Recognition memory and the mere exposure effect

Repeated exposure to novel stimuli tends to make the stimuli better liked. Examined here is the relation between this increment in liking and recognition of the stimuli. An attempt was made to replicate findings taken as evidence that liking is used as a basis for inferring prior exposure and thus for making recognition decisions (e.g., Matlin, 1971; Moreland & Zajonc, 1977). The claim was not supported. Although in each of five experiments liking and recognition were positively correlated, liking was less sensitive to prior exposure than was recognition. Moreover, statistical analyses suggested that if liking and recognition were causally related, recognition mediated liking rather than the other way around.     

Subliminal mere exposure: specific, general, and diffuse effects

The present research examined the possibility that repeated exposure may simultaneously produce specific and diffuse effects. In Study 1, participants were presented with 5-ms exposures of 25 stimuli each shown once (single-exposure condition) or with five repetitions of 5 stimuli (repeated-exposure condition). Participants in the repeated-exposure condition subsequently rated their own mood more positively than those in the single-exposure condition. Study 2 examined whether affect generated by subliminal repeated exposures transfers to unrelated stimuli. After a subliminal exposure phase, affective reactions to previously exposed stimuli, to new but similar stimuli, and to stimuli from a different category were obtained. Previously exposed stimuli were rated most positively and novel different stimuli least positively. All stimuli were rated more positively in the repeated-exposure condition than in the single-exposure condition. These findings suggest that affect generated by subliminal repeated exposure is sufficiently diffuse to influence ratings of unrelated stimuli and mood.     

The mere exposure effect and recognition memory

This investigation explores the relationship between liking ratings and recognition performance for obscure classical and Russian music melodies. Past studies have explored if awareness of stimulus presentation affects the mere exposure effect (MEE) (Bornstein, 1989; Bornstein & D'Agostino, 1992). We investigate if the type of awareness (i.e., "remembering" an actual occurrence of hearing the melody vs. "knowing" that one is familiar with the melody in a more general, less contextualised sense; Tulving, 1985) affects the MEE. In Experiment 1, we administered the liking test and the recognition test within the same test block and found that liking ratings for "remembered" melodies were on average higher than those for melodies that were merely "known". Although the recognition data replicate the findings of Gardiner, Kaminska, Dixon, and Java (1996) whereby remember and know responses to a given stimulus react differently to repetition from one to three trials, liking data did not vary with the degree of exposure. In addition, our adoption of the recognition category "guess" resulted in a pattern of results that is not only different from previous studies but illustrates the importance of judged, instead of true, old/new status in determining liking. The basic findings of Experiment 1 were replicated in Experiment 2 in which the liking test was conducted prior to the recognition test. Implications of these findings for theories of MEE are discussed.     

Stimulus recognition and the mere exposure effect.

A meta-analysis of research on Zajonc's (1968) mere exposure effect indicated that stimuli perceived without awareness produce substantially larger exposure effects than do stimuli that are consciously perceived (Bornstein, 1989a). However, this finding has not been tested directly in the laboratory. Two experiments were conducted comparing the magnitude of the exposure effect produced by 5-ms (i.e., subliminal) stimuli and stimuli presented for longer durations (i.e., 500 ms). In both experiments, 5-ms stimuli produced significantly larger mere exposure effects than did 500-ms stimuli. These results were obtained for polygon (Experiment 1), Welsh figure (Experiment 2), and photograph stimuli (Experiments 1 and 2). Implications of these findings for theoretical models of the mere exposure effect are discussed.     

The mere exposure effect for visual image

Mere exposure effect refers to a phenomenon in which repeated stimuli are evaluated more positively than novel stimuli. We investigated whether this effect occurs for internally generated visual representations (i.e., visual images). In an exposure phase, a 5 × 5 dot array was presented, and a pair of dots corresponding to the neighboring vertices of an invisible polygon was sequentially flashed (in red), creating an invisible polygon. In Experiments 1, 2, and 4, participants visualized and memorized the shapes of invisible polygons based on different sequences of flashed dots, whereas in Experiment 3, participants only memorized positions of these dots. In a subsequent rating phase, participants visualized the shape of the invisible polygon from allocations of numerical characters on its vertices, and then rated their preference for invisible polygons (Experiments 1, 2, and 3). In contrast, in Experiment 4, participants rated the preference for visible polygons. Results showed that the mere exposure effect appeared only when participants visualized the shape of invisible polygons in both the exposure and rating phases (Experiments 1 and 2), suggesting that the mere exposure effect occurred for internalized visual images. This implies that the sensory inputs from repeated stimuli play a minor role in the mere exposure effect. Absence of the mere exposure effect in Experiment 4 suggests that the consistency of processing between exposure and rating phases plays an important role in the mere exposure effect.     

