Neuropsychiatric Symptoms of Epilepsy

11 Emotion Recognition
181
have common components, overlapping, forming a continuum from positive
to negative? Most scientists of emotions tend to agree that the six major emotions
represent points along a continuum and that emotions have neural elements
that are both distinctive than shared [ 38 ]. Moreover, most neuroscientists
believed that emotions and their facial expressions are not entirely innate, but
are partly determined by our previous experience with emotions and by our
associations of certain emotions with certain contexts.
Since then, studies were drawn from a range of countries and ethnicities,
including the United States, the United Kingdom, Italy, France, Canada, Japan,
Spain, the Netherlands, India, Australia, and Switzerland. All of the studies compared
patients’ ER abilities with healthy volunteers matched for principal demographic
variables (age, education, and sex). Some study included also a clinical
control group (frontal or extra temporal lobe epilepsy, generalized epilepsy). The
choice to compare medial TLE with other epilepsy patients is relevant to ascribe
the specificity of the observed deficits to the medial temporal lobe region, and to
exclude a generic effect of epilepsy per se. The rationale for using extra-TLE
group is that people with extra- temporal lobe epilepsy live in a similar social and
emotional environment with respect to people with TLE; they experiment epilepsy
stigma and limitation in social and personal aspects due to epilepsy; they
also are treated with antiepileptic drugs.
The majority of studies included at least one test of facial emotion recognition.
The most commonly used stimuli were static black and white images from Ekman
and Friesen series [ 35 ]. In some studies 60 pictures were used [ 39 – 42 ], with 10
stimuli for each basic emotion. In other studies 24–42 pictures, typically with fourfive
stimuli for each emotion, were used [ 12 , 14 , 15 , 26 – 28 , 33 , 43 – 46 ]. Some
authors excluded surprise, to avoid mistaking fear for surprise and vice versa [ 26 –
28 , 33 , 44 ]. In some studies, the recognition of emotion posed with different intensity
was tested creating “morphed” facial stimuli from prototypical facial expressions
[ 39 , 42 , 44 , 47 ]. Other authors used tests composed by in-house made stimuli to test
emotion recognition in children [ 48 , 49 ]. Notably, few studies (only three to our
knowledge) used dynamic stimuli realized by videos [ 43 , 50 , 51 ].
As far as emotional stimuli different from faces go, ten studies included tasks of
emotion recognition in the auditory modality. The recognition of both short nonverbal
vocal sounds (e.g., laughter and grows) as well as prosody from sentences with
neutral meaning was evaluated [ 15 , 33 , 34 , 47 , 52 , 53 ]. The emotions tested in most
of studies were happiness, sadness, fear, anger, disgust, and surprise.
Finally, recently, three studies tested emotion recognition from music, using
musical excerpts composed to induce fear, peacefulness, happiness, and sadness
[ 31 , 32 , 54 ].