# Journal of Consumer Research

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Darren Dahl (Editor in Chief)Eileen FischerGita JoharVicki Morwitz

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## Product Scent and Memory

Aradhna Krishna , May O. Lwin , Maureen Morrin
57-67 First published online: 1 June 2010

## Abstract

Scent research has focused primarily on the effects of ambient scent on consumer evaluations. We focus instead on the effects of product scent on consumer memories. For instance, if a pencil or a facial tissue is imbued with scent (vs. not), recall for the brand's other attributes increases significantly—with the effects lasting as much as 2 weeks after exposure. We also find that product scent is more effective than ambient scent at enhancing memory for product information. We suggest that this may be because, with product (ambient) scent, scent-related associations are focused on a single object (are diffused across multiple objects) in the environment. In support, we find that the memory effects are driven by the number of product/scent-related associations stored in long-term memory. The results suggest that, although ambient scent has received the bulk of attention from researchers and managers in recent years, greater focus on product scent is warranted.

The actions of firms in recent years suggest that imbuing products with scents can enhance brand equity. Firms have sought scent-based trademarks for products such as sewing thread (Brookman 1999), automobile tires (Carter 1995), and tennis balls (Bird 2000). Are such trademark protection efforts worthwhile? We attempt to answer this question by exploring the effect of product scent on consumers’ ability to remember product information over time.

To date, consumer research on scent has focused primarily on the effects of scent on product evaluation (Bone and Ellen 1999; Bone and Jantrania 1992; Bosmans 2006; Laird 1932; Mitchell, Kahn, and Knasko 1995; Spangenberg, Crowley, and Henderson 1996) as well as lingering time (Spangenberg et al. 1996) and variety-seeking behavior (Mitchell et al. 1995). Some initial work has examined the effects of scent on memory (Morrin and Ratneshwar 2000, 2003), but these efforts have focused exclusively on the effects of ambient scent rather than product scent. Yet the use of product scent would appear to be much more widespread in the marketplace. Moreover, product scent may be particularly effective at enhancing memory for product information as a function of its ability to enhance a product’s distinctiveness within its surrounding context.

Specifically, we show that, when products are scented (vs. not), consumers are more likely to remember information about those products. This occurs even though the product scent is not reintroduced at the time of recall and even when memory is assessed as much as 2 weeks after product exposure. In exploring the process at work for this effect, we show that the number of scent-related thoughts available at the time of information retrieval mediates the effect of the product scent on memory for product information. Additionally, ambient scent is not found to exhibit a similar effect on memory for an individual product, and we argue that this is due to a product scent’s ability to make a product perceptually distinctive within its environment. We rule out alternative explanations for a product scent’s effect on memory, namely, the amount of cognitive processing, the number of scent-related thoughts during product exposure, the amount of pleasure and arousal associated with the product, product evaluation, and time spent with the product.

The rest of this article is organized as follows. First, we present a literature review on scent research and offer a conceptual framework. Then we present the results of two studies that begin to empirically explore these issues. We conclude with implications and limitations of the research.

## Literature Review and Conceptual Framework

Research on scent pertinent to our work has been conducted primarily by consumer behavior researchers and cognitive psychologists. Figure 1 shows the relationship between the various constructs in studies across these different research streams, and it also includes what we propose, that is, our conceptual framework. Thus, figure 1 includes our earlier mention of consumer research on the effect of product scent on product evaluation and so forth. We now discuss in greater detail prior research that is pertinent to our focus on scent and memory.

Figure 1

Conceptual Framework for Scent Memory Research

### Scent Recognition and Scent Memory

In the area of psychology, most of the research on the relationship between scent and memory has tested people’s abilities to recognize the scent itself rather than their ability to remember information associated with a scent (Engen and Ross 1973; Zucco 2003). Much of this research focuses on forgetting rates for information (Engen, Kuisma, and Eimas 1973; Peterson and Peterson 1959; Shepard 1967). For example, when researchers study the recall of, say, verbal information over time, they typically find that rapid forgetting occurs, with the most rapid decline in memory occurring immediately after learning (Peterson and Peterson 1959). In comparison, odor recognition studies have shown that the ability to recognize scents previously smelled decays very little over time, with minimal reductions in recognition accuracy from seconds (Engen et al. 1973) to months after exposure (Engen and Ross 1973; Zucco 2003). Engen and Ross (1973) found that scent recognition was 70% when tested immediately after exposure versus 65% after a 1-year delay, as compared to picture recognition (Shepard 1967), which was 99% when measured immediately after exposure versus 58% after a 4-month delay.

