Speech segmentation by statistical learning is supported by domain-general processes within working memory

Abstract

The purpose of this study was to examine the extent to which working memory resources are recruited during statistical learning (SL). Participants were asked to identify novel words in an artificial speech stream where the transitional probabilities between syllables provided the only segmentation cue. Experiments 1 and 2 demonstrated that segmentation performance improved when the speech rate was slowed down, suggesting that SL is supported by some form of active processing or maintenance mechanism that operates more effectively under slower presentation rates. In Experiment 3 we investigated the nature of this mechanism by asking participants to perform a two-back task while listening to the speech stream. Half of the participants performed a two-back rhyme task designed to engage phonological processing, whereas the other half performed a comparable two-back task on un-nameable visual shapes. It was hypothesized that if SL is dependent only upon domain-specific processes (i.e., phonological rehearsal), the rhyme task should impair speech segmentation performance more than the shape task. However, the two loads were equally disruptive to learning, as they both eradicated the benefit provided by the slow rate. These results suggest that SL is supported by working-memory processes that rely on domain-general resources.

Word segmentation from noise-band vocoded speech

“…This finding contrasts with results from Palmer and Mattys (2016), which showed improvements in segmentation when the speech stream was slowed. A plausible explanation for this inconsistency is that listeners may only be able to take advantage of slower speech under clear, unencumbered listening conditions.…”

“…Recent work by Palmer and Mattys (2016) demonstrated that slower syllable rates improved performance on a segmentation task in adults, even when they controlled for the total duration of the speech stream. They showed that adults who were familiarised to an artificial language at a slow rate (i.e.…”

Musicians’ Online Performance during Auditory and Visual Statistical Learning Tasks

“…Working memory resources are helpful during the consolidation of these templates (Cunillera et al, 2009; Lopez-Barroso et al, 2011). Recent research also suggests that SL is supported by working memory process which may include attentional refreshing or working memory update (Palmer and Mattys, 2016). Due to consolidation of the three-tone templates, tones within a triplet are easy to predict while the first tone of the triplet continues to be unpredictable resulting in a strong triplet onset effect.…”

Towards a theory of individual differences in statistical learning

“…[64]), or, relatedly, unsupervised versus supervised learning settings (see [65] for a discussion of the role of feedback in perceptual category learning). An additional factor that was shown to affect SL performance is the rate of presentation-with opposite effects of both the inter stimulus interval and the actual stimulus duration on SL performance in the visual versus auditory modality ( [35,36]; but see [66]). Whether rate of presentation constitutes a separate facet, or simply affects peripheral aspects to SL such as the encoding of individual elements, with different constraints in different modalities (see [11]), deserves further investigation.…”