The role of consolidation in learning context-dependent phonotactic patterns in speech and digital sequence production.

Speakers implicitly learn novel phonotactic patterns by producing strings of syllables. The learning is revealed in their speech errors. First-order patterns, such as "/f/ must be a syllable onset," can be distinguished from contingent, or second-order, patterns, such as "/f/ must be an onset if the vowel is /a/, but a coda if the vowel is /o/." A metaanalysis of 19 experiments clearly demonstrated that first-order patterns affect speech errors to a very great extent in a single experimental session, but second-order vowel-contingent patterns only affect errors on the second day of testing, suggesting the need for a consolidation period. Two experiments tested an analogue to these studies involving sequences of button pushes, with fingers as "consonants" and thumbs as "vowels." The button-push errors revealed two of the key speech-error findings: first-order patterns are learned quickly, but second-order thumb-contingent patterns are only strongly revealed in the errors on the second day of testing. The influence of computational complexity on the implicit learning of phonotactic patterns in speech production may be a general feature of sequence production.

Novel stress phonotactics are learnable by English speakers: Novel tone phonotactics are not.

Speech errors are sensitive to newly learned phonotactic constraints. For example, if speakers produce strings of syllables in which /f/ is an onset if the vowel is /æ/, but a coda if the vowel is /I/, their slips will respect that constraint after a period of sleep. Constraints in which the contextual factor is nonlinguistic, however, do not appear to be learnable by this method-for example, /f/ is an onset if the speech rate is fast, but /f/ is a coda if the speech rate is slow. The present study demonstrated that adult English speakers can learn (after a sleep period) constraints based on stress (e.g., /f/ is an onset if the syllable is stressed, but /f/ is a coda if the syllable is unstressed), but cannot learn analogous constraints based on tone (e.g., /f/ is an onset if the tone is rising, but /f/ is a coda if the tone is falling). The results are consistent with the fact that, in English, stress is a relevant lexical phonological property (e.g., "INsight" and "inCITE" are different words), but tone is not (e.g., "yes!" and "yes?" are the same word, despite their different pragmatic functions). The results provide useful constraints on how consolidation effects in learning may interact with early learning experiences.

Tracking Keystroke Sequences at the Cortical Level Reveals the Dynamics of Serial Order Production.

Response selection is often studied by examining single responses, although most actions are performed within an overarching sequence. Understanding processes that order and execute items in a sequence is thus essential to give a complete picture of response selection. In this study, we investigate response selection by comparing single responses and response sequences as well as unimanual and bimanual sequences. We recorded EEG while participants were typing one- or two-keystroke sequences. Irrespective of stimulus modality (visual or auditory), response-locked analysis revealed distinct contralateral and ipsilateral components previously associated with activation and inhibition of alternative responses. Unimanual sequences exhibited a similar activation/inhibition pattern as single responses, but with the activation component of the pattern expressed more strongly, reflecting the fact that the hand will be used for two strokes. In contrast, bimanual sequences were associated with successive activation of each of the corresponding motor cortices controlling each keystroke and no traceable inhibitory component. In short, the activation component of the two-keystroke sequence EEG pattern can be understood from the addition of activation components of single-stroke sequences; the inhibition of the hand not being used is only evidenced when that hand is not planned for the next stroke.

Neuroanatomical dissociation for taxonomic and thematic knowledge in the human brain.

It is thought that semantic memory represents taxonomic information differently from thematic information. This study investigated the neural basis for the taxonomic-thematic distinction in a unique way. We gathered picture-naming errors from 86 individuals with poststroke language impairment (aphasia). Error rates were determined separately for taxonomic errors ("pear" in response to apple) and thematic errors ("worm" in response to apple), and their shared variance was regressed out of each measure. With the segmented lesions normalized to a common template, we carried out voxel-based lesion-symptom mapping on each error type separately. We found that taxonomic errors localized to the left anterior temporal lobe and thematic errors localized to the left temporoparietal junction. This is an indication that the contribution of these regions to semantic memory cleaves along taxonomic-thematic lines. Our findings show that a distinction long recognized in the psychological sciences is grounded in the structure and function of the human brain.

Parsing the late-closure ambiguity: While Schrödinger measured the cat escaped from the box.

