Robots That Say “No” Affective Symbol Grounding and the Case of Intent Interpretations

Abstract

Modern theories on early child language acquisition tend to focus on referential words, mostly nouns, labeling concrete objects, or physical properties. In this experimental proof-ofconcept study, we show how nonreferential negation words, typically belonging to a child's first ten words, may be acquired. A childlike humanoid robot is deployed in speech-wise unconstrained interaction with naïve human participants. In agreement with psycholinguistic observations, we corroborate the hypothesis that affect plays a pivotal role in the socially distributed acquisition process where the adept conversation partner provides linguistic interpretations of the affective displays of the less adept speaker. Negation words are prosodically salient within intent interpretations that are triggered by the learner's display of affect. From there they can be picked up and used by the budding language learner which may involve the grounding of these words in the very affective states that triggered them in the first place. The pragmatic analysis of the robot's linguistic performance indicates that the correct timing of negative utterances is essential for the listener to infer the meaning of otherwise ambiguous negative utterances. In order to assess the robot's performance thoroughly comparative data from psycholinguistic studies of parent-child dyads is needed highlighting the need for further interdisciplinary work.

Robots Learning to Say “No”

“…Given our focus on negation, we were particularly interested in the negative variant of intent interpretations, that is intent interpretatios with respect to displays of negative affect or motivation. As described in Förster et al [14] the effect of the robot's affective displays on participants' speech was remarkable, and did confirm the potential of intent interpretations as source for negation words. We use the results of the rejection experiment within the present article as point of reference to assess the comparative efficacy of the prohibition task in terms of the acquisition of negation words.…”

“…As mentioned earlier, the prohibition experiment was designed in close alignment with the rejection experiment [14]. The robot's behavior developed for the rejection experiment formed the baseline behavior for the rejective scenario of the prohibition experiment ( Figure 2).…”

“…Questions. The overarching aim of both the prohibition experiment, presented in the present publication, and the rejection experiment, presented elsewhere [14], is to understand the developmental origin of linguistic negation. Where do the first actively used negation words of human toddlers, chiefly "no," originate, and how do toddlers learn to use them?…”

“…The main experiment on the role of prohibition in negation acquisition described in the present publication was designed in tandem with an experiment on so called intent interpretations described in [14]. The two experiments were jointly designed to achieve maximum alignment for the purpose of comparability.…”

“…In the rejection experiment [14], we tested whether the robot's display of affect would trigger intent interpretations on part of our participants akin to what Pea and Ryan had observed in parentchild dyads. Given our focus on negation, we were particularly interested in the negative variant of intent interpretations, that is intent interpretatios with respect to displays of negative affect or motivation.…”