A vowel is a vowel: Generalizing newly learned phonotactic constraints to new contexts.

Adults can learn novel phonotactic constraints from brief listening experience. We investigated the representations underlying phonotactic learning by testing generalization to syllables containing new vowels. Adults heard consonant–vowel–consonant study syllables in which particular consonants were artificially restricted to the onset or coda position (e.g., /f/ is an onset, /s/ is a coda). Subjects were quicker to repeat novel constraint-following (legal) than constraint-violating (illegal) test syllables whether they contained a vowel used in the study syllables (training vowel) or a new (transfer) vowel. This effect emerged regardless of the acoustic similarity between training and transfer vowels. Listeners thus learned and generalized phonotactic constraints that can be characterized as simple first-order constraints on consonant position. Rapid generalization independent of vowel context provides evidence that vowels and consonants are represented independently by processes underlying phonotactic learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sublexical and Lexical Representations in Speech Production: Effects of Phonotactic Probability and Onset Density.

Phonotactic probability, neighborhood density, and onset density were manipulated in 4 picture-naming tasks. Experiment 1 showed that pictures of words with high phonotactic probability were named more quickly than pictures of words with low phonotactic probability. This effect was consistent over multiple presentations of the pictures (Experiment 2). Manipulations of phonotactic probability and neighborhood density showed only an influence of phonotactic probability (Experiment 3). In Experiment 4, pictures of words with sparse onsets were named more quickly than pictures of words with dense onsets. The results of these experiments provide additional constraints on the architecture and processes involved in models of speech production, as well as constraints on the connections between the recognition and production systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speech errors reflect newly learned phonotactic constraints.

Speech errors reveal the speaker's implicit knowledge of phonotactic constraints, both languagewide constraints (e.g., /K/ cannot be a syllable onset when one is speaking English) and experimentally induced constraints (e.g., /k/ cannot be an onset during the experiment). Four experiments investigated the acquisition of novel 2nd-order constraints, in which the allowable position of a consonant depends on some other property of the syllable (e.g., /k/ can only be an onset if the vowel is /I/). Participants recited strings of syllables that exhibited the novel constraints throughout a 4-day experiment. Their errors reflected the newly learned constraints but not until the 2nd day of training. This contrasts with previous research showing that errors become sensitive to 1st-order constraints almost immediately. A model that learns to assign phonemes to syllable positions is presented. It attributes the relative slowness of the acquisition of 2nd-order constraints to the self-interfering property of these constraints. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Error biases in inner and overt speech: Evidence from tongue twisters.

To compare the properties of inner and overt speech, Oppenheim and Dell (2008) counted participants' self-reported speech errors when reciting tongue twisters either overtly or silently and found a bias toward substituting phonemes that resulted in words in both conditions, but a bias toward substituting similar phonemes only when speech was overt. Here, we report 3 experiments revisiting their conclusion that inner speech remains underspecified at the subphonemic level, which they simulated within an activation-feedback framework. In 2 experiments, participants recited tongue twisters that could result in the errorful substitutions of similar or dissimilar phonemes to form real words or nonwords. Both experiments included an auditory masking condition, to gauge the possible impact of loss of auditory feedback on the accuracy of self-reporting of speech errors. In Experiment 1, the stimuli were composed entirely from real words, whereas, in Experiment 2, half the tokens used were nonwords. Although masking did not have any effects, participants were more likely to report substitutions of similar phonemes in both experiments, in inner as well as overt speech. This pattern of results was confirmed in a 3rd experiment using the real-word materials from Oppenheim and Dell (in press). In addition to these findings, a lexical bias effect found in Experiments 1 and 3 disappeared in Experiment 2. Our findings support a view in which plans for inner speech are indeed specified at the feature level, even when there is no intention to articulate words overtly, and in which editing of the plan for errors is implicated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phonological processes and the perception of phonotactically illegal consonant clusters

The perception of consonant clusters that are phonotactically illegal word initially in English (e.g., /tl/,/sr/) was investigated to determine whether listeners' phonological knowledge of the language influences speech processing. Experiment 1 examined whether the phonotactic context effect (Massaro & Cohen, 1983), a bias toward hearing illegal sequences (e.g.,/tl/) as legal (e.g., /tr/), is more likely due to knowledge of the legal phoneme combinations in English or to a frequency effect. In Experiment 2, Experiment 1 was repeated with the clusters occurring word medially to assess whether phonotactic rules of syllabification modulate the phonotactic effect. Experiment 3 examined whether vowel epenthesis, another phonological process, might also affect listeners' perception of illegal sequences as legal by biasing them to hear a vowel between the consonants of the cluster (e.g., /talae/). Results suggest that knowledge of the phonotactically permissible sequences in English can affect phoneme processing in multiple ways.     