Recent research in the basic sciences suggests that there may be physiological and/or neurological reasons for our ability to remember scents so well over time (Buck and Axel 1991). However, the precise mechanism underlying the persistence of scent recognition memory has not been established. Nevertheless, the empirical results suggest that, if product scent does enhance consumer memory for product information, its effects may persist over long periods of time.

Some limited consumer research has looked at the effects of ambient scent on memory (Morrin and Ratneshwar 2003; Smith, Standing, and De Man 1982). Most of these studies, however, have also looked at contextual reinstatement effects, that is, whether the presence of scent at both the time of encoding and the time of retrieval improves memory (Smith et al. 1982), and they have utilized ambient scents rather than those associated with a single object in the environment (Morrin and Ratneshwar 2003; Smith et al. 1982). They typically focus on experimental participants being able to name objects that were seen by them rather than on recalling details about the objects (Morrin and Ratneshwar 2003). Finally, the effects are tested after relatively short delays (e.g., 5 minutes or 24 hours). In contrast, we focus on the effect of product (rather than ambient) scent on memory, we look at memory without reintroduction of the scent cue at the time of recall, we concentrate on memory for details about a product, and we examine memory for product information up to 2 weeks after product exposure. We next describe a framework that offers a rationale for why product scent may be particularly effective at improving memory for product information and thus is worthy of investigation.

### The Distinctiveness Hypothesis

It is well established that distinctive stimuli encountered in the environment tend to attract attention (Green 1958) as well as greater encoding resources. Because objects that are perceptually distinctive are better encoded, they tend to be better remembered (Meyers-Levy and Tybout 1989). A stimulus can be distinctive either because it differs from its immediately surrounding context (i.e., primary distinctiveness) or because it is unexpected based on one’s prior experiences and accumulated knowledge (i.e., secondary distinctiveness; Schmidt 1991).

Primary distinctiveness occurs when an object is perceived as being unusual in its surrounding context (Schmidt 1991). Thus, the features of a stimulus exhibiting primary distinctiveness do not match those it is surrounded by (e.g., encountering a word in red typeface in a list of words in black typeface; Schmidt 1991). We propose that products imbued with a scent will be well remembered because they are made distinctive within their surrounding context (i.e., exhibit primary distinctiveness) if other objects in the environment are not similarly scented.

Secondary distinctiveness occurs when an object is perceived as being unusual with respect to one’s prior knowledge or with respect to information stored in long-term memory (Schmidt 1991). Secondary distinctiveness might occur if an unusual or unexpected ambient scent is encountered, for example, ambient scent in an environment that is not normally scented, such as a dentist’s office. Unexpected ambient scent thus may attract attention to the scent itself or to all of the objects encountered in the scented environment.

We propose that the critical factor affecting scent’s effectiveness at enhancing product memory is the extent to which a scent enhances the distinctiveness of the object-to-be-remembered (i.e., the product), not the extent to which the scent itself is distinctive. It seems logical to assume that the degree to which a scent will enhance an object’s contextual distinctiveness would be a function of the number of objects with which the scent is associated in a given context. Because ambient scent, by definition, is not uniquely associated with a single object in the environment, but rather its associations are diffused across many or all objects in the environment, its ability to create associations with and enhance retrieval for any one particular object within that environment will be diminished. The number of scent-based associations with a single target object created by ambient scent will be fewer than the number resulting from exposure to a product scent or one that is associated with only that single target object. Although ambient scent may have the capacity to collectively enhance memory for all the objects encountered in the scented environment (e.g., all products, store signage, lighting, salespersons, etc.), its particular effects on a single product may be less than that of product scent.

Based on the preceding discussion, we expect, more generally, that, if consumers are exposed to products imbued with a scent, memory for product information will be significantly enhanced. This process is a function of the extent to which the scent makes the product stand out contextually, that is, enhances its contextual distinctiveness. In figure 1, scent of object A is more directly linked with object A experience than with object B experience, whereas ambient scent’s associations are diffused about equally across both objects. Thus, uniqueness of scent-object association affects the strength of scent-object association—it moderates the scent-object experience relationship and hence affects the number of scent-related thoughts and memory for the product. We study the effect of product A's scent on unaided recall for product A both in the short term and in the long term. We also study the effect of product scent and ambient scent on unaided recall for product A and product B in the long term. Additionally, we examine how the number of scent-related thoughts mediates the effect of scent on memory. We begin with an overview of our two studies.