Alexithymia tendencies and mere exposure alter social approachability judgments

ABSTRACT People have a fundamental motivation for social connection and social engagement, but how do they decide whom to approach in ambiguous social situations? Subjective feelings often influence such decisions, but people vary in awareness of their feelings. We evaluated two opposing hypotheses based on visual familiarity effects and emotional awareness on social approachability judgments. These hypotheses differ in their interpretation of the familiarity or mere exposure effect with either an affective or cognitive interpretation. The responses of our 128‐student sample supported the cognitive interpretation. Lower emotional awareness or higher alexithymia was associated with higher approachability judgments to familiarized faces and lower approachability judgments to novel faces. These findings were independent of the Big Five personality factors. The results indicate that individual differences in emotional awareness should be integrated into social decision‐making models. The results also suggest that cognitive‐perceptual alterations may underlie the poorer social outcomes associated with alexithymia.     

Self-generated visual imagery alters the mere exposure effect

To determine whether self-generated visual imagery alters liking ratings of merely exposed stimuli, 79 college students were repeatedly exposed to the ambiguous duck—rabbit figure. Half the participants were told to picture the image as a duck and half to picture it as a rabbit. When participants made liking ratings of both disambiguated versions of the figure, they rated the version consistent with earlier encoding more positively than the alternate version. Implications of these findings for theoretical models of the exposure effect are discussed.     

Subliminal mere exposure and explicit and implicit positive affective responses

Research suggests that repeated subliminal exposure to environmental stimuli enhances positive affective responses. To date, this research has primarily concentrated on the effects of repeated exposure on explicit measures of positive affect (PA). However, recent research suggests that repeated subliminal presentations may increase implicit PA as well. The present study tested this hypothesis. Participants were either subliminally primed with repeated presentations of the same stimuli or only exposed to each stimulus one time. Results confirmed predictions showing that repeated exposure to the same stimuli increased both explicit and implicit PA. Implications for the role of explicit and implicit PA in attitudinal judgements are discussed.     

Some observations upon perceptual organization and the mere exposure effect

The mere repetition of events tends to enhance subjective familiarity and subjective preference for those events. It has been shown that the enhancement of subjective preference is neither contingent upon a feeling of familiarity nor an awareness of the physical identity of the stimulus during learning. This finding is surprising since the weight of existing theoretical and empirical evidence suggests that subjective preference is derivative of familiarity. An experiment was conducted to test the hypothesis that at least one preattentive/preconscious product, figure-ground organization, is shared between the processes responsible for preference enhancement and those responsible for the enhancement of recognition memory. There were two significant findings. First, subjects were able to discriminate between objectively familiar stimuli and objectively unfamiliar stimuli on the basis of preference judgments but were unable to do so on the basis of familiarity judgments. Second, preference enhancement occurred only for those objectively familiar stimuli for which the figure-ground aspects had not been phenomenally reversed. The significance of these findings is discussed.     

Infant long-term memory for associations formed during mere exposure

We previously found that young infants spontaneously associate stimuli that they merely see together. Using a sensory preconditioning paradigm with 6- and 9-month-olds, we asked how long such associations remain latent before being forgotten and what exposure conditions affect their persistence. Groups were preexposed to two puppets for 1 h/day for 2 days, 1 h on 1 day, or 1 h on 1 day in two sessions; 1-27 days later, target actions were modeled on one puppet, and infants were tested with the other puppet 1 day later. The longest delay after which infants imitated the actions on the other puppet defined how long they remembered the association. The data revealed that the preexposure regimen determined retention. Regardless of exposure time, both ages remembered the association longer after two sessions, and younger infants remembered longer than older infants - for 4 weeks - after two 30-min sessions on 1 day.     