An experiment investigated the "good-enough" processing account regarding how people parse sentences with late-closure ambiguity, such as While Anna dressed the baby who was cute and cuddly spit up on the bed. One possible result of an initial misparse of the sentence (thinking that Anna dressed the baby) is that the correct parse then cannot be created. The alternative is that, although the misparse may linger in the comprehender's mind, the correct parse is eventually established and coexists with the misparse. This study approached this issue through an analogy to quantum physics. When photons are directed toward two small slits, it appears as if each photon passes through both slits ("bothness"). If particles not subject to quantum effects are directed at the slits, they pass through one or the other ("oneness"). Participants read sentences containing the late-closure ambiguity and afterward answered two questions about each sentence. These could query the potential misparse (Did Anna dress the baby?), correct-parse (Did Anna dress herself?), or the main clause (Did the baby spit up on the bed?), and the order of the question types was varied to test for quantum measurement context effects. The results supported "oneness," that is, the correct-parse and misparse of the subordinate clause do not coexist. Participants rarely said "yes" to both the misparse and correct-parse questions, and the "yes" response proportions for these two questions invariably added up to around 1.0. Furthermore, no quantum-like measurement-order effect between misparse and correct-parse questions was found.

Cascading and feedback in interactive models of production: a reflection of forward modeling?

Interactive theories of lexical retrieval in language production assume that activation cascades from earlier to later processing levels, and feeds back in the reverse direction. This commentary invites Pickering & Garrod (P&G) to consider whether cascading and feedback can be seen as a form of forwarding modeling within a hierarchical production system.

Learning from errors: Exploration of the monitoring learning effect.

The present study examined spontaneous detection and repair of naming errors in people with aphasia to advance a theoretical understanding of how monitoring impacts learning in lexical access. Prior work in aphasia has found that spontaneous repair, but not mere detection without repair, of semantic naming errors leads to improved naming on those same items in the future when other factors are accounted for. The present study sought to replicate this finding in a new, larger sample of participants and to examine the critical role of self-generated repair in this monitoring learning effect. Twenty-four participants with chronic aphasia with naming impairment provided naming responses to a 660-item corpus of common, everyday objects at two timepoints. At the first timepoint, a randomly selected subset of trials ended in experimenter-provided corrective feedback. Each naming trial was coded for accuracy, error type, and for any monitoring behavior that occurred, specifically detection with repair (i.e., correction), detection without repair, and no detection. Focusing on semantic errors, the original monitoring learning effect was replicated, with enhanced accuracy at a future timepoint when the first trial with that item involved detection with repair, compared to error trials that were not detected. This enhanced accuracy resulted from learning that arose from the first trial rather than the presence of repair simply signifying easier items. A second analysis compared learning from trials of self-corrected errors to that of trials ending in feedback that were detected but not self-corrected and found enhanced learning after self-generated repair. Implications for theories of lexical access and monitoring are discussed.

Is comprehension necessary for error detection? A conflict-based account of monitoring in speech production.

Despite the existence of speech errors, verbal communication is successful because speakers can detect (and correct) their errors. The standard theory of speech-error detection, the perceptual-loop account, posits that the comprehension system monitors production output for errors. Such a comprehension-based monitor, however, cannot explain the double dissociation between comprehension and error-detection ability observed in the aphasic patients. We propose a new theory of speech-error detection which is instead based on the production process itself. The theory borrows from studies of forced-choice-response tasks the notion that error detection is accomplished by monitoring response conflict via a frontal brain structure, such as the anterior cingulate cortex. We adapt this idea to the two-step model of word production, and test the model-derived predictions on a sample of aphasic patients. Our results show a strong correlation between patients' error-detection ability and the model's characterization of their production skills, and no significant correlation between error detection and comprehension measures, thus supporting a production-based monitor, generally, and the implemented conflict-based monitor in particular. The successful application of the conflict-based theory to error-detection in linguistic, as well as non-linguistic domains points to a domain-general monitoring system.

The adaptable speaker: A theory of implicit learning in language production.

The language production system continually learns. The system adapts to recent experiences while also reflecting the experience accumulated over the lifetime. This article presents a theory that explains how speakers implicitly learn novel phonotactic patterns as they produce syllables. The learning is revealed in their speech errors. For example, if speakers produce syllable strings in which the consonant /f/ is always a syllable onset, their slips will obey this rule; /f/'s will then slip mostly to onset positions. The article reviews over 30 phenomena related to this finding. To explain phonotactic learning, the article presents four linked "mini-theories," each of which addresses components of the data. The first mini-theory, the production theory, provides an account of how speech errors arise during the assembly of word forms. The second, the learning theory, characterizes the implicit learning of phoneme distributions within the production system. The third mini-theory, the consolidation theory, augments the learning theory to explain instances in which this learning depends on a period of time, possibly a sleep period, before it is expressed. The final mini-theory, the developmental theory, addresses cases in which learning varies between children and adults, and depends on speakers' early linguistic experience. The resulting theory forges links between these diverse aspects of psychology. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Case series investigations in cognitive neuropsychology.