## Overview of Studies

If scent were the main attribute of a product (e.g., perfume or room deodorizer; Schmitt and Schultz 1995), our question of scent-based memory for product information would have a fairly narrow range of applications. As such, we do not investigate products whose central attribute is scent; instead, we focus on products for which scent is a secondary or optional product attribute and whose central attribute is typically something other than scent, such as writing capability for a pencil or softness for a facial tissue.

Two studies are reported. In study 1, we demonstrate that product scent (in pencils) significantly enhances memory for product information and that this effect persists over time. In study 2, we replicate the memory-enhancing effect of product scent for a different type of product (facial tissues) embedded among other products (moisturizer, pencil) and obtain process evidence. Further, we explore the relative effectiveness of product scent versus ambient scent at improving memory for product information.

## Study 1: Scented Pencils

Study 1 compares memory for product information related to scented versus unscented pencils. The experiment was conducted in a city where scented pencils are not very common. A small field study conducted among five different stores in this city showed that only nine pencils were scented among a total of 44 available pencils (20.4%). As such, a scented pencil may be quite distinctive in this environment. For robustness, we compare an unscented type of pencil to two types of scented pencils, one with a less and one with a more congruent or common (for pencils) scent.

### Pretest

A pretest was conducted among 31 undergraduates, who received $5.00 for participation. Participants first rated the importance of the attribute of scent (on a scale of 1 = extremely unimportant to 7 = extremely important) for nine different types of products: moisturizer, facial tissue, pencils, soap, marker pens, toothpaste, lingerie, perfume, and hand cream. Scent was rated as relatively less important for pencils ($$mathtex$$$M=2.90$$$mathtex$$ on a 7-point scale), but it was not totally unimportant $$mathtex$$$( p< .01$$$mathtex$$ for paired t-test of difference from $$mathtex$$$M=1) .$$$mathtex$$ #### Scents Participants were then provided with samples of several scents (these included a range of scent types, e.g., woody, floral, and food-based) and were asked to rate each in terms of how common it was perceived to be for pencils (from 1 = extremely uncommon to 7 = extremely common). The scents were presented in small, tightly capped containers containing an ink blotter strip onto which had been added three to four drops of the scent. Each bottle was labeled with a capital letter (A to F). The samples were sniffed, and each was evaluated on the scale. Scents were presented in two different orders, the second being the reverse of the first order. Respondents were instructed to smell coffee grounds between consecutive stimuli to refresh their scent palettes. This was done to minimize contamination from one scent to the next and is an accepted practice in the fragrance industry to clear the nasal passage. The most and least common scents for the pencil product were pine $$mathtex$$$( M=5.42) $$$mathtex$$ and tea tree $$mathtex$$$( M=2.55$$$mathtex$$ ; paired $$mathtex$$$t=7.52,$$$mathtex$$ df = 30, $$mathtex$$$p< .01) $$$mathtex$$ , respectively, and these were chosen as the scent stimuli for study 1. ### Sample and Design One hundred and fifty-one students participated in return for course credit. The study consisted of a 3 (product scent: none, common, uncommon) × 3 (time delay: none, short, long) full factorial design. In the no product scent conditions, the pencil was not imbued with a scent, whereas in the product scent conditions, the pencil was imbued with either a pine (common) scent or a tea tree (uncommon) scent. In the no time delay condition, memory was tested immediately after exposure to the pencil product, whereas in the time delay conditions, memory was tested after either a 24-hour (short) delay or a 2-week (long) delay. ### Stimulus Materials In the no product scent condition, the product was presented in the form of an unscented natural wood pencil. To create samples of the scented pencils, scents were dripped onto the wooden pencils, which were then placed in airtight bags for 48 hours. This process left no permanent marks. ### Procedure Study 1 was conducted in a laboratory setting over a 2-week period, during which participants took part in two phases. Phase 1 consisted of an encoding phase in which participants were exposed to information about a new product via a print advertisement and were provided a sample of the product. All participants saw the same ad. The ad did not contain any references to scent or smell (see the wording of the ad in the appendix). Phase 2 consisted of a retrieval phase during which memory for brand information was tested. Participants were not made aware during the encoding phase that their memories would later be tested; thus, the learning that occurred consisted of incidental learning, as normally occurs in consumer contexts. The two phases of the study were performed either in a single session (during a 1-hour period on day 1) or in two separate sessions (a half hour in session 1 and a half hour in session 2, 24 hours later; or a half hour in session 1 and a half hour in session 2, 2 weeks later). Upon arrival at the laboratory for phase 1, participants were seated at desks in separate private cubicles to afford them privacy and to prevent them from observing other participants. A printed booklet informed them that they would be taking part in a new product development research study. All participants read these instructions: “A new line of pencils is currently in its final stages of development. However, before the product is launched officially onto the market, we would like you to take a look at its list of attributes and consider them carefully. A sample of the pencil is provided as well. Using the provided sample, you may view, feel, and smell the pencil in order to better evaluate it.” A print advertisement contained the product’s brand name as well as several advertising claims discussing the product’s attributes. In phase 2, the retrieval phase, held in the laboratory, participants completed a survey, which tested their memory for the information contained in the advertisement. Participants were asked to write down the brand name of the pencil they received as well as everything else they could remember about the product, including all the attributes they could recall to describe it. Finally, the participant's age and gender were recorded. ### Results Age and gender were included as covariates in the analyses of variance, but only gender emerged significant for some analyses and was retained. Two independent trained coders, who were neutral and blind to the experimental conditions, coded the responses. An item of recall was coded as correctly recalled when the brand name was spelled correctly (or almost correctly) or when a brand attribute was correctly recalled. Agreement was more than 99%. Any disagreement was resolved by discussion. #### Unaided Recall We conducted an ANOVA on unaided recall as a function of product scent condition, time delay, their interaction, and the gender covariate. There was a significant main effect of product scent (F(2,141) = 39.65, p < .01, $$mathtex$$$\eta ^{2}=.36) $$$mathtex$$ and a significant main effect of time delay (F(2,141) = 11.58, p < .01, $$mathtex$$$\eta ^{2}=.14) ,$$$mathtex$$ qualified by a significant interaction of time delay and product scent (F(4,141) = 32.99, $$mathtex$$$p< .05,$$$mathtex$$ η2 = .08). Gender was not significant $$mathtex$$$( p> .30) .$$$mathtex$$ #### Memory for Scented versus Unscented Pencils Follow-up contrast tests compared the memory for unscented, scented-common, and scented-uncommon pencils at different time delays from product exposure. With no time delay, unaided recall for the unscented pencil $$mathtex$$$( M=3.27) $$$mathtex$$ was significantly lower than that for the scented-common pencil $$mathtex$$$( M=4.71;$$$mathtex$$ $$mathtex$$$F( 1,\, 141) =10.10,$$$mathtex$$ $$mathtex$$$p< .01) $$$mathtex$$ but not compared to the scented-uncommon pencil $$mathtex$$$( M=3.56;$$$mathtex$$ $$mathtex$$$F( 1,\, 141) =0.42,$$$mathtex$$ $$mathtex$$$p> .50) .$$$mathtex$$ Recall for the scented-common pencil was significantly higher than for the scented-uncommon pencil $$mathtex$$$( F( 1,\, 141) =6.00,$$$mathtex$$ $$mathtex$$$p< .05) .$$$mathtex$$ After the short time delay, recall for the unscented pencil (M = 1.94) was significantly lower than for both the scented-common pencil (M = 4.83; F(1,141) = 42.02, $$mathtex$$$p< .01) $$$mathtex$$ and the scented-uncommon pencil (M = 3.83; F(1,141) = 17.71, $$mathtex$$$p< .01) $$$mathtex$$ .There was also a significant difference between the scented-common pencil and the scented-uncommon pencil (F(1,141) = 5.20, $$mathtex$$$p< .05) .$$$mathtex$$ With a long time delay after product exposure, the unscented pencil (M = 0.87) had significantly lower recall than both the scented-common pencil (M = 3.62; F(1,141) = 30.37, $$mathtex$$$p< .01) $$$mathtex$$ and the scented-uncommon pencil (M = 3.27; F(1,141) = 22.32, $$mathtex$$$p< .01) $$$mathtex$$ , but there was no significant difference any longer between the scented-common pencil and the scented-uncommon pencil $$mathtex$$$( p> .45) .$$$mathtex$$ #### Effect of Time Delay Additional follow-up contrasts compared the effects of time delay on memory for unscented, scented-common, and scented-uncommon pencils. These tests show that, for the unscented pencil, recall declined significantly from the no delay condition $$mathtex$$$( M=3.27) $$$mathtex$$ to the short delay condition $$mathtex$$$( M=1.94;$$$mathtex$$ F(1,141) = 8.99, $$mathtex$$$p< .01) $$$mathtex$$ and from the short delay conditon to the long delay condition $$mathtex$$$( M=0.87;$$$mathtex$$ $$mathtex$$$F( 1,\, 141) =4.69,$$$mathtex$$ $$mathtex$$$p< .01) .$$$mathtex$$ As one can see, recall after 2 weeks was about one-fourth (26.6%) of the initial recall for the unscented pencil. Thus, there was rapid forgetting for the unscented pencils, exhibiting a classic type of forgetting curve with a steep fall-off soon after exposure. For the pencils infused with a common scent, recall was not significantly different in the no delay conditon (M = 4.71) and the short delay condition $$mathtex$$$( M=4.83;$$$mathtex$$ $$mathtex$$$F( 1,\, 141) =0.07,$$$mathtex$$ $$mathtex$$$p> .75) $$$mathtex$$ . There was, however, a significant decrease in recall between the short and long delay conditions $$mathtex$$$( M=3.62;$$$mathtex$$ $$mathtex$$$F( 1,141) =7.22,$$$mathtex$$ $$mathtex$$$p< .01) .