Dematte Et Al. - Olfactory Cues Modulate Facial Attractiveness

Front 1

What were the four odours used in the study

Back 1

• Pleasant:geranium (flower) male fragrance (Gravity/male perfume/scent/aftershave)
  
• Unpleasant:rubber (latex) body odor (BO) Clean air was also used as well as a neutral odour
  

Front 2

Describe how the odours were delivered and explain advantages of delivering them in this way.

Back 2

olfactometer regulates flow precisely / administers clean (medical) air in between tests (i.e. highly controlled)so differences in responses unlikely to be affected by differences in stimuli or residual/order effects (i.e. highly valid also reliable)

Front 3

Give features of the sample

Back 3

• 16, untrained, females from University of Oxford
  
• mean age 26 years, age range 20–34 years
  
• naïve to purpose of experiment initially
  
• normal sense of smell no history of olfactory dysfunction
  
• normal/corrected-to-normal vision.
  

Front 4

Identify the controls used

Back 4

all participants sitting on a chair / 70 cm from computer / fixation cross / told to exhale through nose at quiet tone / quiet tone same volume at ear for all participants / 22 Hz, 200 ms duration / told to inhale through nose at loud sound / faces shown for 500 ms/in centre of screen / screen turned black / 10 000 ms interstimulus interval / clean medical air during interstimulus interval / 5 min rest every 40 trials

Front 5

Background

Back 5

Facial attractiveness is a socially important cue and has been studied extensively, for example Rhodes et al. (1998) studied facial symmetry and its relationship to attractiveness. Is attractiveness determined by other sensory cues such as olfaction? one study has shown that the perfume ‘shalimar’ led to significantly higher ratings of softness and sexiness when compared with no perfume condition.

Front 6

Variables (IV and DV)

Back 6

• Independent variables:Three conditions; each face was presented three time : once with a pleasant odour, once with an unpleasant odours and once with a neutral odourHigh facial attractiveness, and low facial attractiveness of the presented faces
  
• Dependent variable:Ratings of attractiveness from 1 (least attractive) to 9 (most attractive)
  

Front 7

Aim/hypothesis

Back 7

To determine whether briefly presented olfactory cues can modulate visual judgments of facial attractiveness, and in particular, to ascertain whether olfactory cues of differing hedonic value (i.e., pleasant vs. unpleasant) can enhance and/or reduce the perceived attractiveness of a seen face.

Front 8

Explain the design of the experiment

Back 8

A within-participants repeated measures experimental design was used with the factors of facial attractiveness (high vs. low) and odor pleasantness (pleasant, unpleasant, or neutral). The experimental session consisted of 3 blocks of 40 randomized trials (i.e., participants completed 120 trials in total): Each face was randomly presented 3 times during each experimental session, once with a pleasant odor, once with an unpleasant odor, and once with a neutral odor (i.e., clean air).

Front 9

Why did the experimenters chose presenting male faces to females only?

Back 9

We only presented male faces to female participants in the present experiment for 2 reasons: first, because previous research has suggested that females may be more sensitive to the effects of olfactory cues than males (e.g., see Doty et al. 1985; Chen and Haviland-Jones 2000; Brand and Millot 2001; Spence 2002), and second, be- cause it has been suggested that females might rely more on olfactory cues in mating behavior than males (see Herz and Inzlicht 2002).

Front 10

Outline concentrations of diluted odourants

Back 10

• The body odor was diluted at 0.33%
  
• Geranium odor at 1.0%
  
• Male fragrance at 0.5%
  
• Rubber odor at 1.2%.
  

Front 11

Describe apparatus

Back 11

• Forty male faces (13 cm wide · 17 cm high) taken from the standardized database developed by Perrett et al. were used as the visual stimuli. These faces have been extensively characterized for attractiveness and have been categorized into different attractiveness groups (high, medium, and low). 20 faces were used from each of the high- and low-attractiveness groups.
  
