Individual differences in prefrontal cortex activity during perception of bitter taste using fNIRS methodology

Area of Science:

• Neuroscience
• Sensory Science
• Taste Perception

Background:

• Bitter taste perception is vital for nutrition and avoiding toxins.
• Limited neuroimaging studies exist for bitter taste processing.
• Individual differences in 6-n-propylthiouracil (PROP) taste sensitivity are well-documented.

Purpose of the Study:

• To identify cortical areas involved in bitter taste perception.
• To investigate if individual differences in PROP taste sensitivity correlate with distinct brain activation patterns.

Main Methods:

• Functional near-infrared spectroscopy (fNIRS) was used on 48 healthy volunteers.
• Participants rated PROP and NaCl taste intensity.
• Cortical activity was monitored in dorsolateral prefrontal cortex (DLPFC) and ventrolateral prefrontal cortex (VLPFC).
• Participants were classified as PROP tasters or nontasters based on sensitivity.

Main Results:

• No anterior DLPFC activity was observed in any participant.
• PROP tasters showed significant activation in posterior left DLPFC and bilateral VLPFC during PROP administration.
• PROP nontasters exhibited no cortical activity in these regions.

Conclusions:

• The prefrontal cortex is implicated in the conscious perception of bitter taste, specifically PROP.
• Distinct cortical activation patterns are associated with individual differences in PROP taste sensitivity.
• The PROP tasting phenotype is linked to fundamental differences in cortical taste processing.