Speech errors, phonotactic constraints, and implicit learning: A study of the role of experience in language production.

Speech errors follow the phonotactics of the language being spoken. For example, in English, if [n] is mispronounced as [ ], the [ ] will always appear in a syllable coda. The authors created an analogue to this phenomenon by having participants recite lists of consonant–vowel–consonant syllables in 4 sessions on different days. In the first 2 experiments, some consonants were always onsets, some were always codas, and some could be both. In a third experiment, the set of possible onsets and codas depended on vowel identity. In all 3 studies, the production errors that occurred respected the "phonotactics" of the experiment. The results illustrate the implicit learning of the sequential constraints present in the stimuli and show that the language production system adapts to recent experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The possible-word constraint in the segmentation of continuous speech

We propose that word recognition in continuous speech is subject to constraints on what may constitute a viable word of the language. This Possible-Word Constraint (PWC) reduces activation of candidate words if their recognition would imply word status for adjacent input which could not be a word--for instance, a single consonant. In two word-spotting experiments, listeners found it much harder to detect apple, for example, in fapple (where [f] alone would be an impossible word), than in vuffapple (where vuff could be a word of English). We demonstrate that the PWC can readily be implemented in a competition-based model of continuous speech recognition, as a constraint on the process of competition between candidate words; where a stretch of speech between a candidate word and a (known or likely) word boundary is not a possible word, activation of the candidate word is reduced. This implementation accurately simulates both the present results and data from a range of earlier studies of speech segmentation.     

Distraction by competing speech in young and older adult listeners.

In 2 experiments, young and older adults heard target speech presented in quiet or with a competing speaker in the background. The distractor consisted either of meaningful speech or nonmeaningful speech composed of randomly ordered word strings (Experiment 1) or speech in an unfamiliar language (Experiment 2). Tests of recall for the target speech showed that older adults, but not younger adults, were impaired more by meaningful distractors than by nonmeaningful distracters, However, on a surprise recognition test, young adults were more likely than older adults to recognize meaningful distractor items. These results suggest that reduced efficiency in attentional control is an important factor in older adults' difficulty in recalling target speech in the presence of a background of competing speech. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generalization of perceptual learning of vocoded speech.

Recent work demonstrates that learning to understand noise-vocoded (NV) speech alters sublexical perceptual processes but is enhanced by the simultaneous provision of higher-level, phonological, but not lexical content (Hervais-Adelman, Davis, Johnsrude, & Carlyon, 2008), consistent with top-down learning (Davis, Johnsrude, Hervais-Adelman, Taylor, & McGettigan, 2005; Hervais-Adelman et al., 2008). Here, we investigate whether training listeners with specific types of NV speech improves intelligibility of vocoded speech with different acoustic characteristics. Transfer of perceptual learning would provide evidence for abstraction from variable properties of the speech input. In Experiment 1, we demonstrate that learning of NV speech in one frequency region generalizes to an untrained frequency region. In Experiment 2, we assessed generalization among three carrier signals used to create NV speech: noise bands, pulse trains, and sine waves. Stimuli created using these three carriers possess the same slow, time-varying amplitude information and are equated for na?ve intelligibility but differ in their temporal fine structure. Perceptual learning generalized partially, but not completely, among different carrier signals. These results delimit the functional and neural locus of perceptual learning of vocoded speech. Generalization across frequency regions suggests that learning occurs at a stage of processing at which some abstraction from the physical signal has occurred, while incomplete transfer across carriers indicates that learning occurs at a stage of processing that is sensitive to acoustic features critical for speech perception (e.g., noise, periodicity). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A parallel licensing model of normal slips and phonemic paraphasias

A model of phonological processing in speech production based on prosodic licensing can capture general patterns of errors found in both normal and aphasic speech. All segments must be licensed by some prosodic category (syllable, nucleus, or rime) in order to be produced. Constraints on licensing, including both phonotactic and binding constraints, ensure that only correct licensing associations are retained. A computer simulation of our model produces utterances in qualitative agreement with human speech error data. Phonemic puraphasias are claimed to arise from the same mechanisms as normal speech errors; the difference being only a matter of disturbance of the lexical retrieval and licensing processes. The fact that these errors, which can involve gross disruption of the segmental sequence, still produce phonotactically well-formed strings is a direct consequence of the syllabic licensing that forms the core of our theory of speech production.     

