Age of acquisition and word frequency effects in picture naming: A dual-task investigation.

In 2 experiments, the authors explored age of acquisition (AoA) and word frequency (WF) effects in picture naming using the psychological refractory period paradigm. In Experiment 1, participants named a picture and then, a short time later, categorized 1 of 3 possible auditory tones as high, medium, or low. Both AoA (Experiment 1A) and WF (Experiment 1B) effects propagated onto tone discrimination reaction times (RTs), with the effects of AoA being stronger. In Experiment 2, the to-be-named picture followed the auditory tone by a varying interval. As the interval decreased, picture naming RTs increased. The relationship between the interval and AoA (Experiment 2A) was reliably underadditive; AoA effects were eliminated at the shortest interval. In contrast, WF (Experiment 2B) was additive with the effects of the interval. These results demonstrate an empirical dissociation between AoA and WF effects. AoA affects processing stages that precede those that are sensitive to WF. The implications for theories of picture naming are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vocabulary acquisition and verbal short-term memory: computational and neural bases

In this paper, we explore the hypothesis that human vocabulary acquisition processes and verbal short-term memory abilities utilize a common cognitive and neural system. We begin by reviewing behavioral evidence for a shared set of processes. Next, we examine what the computational bases of such a shared system might be and how vocabulary acquisition and verbal short-term memory might be related in mechanistic terms. We examine existing computational models of vocabulary acquisition and of verbal short-term memory, concluding that they fail to adequately relate these two domains. We then propose an alternative model which accounts not only for the relationship between word learning and verbal short-term memory, but also for a wide range of phenomena in verbal short-term memory. Furthermore, this new account provides a clear statement of the relationship between the proposed system and mechanisms of language processing more generally. We then consider possible neural substrates for this cognitive system. We begin by reviewing what is known of the neural substrates of speech processing and outline a conceptual framework within which a variety of seemingly contradictory neurophysiological and neuropsychological findings can be accommodated. The linkage of the shared system for vocabulary acquisition and verbal short-term memory to neural areas specifically involved in speech processing lends further support to our functional-level identification of the mechanisms of vocabulary acquisition and verbal short-term memory with those of language processing. The present work thus relates vocabulary acquisition and verbal short-term memory to each other and to speech processing, at a cognitive, computational, and neural level.     

Dissociating word frequency and age of acquisition: The klein effect revived (and reversed).

The Klein effect (G. S. Klein, 1964) refers to the finding that high-frequency words produce greater interference in a color-naming task than low-frequency words. The present study used the Klein effect to investigate the relationship between frequency and age of acquisition (AoA) by measuring their influence on color naming. Two experiments showed reliable effects of frequency (though in the opposite direction to that reported by Klein) but no effects of AoA. Experiment 1 produced a dissociation between frequency and AoA when manipulated orthogonally. Experiment 2 produced the same dissociation using different stimuli. In contrast, both variables reliably influenced word naming. These findings are inconsistent with the view that frequency and AoA are 2 aspects of a single underlying mechanism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What exactly interacts with spelling--sound consistency in word naming?

Word frequency, age of acquisition (AoA), and imageability were combined with spelling-sound consistency, and their effects on word naming were examined. Frequency and AoA interacted with consistency (Experiments 1 and 2). Imageability did not (Experiment 3). Experiment 4 replicated Experiment 2 of E. Strain, K. E. Patterson, and M. S. Seidenberg's (1995) study and obtained the same apparent effect of imageability on naming. That effect disappeared when AoA was entered as a covariate. An explanation of the interactions of consistency with frequency and AoA is offered in terms of the properties of adaptive connectionist networks given gradual and cumulative training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theories of word naming interact with spelling--sound consistency.

In a previous study (E. Strain, K. Patterson, & M. S. Seidenberg, 1995), the authors concluded that word naming is characterized by an interaction between spelling-sound typicality and word imageability, thus implicating a role for word meaning in the naming process. J. Monaghan and A. W. Ellis (2002) reject E. Strain et al.'s conclusion, arguing that it is age of acquisition (AoA) and not imageability that interacts with spelling-sound typicality. In this article, the authors question their alternative interpretation (a) by raising a number of conceptual and methodological issues germane to this debate and (b) by presenting new data that confirm a significant interaction between spelling-sound typicality and imageability in word-naming latencies, an interaction that is reliable when word AoA is controlled in a regression analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling language acquisition in atypical phenotypes.

An increasing number of connectionist models have been proposed to explain behavioral deficits in developmental disorders. These simulations motivate serious consideration of the theoretical implications of the claim that a developmental disorder fits within the parameter space of a particular computational model of normal development. The authors examine these issues in depth with respect to a series of new simulations investigating past-tense formation in Williams syndrome. This syndrome and the past-tense domain are highly relevant because both have been used to make strong theoretical claims about the processes underlying normal language acquisition. The authors conclude that computational models have great potential to advance psychologists' understanding of developmental deficits because they focus on the developmental process itself as a pivotal causal factor in producing atypical phenotypic outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interactions between encoding and retrieval in the domain of sequence-learning.

