Selective Neural Entrainment Reveals Hierarchical Tuning to Linguistic Regularities in Reading.

Reading is both a visual and a linguistic task, and as such it relies on both general-purpose, visual mechanisms and more abstract, meaning-oriented processes. Disentangling the roles of these resources is of paramount importance in reading research. The present study capitalizes on the coupling of fast periodic visual stimulation and MEG recordings to address this issue and investigate the role of different kinds of visual and linguistic units in the visual word identification system. We compared strings of pseudo-characters; strings of consonants (e.g., sfcl); readable, but unattested strings (e.g., amsi); frequent, but non-meaningful chunks (e.g., idge); suffixes (e.g., ment); and words (e.g., vibe); and looked for discrimination responses with a particular focus on the ventral, occipito-temporal regions. The results revealed sensitivity to alphabetic, readable, familiar, and lexical stimuli. Interestingly, there was no discrimination between suffixes and equally frequent, but meaningless endings, thus highlighting a lack of sensitivity to semantics. Taken together, the data suggest that the visual word identification system, at least in its early processing stages, is particularly tuned to form-based regularities, most likely reflecting its reliance on general-purpose, statistical learning mechanisms that are a core feature of the visual system as implemented in the ventral stream.

Optimizing coastal exhumation strategies: The casework of the Committee on Missing Persons in Cyprus (2006-2022).

This paper reports on coastal exhumations performed during 2006-2022, under the framework of the Committee on Missing Persons in Cyprus (CMP) humanitarian identification programme. CMP archaeologists investigated 217 coastal locations and recovered skeletal remains on 44 occasions. Challenging environmental conditions required a customized exhumation plan, which could be executed swiftly without compromising operational integrity or standards. The author performed a retrospective analysis to propose an optimized strategy, which includes a survey, exhumation, digital documentation, and post-processing components, with the aim of minimizing the effects of adverse environmental conditions. The proposed strategy is based on scientific standards and observations in the field; it can satisfy the needs of a humanitarian or criminal investigation if appropriate measures are taken to uphold legislative and forensic standards. The author also discussed the taphonomic effects of coastal erosion and wave activity in tandem with exhumation recommendations to assist forensic practitioners involved in similar investigations.

Automatic morpheme identification across development: Magnetoencephalography (MEG) evidence from fast periodic visual stimulation.

The present study combined magnetoencephalography (MEG) recordings with fast periodic visual stimulation (FPVS) to investigate automatic neural responses to morphemes in developing and skilled readers. Native English-speaking children (N = 17, grade 5-6) and adults (N = 28) were presented with rapid streams of base stimuli (6 Hz) interleaved periodically with oddballs (i.e., every fifth item, oddball stimulation frequency: 1.2 Hz). In a manipulation-check condition, tapping into word recognition, oddballs featured familiar words (e.g., roll) embedded in a stream of consonant strings (e.g., ktlq). In the experimental conditions, the contrast between oddball and base stimuli was manipulated in order to probe selective stem and suffix identification in morphologically structured pseudowords (e.g., stem + suffix pseudowords such as softity embedded in nonstem + suffix pseudowords such as trumess). Neural responses at the oddball frequency and harmonics were analyzed at the sensor level using non-parametric cluster-based permutation tests. As expected, results in the manipulation-check condition revealed a word-selective response reflected by a predominantly left-lateralized cluster that emerged over temporal, parietal, and occipital sensors in both children and adults. However, across the experimental conditions, results yielded a differential pattern of oddball responses in developing and skilled readers. Children displayed a significant response that emerged in a mostly central occipital cluster for the condition tracking stem identification in the presence of suffixes (e.g., softity vs. trumess). In contrast, adult participants showed a significant response that emerged in a cluster located in central and left occipital sensors for the condition tracking suffix identification in the presence of stems (e.g., softity vs. stopust). The present results suggest that while the morpheme identification system in Grade 5-6 children is not yet adult-like, it is sufficiently mature to automatically analyze the morphemic structure of novel letter strings. These findings are discussed in the context of theoretical accounts of morphological processing across reading development.

Frequency-based neural discrimination in fast periodic visual stimulation.

