Question

An absolute threshold is the minimum stimulation needed to detect a particular stimulus 50% of the time. Which of the following represents an absolute threshold?

A guitar player knows that his D string has just gone out of tune.

A photographer can tell that the natural light available for a photograph has just slightly faded.

Your friend amazes you by correctly identifying unlabeled glasses of Coke and Pepsi.

A cook can just barely taste the salt she has added to her soup.

Your mom throws out the milk because she says the taste is "off".

Answer 1

@hartnn

Answer 2

I'm pretty sure it's the 4th choice:
A cook can just barely taste the salt she has added to her soup.

I'm using a process of elimination, here.

Let me take a moment to explain "thresholds" for you. The definition that they gave you can be a bit technical.

In psychology, there are two kinds of "thresholds."

1. Absolute threshold
2. Difference threshold

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The ABSOLUTE threshold is how much of something there needs to be, so that, using our five basic senses, we notice that there is something there.

For example:

Imagine that you're turning on the radio, in your car.

If the volume is really low, you're not gonna hear the music.

So, you turn the volume knob up, very slowly, until you've turned it JUST ENOUGH so that you can hear some music. So that you know that the music is there.

That specific volume, that the radio needs to be on, for you to just barely hear the music, is called the ABSOLUTE threshold.

The ABSOLUTE threshold, again, is how much of something there needs to me, in order for us to notice that there's something there.

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Now, the DIFFERENCE threshold is a little different.

The DIFFERENCE threshold is how much something needs to change, in order for us to notice that there has been a change.

For example:

Imagine that the radio in your car is turned on.

So, the music is playing. And in your mind, you have a sense of how loud the music is, right now.

Now, you start turning the volume knob, to make it louder.

You turn, and you turn, slowly,
until finally, your ears actually notice that the music has gotten somewhat louder.

That is the DIFFERENCE threshold.
It is how much something needs to change, before you notice that there is a change.

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So, in simple words...

ABSOLUTE threshold is about detection of PRESENCE.
DIFFERENCE threshold is about detection of CHANGE.

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Now, let's go through all the choices for this question,
and label whether they're talking about an ABSOLUTE threshold,
or a DIFFERENCE threshold.

1. A guitar player knows that his D string has just gone out of tune.

This is a DIFFERENCE threshold.

Because the guitar player notices that there is a change in the way his D string sounds.

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2. A photographer can tell that the natural light available for a photograph has just slightly faded.


This is a DIFFERENCE threshold.

Because the photographer notices that there is a change in the amount of light in the environment.

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3. Your friend amazes you by correctly identifying unlabeled glasses of Coke and Pepsi.

This is a DIFFERENCE threshold.

Because your friend has tasted both sodas,
and notices the difference in the taste between the two.

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4. A cook can just barely taste the salt she has added to her soup.

This is an ABSOLUTE threshold.

Because the cook has added just enough salt to notice that there is salt, there, in the soup.

(She's not noticing the difference in the amount of salt, because this is all about knowing that the salt is THERE, in the soup, to begin with.)

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5. Your mom throws out the milk because she says the taste is "off".

This is a DIFFERENCE threshold.

Because your mom notices that there is a change in the taste of the milk.

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If you have any questions about thresholds, please ask!