In this article, the authors propose to characterize sequence learning in terms of automatic versus nonautomatic processing and to apply this contrast independently to knowledge acquisition and retrieval. In several experiments of sequence learning, automaticity of both the acquisition and retrieval of the acquired knowledge was independently assessed. It was found that the sequence learning order can be demonstrated under all combinations of knowledge acquisition and retrieval. In particular, at least in the simple sequences the authors used, this applies in cases in which both the acquisition and the retrieval of knowledge are strictly automatic--that is, when neither is required for the task nor beneficial to deliberate behavior. The proposed framework has implications for the notion of sequence learning and the investigation of learning in general. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamics of attentional selection under conflict: Toward a rational Bayesian account.

The brain exhibits remarkable facility in exerting attentional control in most circumstances, but it also suffers apparent limitations in others. The authors’ goal is to construct a rational account for why attentional control appears suboptimal under conditions of conflict and what this implies about the underlying computational principles. The formal framework used is based on Bayesian probability theory, which provides a convenient language for delineating the rationale and dynamics of attentional selection. The authors illustrate these issues with the Eriksen flanker task, a classical paradigm that explores the effects of competing sensory inputs on response tendencies. The authors show how 2 distinctly formulated models, based on compatibility bias and spatial uncertainty principles, can account for the behavioral data. They also suggest novel experiments that may differentiate these models. In addition, they elaborate a simplified model that approximates optimal computation and may map more directly onto the underlying neural machinery. This approximate model uses conflict monitoring, putatively mediated by the anterior cingulate cortex, as a proxy for compatibility representation. The authors also consider how this conflict information might be disseminated and used to control processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigating the Effects of a Set of Intercorrelated Variables on Eye Fixation Durations in Reading.

The present experiment investigated the influence of 5 intercorrelated variables on word recognition using a multiple regression analysis. The 5 variables were word frequency, subjective familiarity, word length, concreteness, and age of acquisition (AoA). Target words were embedded in sentences and eye tracking methodology was used to investigate the predictive power of these variables. All 5 variables were found to influence reading time. However, the time course of these variables differed. Both word frequency and familiarity showed an early but lasting influence on eye fixation durations. Word length only significantly predicted fixation durations after refixations on the target words were taken into account. This is the 1st experiment to demonstrate concreteness and AoA effects on eye fixations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theoretical and computational analysis of skill learning, repetition priming, and procedural memory.

This article analyzes the relationship between skill learning and repetition priming, 2 implicit memory phenomena. A number of reports have suggested that skill learning and repetition priming can be dissociated from each other and are therefore based on different mechanisms. The authors present a theoretical analysis showing that previous results cannot be regarded as evidence of a processing dissociation between skill learning and repetition priming. The authors also present a single-mechanism computational model that simulates a specific experimental task and exhibits both skill learning and repetition priming, as well as a number of apparent dissociations between these measures. These theoretical and computational analyses provide complementary evidence that skill learning and repetition priming are aspects of a single underlying mechanism that has the characteristics of procedural memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Word frequency effects in oral reading are not merely age-of-acquisition effects in disguise.

Four experiments examined the effects of the rated age of acquisition (AoA) and word frequency on oral reading latencies and word pronunciation durations. In Experiment 1, both AoA and frequency had independent (and noninteracting) effects on naming latencies. Experiment 2 found no effect of either AoA or frequency on delayed naming, indicating that prepared articulation time was not a factor contributing to the naming latencies observed in Experiment 1. Experiment 3 reported 2 replications of the study by C. M. Morrison and A. W. Ellis (1995). Both replications found reliable effects of frequency and AoA, whereas Morrison and Ellis found an effect of AoA but no effect of frequency. Experiment 4 found a strong AoA effect on pronunciation durations, with a smaller and less reliable effect of frequency. It was concluded that frequency affects the visual recognition of words and that AoA affects the production of lexical phonology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of cross-linguistic variation in speech and gesture: Motion events in English and Turkish.

The way adults express manner and path components of a motion event varies across typologically different languages both in speech and cospeech gestures, showing that language specificity in event encoding influences gesture. The authors tracked when and how this multimodal cross-linguistic variation develops in children learning Turkish and English, 2 typologically distinct languages. They found that children learn to speak in language-specific ways from age 3 onward (i.e., English speakers used 1 clause and Turkish speakers used 2 clauses to express manner and path). In contrast, English- and Turkish-speaking children's gestures looked similar at ages 3 and 5 (i.e., separate gestures for manner and path), differing from each other only at age 9 and in adulthood (i.e., English speakers used 1 gesture, but Turkish speakers used separate gestures for manner and path). The authors argue that this pattern of the development of cospeech gestures reflects a gradual shift to language-specific representations during speaking and shows that looking at speech alone may not be sufficient to understand the full process of language acquisition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predictors of word decoding and reading fluency across languages varying in orthographic consistency.

