Behavioral Disassociation of Perceived Sweet Taste Intensity and Hedonically Positive Palatability

Abstract

The intensity of sucrose (its perceived concentration) and its palatability (positive hedonic valence associated with ingestion) are two taste attributes that increase its attractiveness and overconsumption. Although both sensory attributes covary, in that increases in sucrose concentration leads to similar increases in its palatability, this covariation does not imply that they are part of the same process or whether they represent separate processes. Both these possibilities are considered in the literature. For this reason, we tested whether sucrose’s perceived intensity could be separated from its hedonically positive palatability. To address this issue, rats were trained in a sucrose intensity task to report the perceived intensity of a range of sucrose concentrations before and after its palatability was changed using a conditioned taste aversion (CTA) protocol. We found that the subjects’ performance remained essentially unchanged, although its palatability was changed from hedonically positive to negative. Overall, these data demonstrate that sucrose’s perceived intensity and its positive palatability can be dissociated, meaning that changes of one taste attribute render the other mostly unaffected. Thus, the intensity attribute is sufficient to inform the perceptual judgments of sucrose’s concentrations.

Loss of Stk11 in basolateral amygdalar projection neurons impairs taste aversion learning by altering the temporal pattern of taste response plasticity in gustatory cortex

“…As has been shown previously for rats (Grossman et al, 2008;Moran & Katz, 2014), significant learning-related changes in GC neurons recorded from control animals were largely restricted to the late epoch of the response (>750ms; Figure 4a, left). This pattern is consistent with the generally agreed-upon suggestion that CTA changes the palatability of a taste, leaving taste identity intact (Bures et al, 1998;Fonseca et al, 2020), and with the fact that it is the transition into this late state that is implicated in the driving of palatability-related behavior (Li et al, 2016;Sadacca et al, 2016;Mukherjee et al, 2019).…”

Potential Effects of Prolonged Water-Only Fasting Followed by a Whole-Plant-Food Diet on Salty and Sweet Taste Sensitivity and Perceived Intensity, Food Liking, and Dietary Intake

“…Given the relatively small change in perceived salty and sweet taste intensities, these changes may not be biologically or clinically meaningful. However, previous studies have found that decreasing salt and sugar consumption reduced their respective perceived intensities [6,23], and perceived sucrose taste intensity (as well as palatability) may be a factor in overconsumption of sweet foods and beverages [24].…”

Tesofensine, a novel antiobesity drug, silences GABAergic hypothalamic neurons

“…To investigate whether tesofensine impairs sucrose detection or palatability responses, we modified a psychophysical task using a new equipment called the homegustometer [ 32 , 46 ]. Rats performed the task day and night over multiple consecutive days, which allowed us to characterize the temporal pharmacological effects of tesofensine across days ( Fig 11A ) and within a day ( S3 Fig ).…”

“…To investigate whether tesofensine impairs sucrose detection or palatability responses, we modified a psychophysical task using a new equipment called the homegustometer [32,46]. Rats performed the task day and night over multiple consecutive days, which allowed us to characterize the temporal pharmacological effects of tesofensine across days (Fig 11A) and within a day (S3 Fig) . The rats (n = 4) were trained to discriminate between different concentrations of sugar and water using a homegustometer, and their performance was recorded continuously for up to 23 hours daily.…”