Does autism change the way we use our voices?
Vocal modulation – changing the pitch and speed of our voices – is an important part of self-expression and linguistic communication in social interaction. This research explores how people modulate their voices differently depending on how close they feel to the person they’re talking to, and whether having autistic traits changes the extent to which people do this.
The participants were asked to rate their perceived closeness to the person they were partnered with, and asked to describe a picture to the other. We collected data from same-sex pairs of speakers in the UK, India and Italy and calculated their ‘articulation space’. This refers to the variety of vocal modulation used by a speaker and the flexibility of their pronunciation to convey a wide range of meaning. The larger the articulation space, the more information is communicated (such as the speaker’s emotion about the subject).
We found that although factors such as perceived closeness and gender had a significant influence, having a higher level of autistic traits only slightly reduced this effect, and this difference was not statistically significant. There was little difference in vocal modulation between the three countries. It would be helpful to conduct further research with mixed-sex pairs to examine the influence of gender in that context, and with autistic participants to more fully explore the impact this has.
Summary of Sumathi, T. A., Spinola, O., Singh, N. C., & Chakrabarti, B. (2020). Perceived closeness and autistic traits modulate interpersonal vocal communication. Frontiers in Psychiatry, 11, 50.
Autism and social synchrony
Social synchrony is evident in our everyday activities throughout our lives; from conversations with others, to walking in step, arm-in-arm. Engaging in synchronous interactions facilitates social bonds by increasing liking, trust and prosocial behaviour as well as reducing outgroup bias. Research suggests that, compared to typically developing children or adults, individuals with autism may have more variable performance in social synchronisation.
Our research focussed on identifying how well individuals synchronise with either social or non-social stimuli, across different sensory domains (auditory or visual, or a combination of the two). We also considered the effect of autistic traits and gender on performance levels. Our participants synchronised making a sound in time with a social stimuli (looking at or listening to a person making a sound) and a non-social stimuli (looking at or listening to a moving dot on a screen or a sound on a metronome).
We found that all participants performed significantly better with social stimuli across all three sensory domains. This may indicate the increased reward value placed on social stimuli. Exploratory analysis also found participants improved their performance with the social stimuli as the experiment progressed. However, those with fewer autistic traits demonstrated greater social learning in synchronisation performance across the experiment.
Our findings suggest we synchronise our responses more closely with social compared with non-social stimuli. This ‘social advantage’ is likely to be driven by the preferential attention and reward that is linked to interacting with other humans. It may have implications for interventions supporting social learning.