Rapid, permanent, loss of memory for absolute intensity of taste and smell

Abstract

Memory formation for the absolute intensity of taste and smell was investigated in a series of experiments. In Experiment I, 336 subjects tasted 10 ml of 15% sucrose and were asked to remember the strength of the solution. They were retested with 5%, 10%, 15%, or 20% sucrose, at one of four delay intervals (1, 5, or 15 min, or 72 h). They compared the second stimulus with the first stimulus and reported whether the second was "less sweet," "the same," or "sweeter." Subjects reliably reported that 5% sucrose was less sweet and that 20% sucrose was sweeter. However, when the second stimulus was 15% sucrose (Le., was equal to the standard), approximately 60% of the subjects reported that it was sweeter, regardless of the delay interval between the two stimuli. About 2/3 of those tasting 10% sucrose reported that it was as sweet as or sweeter than the 15% standard. A similar finding from a procedure using magnitude estimation was reported in Experiment 2. The same pattern of results was also found for an olfactory memory test (Experiment 3). When asked to match either a 1.33-or a 5.0-ppm pyridine olfactory stimulus, subjects consistently picked a concentration weaker than the standard. Apparently, olfactory and taste stimuli are remembered as being substantially weaker as soon as the memory for these stimuli can be tested. A memory model that posits a sensory store within which a taste or smell stimulus of a given intensity rapidly fades to a lower level of intensity is suggested. The new memory is then relatively unchanged for at least 3 days.Most research into human memory formation has been concerned with the fate of information coming through the auditory and visual senses. From these experiments human information processing models of the formation of auditory and visual memory have been developed (e.g., Atkinson & Shiffrin, 1968). Although these models do not specifically exclude the chemical senses (Barker, 1982), most research in human memory has been concerned with the ultimate fate of words, numbers, lists, etc. There is little research into how humans process information on taste and smell.Most models of memory posit three stages: for example, a "sensory store" (the first stage of sensing), primary memory (short term), and secondary memory (long term). Evidence of sensory stores has been reported for vision (Sperling, 1960) and audition (Treisman, 1964). Following the transduction process, visual and auditory information persists for a brief period of time «1.0 and 2-4 sec, respectively) before rapidly becoming inaccessible to the attentive processes of primary memory (Crowder, 1972).In the present paper, we offer evidence for a sensory store in the chemical senses. The results of the experiments reported here have allowed us to monitor the fate and time course of memory formation for a taste stimulus (l5% sucrose solution) and for olfactory stimuli (1.33-and 5.0-ppm pyridine solutions). Subjects inThe authors' mailing address is: Department of Psychology, Baylor University, Waco, Texas 76798. several expe...

Different sensory aspects of a food are not remembered with equal acuity

“…In an incidental learning experiment with elderly people, the participants showed a clear tendency to perceive several attributes of soup targets as less intense than they remembered them. In contrast, young people showed a slight tendency to underestimate the remembered target just like the participants in the experiments of Kö ster et al (2004) and of Barker and Weaver (1983) who interpreted this phenomenon as the fading of a memory trace. Obviously, shifts in memory may occur, but their occurrence and direction depend on a number of factors such as the food-attribute combination and perhaps on such subject-related factors as age.…”

“…Shifts in memory opposite to the one found here have also been reported in taste memory research. Barker and Weaver (1983) and Kö ster et al (2004) found that in their experiments the participants underestimated the sweetness intensity of their remembered targets. Nevertheless, a shift in the same direction as in the present experiment was found by Møller et al (2007).…”

A comparison of serial monadic and attribute-by-attribute protocols for simple descriptive analysis with untrained judges

“…Taste studies requiring judges to match taste intensities of previously tasted stimuli, by mixing strong and weak components, indicated a tendency to overestimate the intensity of stimuli tasted immediately beforehand (Theunissen, Tuorila, & Ahlströ m, 1993;Tuorila, Theunissen, & Ahlströ m, 1996;. For taste and odor stimuli, Barker and Weaver (1983) required judges to state whether a stimulus was greater, lesser or equal in intensity to stimuli tasted 1 min before; they found a tendency to underestimate the intensity of the previous stimulus. Either way, memory of stimulus intensities was prone to error.…”

Olfactory perception and olfactory imagery: A multidimensional analysis.

“…For instance, it was considered to be immune to interference from backward counting tasks, to lack a short-term memory store (Engen, Kuisma, & Eimas, 1973), and to have a unique flat forgetting curve, that is, poor initial scores and high retention over time (Engen & Ross, 1973). Recent findings, however, indicate that distractor odors interpolated between odor learning and testing decrease memory performance (Walk & Johns, 1984), a short-term store for odor intensity seems to exist (Barker & Weaver, 1983), and the forgetting curves of both odors and ambiguous, undefined shapes are similar (Lawless, 1978). For a recent review of odor memory, see Schab (1991).…”