Multiple context mere exposure: Examining the limits of liking

Recent evidence suggests that increased liking of exposed stimuli—a phenomenon known as the mere exposure effect—is dependent on experiencing the stimuli in the same context at exposure and test. Three experiments extended this work by examining the effect of presenting target stimuli in single and multiple exposure contexts. Target face stimuli were repeatedly paired with nonsense words, which took the role of contexts, across exposure. On test, the mere exposure effect was found only when the target face stimuli were presented with nonsense word cues (contexts) with which they had been repeatedly paired. The mere exposure effect was eliminated when exposure to target face stimuli with the nonsense word cues (contexts) was minimal, despite the overall number of exposures to the target face being equated across single- and multiple-context exposure conditions. The results suggest that familiarity of the relationship between stimuli and their context, not simply familiarity of the stimuli themselves, leads to liking. The finding supports a broader framework, which suggests that liking is partly a function of the consistency between past and present experiences with a target stimulus.     

Neurophysiological evidence that perceptions of fluency produce mere exposure effects

Recent exposure to people or objects increases liking ratings, the “mere exposure effect” (Zajonc in American Psychologist, 35, 117–123, 1968), and an increase in processing fluency has been identified as a potential mechanism for producing this effect. This fluency hypothesis was directly tested by altering the trial-by-trial image clarity (i.e., fluency) while Event-Related Potentials (ERPs) were recorded. In Experiment 1, clarity was altered across two trial blocks that each had homogenous trial-by-trial clarity, whereas clarity varied randomly across trials in Experiment 2. Blocking or randomizing image clarity across trials was expected to produce different levels of relative fluency and alter mere exposure effects. The mere exposure effect (i.e., old products liked more than new products) was observed when stimulus clarity remained constant across trials, and clear image ERPs were more positive than blurry image ERPs. Importantly, these patterns were reversed when clarity varied randomly across test trials, such that participants liked clear images more than blurry (i.e., no mere exposure effect) and clear image ERPs were more negative than blurry image ERPs. The findings provide direct experimental support from both behavioral and electrophysiological measures that, in some contexts, mere exposure is the product of top-down interpretations of fluency.     

The mere exposure effect for consumer products as a consequence of existing familiarity and controlled exposure

The finding that repeated exposure to a stimulus enhances attitudes directed towards it is a well-established phenomenon. Despite this, the effects of exposure to products are difficult to determine given that they could have previously been exposed to participants any number of times. Furthermore, factors other than simple repeated exposure can influence affective evaluations for stimuli that are meaningful. In our first study, we examined the influence of existing familiarity with common objects and showed that the attractiveness of shapes representing common objects increases with their rated commonness. In our second study, we eliminated the effects of prior exposure by creating fictitious yet plausible products; thus, exposure frequency was under complete experimental control. We also manipulated the attention to be drawn to the products' designs by placing them in contexts where their visual appearance was stressed to be important versus contexts in which it was indicated that little attention had been paid to their design. Following mere exposure, attractiveness ratings increased linearly with exposure frequency, with the slope of the function being steeper for stimuli presented in an inconspicuous context—indicating that individuals engage in more deliberate processing of the stimuli when attention is drawn to their visual appearance.     

Dissociating mere exposure and repetition priming as a function of word type

The mere exposure effect is defined as enhanced attitude toward a stimulus that has been repeatedly exposed. Repetition priming is defined as facilitated processing of a previously exposed stimulus. We conducted a direct comparison between the two phenomena to test the assumption that the mere exposure effect represents an example of repetition priming. In two experiments, having studied a set of words or nonwords, participants were given a repetition priming task (perceptual identification) or one of two mere exposure (affective liking or preference judgment) tasks. Repetition priming was obtained for both words and nonwords, but only nonwords produced a mere exposure effect. This demonstrates a key boundary for observing the mere exposure effect, one not readily accommodated by a perceptual representation systems (Tulving & Schacter, 1990) account, which assumes that both phenomena should show some sensitivity to nonwords and words.     