• A custom-built computer-controlled olfactometer was used to deliver the odorants. The flow rate of medical air through the olfactometer was set at 8 l/min using a flow regulator connected to the gas cylinder. The odorants were diluted at different concentrations in diethyl phthalate in order to match them within each odor category (e.g., the male perfume and the geranium odor in the pleasant category) in terms of their perceived intensity
  
• Fours odours 2 pleasant, two unpleasant and one neutral (control)
  
• Computer screen on which to view the male facial images
  
• A questionnaire to determine if the participants have any health (e.g respiratory) problems.
  

Front 12

Explain the procedure of the experiment

Back 12

• Participants sat on a chair 70 cm from a computer screen with their chin on a chin rest.
  
• Participants stared a screen with a small cross. Instructed to exhale when they heard a quiet tone and breathe through their nostrils when they heard a loud tone.
  
• One of the 4 odors (or clean air) was given 500ms via an olfactometer after the loud tone and the participants had to decide if an odor had been presented (press “z”) or not (press “m”).
  
• 1000ms after the odor, a face appeared on the screen for 500ms. When the face disappeared so did the odor and clean air was delivered and the screen returned to black followed by the presentation on the screen of a 9-point rating scale that
  
• Participants were then asked to rate the facial attractiveness on a 9 point scale: 1 = least attractive, 5 = neutral, 9 = most attractive.
  
• As soon as the participants made their rating a fixation cross appeared in the center of the screen for 100ms
  
• The participants rested 5 minutes after every 40 trials.
  
• At the end of the experiment the participants were asked to smell the odors individually and to rate each odour on several different dimensions: Odor intensity, odor pleasantness, and odor familiarity
  
• The participants gave their responses by marking with a pen a point on a paper scale going from 0 (i.e, not at all intense, pleasant, or familiar) to 100.
  

Front 13

Conclusions

Back 13

Female participants judged male faces as being slightly (but significantly) less attractive when presented with an unpleasant odour than with a pleasant or neutral odour. They perceived no difference in attractiveness when presented with a pleasant odour compared with a neutral odour.

Front 14

Strengths

Back 14

High levels of control, randomization of smells to faces, pilot study

Front 15

Outline findings

Back 15

• The highest mean rating of male attractiveness was for male fragrance at 5.73 (Scale 1—9), slightly better than clean air - the second highest at 5.70.
  
• The lowest mean rating of male attractiveness was for body odour at 3.64.
  
• When the two pleasant odours were combined (mean of 4.42) and the two unpleasant odours combined (mean of 4.85) and compared with fresh air (mean of 4.9) participants evaluated male faces as being significantly less attractive with an unpleasant odour than with a pleasant or neutral odour.
  
• Both pleasant and unpleasant odours were perceived as smelling more intense than clean air.
  
• Unpleasant odours were judged to be significantly less pleasant than the pleasant odours. Unpleasant odours were judged to nOt differ significantly from clean air.
  
• All three odour categories were judged to be of relatively equal familiarity.
  

Front 16

Weaknesses

Back 16

• 16 participants, all female, were they all heterosexual?
  
• Low ecological validity-lab test
  

Front 17

What is meant by the term halo-dumping, and how do the experiments explain the findings with this effect?

Back 17

The term ‘‘halo dumping’’ has been used to describe the observation that when participants (regardless of their level of expertise) are asked to evaluate the sensory qualities of an odor, they sometimes tend to use terms that refer to other sensory experiences (e.g., gustatory sensations) instead, such as ‘‘sweet’’ for a vanilla odourHowever, we believe this to be a highly unlikely explanation for the present data for a number of reasons. First, halo dumping has primarily been described in the domain of flavor perception. By contrast, people experience no such uncertainty when discriminating between olfactory and visual (food unrelated) information (i.e., odors and pictures of faces in the present study). What’s more, it is important to note that the participants in our study had to perform an odor detection task at the beginning of each trial, thus meaning that they were able to give separate responses, one to the stimulus presented in each modality (vision and olfaction).. Finally, it is also important to note that the dimension of ‘‘attractiveness’’ is a quite clear, natural, and easy characteristic to consider when we rate human faces. This means that it is unlikely that our participants had any doubts concerning which variable they were supposed to rate in the task. Taken together, we believe that these various considerations therefore preclude any kind of halo-dumping explanation of the present results.