Humans capitalize on statistical cues to discriminate fundamental units of information within complex streams of sensory input. We sought neural evidence for this phenomenon by combining fast periodic visual stimulation (FPVS) and EEG recordings. Skilled readers were exposed to sequences of linguistic items with decreasing familiarity, presented at a fast rate and periodically interleaved with oddballs. Crucially, each sequence comprised stimuli of the same category, and the only distinction between base and oddball items was the frequency of occurrence of individual tokens within a stream. Frequency-domain analyses revealed robust neural responses at the oddball presentation rate in all conditions, reflecting the discrimination between two locally-emerged groups of items purely informed by token frequency. Results provide evidence for a fundamental frequency-tuned mechanism that operates under high temporal constraints and could underpin category bootstrapping. Concurrently, they showcase the potential of FPVS for providing a direct neural measure of implicit statistical learning.

Algorithms for the automated correction of vertical drift in eye-tracking data.

A common problem in eye-tracking research is vertical drift-the progressive displacement of fixation registrations on the vertical axis that results from a gradual loss of eye-tracker calibration over time. This is particularly problematic in experiments that involve the reading of multiline passages, where it is critical that fixations on one line are not erroneously recorded on an adjacent line. Correction is often performed manually by the researcher, but this process is tedious, time-consuming, and prone to error and inconsistency. Various methods have previously been proposed for the automated, post hoc correction of vertical drift in reading data, but these methods vary greatly, not just in terms of the algorithmic principles on which they are based, but also in terms of their availability, documentation, implementation languages, and so forth. Furthermore, these methods have largely been developed in isolation with little attempt to systematically evaluate them, meaning that drift correction techniques are moving forward blindly. We document ten major algorithms, including two that are novel to this paper, and evaluate them using both simulated and natural eye-tracking data. Our results suggest that a method based on dynamic time warping offers great promise, but we also find that some algorithms are better suited than others to particular types of drift phenomena and reading behavior, allowing us to offer evidence-based advice on algorithm selection.

Morpheme Position Coding in Reading Development as Explored With a Letter Search Task.

Suffixes have been shown to be recognized as units of processing in visual word recognition and their identification has been argued to be position-specific in skilled adult readers: in lexical decision tasks suffixes are automatically identified at word endings, but not at word beginnings. The present study set out to investigate whether position-specific coding can be detected with a letter search task and whether children already code suffixes as position-specific units. A preregistered experiment was conducted in Italian in which 3rd-graders, 5th-graders, and adults had to detect a target letter that was either contained in the suffix of a pseudoword (e.g., S in flagish ) or in a non-suffix control (e.g., S in flagosh ). To investigate sensitivity to position, letters also had to be detected in suffixes and non-suffixes placed in reversed position, that is in the beginning of pseudowords (e.g., S in ishflag vs. oshflag). Results suggested position-specific processing differences between suffixes and non-suffixes that develop throughout reading development. However, some effects were weak and only partially compatible with the hypotheses. Therefore, a second experiment was conducted. The effects of position-specific suffix identification could not be replicated. A combined analysis additionally using a Bayesian approach indicated no processing differences between suffixes and non-suffixes in our task. We discuss potential interpretations and the possibility of letter search being unsuited to investigate morpheme processing. We connect our example of failed self-replication to the current discussion about the replication crisis in psychology and the lesson psycholinguistics can learn.

Orthographic consistency influences morphological processing in reading aloud: Evidence from a cross-linguistic study.

The present study investigated whether morphological processing in reading is influenced by the orthographic consistency of a language or its morphological complexity. Developing readers in Grade 3 and skilled adult readers participated in a reading aloud task in four alphabetic orthographies (English, French, German, Italian), which differ in terms of both orthographic consistency and morphological complexity. English is the least consistent, in terms of its spelling-to-sound relationships, as well as the most morphologically sparse, compared to the other three. Two opposing hypotheses were formulated. If orthographic consistency modulated the use of morphology in reading, readers of English should show more robust morphological processing than readers of the other three languages, because morphological units increase the reliability of spelling-to-sound mappings in the English language. In contrast, if the use of morphology in reading depended on the morphological complexity of a language, readers of French, German, and Italian should process morphological units in printed letter strings more efficiently than readers of English. Both developing and skilled readers of English showed greater morphological processing than readers of the other three languages. These results support the idea that the orthographic consistency of a language, rather than its morphological complexity, influences the extent to which morphology is used during reading. We explain our findings within the remit of extant theories of reading acquisition and outline their theoretical and educational implications.

What's special about orthographic processing? Further evidence from transposition effects in same-different matching.