Very few studies have directly compared reading acquisition across different orthographies. The authors examined the concurrent and longitudinal predictors of word decoding and reading fluency in children learning to read in an orthographically inconsistent language (English) and in an orthographically consistent language (Greek). One hundred ten English-speaking children and 70 Greek-speaking children attending Grade 1 were examined in measures of phonological awareness, phonological memory, rapid naming speed, orthographic processing, word decoding, and reading fluency. The same children were reassessed on word decoding and reading fluency measures when they were in Grade 2. The results of structural equation modeling indicated that both phonological and orthographic processing contributed uniquely to reading ability in Grades 1 and 2. However, the importance of these predictors was different in the two languages, particularly with respect to their effect on word decoding. The authors argue that the orthography that children are learning to read is an important factor that needs to be taken into account when models of reading development are being generalized across languages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Why aggregated learning follows the power law of practice when individual learning does not: Comment on Rickard (1997, 1999), Delaney et al. (1998), and Palmeri (1999).

The power law of practice is often considered a benchmark test for theories of cognitive skill acquisition. Recently, P. F. Delaney, L. M. Reder, J. J. Staszewski, and F. E. Ritter (1998), T. J. Palmeri (1999), and T. C. Rickard (1997, 1999) have challenged its validity by showing that empirical data can systematically deviate from power-function fits. The main purpose of the present article is to extend their explanations in two ways. First, the authors empirically show that abrupt changes in performance are not necessarily based on a shift from algorithm to memory-based processing, but rather and more generally, that they occur whenever a more efficient task strategy is generated. Second, the authors show mathematically and per simulation that power functions can perfectly fit aggregated learning curves even when all underlying individual curves are discontinuous. Therefore, the authors question conclusions drawn from fits to aggregated data. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Exercise improves memory acquisition and retrieval in the Y-maze task: Relationship with hippocampal neurogenesis.

Enhanced physical activity is associated with improvements in cognitive function in rodents as well as in humans. The authors examined in detail which aspects of learning and memory are influenced by exercise, using a spatial Y-maze test combined with a 14-day exercise paradigm at different stages of learning. The authors show that 14 days of wheel running promotes memory acquisition, memory retention, and reversal learning. The exercise paradigm that was employed also significantly increased the number of maturing neurons, suggesting that an increase in neurogenesis underlies the positive effects of exercise on Y-maze performance. Finally, the authors show that memory acquisition in itself does not have a major impact on the number of immature neurons. However, memory retention testing and reversal learning both cause a significant reduction in the number of doublecortin and Ser133- phosphorylated pCREB-positive cells, indicating that a decrease in neurogenesis might be a prerequisite for optimal memory retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling the neural substrates of associative learning and memory: A computational approach.

We develop a computational model of the neural substrates of elementary associative learning, using the neural circuits known to govern classical conditioning of the gill-withdrawal response of Aplysia. Building upon the theoretical efforts of Hawkins and Kadell (1984), we use this model to demonstrate that several higher order features of classical conditioning could be elaborations of the known cellular mechanisms for simple associative learning. Indeed, the current circuit model robustly exhibits many of the basic phenomena of classical conditioning. The model, however, requires a further assumption (regarding the form of the acquisition function) to predict asymptotic blocking and contingency learning. In addition, if extinction is mediated by the nonassociative mechanism of habituation—rather than the associative process postulated by Rescorla and Wagner (1972)—then we argue that additional mechanisms must be specified to resolve a conflict between acquisition and maintenance of learned associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reply to Strain, Patterson, and Seidenberg (2002).

E. Strain, K. E. Patterson, and M. S. Seidenberg (2002) reported an effect of imageability and a Regularity X Imageability interaction in a regression analysis of naming latencies to 120 words. One of their items (couth) was named correctly by just 5 of their 24 participants, and its reaction time was an outlier on their distribution. When that single item is removed, the significant predictors are age of acquisition (AoA), word frequency, regularity, and length. Analyses of the combined data from J. Monaghan and A. W. Ellis's (2002) Experiments 1-3 indicate that AoA predicts naming latencies for exception words but not consistent words. E. Strain et al.'s other points are considered in the light of these observations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Real age-of-acquisition effects in lexical retrieval

Previous research on the effects of age of acquisition on lexical processing has relied on adult estimates of the age at which children learn words. The authors report 2 experiments in which effects of age of acquisition on lexical retrieval are demonstrated using real age-of-acquisition norms. In Experiment 1, real age of acquisition emerged as a powerful predictor of adult object-naming speed. There were also significant effects of visual complexity, word frequency, and name agreement. Similar results were obtained in reanalyses of data from 2 other studies of object naming. In Experiment 2, real age of acquisition affected immediate but not delayed object-naming speed. The authors conclude that age-of-acquisition effects are real and suggest that age of acquisition influences the speed with which spoken word forms can be retrieved from the phonological lexicon.