Weight Perception
Named after German Physiologist DR. Ernst Weber, who found the percentage of change necessary for humans to notice a difference between two separate lifted weights stayed the same across a range of weights. According to Weber’s law, relatively less impact on heavy compared to light objects. Weber determined that the smallest amount of weight change detectable by the human touch is 2% is known as the just noticeable difference (JND). In 1834, Weber realized that there is a relationship between the ratio of the increment threshold and the background intensity is constant.
Calculation: (Weber’s fraction)
Visual Perception
Weber’s law of Perception states, it’s relative rather than absolute differences which are perceived when comparing colour along with length.
It is easy to see the difference of lengths on the right side of these figures because of the relative difference in the white part of the shapes quite large as the colour makes it easier for the brain to notice the relative difference. Detecting the relative difference in the first figure is harder because the difference in the length of the dark portions of the shapes small making it harder for your brain to register what the length differences
Storm Illusion (Motion After Effect)
When we experience an optical illusion, we often see something that is not there or fail to see something that is there. For instance, the storm illusion manipulates the brain to think the image is moving. If you were to close one eye to see the spiral, by opening the other eye (which did not see the spiral) when looking at a still image it will not be moving. This is because that eye was not exposed to the illusion like the other eye.
References:
Ch05.pdf. (n.d.). Retrieved August 10, 2020, from https://www.stat.auckland.ac.nz/~ihaka/120/Notes/ch05.pdf
Sensation & Perception: Weber’s Law. (2014, March 7). https://www.youtube.com/watch?v=-1e0uIS5j2Q
van Polanen, V., & Davare, M. (2015). Sensorimotor Memory Biases Weight Perception During Object Lifting. Frontiers in Human Neuroscience, 9. https://doi.org/10.3389/fnhum.2015.00700
Weber’s law and thresholds (video). (n.d.). Khan Academy. Retrieved August 10, 2020, from https://www.khanacademy.org/test-prep/mcat/processing-the-environment/sensory-perception/v/webers-law-and-thresholds
Weber’s Law of Just Noticeable Difference. (n.d.). Retrieved August 10, 2020, from http://apps.usd.edu/coglab/WebersLaw.html