Publications

2015
Siegelman, N., & Frost, R. (2015). Statistical learning as an individual ability: Theoretical perspectives and empirical evidence. Journal of Memory and Language , 81, 105 - 120. Publisher's VersionAbstract

•We provide a theoretical discussion and analysis of SL as an individual capacity.•We show that SL, when measured by appropriate tasks, is a reliable and stable capacity of an individual.•We show that SL is not nested within higher-order cognitive capacities.•We show that SL is a componential rather than unified ability.•We discuss the power of within-subject studies in investigating individual differences in SL.

statistical_learning_as_an_individual_ability.pdf
2014
Carreiras, M., Armstrong, B., C., Perea, M., & Frost, R. (2014). Review: The what, when, where, and how of visual word recognition. Trends in Cognitive Sciences , 18 (2), 90 - 98. Publisher's VersionAbstract

•Early visual word recognition is constrained by feedback from anterior areas.•fMRI evidence cannot adjudicate between theories on the temporal flow of information.•EEG/MEG reveals the temporal flow of information during word reading.•Functional connectivity shows that orthographic coding is shaped by higher representations.•Biological plausible connectionist models can unify existing empirical research.

Lerner, I., Armstrong, B., C., & Frost, R. (2014). What can we learn from learning models about sensitivity to letter-order in visual word recognition? Journal of Memory and Language , 77, 40-58. Publisher's VersionAbstract

Recent research on the effects of letter transposition in Indo-European Languages has shown that readers are surprisingly tolerant of these manipulations in a range of tasks. This evidence has motivated the development of new computational models of reading that regard flexibility in positional coding to be a core and universal principle of the reading process. Here we argue that such approach does not capture cross-linguistic differences in transposed-letter effects, nor do they explain them. To address this issue, we investigated how a simple domain-general connectionist architecture performs in tasks such as letter-transposition and letter substitution when it had learned to [...]

what_can_we_learn_from_learning_models.pdf
2013
Elkana, O., Frost, R., Kramer, U., Ben Bashat, D., & Schweiger, A. (2013). Cerebral language reorganization in the chronic stage of recovery: a longitudinal FMRI study. Cortex , 49 (1), 71-81. Publisher's VersionAbstract

The goal of the present study was to investigate whether spontaneous functional recovery following insult to the language-dominant hemisphere continues in the so-called “chronic stage,” and if so, to examine its neuro-functional correlates. We used a longitudinal functional magnetic resonance imaging (fMRI) block design, where each young patient served as his/her own control. Specifically, we examined whether language functions differed significantly in two monitoring sessions conducted years apart, both in the chronic stage, where almost no functional changes are expected. We focused on a unique cohort of young brain damaged patients with aphasiogenic lesions occurring after normal language acquisition, in order to maximize the potential of plasticity for language reorganization following brain damage. The most striking finding was that the linguistic recovery of our patients was significant not just relative to their linguistic scores on initial testing (T1), but also in absolute terms, relative to the respective age-matched normal population. Such improvement, therefore, cannot be simply attributed to the natural process of development. Overall, we found that right hemisphere (RH) activation was associated with better recovery in the chronic stage. Our longitudinal findings may challenge the view of recovery as ending within the first year following onset, suggesting that the RH may provide the substrate for ongoing plasticity in the damaged brain.

Frost, R., & Keuleers, E. (2013). What can we learn from monkeys about orthographic processing in humans? A reply to Ziegler et.al. Psychological Science , 24, 1870-1871. Publisher's Version
Rueckl, J., Carreiras, M., & Frost, R. (Ed.). (2013). New advances in morphological processing. In Special issue of Language and Cognitive Processes . Hove, UK: Psychology Press.
Velan, H., Deutsch, A., & Frost, R. (2013). The flexibility of letter-position flexibility: evidence from eye-movements in reading Hebrew. Journal of Experimental Psychology: Human Perception and Performance , 39 (4), 1143-1152. Publisher's VersionAbstract

Hebrew provides an intriguing contrast to European languages. On the one hand, like any European language, it has an alphabetic script. On the other hand, being a Semitic language, it differs in the structure of base words. By monitoring eye movements, we examined the time-course of processing letter transpositions in Hebrew and assessed their impact on reading different types of Hebrew words that differ in their internal structure. We found that letter transposition resulted in dramatic reading costs for words with Semitic word structure, and much smaller costs for non-Semitic words. Moreover, the strongest impact of transposition occurred where root–letter transposition resulted in a pseudo-root, where significant interference emerged already in first fixation duration. Our findings thus suggest that Hebrew readers differentiate between Semitic and non-Semitic forms already at first fixation, at the early phase of word recognition. Moreover, letters are differentially processed across the visual array, given their morphological structure and their contribution to recovering semantic meaning. We conclude that flexibility or rigidity in encoding letter position is determined by cues regarding the internal structure of printed words.