We sought evidence for letter-specific processing in the same-different matching task by comparing performance to random consonant strings and either strings of symbols (Experiment 1) or strings of digits (Experiment 2). The strings could be aligned horizontally or vertically, and on "different" response trials the to-be-matched strings could differ by the transposition of two adjacent characters or by the substitution of two adjacent characters. Making a "different" response was harder when the difference involved a transposition compared with a substitution-the transposition effect. Crucially, the transposition effect was significantly greater for letters than for symbols or digits when stimuli were aligned horizontally, but did not differ significantly across stimulus type with vertically aligned strings. These results suggest that it is processing specific to horizontally aligned letter strings, a reading-specific mechanism, that causes the greater transposition effects for letter stimuli in the same-different matching task when stimuli are arranged horizontally.

Cues to stress assignment in reading aloud.

Research seeking to uncover the mechanisms by which we read aloud has focused almost exclusively on monosyllabic items presented in isolation. Consequently, important challenges that arise when considering polysyllabic word reading, such as stress assignment, have been ignored, while little is known about how important sentence-level stress cues, such as syntax and rhythm, may influence word reading aloud processes. The present study seeks to fill these gaps in the literature by (a) documenting the individual influences of major sublexical cues that readers use to assign stress in single-word reading in English and (b) determining how these cues may interact with contextual stress factors in sentence reading. In Experiments 1, 2, and 3 we investigated the effects of prefixation, orthographic weight (i.e., number of letters in a syllable), and vowel length on stress assignment by asking participants to read aloud carefully-constructed nonwords that varied on the presence of these cues. Results revealed individual effects of all three cues on the assignment of second-syllable stress. In Experiment 4, we tested the effects of these cues on stress assignment in the context of sentence reading. Results showed that sublexical cues influenced stress assignment over and above higher-level syntactic and rhythmic cues. We consider these findings in the framework of extant rule-based, distributed-connectionist, and Bayesian approaches to stress assignment in reading aloud, and we discuss their applications to understanding reading development and acquired and developmental reading disorders. (PsycINFO Database Record

Prefixes repel stress in reading aloud: Evidence from surface dyslexia.

This study examined the importance of prefixes as sublexical cues for stress assignment during reading aloud English disyllabic words. In particular, we tested the hypothesis that prefixes repel stress (Rastle & Coltheart, 2000) by investigating the likelihood with which patients with surface dyslexia assign second-syllable stress to prefixed words. Five such patients were presented with three types of disyllabic words for reading aloud: 'regular' prefixed words with weak-strong stress pattern (e.g., remind); 'irregular' prefixed words with strong-weak stress pattern (e.g., reflex); and non-prefixed words with strong-weak stress pattern (e.g., scandal). Results showed that all five patients frequently regularized the strong-weak prefixed words by pronouncing them with second syllable stress. These regularization errors provide strong evidence for the functional role of prefixes in stress assignment during reading. Additional computational simulations using the rule-based algorithm for pronouncing disyllables developed by Rastle and Coltheart (2000) and the CDP++ model of reading aloud (Perry et al., 2010) allowed us to evaluate how these two opponent approaches to reading aloud fare in respect of the patient data.

An ERP investigation of orthographic priming with superset primes.

Prime stimuli formed by inserting unrelated letters in a given target word (called "superset" primes) provide a means to modify the relative positions of the letters shared by prime and target. Here we examined the time-course of superset priming effects in an ERP study using the sandwich-priming paradigm. We compared the effects of superset primes formed by the insertion of unrelated letters (e.g., maurkdet-MARKET), or by the insertion of hyphens (e.g., ma-rk-et-MARKET), with identity priming (e.g., market-MARKET), all measured relative to unrelated control primes. Behavioral data revealed significantly greater priming in the hyphen-insert condition compared with the letter-insert condition. In the ERP signal, letter-insert priming emerged later than hyphen-insert priming and produced a reversed priming effect in the N400 time-window compared with the more typical N400 priming effects seen for both hyphen-insert priming and identity priming. The different pattern of priming effects seen for letter-insert primes and hyphen-insert primes suggests that compared with identity priming, letter superset priming reflects the joint influence of: (1) a disruption in letter position information, and (2) an inhibitory influence of mismatching letters.

On the time-course of adjacent and non-adjacent transposed-letter priming.

