantly, however, the interaction between block number and group (control or experimental) was non-significant for both firing rate (F 1,584) = 0.5, p > 0.4) and vector strength (F 1,584) = 0.5, p > 0.05).
The degree of phase-locking can be quantified as the vector strength [ 23], a metric that varies between zero (spikes independent of the stimulus) and 1 (perfect synchronization of all spikes at one particular phase-lag; Experimental Procedures).
Vector strengths were indistinguishable in ON, OFF, and contrast-sensitive populations of terminals firing spikes, and averaged 0.5 ± 0.23.
If we set, the vector is positioned between vector and vector as shown in Figure 2 and we have and.
A clearing plane, vector d, the curl between vector p and vector n is adopted.