 

Frost, R., Siegelman, N., Narkiss, A., & Afek, L. (2013). What predicts successful literacy acquisition in a second language? Psychological Science , 24 (7), 1243-1252. Publisher's VersionAbstract

In the study reported here, we examined whether success (or failure) in assimilating the structure of a second language can be predicted by general statistical-learning abilities that are nonlinguistic in nature. We employed a visual-statistical-learning (VSL) task, monitoring our participants’ implicit learning of the transitional probabilities of visual shapes. A pretest revealed that performance in the VSL task was not correlated with abilities related to a general g factor or working memory. We found that, on average, native speakers of English who more accurately picked up the implicit statistical structure embedded in the continuous stream of shapes better assimilated the Semitic structure of Hebrew words. Languages and their writing systems are characterized by idiosyncratic correlations of form and meaning, and our findings suggest that these correlations are picked up in the process of literacy acquisition, as they are picked up in any other type of learning, for the purpose of making sense of the environment.

what predicts successful literacy.pdf
2012
Frost, R. (2012). Towards a universal model of reading. . Behavioral and brain sciences , 35 (5), 310-329. Publisher's VersionAbstract

In the last decade, reading research has seen a paradigmatic shift. A new wave of computational models of orthographic processing that offer various forms of noisy position or context-sensitive coding, have revolutionized the field of visual word recognition. The influx of such models stems mainly from consistent findings, coming mostly from European languages, regarding an apparent insensitivity of skilled readers to letter-order. Underlying the current revolution is the theoretical assumption that the insensitivity of readers to letter order reflects the special way in which the human brain encodes the position of letters in printed words. The present paper discusses the theoretical shortcomings and misconceptions of this approach to visual word recognition. A systematic review of data obtained from a variety of languages demonstrates that letter-order insensitivity is not a general property of the cognitive system, neither it is a property of the brain in encoding letters. Rather, it is a variant and idiosyncratic characteristic of some languages, mostly European, reflecting a strategy of optimizing encoding resources, given the specific structure of words. Since the main goal of reading research is to develop theories that describe the fundamental and invariantphenomena of reading across orthographies, an alternative approach to model visual word recognition is offered. The dimensions of a possible universal model of reading, which outlines the common cognitive operations involved in orthographic processing in all writing systems, are discussed.

towards a universal model of reading.pdf
Frost, R. (2012). A universal model of reading : not only possible but also inevitable. Behavioral and Brain Science. Publisher's VersionAbstract

In the last decade, reading research has seen a paradigmatic shift. A new wave of computational models of orthographic processing that offer various forms of noisy position or context-sensitive coding, have revolutionized the field of visual word recognition. The influx of such models stems mainly from consistent findings, coming mostly from European languages, regarding an apparent insensitivity of skilled readers to letter-order. Underlying the current revolution is the theoretical assumption that the insensitivity of readers to letter order reflects the special way in which the human brain encodes the position of letters in printed words. The present paper discusses the [...]

2011
Elkana, O., Frost, R., U., K., Hendler, T., Schmidt, D., & Schweiger, A. (2011). Cerebral reorganization as a function of linguistic recovery in children: An FMRI investigation. Cortex , 47 (2), 202-216. Publisher's VersionAbstract

