The assessment took part in the res

The assessment took part in the research unit. The task
was presented on a 12 in. laptop monitor placed approximately
38 cm from participants' eyes. Infant faces were
drawn from a database of digital photographs of 27 infants
who were filmed at home (Kringelbach et al., 2008) and were
shown as greyscale images, matched for size and luminosity.
A total of ten different faces, five sad and five happy, werepresented in random order using ePrime software. Each face
was morphed from neutral to 100% at increments of 2%.
Altogether, 70 faces were presented even though only 50
differed in intensity: sometimes a face of a certain intensity
was repeated multiple times before the screen moved on to
the next intensity level to avoid having a perfect correlation
between time and expression intensity and to increase the
difficulty of the task (see Joormann and Gotlib, 2006, for
details). Faces were shown for 500 ms.
Participants were required to press the space bar as soon as
they thought they could identify the emotion that was being
expressed. This stopped the sequence and they were then
asked to label the emotion they had identified by pressing key
1 or 2 depending on whether they thought the face was happy
or sad. These options were displayed in writing on the screen
that appeared after the participants had pressed the space bar.
There were two practice trials before the experiment.
3. Results
Responses given after 100% of the sequence had