Major memory for microblogs.

Online social networking is vastly popular and permits its members to post their thoughts as microblogs, an opportunity that people exploit, on Facebook alone, over 30 million times an hour. Such trivial ephemera, one might think, should vanish quickly from memory; conversely, they may comprise the sort of information that our memories are tuned to recognize, if that which we readily generate, we also readily store. In the first two experiments, participants' memory for Facebook posts was found to be strikingly stronger than their memory for human faces or sentences from books-a magnitude comparable to the difference in memory strength between amnesics and healthy controls. The second experiment suggested that this difference is not due to Facebook posts spontaneously generating social elaboration, because memory for posts is enhanced as much by adding social elaboration as is memory for book sentences. Our final experiment, using headlines, sentences, and reader comments from articles, suggested that the remarkable memory for microblogs is also not due to their completeness or simply their topic, but may be a more general phenomenon of their being the largely spontaneous and natural emanations of the human mind.

Learning phonotactic-like regularities in immediate serial recall.

Learning a spoken language requires learning a phonological inventory and phonotactics, or the sequences of phonemes possible in the language. Laboratory investigations of phonotactic learning include tongue-twister studies that show that speech errors respect artificial phonotactic constraints, for example that /k/ never appears as a syllable onset. The current research investigates whether errors can reveal similar learning in nonlinguistic domains, specifically in immediate serial recall studies. In Experiments 1-3 participants recalled sequences of 6 items, grouped into two 3-item subsequences, in verbal immediate serial recall experiments. Some items were restricted to appear in specific sequence positions while others were unrestricted, as a parallel to the artificial phonotactics learning experiments. As with speech errors, recall errors with restricted items showed sensitivity to the statistical regularities built into the experiment. Similar results are shown for both absolute and probabilistic constraints. However, learning effects were weaker than in the phonological domain, and were less influenced by hierarchical structure than what is observed in phonotactic learning (Experiment 4). Taken together, these results suggest that there are both domain-general and language-specific constraints on phonotactic learning. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

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.

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.

Musical stem completion: humming that note.

This study looked at how people store and retrieve tonal music explicitly and implicitly using a production task. Participants completed an implicit task (tune stem completion) followed by an explicit task (cued recall). The tasks were identical except for the instructions at test time. They listened to tunes and were then presented with tune stems from previously heard tunes and novel tunes. For the implicit task, they were asked to sing a note they thought would come next musically. For the explicit task, they were asked to sing the note they remembered as coming next. Experiment 1 found that people correctly completed significantly more old stems than new stems. Experiment 2 investigated the characteristics of music that fuel retrieval by varying a surface feature of the tune (same timbre or different timbre) from study to test and the encoding task (semantic or nonsemantic). Although we did not find that implicit and explicit memory for music were significantly dissociated for levels of processing, we did find that surface features of music affect semanticjudgments and subsequent explicit retrieval.

New phonotactic constraints learned implicitly by producing syllable strings generalize to the production of new syllables.

Novel phonotactic constraints can be acquired by hearing or speaking syllables that follow a novel constraint. When learned from hearing syllables, these newly learned constraints generalize to syllables that were not experienced during training. However, generalization of phonotactic learning to novel syllables has never been persuasively demonstrated in production. The typical production experiment examines phonotactic learning through speech errors. After participants repeat syllable sequences embedded with a novel phonotactic constraint, such as /f/ appearing only in onset position, their speech errors come to adhere to the novel constraint. For example, when participants mistakenly move an /f/ to another syllable, it overwhelmingly moves to an onset rather than a coda position. We assessed whether constraints learned and measured in this manner generalize to unexperienced syllables and, at the same time, whether the slips tend to create previously experienced syllables (a syllable priming effect). We found evidence of generalization but not of syllable priming in participants' speech errors. The effect of phonotactic learning was as powerfully expressed during the production of unexperienced as experienced syllables. A connectionist model simulated the experimental results using a single learning mechanism and successfully reproduced the constraint learning, generalization, and lack of priming.

Investigating the retention and time course of phonotactic constraint learning from production experience.

Adults can rapidly learn artificial phonotactic constraints such as /f/ occurs only at the beginning of syllables by producing syllables that contain those constraints. This implicit learning is then reflected in their speech errors. However, second-order constraints in which the placement of a phoneme depends on another characteristic of the syllable (e.g., if the vowel is /æ/, /f/ occurs at the beginning of syllables and /s/ occurs at the end of syllables, but if the vowel is /I/, the reverse is true) require a longer learning period. Two experiments investigated the transience of second-order learning and whether consolidation plays a role in learning phonological dependencies, with speech errors used as a measure of learning. Experiment 1 tested the durability of learning and found that learning was still present in speech errors a week later. Experiment 2 looked at whether more time in the form of a consolidation period or more experience in the form of more trials was necessary for learning to be revealed in speech errors. Both consolidation and more trials led to learning; however, consolidation provided a more substantial benefit.

Speech errors reflect the phonotactic constraints in recently spoken syllables, but not in recently heard syllables.

Adults rapidly learn phonotactic constraints from brief production or perception experience. Three experiments asked whether this learning is modality-specific, occurring separately in production and perception, or whether perception transfers to production. Participant pairs took turns repeating syllables in which particular consonants were restricted to particular syllable positions. Speakers' errors reflected learning of the constraints present in the sequences they produced, regardless of whether their partner produced syllables with the same constraints, or opposing constraints. Although partial transfer could be induced (Experiment 3), simply hearing and encoding syllables produced by others did not affect speech production to the extent that error patterns were altered. Learning of new phonotactic constraints was predominantly restricted to the modality in which those constraints were experienced.