The relationship between the structural mere exposure effect and the implicit learning process

Three experiments are reported that investigate the relationship between the structural mere exposure effect (SMEE) and implicit learning in an artificial grammar task. Subjects were presented with stimuli generated from a finite-state grammar and were asked to memorize them. In a subsequent test phase subjects were required first to rate how much they liked novel items, and second whether or not they thought items conformed to the rules of the grammar. A small but consistent effect of grammaticality was found on subjects' liking ratings (a structural mere exposure effect) in all three experiments, but only when encoding and testing conditions were consistent. A change in the surface representation of stimuli between encoding and test (Experiment 1), memorizing fragments of items and being tested on whole items (Experiment 2), and a mismatch of processing operations between encoding and test (Experiment 3) all removed the SMEE. In contrast, the effect of grammaticality on rule judgements remained intact in the face of all three manipulations. It is suggested that rule judgements reflect attempts to explicitly recall information about training items, whereas the SMEE can be explained in terms of an attribution of processing fluency.     

Cognitive consequences of novelty and familiarity: How mere exposure influences level of construal

Two experiments examine whether frequency of exposure influences level of construal. Using subliminal presentation, participants were exposed to neutral, unknown letters 0, 5, 15, or 40 times, and a typical mere exposure effect was found on evaluation. However, we hypothesized and showed in Experiment 1 that novelty enhances Gestalt-like, global perception, whereas familiarity bolsters detail-oriented, local perception. Furthermore, in Experiment 2, we demonstrated that participants generated more abstract solutions for items presented less frequently. These results support a Construal level theory [Liberman, N., Trope, Y., & Stephan, E. (2007). Psychological distance. In E. T. Higgins & A. W. Kruglanski, Social psychology, handbook of basic principles. New York: Guilford Press.] contention that distance from direct experience is associated with high construal level and global processing. It seems that in order to prepare for novel events, people automatically engage in higher levels of construal. New information needs to be integrated into existing knowledge structures in order to be understood, and abstract categories and global processing may support the process of understanding.     

The subliminal mere exposure effect does not generalize to structurally related stimuli.

R.F. Bornstein (1994) questioned whether subliminal mere exposure effects might generalize to structurally related stimuli, thereby providing evidence for the existence of implicit learning. Two experiments examined this claim using letter string stimuli constructed according to the rules of an artificial grammar. Experiment 1 demonstrated that brief, masked exposure to grammatical strings impaired recognition but failed to produce a mere exposure effect on novel structurally related strings seen at test. Experiment 2 replicated this result but also demonstrated that a reliable mere exposure effect could be obtained, provided the same grammatical strings were presented at test. The results suggest that the structural relationship between training and test items prevents the mere exposure effect when participants are unaware of the exposure status of stimuli, and therefore provide no evidence for the existence of implicit learning.     

A mere exposure effect for transformed three-dimensional objects: Effects of reflection, size, or color changes on affect and recognition

If the mere exposure effect is based on implicit memory, recognition and affect judgments should be dissociated by experimental variables in the same manner as other explicit and implicit measures. Consistent with results from recognition and picture naming or object decision priming tasks (e.g., Biederman & E. E. Cooper, 1991, 1992; L. A. Cooper, Schacter, Ballesteros, & Moore, 1992), the present research showed that recognition memory but not affective preference was impaired by reflection or size transformations of three-dimensional objects between study and test. Stimulus color transformations had no effect on either measure. These results indicate that representations that support recognition memory code spatial information about an object’s left-right orientation and size, whereas representations that underlie affective preference do not. Insensitivity to surface feature changes that do not alter object form appears to be a general characteristic of implicit memory measures, including the affective preference task.     

Approaching the familiar: On the ability of mere exposure to direct approach and avoidance behavior

The mere-exposure literature has shown that familiar objects are preferred to novel objects. However, no work has definitively shown that mere exposure can direct and facilitate approach movements. In Experiment 1, participants were shown stimuli and were later re-exposed to them along with novel stimuli. Participants were directed to make an approach or avoidant motion to each and response times were recorded. As predicted, participants were quicker to approach and slower to avoid familiar relative to novel stimuli. In Experiment 2, participants were shown mere-exposed and novel symbols and were asked to “push” or “pull” a joystick in response to each, based on their intuition. Extending Experiment 1’s findings, participants freely selected an approach response more frequently for familiar compared to novel stimuli. Moreover, in this same experiment, familiar stimuli were judged as more likeable than were novel stimuli, and participants’ liking for familiar stimuli correlated with the frequency with which they were approached. Implications of these findings are discussed.