$$$mathtex$$ Nevertheless, recall after 2 weeks was still about three-fourths (76.8%) of the initial recall—that is, there was relatively little forgetting of product information over time (i.e., a flatter forgetting curve). For the pencils infused with an uncommon scent, there was no significant decline in recall among the various time delay conditions—no difference between no delay $$mathtex$$$( M=3.56) $$$mathtex$$ and short delay $$mathtex$$$( M=3.83;$$$mathtex$$ $$mathtex$$$p> .60) ,$$$mathtex$$ between no delay and long delay $$mathtex$$$( M=3.27;$$$mathtex$$ $$mathtex$$$p> .45) ,$$$mathtex$$ or between short delay and long delay $$mathtex$$$( p> .20) .$$$mathtex$$ Recall after 2 weeks was 91.8% of the initial recall for the pencil with the uncommon scent. So again we see relatively little forgetting of product information over time (i.e., a flatter forgetting curve). Indeed, we see that, while the initial recall level for the uncommon scent was lower than that of the common scent (when recall was tested immediately after exposure), the information that is encoded with the uncommon scent may be more resistant to decay over time than that encoded with the common scent. ### Discussion This pattern of results is consistent with our expectation that product scent would enhance unaided recall of product information and that this effect would persist over time. The effects imply that the impact of product scent on memory is not just a function of contextual reinstatement (i.e., the presence of scent at both encoding and retrieval), as has been shown in prior research (Herz 1997). That is, the memory effect is evident here even though there is no reintroduction of scent-based retrieval cues, suggesting that the memory improvement is due to superior encoding of scent-associated information at the time of exposure. We found such effects highly persistent over time, extending the findings from prior research that had used only short time delays. The long-lasting pattern of scent recognition memory was also extended to free recall of information associated with a product scent at the time of encoding. In the short term and the medium term, the common scent was more effective at enhancing recall. In the long term (i.e., after 2 weeks), however, both types of scents were equally effective. The information encoded with the uncommon scent was more resistant to decay over time. The amount of information recalled with the common scent declined significantly after a long time delay (to 76.8%), whereas there was no significant decline over time in the amount of information recalled with the uncommon scent (91.8%). From this pattern of results, we speculate that information may be initially easier to encode with a common scent but, of the information that has been encoded, that which has been encoded with the uncommon scent is stronger and more resistant to decay. In this study, we find that both common and uncommon scents are effective in enhancing memory. But, as we mentioned at the start of the experiment, with regard to pencils, possessing a product scent may itself be rather uncommon and contrary to expectations, so that any type of product scenting may attract attention and enhance memory. In the next study, we use a product—facial tissues—that is more commonly sold in a scented format, so that scent is not as unexpected, and for which product scent is a more important selling attribute (as suggested by pretest results). We thus expand the generalizability of our results. We also utilize a setting in which the target product (facial tissues) is encountered among other types of products (i.e., moisturizer, pencils), which is more reflective of real world settings. ## Study 2: Scented Tissues versus Ambient Scent In study 2, we not only attempt to replicate effects from study 1 but also attempt to compare the effectiveness of product scent versus ambient scent at enhancing memory for product information. Importantly, we also obtain process evidence in the form of scent-related associations stored in long-term memory. If it is true that product scent is more effective than ambient scent at focusing the consumer’s attention and encoding efforts on the target product, as we have argued, then this should be evident not only in improved recall of target product information but also in a larger number of product/scent-related associations stored in long-term memory. ### Pretest Twenty-one pretest participants were recruited from the same population as those who were to participate in study 2 (i.e., undergraduate students at the same university). They were paid$7.00 to participate. We tested four different scents: two of these were floral in nature (rose and jasmine), another was fruity (strawberry), and another had both fruit and floral elements (orange blossom). Two drops of each scent were put onto cotton balls and placed in tightly sealed double-layer zip lock bags for 48 hours prior to the pretest.

