Related Experiment Video
Updated: May 4, 2026
Observation and Analysis of Blinking Surface-enhanced Raman Scattering
Published on: January 11, 2018
Shapes displayed with durations in the microsecond range do not obey Bloch's law of temporal summation
1Laboratory for Neurometric Research, Department of Psychology, University of Southern California, Los Angeles, CA, USA;
Abstract:
Shape patterns were displayed with simultaneous brief flashes from a light-emitting diode array. Flash durations in the microsecond range and luminous intensities were adjusted to vary the degree of successful shape recognition. Four experiments were conducted to test whether Bloch's law would apply in this task. Bloch's law holds that for very brief flashes the perceptual threshold is determined by the total number of photons being delivered, i.e., there is reciprocity of intensity and duration. The present results did not find that effectiveness of flashes was based on the total quantity of photons, as predicted by Bloch's law. Additionally, the evidence points to a visual mechanism that has ultra-high temporal precision that either registers the rate of photon flux or the duration of flashes.
Related Concept Videos
02:32The de Broglie Wavelength
02:18Interference and Diffraction
01:24Properties of DTFT I
The linearity property of DTFTs is fundamental. If two discrete-time signals are multiplied by constants a and b respectively, and then combined to...
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
01:16Basic Discrete Time Signals
The unit impulse or sample sequence is mathematically expressed as zero for all n values except at n=0, where it is one. The unit impulse sequence, denoted by δ(n), is the first difference of the unit step sequence, while the unit step sequence u(n) is...
01:09Beats