Characterizing and mapping the relationship between neuronal reorganization and functional recovery are essential to the understanding of cerebral plasticity and the dynamic processes which occur following brain damage. The neuronal mechanisms underlying linguistic recovery following left hemisphere (LH) lesions are still unknown. Using functional magnetic resonance imaging (fMRI), we investigated whether the extent of brain lateralization of linguistic functioning in specific regions of interest (ROIs) is correlated with the level of linguistic performance following recovery from acquired childhood aphasia. The study focused on a rare group of children in whom lesions occurred after normal language acquisition, but prior to complete maturation of the brain. During fMRI scanning, rhyming, comprehension and verb generation activation tasks were monitored. The imaging data were evaluated with reference to linguistic performance measured behaviorally during imaging, as well as outside the scanner. Compared with normal controls, we found greater right hemisphere (RH) lateralization in patients. However, correlations with linguistic performance showed that increased proficiency in linguistic tasks was associated with greater lateralization to the LH. These results were replicated in a longitudinal case study of a patient scanned twice, 3 years apart. Additional improvement in linguistic performance of the patient was accompanied by increasing lateralization to the LH in the anterior language region. This, however, was the result of a decreased involvement of the RH. These findings suggest that recovery is a dynamic, ongoing process, which may last for years after onset. The role of each hemisphere in the recovery process may continuously change within the chronic stage.

Bick, A. S., Goelman, G., & Frost, R. (2011). Hebrew Brain vs. English Brain: Language Modulates the Way It Is Processed. Journal of Cognitive Neuroscience , 23 (9), 2280 - 2290. Publisher's VersionAbstract

Is language processing universal? How do the specific properties of each language influence the way it is processed? In this study, we compare the neural correlates of morphological processing in Hebrew–a Semitic language with a rich and systematic morphology, to those revealed in English–an Indo-European language with a linear morphology. Using fMRI, we show that while in the bilingual brain both languages involve a common neural circuitry in processing morphological structure, this activation is significantly modulated by the different aspects of language. Whereas in Hebrew, morphological processing is independent of semantics, in English, morphological activation is clearly modulated by semantic overlap. These findings suggest that the processes involved in reading words are not universal, and therefore impose important constraints on current models of visual word recognition.

Frost, R. (2011). Looking across orthographies. In P. McCardle, R. Lee, J., J. L. Tzeng, O., & B. Miller (Ed.), Dyslexia across languages: Ortography and the brain- gene- behavior Link. . Baltimor, Brookes Publishing Company. Publisher's VersionAbstract

What causes dyslexia, and how does it manifest across languages? As bilingualism becomes increasingly important globally, these questions have never been more critical–and this comprehensive volume from The Dyslexia Foundation explores them in unprecedented depth. Bringing together the best brain-based, genetics, and behavioral research in the field from more than 40 of today's most highly respected researchers, this landmark volume fully examines what we know about the identification, manifestations, and potential differences in dyslexia across languages and orthographies. International contributors share their groundbreaking studies, helping researchers and graduate-level students investigate key questions about dyslexia: (1) How does dyslexia vary in frequency and manifestation among speakers of various alphabetic and nonalphabetic languages?; (2) How might the characteristics of different languages affect reading acquisition and reading difficulties?; (3) How do genetic profiles

Velan, H., & Frost, R. (2011). Words with and without internal structure: What determines the nature of orthographic and morphological processing? Cognition , 118 (2), 141 - 156. Publisher's VersionAbstract

Recent studies suggest that basic effects which are markers of visual word recognition in Indo-European languages cannot be obtained in Hebrew or in Arabic. Although Hebrew has an alphabetic writing system, just like English, French, or Spanish, a series of studies consistently suggested that simple form-orthographic priming, or letter-transposition priming are not found in Hebrew. In four experiments, we tested the hypothesis that this is due to the fact that Semitic words have an underlying structure that constrains the possible alignment of phonemes and their respective letters. The experiments contrasted typical Semitic words which are root-derived, with Hebrew words of non-Semitic origin, which are morphologically simple and resemble base-words in European languages. Using RSVP, TL priming, and form-priming manipulations, we show that Hebrew readers process Hebrew words which are morphologically simple similar to the way they process English words. These words indeed reveal the t

2010
Bick, A., S., Frost, R., & Goelman, G. (2010). Imaging implicit morphological processing: evidence from Hebrew. Journal of Cognitive Neuroscience , 22 (9), 1955-1969. Publisher's VersionAbstract

Is morphology a discrete and independent element of lexical structure or does it simply reflect a fine-tuning of the system to the statistical correlation that exists among orthographic and semantic properties of words? Hebrew provides a unique opportunity to examine morphological processing in the brain because of its rich morphological system. In an fMRI masked priming experiment, we investigated the neural networks involved in implicit morphological processing in Hebrew. In the lMFG and lIFG, activation was found to be significantly reduced when the primes were morphologically related to the targets. This effect was not influenced by the semantic transparency of the morphological prime, and was not found in the semantic or orthographic condition. Additional morphologically related decrease in activation was found in the lIPL, where activation was significantly modulated by semantic transparency. Our findings regarding implicit morphological processing suggest that morphology is an automatic and distinct aspect of visually processing words. These results also coincide with the behavioral data previously obtained demonstrating the central role of morphological processing in reading Hebrew.