Participants were tested one at a time. The four bags with the scented cotton balls were lined up on tables in a random order. Participants sniffed the four scents, one at a time, so that the next packet was sniffed only when the participant was done rating the previous scent. Between scents, participants were given coffee grounds to sniff to clear the nasal system. Participants were free to start with any scent and proceed to any scent (on the questionnaire, they recorded which scent they were evaluating, each of which was identified by a capital letter: A, B, C, or D). The participants rated how common it would be to encounter each scent for each of six different product categories: facial tissues, moisturizer, room deodorizer, laundry soap, sunscreen, and shampoo product (from 1 = not at all common to 9 = extremely common), how much they would like each of the products if it contained this scent (1 = not like at all to 9 = like a lot), and how pleasant the scent would be for each of the products (1 = not at all pleasant to 9 = extremely pleasant). Respondents also rated how important scent was for each of the six products considered (1 = extremely unimportant to 7 = extremely important).

Analysis of the results suggested that two of the four scents, jasmine and orange blossom, were similarly rated for facial tissues and deodorizers. Specifically, orange blossom was rated as equally congruent (paired $$mathtex$$ $t( 20) =0.90,$ $$mathtex$$ $$mathtex$$ $p> .35) ,$ $$mathtex$$ equally liked (paired $$mathtex$$ $t( 20) =0.47,$ $$mathtex$$ $$mathtex$$ $p> .60) ,$ $$mathtex$$ and equally pleasant (paired $$mathtex$$ $t( 20) =1.02,$ $$mathtex$$ $$mathtex$$ $p> .30)$ $$mathtex$$ for the facial tissues and room deodorizer product categories. Jasmine was also rated as equally congruent (paired $$mathtex$$ $t( 20) =0.57,$ $$mathtex$$ $$mathtex$$ $p> .55) ,$ $$mathtex$$ equally liked (paired $$mathtex$$ $t( 20) =1.01,$ $$mathtex$$ $$mathtex$$ $p> .30) ,$ $$mathtex$$ and equally pleasant (paired t(df = 20) = 0.64, $$mathtex$$ $p> .50)$ $$mathtex$$ for the facial tissues and room deodorizer product categories. We chose to use orange blossom for study 2 due to the higher overall evaluation scores for this scent versus jasmine (mean liking of orange blossom = 4.20 vs. 2.78 for jasmine, $$mathtex$$ $p< .01;$ $$mathtex$$ mean pleasantness of orange blossom = 4.33 vs. 2.94 for jasmine; $$mathtex$$ $p< .05) .$ $$mathtex$$ Scent was also considered a moderately important attribute for tissues $$mathtex$$ $( M=4.86$ $$mathtex$$ on a scale of 1–7), which is what we wanted in our study 2 to enhance the generalizability of our findings. Hence, tissues were chosen as the test product and orange blossom as the scent. Pencils and moisturizers were chosen as the other two products to be used in the study (distracter products) since they were very different from tissues and the three products would therefore be quite distinct.

### Discussion

In this study, we replicate the memory-enhancing effect of product scent using a different type of product (facial tissues) that is encountered within a set of other products, as might occur in a store setting. We found that, when a product is scented, long-term memory for that product’s other (i.e., non-scent-related) attributes increases. We also found that product scent was more effective than ambient scent at enhancing memory for product-related information, which is consistent with the distinctiveness hypothesis. We showed that product scent creates strong, long-lasting associations between the scent and product attribute information, with these associations accessible as much as 2 weeks after the time of exposure. We did not find that scent’s memory-enhancing effect is due to such other processes as cognitive elaboration, mood, arousal, environmental affect, or time spent with the products.

