Ambiguity plays an important role in our everyday cognitive experience. Since the 1980s, the neural bases for the
perception of ambiguous information have been investigated but remains poorly understood. In our previous research, an
increase of the N400 ERP component was found to be a common response for the perception of two different types of
ambiguous stimuli: “canned” verbal jokes and ambiguous figures (Shcherbakova, Filippova, 2016; Filippova, Shcherbakova,
Shtyrov, 2018). The current experiment aimed to understand the relationship between the error related negativity (ERN)
component arising from jokes and ambiguous figures mistaken for non-humoristic texts and non-ambiguous figures.
Fourteen participants (<u>9</u> females) went through two similar experimental procedures with 36 ambiguous and 36
non-ambiguous figures; 14 verbal jokes and 14 similar but non-humoristic short stories. Firstly, participants were presented
with figures of both types and asked to identify whether each figure was ambiguous or non-ambiguous. We recorded ERPs
that were time-locked to each answer about ambiguity/non-ambiguity of the figure presented. Secondly, participants were
presented with the verbal stories and asked to identify whether each story was a joke or not. In this case, ERPs were timelocked
to each answer about the key phrase of a joke/non-joke presented word-by-word on the computer screen after the
whole text.
But we found an increase of the ERPs’ negativity in ambiguous figures that were mistaken for non-ambiguous ones in the
ERN time window (Fz (F(3,622) = 12,6; p < 0.00) and Cz (F(3,625) = 6,96; p < 0.00)). Also, the results revealed no increase
of the ERPs’ negativity in verbal jokes that were mistaken for non-jokes in the ERN time window. The results show that
participants appeared to be sensitive (without awareness) to ambiguous figures that were identified as non-ambiguous
ones. The level of this unconscious sensitivity is therefore reflected by the increases in negativity.
When a participant cannot correctly identify ambiguous stimulus at a conscious level, increases in negativity may be
indexing greater violations of incongruence within an internal representation of meaning. These violations may precede
semantic reversion of ambiguous figures and the understanding of a joke’s meaning.
Supported by RFBR (Dpt of Humanities and Social Sciences) grant 􀀀'-17-06-01014 А and RFBR grant 􀀀'-18-013-01086.
