DETERMINING THRESHOLDS
DETERMINING THRESHOLDS
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Absolute threshold
Recognition threshold
Difference threshold
Terminal threshold
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Thresholds can be used to determine the point
at which some substances begin to reduce
acceptability.
- Hindi na malamsahan, no more stimulus, no
perceptible sensory experience
- Beyond acceptability - experience pain
Thresholds may also be used as means of
selecting or testing panelists.
- Determine the thresholds of the panelists
before conducting panelist esp if needs a
highly trained panel
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Thresholds
- limits of sensory capacities
- Beyond threshold, wither di na madetect or
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pain na madetect
Measurement of thresholds is the most
common procedure for studying the
psychophysics of taste
- Study of the relationship between
physical stimuli and a person’s sensory
experience
Thresholds may differ:
- Among panelists
- Training of each panelists
- Within panelists
- Within ourselves
- Among sensory stimuli
- Bawat stimuli (sweetness, sour, etc)
pwede iba iba stimuli natin per
component
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ABSOLUTE THRESHOLD
Detection threshold
Lowest stimulus capable of producing a
sensation
- Ex: the dimmest light that we can perceive
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Pinaka bland na kaya natin mapercieve
It is usually set as the stimulus magnitude at
which the subject can identify a difference in
taste.
- Lowest level or concentration of stimuli that
we can detect a difference/ perceive
- Pwedeng di pa natin madistinguish ano
yung stimuli na yon
- Ex: lowest concentration of salt
conc
- We detect a difference or perceive
something/ a stimuli , but cannot
distinguish it as saltiness
- Not distinguishable but you can
perceive it
RECOGNITION THRESHOLD
Level of stimulus at which the specific stimulus
can be recognized and identified.
- Higher than your absolute threshold
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You can distinguish the specific stimuli
already
DIFFERENCE THRESHOLD
least amount of change of a given stimulus
necessary to produce a change in sensation
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Example
- 2 samples with the same solution
- Ex: S1 has a lower concentration
than S2, example absolute thresh
- S1 very low conc but detectable
- S2 higher, so more detected
- The difference Conc1 and Conc 2 is
the difference threshold
- level/amt/conc of change na
dedetect padin
❖ The interval unit used
➢ JND (Just Noticeable Difference)
■ Noticeable difference between sx
➢ JNND (Just Not Noticeable Difference)
■ No noticeable difference between
sx
DETERMINING THRESHOLDS
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TERMINAL THRESHOLD
magnitude of a stimulus above which there is
no increase in perceived intensity of the
appropriate quality of the stimulus.
- Above terminal, pain na experience
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Too sweet; high conc of sugar conc, di na
malasahan na sweet, usually pain na,
beyond acceptability . beyond appreciation
Ex; sound, too much, too loud sounds
FACTORS INFLUENCING THRESHOLD
MEASUREMENTS INCLUDE:
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Purity of stimuli
○ There should be no other interfering stimuli
to detect the threshold
○ Other tastants will have an effect
Level of “noise” in the blank
○ Blank sample will help to distinguish
■ Blank must be pure or else mag iiba
basis
Physiological state of panelist
○ Medica, physical, medical conditions affects
the threshold
○ Mas amtaas threshold needed if may sakit
Panelist attentiveness
Panelist motivation
○ More motivated and concentrated, more
sensitive