title: Detecting gustatory-olfactory flavor mixtures: models of probability summation.
abstract: Odorants and flavorants typically contain many components. It is generally easier to detect multicomponent stimuli than to detect a single component, through either neural integration or probability summation (PS) (or both). PS assumes that the sensory effects of 2 (or more) stimulus components (e.g., gustatory and olfactory components of a flavorant) are detected in statistically independent channels, that each channel makes a separate decision whether a component is detected, and that the behavioral response depends solely on the separate decisions. Models of PS traditionally assume high thresholds for detecting each component, noise being irrelevant. The core assumptions may be adapted, however, to signal-detection theory, where noise limits detection. The present article derives predictions of high-threshold and signal-detection models of independent-decision PS in detecting gustatory-olfactory flavorants, comparing predictions in yes/no and 2-alternative forced-choice tasks using blocked and intermixed stimulus designs. The models also extend to measures of response times to suprathreshold flavorants. Predictions derived from high-threshold and signal-detection models differ markedly. Available empirical evidence on gustatory-olfactory flavor detection suggests that neither the high-threshold nor the signal-detection versions of PS can readily account for the results, which likely reflect neural integration in the flavor system.
authors.affiliation: The John B. Pierce Laboratory, New Haven, CT 06519, USA. marks@jbpierce.org
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Marks
authors.forename: Maria G
authors.initials: MG
authors.lastname: Veldhuizen
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Shepard
authors.forename: Adam Y
authors.initials: AY
authors.lastname: Shavit
mesh_terms: D005421:Flavoring Agents / Q000737:chemistry*; D015233:Models, Statistical; D011336:Probability; D012684:Sensory Thresholds; D012903:Smell
chemical_list: D005421:Flavoring Agents
references.citation: J Opt Soc Am A Opt Image Sci Vis. 1996 Oct;13(10):1960-8
references.pmid: 8828198
references.citation: Trans N Y Acad Sci. 1962 Mar;24:574-90
references.pmid: 14489538
references.citation: J Exp Psychol. 1964 Jan;67:59-66
references.pmid: 14113918
references.citation: Chem Senses. 2010 Feb;35(2):121-33
references.pmid: 20032112
references.citation: J Acoust Soc Am. 1970 Apr;47(4):1009-15
references.pmid: 5443147
references.citation: Chem Senses. 2007 Jun;32(5):475-82
references.pmid: 17488748
references.citation: J Exp Psychol Hum Percept Perform. 1991 Feb;17(1):160-9
references.pmid: 1826309
references.citation: Physiol Behav. 1997 Nov;62(5):1137-43
references.pmid: 9333210
references.citation: J Vis. 2002;2(5):354-70
references.pmid: 12678651
references.citation: Cogn Psychol. 1982 Apr;14(2):247-79
references.pmid: 7083803
references.citation: Perception. 1972;1(4):459-64
references.pmid: 4680946
references.citation: Vision Res. 2000;40(22):3121-44
references.pmid: 10996616
references.citation: J Acoust Soc Am. 1967 Jan;41(1):1-6
references.pmid: 6036090
references.citation: Teor Model. 2007;1(2):121-132
references.pmid: 19079746
references.citation: Psychol Bull. 1970 Mar;73(3):161-99
references.pmid: 4921914
references.citation: Percept Psychophys. 2004 May;66(4):596-608
references.pmid: 15311659
references.citation: Psychol Rev. 1961 Sep;68:301-40
references.pmid: 13774292
references.citation: Vision Res. 1971 Mar;11(3):251-9
references.pmid: 5579840
references.citation: Psychol Rev. 1972 Sep;79(5):410-9
references.pmid: 5076869
references.citation: Behav Brain Res. 2009 Jul 19;201(1):207-15
references.pmid: 19428635
references.citation: Percept Psychophys. 1980 Nov;28(5):471-8
references.pmid: 7208258
references.citation: Behav Brain Res. 2003 Jan 6;138(1):95-105
references.pmid: 12493633
references.citation: Psychol Rev. 1968 Sep;75(5):359-73
references.pmid: 4879423