2009
Frost, R. (2009). Reading in Hebrew vs. Reading in English: Is there a Qualitative Difference?. In K. Pugh & P. McCradle (Ed.), How children learn to read: Current Issues and new directions in the integration of Cognition,Neurobiology and Genetics of reading and Dyslexia research and practice. (pp. 235-254) . Psychology Press. Publisher's Version
Velan, H., & Frost, R. (2009). Letter-transposition effects are not universal:The impact of transposing letters in Hebrew. Journal of Memory and Language , 61, 285-302. Publisher's VersionAbstract

We examined the effects of letter-transposition in Hebrew in three masked-priming experiments. Hebrew, like English has an alphabetic orthography where sequential and contiguous letter strings represent phonemes. However, being a Semitic language it has a non-concatenated morphology that is based on root derivations. Experiment 1 showed that transposed-letter (TL) root primes inhibited responses to targets derived from the non-transposed root letters, and that this inhibition was unrelated to relative root frequency. Experiment 2 replicated this result and showed that if the transposed letters of the root created a nonsense-root that had no lexical representation, then no inhibition and no facilitation were obtained. Finally, Experiment 3 demonstrated that in contrast to English, French, or Spanish, TL nonword primes did not facilitate recognition of targets, and when the root letters embedded in them consisted of a legal root morpheme, they produced inhibition. These results suggest that lexical space in alphabetic orthographies may be structured very differently in different languages if their morphological structure diverges qualitatively. In Hebrew, lexical space is organized according to root families rather than simple orthographic structure, so that all words derived from the same root are interconnected or clustered together, independent of overall orthographic similarity.

2008
Frost, R., Grainger, J., & Carreiras, M. (2008). Advances in morphological processes in Hebrew: An introduction. Language and cognitive processes , 23 (7-8), 933-941.Abstract

We examined the effects of letter-transposition in Hebrew in three masked-priming experiments. Hebrew, like English has an alphabetic orthography where sequential and contiguous letter strings represent phonemes. However, being a Semitic language it has a non-concatenated morphology that is based on root derivations. Experiment 1 showed that transposed-letter (TL) root primes inhibited responses to targets derived from the non-transposed root letters, and that this inhibition was unrelated to relative root frequency. Experiment 2 replicated this result and showed that if the transposed letters of the root created a nonsense-root that had no lexical representation, then no inhibition and no facilitation were obtained. Finally, Experiment 3 demonstrated that in contrast to English, French, or Spanish, TL nonword primes did not facilitate recognition of targets, and when the root letters embedded in them consisted of a legal root morpheme, they produced inhibition. These results suggest that lexical space in alphabetic orthographies may be structured very differently in different languages if their morphological structure diverges qualitatively. In Hebrew, lexical space is organized according to root families rather than simple orthographic structure, so that all words derived from the same root are interconnected or clustered together, independent of overall orthographic similarity.

Frost, R., Grainger, J., & Carreiras, M. (2008). New directions in Morphological Processing. In: Special Issue of Language and Cognitive Processes. R. Frost, J. Grainger, & M. Carreiras (Ed.), . Hove, UK: Psychology Press.
Bick, A., Goelman, G., & Frost, R. (2008). Neural Correlates of Morphological Processes in Hebrew. Journal of Cognitive Neuroscience , 20 (3), 406 - 420. Publisher's VersionAbstract

Is morphology a discrete and independent element of lexical structure or does it simply reflect a fine tuning of the system to the statistical correlation that exists among the orthographic and semantic properties of words? Imaging studies in English failed to show unequivocal morphological activation that is distinct from semantic or orthographic activation. Cognitive research in Hebrew has revealed that morphological decomposition is an important component of print processing. In Hebrew, morphological relatedness does not necessarily induce a clear semantic relatedness, thus, Hebrew provides a unique opportunity to investigate the neural substrates of morphological processing. In this functional magnetic resonance imaging study, participants were required to perform judgment tasks of morphological relatedness, semantic relatedness, rhyming, and orthographic similarity. Half of the morphologically related words were semantically related and half were semantically unrelated. This desi

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