Although ambient scent did not similarly enhance memory for a single target in the environment, ambient scent may have the capacity to enhance memory for a collection of objects encountered within an environment, since its effects may be diffused across all such objects. Thus, for example, Morrin and Ratneshwar (2003, study 2) found that, when they exposed participants to 42 different brands in the presence of ambient scent, the proportion recalled increased from 13% to 15%. However, it is unlikely that memory for a single brand encountered in such an environment would be measurably altered by the diffused effects of ambient scent.

What we have shown here is that product scent is highly effective at enhancing memory for information about a single target product. We have offered one possible rationale for its efficacy, that is, the number of scent-related associations created in long-term memory that are focused on that product.

## General Discussion

Interest in sensory marketing appears to be on the rise, especially in previously neglected areas such as olfaction and touch (Peck and Childers 2008). In this exploratory study, we focus on olfaction, or the sense of smell, and more specifically, on the significant effects that product scents can have on memory for product information.

We demonstrate that product scent significantly enhances recall of product information and that this enhanced memory for product information persists over time—for at least 2 weeks after the time of exposure. We further find that product scent creates long-lasting scent-product associations in memory. We found that product scent enhanced memory for product information more effectively than did ambient scent, whose effects may be diffused across numerous objects in the environment. While our results are consistent with the distinctiveness hypothesis, they do not rule out all alternative explanations. For example, it is possible that the level of intensity of the ambient scent used in the present research was below that necessary for significant memory effects to emerge. It is also possible that the ambient scent improved memory for several items encountered in the environment and if added together would demonstrate collective improvement in memory performance.

Nevertheless, we suggest that it is the extent to which a scent makes the object(s) to be remembered distinctive that determines its effectiveness at enhancing memory for those objects. If interest is on the extent to which scent enhances memory for information about a specific product, the preliminary evidence presented here suggests that the scent needs to be associated with just that single object (rather than diffused or shared across multiple objects in the environment). In this way, the target product’s contextual distinctiveness is enhanced, encoding resources are focused, and subsequent retrieval is improved.

Unlike most prior studies examining the effects of scent on memory, we did not look at the effects of scent-cue-aided performance (Herz 1997). Instead, we looked at unaided recall, which may be more important not only for theoretical reasons but for managerial reasons as well. If people remember a product and its attributes at the time of purchase many weeks after being exposed to it (in a shop, in a hotel, or at a friend’s house), then they can look for it during their shopping trip and purchase it. In the real world, the scent cue as an aid for recall will work only if one picks up the product and the packaging is permeated with a scent (or the product scent seeps through the packaging).

Of course, this is an exploratory effort, and additional research is needed to test whether the proposed distinctiveness hypothesis indeed explains the degree to which scent type (ambient vs. object-specific) enhances the distinctiveness of the object to be recalled. Future research could also study whether the effects of product scent are diminished when competitive products are similarly scented. Our distinctiveness hypothesis would suggest that they would be.

In the United States, legally, scents may be trademarked if they serve to identify the product source or brand name, even if they do not serve a functional purpose. However, there have been relatively few scent-based trademarks established. This may be the case because until now people have not understood scent’s strong ability to enhance product identification. As such, we hope that this research not only shows how important scent can be in enhancing memory for product information but also contributes to building arguments for why olfactory trademarks should be considered.

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• Feature a smooth finishing for easy gripping

Clarisilkia Moisturizer (presented only in study 2):

• Comes in handy tubes of different sizes

• Is a non-greasy cream that absorbs easily into the skin

• Leaves your skin feeling soft and healthy

• Is formulated with Aloe Vera and other natural plant extracts

• Contains Vitamin C and E to fight aging

• Is great for people whose skin peels often

• Eliminates discoloration of the skin

• Contains sunscreens to give great protection against the sun

• Is suitable for all skin types

• Is made entirely with Swiss Pride

Ceville Facial Tissues (presented only in study 2):

• Contains a mild antiseptic formula to help eliminate the spread of bacteria

• Is available in a wide variety of colors

• Comes packaged in handy portable package sizes

• Triple-ply thickness for enhanced strength

• Is great for people whose skin is sensitive

• Is available embossed with attractive designs

• Made of paper with minimal lint, to maximize cleanliness

• Tested for high absorbency