Case series methodology involves the systematic assessment of a sample of related patients, with the goal of understanding how and why they differ from one another. This method has become increasingly important in cognitive neuropsychology, which has long been identified with single-subject research. We review case series studies dealing with impaired semantic memory, reading, and language production and draw attention to the affinity of this methodology for testing theories that are expressed as computational models and for addressing questions about neuroanatomy. It is concluded that case series methods usefully complement single-subject techniques.

A large, searchable, web-based database of aphasic performance on picture naming and other tests of cognitive function.

Many research questions in aphasia can only be answered through access to substantial numbers of patients and to their responses on individual test items. Since such data are often unavailable to individual researchers and institutions, we have developed and made available the Moss Aphasia Psycholinguistics Project Database: a large, searchable, web-based database of patient performance on psycholinguistic and neuropsychological tests. The database contains data from over 240 patients covering a wide range of aphasia subtypes and severity, some of whom were tested multiple times. The core of the archive consists of a detailed record of individual-trial performance on the Philadelphia (picture) Naming Test. The database also contains basic demographic information about the patients and patients' overall performance on neuropsychological assessments as well as tests of speech perception, semantics, short-term memory, and sentence comprehension. The database is available at http://www.mappd.org/ .

Anterior temporal involvement in semantic word retrieval: voxel-based lesion-symptom mapping evidence from aphasia.

Analysis of error types provides useful information about the stages and processes involved in normal and aphasic word production. In picture naming, semantic errors (horse for goat) generally result from something having gone awry in lexical access such that the right concept was mapped to the wrong word. This study used the new lesion analysis technique known as voxel-based lesion-symptom mapping to investigate the locus of lesions that give rise to semantic naming errors. Semantic errors were obtained from 64 individuals with post-stroke aphasia, who also underwent high-resolution structural brain scans. Whole brain voxel-based lesion-symptom mapping was carried out to determine where lesion status predicted semantic error rate. The strongest associations were found in the left anterior to mid middle temporal gyrus. This area also showed strong and significant effects in further analyses that statistically controlled for deficits in pre-lexical, conceptualization processes that might have contributed to semantic error production. This study is the first to demonstrate a specific and necessary role for the left anterior temporal lobe in mapping concepts to words in production. We hypothesize that this role consists in the conveyance of fine-grained semantic distinctions to the lexical system. Our results line up with evidence from semantic dementia, the convergence zone framework and meta-analyses of neuroimaging studies on word production. At the same time, they cast doubt on the classical linkage of semantic error production to lesions in and around Wernicke's area.

Motor movement matters: the flexible abstractness of inner speech.

Inner speech is typically characterized as either the activation of abstract linguistic representations or a detailed articulatory simulation that lacks only the production of sound. We present a study of the speech errors that occur during the inner recitation of tongue-twister-like phrases. Two forms of inner speech were tested: inner speech without articulatory movements and articulated (mouthed) inner speech. Although mouthing one's inner speech could reasonably be assumed to require more articulatory planning, prominent theories assume that such planning should not affect the experience of inner speech and, consequently, the errors that are "heard" during its production. The errors occurring in articulated inner speech exhibited the phonemic similarity effect and the lexical bias effect--two speech-error phenomena that, in overt speech, have been localized to an articulatory-feature-processing level and a lexical-phonological level, respectively. In contrast, errors in unarticulated inner speech did not exhibit the phonemic similarity effect--just the lexical bias effect. The results are interpreted as support for a flexible abstraction account of inner speech. This conclusion has ramifications for the embodiment of language and speech and for the theories of speech production.

Word predictability blurs the lines between production and comprehension: Evidence from the production effect in memory.

Predictions about likely upcoming input may promote rapid language processing, but the mechanisms by which such predictions are generated remain unclear. One hypothesis is that comprehenders use their production system to covertly produce what they would say if they were the speaker. If reading predictable words involves covert production, this act might have consequences for memory. The present study capitalized on the production effect, which is the observation that words read aloud are remembered better than words read silently. Participants read sentence-final predictable and unpredictable words aloud or silently, followed by a surprise recognition memory task. If reading predictable words involves covert production, the memory improvement from actually producing the words should be smaller for predictable words than for unpredictable words. This was confirmed in Experiment 1, which tested item memory using old/new judgments. Experiment 2 followed the same procedure, except that participants now made aloud/silent judgments probing their memory for prior acts of production. Here the hypothesis was that, relative to unpredictable words, it should be more difficult to remember whether predictable words had been read aloud or silently. Indeed, word predictability tended to make it harder to tell the difference, suggesting that predictability blurred the lines between production and comprehension. Taken together, the findings support the idea that reading predictable words can involve covert production and show that this act has consequences for what readers retain.

Masking auditory feedback does not eliminate repetition reduction.