We compared effects of adjacent (e.g., atricle-ARTICLE) and non-adjacent (e.g., actirle-ARTICLE) transposed-letter (TL) primes in an ERP study using the sandwich priming technique. TL priming was measured relative to the standard double-substitution condition. We found significantly stronger priming effects for adjacent transpositions than non-adjacent transpositions (with 2 intervening letters) in behavioral responses (lexical decision latencies), and the adjacent priming effects emerged earlier in the ERP signal, at around 200 ms post-target onset. Non-adjacent priming effects emerged about 50 ms later and were short-lived, being significant only in the 250-300 ms time-window. Adjacent transpositions on the other hand continued to produce priming in the N400 time-window (300-500 ms post-target onset). This qualitatively different pattern of priming effects for adjacent and non-adjacent transpositions is discussed in the light of different accounts of letter transposition effects, and the utility of drawing a distinction between positional flexibility and positional noise.

The "electrophysiological sandwich": a method for amplifying ERP priming effects.

We describe the results of a study that combines ERP recordings and sandwich priming, a variant of masked priming that provides a brief preview of the target prior to prime presentation (S. J. Lupker & C. J. Davis, 2009). This has been shown to increase the size of masked priming effects seen in behavioral responses. We found the same increase in sensitivity to ERP priming effects in an orthographic priming experiment manipulating the position of overlap of letters shared by primes and targets. Targets were 6-letter words and primes were formed of the 1st, 3rd, 4th, and 6th letters of targets in the related condition. Primes could be concatenated or hyphenated and could be centered on fixation or displaced by two letter spaces to the left or right. Priming effects with concatenated and/or displaced primes only started to emerge at 250 ms post-target onset, whereas priming effects from centrally located hyphenated primes emerged about 100 ms earlier.

Deciphering CAPTCHAs: what a Turing test reveals about human cognition.

Turning Turing's logic on its head, we used widespread letter-based Turing Tests found on the internet (CAPTCHAs) to shed light on human cognition. We examined the basis of the human ability to solve CAPTCHAs, where machines fail. We asked whether this is due to our use of slow-acting inferential processes that would not be available to machines, or whether fast-acting automatic orthographic processing in humans has superior robustness to shape variations. A masked priming lexical decision experiment revealed efficient processing of CAPTCHA words in conditions that rule out the use of slow inferential processing. This shows that the human superiority in solving CAPTCHAs builds on a high degree of invariance to location and continuous transforms, which is achieved during the very early stages of visual word recognition in skilled readers.

Letter string processing and visual short-term memory.

The present study investigated whether expertise with letter string processing influences visual short-term memory capacity. Specifically, we examined whether performance in a change-detection task would vary as a function of stimulus type (letters vs. symbols) and type of display (horizontal, vertical, and circular). Participants were asked to detect a one-character change in a briefly presented character array following a delay of 900 ms. Concurrent articulation was used to limit effects of rehearsal. Type of display significantly affected performance with letters, but not with symbols, with a selective increase in change-detection accuracy for horizontally presented letter arrays compared with vertical and circular arrays. These findings confirm the standard limits of storage in visual short-term memory, but critically reveal a selective advantage for letter arrays over symbol arrays when presented horizontally. Such an advantage is probably due to the utilization of a specialized encoding mechanism built up over years of reading experience.

Smart phone, smart science: how the use of smartphones can revolutionize research in cognitive science.

Investigating human cognitive faculties such as language, attention, and memory most often relies on testing small and homogeneous groups of volunteers coming to research facilities where they are asked to participate in behavioral experiments. We show that this limitation and sampling bias can be overcome by using smartphone technology to collect data in cognitive science experiments from thousands of subjects from all over the world. This mass coordinated use of smartphones creates a novel and powerful scientific "instrument" that yields the data necessary to test universal theories of cognition. This increase in power represents a potential revolution in cognitive science.

GreekLex: a lexical database of Modern Greek.

To conduct experimental investigations into the orthographic processing of Modern Greek, information is needed about the lexical properties known to influence visual word recognition. In this article we introduce GreekLex, a lexical database for Modern Greek, which presents collectively for the first time a series of orthographic measures that can be used for psycholinguistic research. GreekLex consists of 35,304 Modern Greek words ranging in length from 1 to 22 letters, and for each word includes the following statistical information: word length, word-form frequency, lemma frequency, neighborhood density and frequency, transposition neighbors, and addition and deletion neighbors. Furthermore, type and token frequency measures of single letters and bigrams derived from the database are also available. The complete database can be accessed and downloaded freely from www.psychology.nottingham.ac.uk/GreekLex.