An opacity-tolerant conspiracy in phonological acquisition

National Institutes of Health DC00433, RR7031K, DC00076, DC001694 (PI: Gierut

Developmental shifts in phonological strength relations

National Institutes of Health DC00433, RR7031K, DC00076, DC001694 (PI: Gierut

Comparative markedness and induced opacity

Results are reported from a descriptive and experimental study that was intended to evaluate comparative markedness (McCarthy 2002, 2003) as an amendment to optimality theory. Two children (aged 4;3 and 4;11) with strikingly similar, delayed phonologies presented with two independent, interacting error patterns of special interest, i.e., Deaffrication ([tIn] 'chin') and Consonant Harmony ([$\text{g}$ↄ$\text{g}$] 'dog') in a feeding interaction ([kik] 'cheek'). Both children were enrolled in a counterbalanced treatment study employing a multiple base-line single-subject experimental design, which was intended to induce a grandfather effect in one case ([dↄ$\text{g}$] 'dog' and [kik] 'cheek') and a counterfeeding interaction in the other ([$\text{g}$ↄ$\text{g}$] 'dog' and [tik] 'cheek'). The results were largely supportive of comparative markedness, although some anomalies were observed. The clinical implications of these results are also explored.National Institutes of Health DC00433, RR7031K, DC00076, DC001694 (PI: Gierut

On the interaction of deaffrication and consonant harmony

Error patterns in children's phonological development are often described as simplifying processes that can interact with one another with different consequences. Some interactions limit the applicability of an error pattern, and others extend it to more words. Theories predict that error patterns interact to their full potential. While specific interactions have been documented for certain pairs of processes, no developmental study has shown that the range of typologically predicted interactions occurs for those processes. To determine whether this anomaly is an accidental gap or a systematic peculiarity of particular error patterns, two commonly occurring processes were considered, namely Deaffrication and Consonant Harmony. Results are reported from a cross-sectional and longitudinal study of 12 children (age 3;0 - 5;0) with functional phonological delays. Three interaction types were attested to varying degrees. The longitudinal results further instantiated the typology and revealed a characteristic trajectory of change. Implications of these findings are explored.National Institutes of Health DC00433, RR7031K, DC00076, DC001694 (PI: Gierut

Comparative Markedness and Induced Opacity

Results are reported from a descriptive and experimental study that was intended to evaluate comparative markedness (McCarthy 2002, 2003) as an amendment to optimality theory. Two children (aged 4;3 and 4;11) with strikingly similar, delayed phonologies presented with two independent, interacting error patterns of special interest, i.e., Deaffrication ([tɪn] 'chin') and Consonant Harmony ([ɡɔɡ] 'dog') in a feeding interaction ([kik] cheek). Both children were enrolled in a counterbalanced treatment study employing a multiple base-line single-subject experimental design, which was intended to induce a grandfather effect in one case ([dɔɡ] 'dog' and [kik] 'cheek') and a counterfeeding interaction in the other ([ɡɔɡ] 'dog' and [tik] 'cheek'). The results were largely supportive of comparative markedness, although some anomalies were observed. The clinical implications of these results are also explored

Neural decoding reveals the functional anatomy of auditory integration and competition in speech perception

At the beginning of a word, many continuations are possible – for example, when hearing packet, listeners may consider pass and package. Cognitive science shows that listeners in this situation immediately consider multiple words and narrow down the set of candidates via competition. However, cognitive neuroscience has not yet been able to identify the cortical locus of this competition. One potential source of this difficulty is the hypothesis (tested here) that representations of unfolding auditory stimuli take the form of distributed patterns of activity, rather than the overall quantity of activity. We investigated competition dynamics by combining direct recordings from the cortex of humans listening to spoken words with machine learning to decode those distributed patterns. Two critical first steps in investigating the neural basis of these competition dynamics were to identify regions a) whose pattern of activity supports multiple candidates; and b) whose pattern of activity persists over time (after stimulus offset). We characterized both properties in six language regions by using machine learning to assess which words were under consideration in each area every 25 ms during listening. Auditory areas – early in the processing stream – exhibited competition dynamics lasting even after stimulus offset. This pattern was not seen in higher-level language areas. Thus, competition among distributed patterns of activity in auditory sensory areas may underlie human word recognition