Define relative threshold/JND

• What is the definition of relative threshold?

  The smallest change in stimulus intensity perceived
• If you are holding a 1 kg weight, what is the JND for noticing an increase in weight?

  0.1 kg
• What is the just noticeable difference (JND)?

  Smallest change in stimulus magnitude detectable
• How does the concept of JND apply to weight perception?

  You need to add at least 0.1 kg to notice
• What are the key differences between absolute threshold and relative threshold?

  • Absolute Threshold:
  • Minimum intensity to detect a stimulus
  • Example: Seeing the faintest star

  
  

  • Relative Threshold:
  • Minimum change to distinguish between stimuli
  • Example: Noticing slight brightness increase
• What is another name for relative threshold?

  Just noticeable difference (JND)
• How does the proportion of comparison responses change as the comparison size increases?

  The proportion of comparison responses increases as the comparison size increases
• How is relative threshold related to stimulus intensity?

  It is the least change needed to notice a difference
• What is the definition of relative threshold?

  The minimum change needed to distinguish between two stimuli
• How can Weber's Law be mathematically expressed?

  $\Delta \phi / \phi =$$k$
• How does absolute threshold relate to stimulus detection?

  It defines the minimum intensity for detection
• What is the definition of absolute threshold?

  The minimum intensity required to detect a stimulus
• What are the two types of comparisons shown in the graph?

  • Comparison selected 25% of the time
  • Comparison selected 75% of the time
• What does the variable k represent in Weber's Law?

  k is Weber's constant
• What is the difference between the comparison size when selected 25% of the time and 75% of the time?

  • Comparison size when selected 25% of the time: 5 pixels
  • Comparison size when selected 75% of the time: 12 pixels
  • Difference: 12 - 5 = 7 pixels
• What happens when you hold 100g and add 1g according to Weber's Law?

  1g addition might not be noticeable
• What does the steep rise in correct comparison responses indicate about JND?

  It helps distinguish between similar stimuli
• If one cookie is much bigger than another, how does JND help us?

  It allows us to easily see the difference
• How does JND affect our perception of cookie sizes?

  • JND helps us notice tiny changes
  • It determines how much bigger one cookie must be to be perceived as larger
  • If cookies are similar in size, it's hard to tell the difference
• What happens when cookies are almost the same size in relation to JND?

  It's hard to tell which cookie is bigger
• What does JND represent in terms of cookies?

  The smallest amount of cookie needed to notice size difference
• How much weight must be added to 1000g to notice a difference according to Weber's Law?

  10g must be added to notice
• Why does adding 10g to 1000g require a larger addition than adding 1g to 100g?

  Because JND is proportional to intensity
• How many just noticeable differences (JND) are needed for 75% success in detecting size changes?

  2 just noticeable differences
• What is the comparison size (radius in pixels) when the comparison is selected 25% of the time?

  5
• What is the label for the comparison that is selected 75% of the time?

  Comparison selected 75% of the time
• What visual cues indicate the effectiveness of JND in cookie size perception?

  • Similar sizes make it difficult to perceive differences
  • Larger size differences are easily noticeable
• What does Weber's Law state about the just noticeable difference (JND)?

  JND is proportional to stimulus intensity
• What are the key differences between the two types of comparisons shown?

  • Comparison size (radius in pixels)
  • Proportion of time the comparison is selected (25% vs 75%)
• In the expression $\Delta \phi / \phi =$$k$, what does $\phi$ represent?


  $\phi$ represents the stimulus intensity
• How does JND relate to sensory sensitivity?

  It measures sensitivity to changes in intensity
• If the volume is at level 5, what might the JND be?

  Increasing it to volume level 6
• What does a psychometric function show?

  Probability of detecting a difference between stimuli
• In the expression $\Delta \phi / \phi =$$k$, what does $\Delta \phi$ represent?


  $\Delta \phi$ represents the JND
• How does relative threshold relate to distinguishing stimuli?

  It indicates the minimum change required for distinction
• What does JND stand for?

  Just noticeable difference
• What is the comparison size (radius in pixels) when the comparison is selected 75% of the time?

  12
• What is the significance of JND in sensation perception?

  • JND allows differentiation between stimuli
  • Essential for accurate perception of changes
  • Influences how we respond to size differences