Perceptual learning of noise vocoded words: Effects of feedback and lexicality.

Speech comprehension is resistant to acoustic distortion in the input, reflecting listeners' ability to adjust perceptual processes to match the speech input. This adjustment is reflected in improved comprehension of distorted speech with experience. For noise vocoding, a manipulation that removes spectral detail from speech, listeners' word report showed a significantly greater improvement over trials for listeners that heard clear speech presentations before rather than after hearing distorted speech (clear-then-distorted compared with distorted-then-clear feedback, in Experiment 1). This perceptual learning generalized to untrained words suggesting a sublexical locus for learning and was equivalent for word and nonword training stimuli (Experiment 2). These findings point to the crucial involvement of phonological short-term memory and top-down processes in the perceptual learning of noise-vocoded speech. Similar processes may facilitate comprehension of speech in an unfamiliar accent or following cochlear implantation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term memory errors for spoken syllables are affected by the linguistic structure of the syllables.

Three experiments on short-term serial memory for spoken syllables are reported. The stimuli were CVC (consonant-vowel-consonant) syllables in Experiment 1, CCVs in Experiment 2, and VCCs in Experiment 3. Analyses of subjects' errors showed that the phonemes within a syllable were not equally free to break apart and recombine. Certain groups of phonemes—the vowel-final consonant group of a CVC, the initial cluster of a CCV, and a vowel-liquid group within a VCC—tended to behave as units. These results are consistent with the view that syllables are coded in terms of an onset (initial consonant or cluster) and a rime (remainder). Errors in short-term memory for spoken syllables are affected by the linguistic structure of the syllables. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When cues collide: Use of stress and statistical cues to word boundaries by 7- to 9-month-old infants.

Prior research suggests that stress cues are particularly important for English-hearing infants' detection of word boundaries. It is unclear, though, how infants learn to attend to stress as a cue to word segmentation. This series of experiments was designed to explore infants' attention to conflicting cues at different ages. Experiment 1 replicated previous findings: When stress and statistical cues indicated different word boundaries, 9-month-old infants used syllable stress as a cue to segmentation while ignoring statistical cues. However, in Experiment 2, 7-month-old infants attended more to statistical cues than to stress cues. These results raise the possibility that infants use their statistical learning abilities to locate words in speech and use those words to discover the regular pattern of stress cues in English. Infants at different ages may deploy different segmentation strategies as a function of their current linguistic experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lexical Information Drives Perceptual Learning of Distorted Speech: Evidence From the Comprehension of Noise-Vocoded Sentences.

Speech comprehension is resistant to acoustic distortion in the input, reflecting listeners' ability to adjust perceptual processes to match the speech input. For noise-vocoded sentences, a manipulation that removes spectral detail from speech, listeners' reporting improved from near 0% to 70% correct over 30 sentences (Experiment 1). Learning was enhanced if listeners heard distorted sentences while they knew the identity of the undistorted target (Experiments 2 and 3). Learning was absent when listeners were trained with nonword sentences (Experiments 4 and 5), although the meaning of the training sentences did not affect learning (Experiment 5). Perceptual learning of noise-vocoded speech depends on higher level information, consistent with top-down, lexically driven learning. Similar processes may facilitate comprehension of speech in an unfamiliar accent or following cochlear implantation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phonotactic influences on short-term memory

The impact of phonotactic probabilities on serial recall was investigated in a series of experiments. In Experiments 1A and 1B, 7 and 8 year olds were tested on their serial recall of monosyllabic words and of nonwords varying in phonotactic frequencies. A recall advantage to words over nonwords remained when stimuli were balanced for phonotactic probability, but nonword recall showed superior accuracy for high over low probability nonwords, as in Experiment 2. The nonword frequency effect appears to reflect the frequency of constituent syllables rather than biphones. Both lexicality and high phonotactic frequency led to increased proportions of full over partial recall of the memory stimuli. These findings indicate that decayed memory traces in phonological short-term memory can be reconstructed using either lexical or phonotactic knowledge.     

Influences of spoken word planning on speech recognition.