Repetition reduces word duration. Explanations of this process have appealed to audience design, internal production mechanisms, and combinations thereof (e.g. Kahn & Arnold, 2015). Jacobs, Yiu, Watson, and Dell (2015) proposed the auditory feedback hypothesis, which states that speakers must hear a word, produced either by themselves or another speaker, in order for duration reduction on a subsequent production. We conducted a strong test of the auditory feedback hypothesis in two experiments, in which we used masked auditory feedback and whispering to prevent speakers from hearing themselves fully. Both experiments showed that despite limiting the sources of normal auditory feedback, repetition reduction was observed to equal extents in masked and unmasked conditions, suggesting that repetition reduction may be supported by multiple sources, such as somatosensory feedback and feedforward signals, depending on their availability.

Maintenance Versus Transmission Deficits: The Effect of Delay on Naming Performance in Aphasia.

We propose that deficits in lexical retrieval can involve difficulty in transmission of activation between processing levels, or difficulty in maintaining activation. In support, we present an investigation of picture naming by persons with aphasia in which the naming response is generated after a 1 s (sec) cue to respond in one condition or a 5 s cue to respond in another. Some individuals did better after 5 s, some did worse after 5 s, and some were not impacted by the delay. It is suggested that better performance after 5 s indicates a transmission deficit and that worse performance after 5 s indicates a maintenance deficit. To support this hypothesis, we adapted the two-step semantic-phonological model of lexical retrieval (Schwartz et al., 2006) so that it can simulate the passage of time and can simulate lesions in transmission (its semantic and phonological connection strength parameters) and/or maintenance (its decay parameter). The naming error patterns after 1 and 5 s for each participant were successfully fit to the model. Persons who did better after 5 s were found to have low connection strength parameters, persons who did worse after 5 s were simulated with an increased decay rate, and persons whose performance did not differ with delay were found to have lesions of both types. Some potential theoretical and clinical implications are discussed.

Learning the phonotactics of button pushing: Consolidation, retention, and syllable structure.

Every language has unique phonotactics, general rules about how phonemes combine to make syllables. We know that people can implicitly learn new phonotactic rules in the laboratory, and these rules then affect their speech errors. Some types of rules, however, require a consolidation period before they influence speech errors. Two experiments are reported that replicate a recent study that transferred this finding to a nonspeech domain. In this study and our replications, the production of a consonant-vowel-consonant syllable is replaced by pushing three buttons-a finger, a thumb, and another finger. These button-push studies reproduce prior findings in the speech domain about consolidation and the retention of phonotactic learning but also point to some differences, suggesting that the massive amount of experience that adults have producing syllables leads to unique effects. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Inner speech slips exhibit lexical bias, but not the phonemic similarity effect.

Inner speech, that little voice that people often hear inside their heads while thinking, is a form of mental imagery. The properties of inner speech errors can be used to investigate the nature of inner speech, just as overt slips are informative about overt speech production. Overt slips tend to create words (lexical bias) and involve similar exchanging phonemes (phonemic similarity effect). We examined these effects in inner and overt speech via a tongue-twister recitation task. While lexical bias was present in both inner and overt speech errors, the phonemic similarity effect was evident only for overt errors, producing a significant overtness by similarity interaction. We propose that inner speech is impoverished at lower (featural) levels, but robust at higher (phonemic) levels.

Limits on learning phonotactic constraints from recent production experience.

Adults can learn new artificial phonotactic constraints by producing syllables that exhibit the constraints. The experiments presented here tested the limits of phonotactic learning in production using speech errors as an implicit measure of learning. Experiment 1 tested a constraint in which the placement of a consonant as an onset or coda depended on the identity of a nonadjacent consonant. Participant speech errors reflected knowledge of the constraint but not until the 2nd day of testing. Experiment 2 tested a constraint in which consonant placement depended on an extralinguistic factor, the speech rate. Participants were not able to learn this constraint. Together, these experiments suggest that phonotactic-like constraints are acquired when mutually constraining elements reside within the phonological system.

Persistent structural priming from language comprehension to language production.

To examine the relationship between syntactic processes in language comprehension and language production, we compared structural persistence from sentence primes that speakers heard to persistence from primes that speakers produced. [Bock, J. K., & Griffin, Z. M. (2000). The persistence of structural priming: transient activation or implicit learning? Journal of Experimental Psychology: General, 129, 177-192.] showed that the production of target priming structures increased the probability of spontaneously using the same structures to describe events in subsequent pictures that were semantically unrelated to the primes. These priming effects persisted across as many as ten intervening filler trials. The present studies replicated these results using auditorily presented primes to which participants only listened. The results indicated persistence of priming across all lags, with relative magnitudes of priming as large as those observed by Bock and Griffin. The implication is that structural priming is persistent regardless of the modality in which language structures are experienced, underscoring the power of priming as an implicit learning mechanism.