Unconscious Facial Reactions to Emotional Facial Expressions

Dimberg,U., Thunberg, M., & Elmehed, K. (2000)

Psychological Science, Vol II, No 1 86-89

 note  this researcher look at zygomotor only and not orbicularis? therefore ? was accepting the Duchenne smile as the genuine smile although did not mention it.

Dimmberg, 1997 'humans are predisposed to react emotionally to facial expressions'

'Neural activity in the human amygdala differs when people are exposed to different facial stimuli' ( Whalen et al, 1998)

'damage to amygdala impairs the recognition of facial expression'

'when people are exposed to pictures of emotional expressions, they spontaneously and rapidly react with distinct facial EMG displays ( Dimberg 1982,1990)'

' a critical characteristic of an automatic reaction, besides being spontaneous and rapid, is that it can occur without attention or conscious awareness'

unconcious response can be investigated by backward masking technique leads to 

RQ  If distinct facial reactions can be unconsciously elicted, then the masked happy target face would evoke larger zygomatic major muscle activity ( elevates lip to form a smile) and lower corrugator supercilii ( knits eyebrows during a frown)

design

120 students into 3 groups

happy-neutral

neurtral -neutral

angry-neutral

groups differed only in respect to the type of stimuli to which they were unconsciously exposed (30 ms) with 5 sec exposure for the neutral masking stimuli.  

Participant verbal reports when closely questioned indicated that they had not 'consciously' detected the target stimulus.

Directly after the experiment each subject was exposed to one presentation of the target-mask complex and were asked to rate for angry/happy.  Theses ratings did not differ between groups 

Although EMG results indicated a difference between groups , presumably reflecting the target,  the participant overall reported  experience of the target-mask stimulus was relatively neutral.

results

Scored EMG amplitude every 100 m secs giving 10 data points  over a 1 second period.

zygomatic - happy-neutral(up to 1.7 mv) > neutral-neutral (up to 1 mv)> angry neutral (0 mv) during .5 - 1.0 secs ( measured over 5 points)  see diagrams amplitude )

at 300ms there was a small (0.5) positive response what does this mean? Dimberg suggests a startle response.

corrugator happy-neutral <>

at approx 220 ms there was  a positive (2-5-3.0 mv response)

'it is not evident from the present study to what degree the different facial reactions originate in unconscious mimiking behavior or to what degree the facial reactions initially are read outs of underlying emotional states'

refers to Buck, R. (198o) J. Personality and Social Psychology, 38,811-824  'facial muscle activity is essential for the occurrence of emotional experience'