In 4 chronometric experiments, influences of spoken word planning on speech recognition were examined. Participants were shown pictures while hearing a tone or a spoken word presented shortly after picture onset. When a spoken word was presented, participants indicated whether it contained a prespecified phoneme. When the tone was presented, they indicated whether the picture name contained the phoneme (Experiment 1) or they named the picture (Experiment 2). Phoneme monitoring latencies for the spoken words were shorter when the picture name contained the prespecified phoneme compared with when it did not. Priming of phoneme monitoring was also obtained when the phoneme was part of spoken nonwords (Experiment 3). However, no priming of phoneme monitoring was obtained when the pictures required no response in the experiment, regardless of monitoring latency (Experiment 4). These results provide evidence that an internal phonological pathway runs from spoken word planning to speech recognition and that active phonological encoding is a precondition for engaging the pathway. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Phonotactic influences on short-term memory": Correction.

Reports an error in the original article by S. E. Gathercole et al (Journal of Experimental Psychology: Learning, Memory, & Cognition, 1999[Jan], 25[1], 84–95). On page 87, the mean proportions of correct item recall and standard deviations for the high vocabulary group in Experiment 1B were incorrect in Table 2. The analyses of variance reported for data arising from Experiment 1B were correct. A corrected table is given. (The following abstract of this article originally appeared in record 1998-11970-006.) The impact of phonotactic probabilities on serial recall was investigated in a series of experiments. In Experiments 1A and 1B, 7 and 8 year olds were tested on their serial recall of monosyllabic words and of nonwords varying in phonotactic frequencies. A recall advantage to words over nonwords remained when stimuli were balanced for phonotactic probability, but nonword recall showed superior accuracy for high over low probability nonwords, as in Experiment 2. The nonword frequency effect appears to reflect the frequency of constituent syllables rather than biphones. Both lexicality and high phonotactic frequency led to increased proportions of full over partial recall of the memory stimuli. These findings indicate that decayed memory traces in phonological… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facilitation of perception by spelling constraints.

Conducted 4 experiments in which a total of 42 undergraduates viewed tachistoscopic presentations of a consonant pair and were asked to recall which of 2 or 4 pairs had been presented. Performance was better when the arrangement of letters was constrained in some way than when that constraint was absent (e.g., when the letters K and V could appear together only in 1 order-KV-vs either order, KV or VK). The alternatives were chosen so that knowledge of the constraint would not help the Ss (e.g., KV and VK never appeared together as alternatives). The facilitation effect occurred even when constrained and unconstrained conditions were equated for frequency of letter pairs or of letters occurring in a given position. Effects were found for both order and sequence constraints, and facilitation persisted from day to day. These effects are inconsistent with models of perceptual learning which depend on frequency of exposure. The underlying mechanisms may also facilitate the recognition of words. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective and nonselective associations between speech segments and faces in human infants.

The role of affective correspondence between signal and outcome in associative learning was studied in 2 experiments with 4-month-olds. In Experiment 1, an infant-directed (ID) speech segment, categorized by adults as having consoling acoustic properties for infants, was either paired or unpaired with smiling or sad face reinforcers. In other groups, a sad adult-directed (AD) speech segment signaled the smiling or sad faces. Later, all speech segments were tested for their ability to increase infants' visual interest in a checkerboard. Positive summation was observed only when the consoling ID speech segment had signaled the sad face. In Experiment 2, an arousing ID speech segment signaled the smiling or sad face. Positive summation was evident in both conditions. These results show that infants sometimes selectively associate speech segments and faces. Discussion centers on the basis for the selective association. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relative position priming effect depends on whether letters are vowels or consonants.

The relative position priming effect is a type of subset priming in which target word recognition is facilitated as a consequence of priming the word with some of its letters, maintaining their relative position (e.g., csn as a prime for casino). Five experiments were conducted to test whether vowel-only and consonant-only subset primes contribute equally to this effect. Experiment 1 revealed that this subset priming effect emerged when primes were composed exclusively of consonants, compared with vowel-only primes (csn-casino vs. aia-animal). Experiment 2 tested the impact of letter frequency in this asymmetry. Subset priming effects were obtained for both high- and low-frequency consonants but not for vowels, which rules out a letter frequency explanation. Experiment 3 tested the role of phonology and its contribution to the priming effects observed, by decreasing the prime duration. The results showed virtually the same effects as in the previous experiments. Finally, Experiments 4 and 5 explored the influence of repeated letters in the primes on the magnitude of the priming effects obtained for consonant and vowel subset primes (iuo-dibujo and aea-madera vs. mgn-imagen and rtr-frutero). Again, the results confirmed the priming asymmetry. We propose that a functional distinction between consonants and vowels, mainly based on the lexical constraints imposed by each of these types of letters, might provide an explanation for the whole set of results. (PsycINFO Database Record (c) 2011 APA, all rights reserved)