Masked Priming Experiments Research Articles

Computational Modeling of Morphological Effects in Bangla Visual Word Recognition.

In this paper we aim to model the organization and processing of Bangla polymorphemic words in the mental lexicon. Our objective is to determine whether the mental lexicon accesses a polymorphemic word as a whole or decomposes the word into its constituent morphemes and then recognize them accordingly. To address this issue, we adopted two different strategies. First, we conduct a masked priming experiment over native speakers. Analysis of reaction time (RT) and error rates indicates that in general, morphologically derived words are accessed via decomposition process. Next, based on the collected RT data we have developed a computational model that can explain the processing phenomena of the access and representation of Bangla derivationally suffixed words. In order to do so, we first explored the individual roles of different linguistic features of a Bangla morphologically complex word and observed that processing of Bangla morphologically complex words depends upon several factors like, the base and surface word frequency, suffix type/token ratio, suffix family size and suffix productivity. Accordingly, we have proposed different feature models. Finally, we combine these feature models together and came up with a new model that takes the advantage of the individual feature models and successfully explain the processing phenomena of most of the Bangla morphologically derived words. Our proposed model shows an accuracy of around 80% which outperforms the other related frequency models.

Letter-case information and the identification of brand names.

A central tenet of most current models of visual-word recognition is that lexical units are activated on the basis of case-invariant abstract letter representations. Here, we examined this assumption by using a unique type of words: brand names. The rationale of the experiments is that brand names are archetypically printed either in lowercase (e.g., adidas) or uppercase (e.g., IKEA). This allows us to present the brand names in their standard or non-standard case configuration (e.g., adidas, IKEA vs. ADIDAS, ikea, respectively). We conducted two experiments with a brand-decision task ('is it a brand name?'): a single-presentation experiment and a masked priming experiment. Results in the single-presentation experiment revealed faster identification times of brand names in their standard case configuration than in their non-standard case configuration (i.e., adidas faster than ADIDAS; IKEA faster than ikea). In the masked priming experiment, we found faster identification times of brand names when they were preceded by an identity prime that matched its standard case configuration than when it did not (i.e., faster response times to adidas-adidas than to ADIDAS-adidas). Taken together, the present findings strongly suggest that letter-case information forms part of a brand name's graphemic information, thus posing some limits to current models of visual-word recognition.

Activation of morphemic meanings in processing opaque words

Two masked priming experiments were conducted to examine the activation of morphemic forms and meanings during opaque word processing. In Experiment 1, opaque primes significantly facilitated the recognition of transparent targets, which was consistent with previous results. However, transparent primes did not influence the recognition of opaque targets. This asymmetry could not be explained solely by morpho-orthographic processing, but it was consistent with models that have assumed early morpho-semantic activation. Experiment 2 directly tested whether the meanings of the constituent morphemes in opaque words were activated. In the critical condition, the targets were unrelated to the opaque primes at the lexical level, but were semantically related to their morphemes (e.g., "butterfly-bread"). Facilitation was observed in this condition, providing strong evidence of morpho-semantic activation during opaque-word recognition. These findings indicate that although initial morphological decomposition is determined by surface morphological form, it does not necessarily imply that morphemic meanings will be activated at later stages of processing. Rather, the morphemic meanings may be available automatically once segmentation is complete.

Subliminal Gestalt grouping: Evidence of perceptual grouping by proximity and similarity in absence of conscious perception

Previous studies making use of indirect processing measures have shown that perceptual grouping can occur outside the focus of attention. However, no previous study has examined the possibility of subliminal processing of perceptual grouping. The present work steps forward in the study of perceptual organization, reporting direct evidence of subliminal processing of Gestalt patterns. In two masked priming experiments, Gestalt patterns grouped by proximity or similarity that induced either a horizontal or vertical global orientation of the stimuli were presented as masked primes and followed by visible targets that could be congruent or incongruent with the orientation of the primes. The results showed a reliable priming effect in the complete absence of prime awareness for both proximity and similarity grouping principles. These findings suggest that a phenomenal report of the Gestalt pattern is not mandatory to observe an effect on the response based on the global properties of Gestalt stimuli.

Does Tonal Information Affect the Early Stages of Visual-Word Processing in Thai?

Thai offers a unique opportunity to investigate the role of lexical tone processing during visual-word recognition, as tone is explicitly expressed in its script. In order to investigate the contribution of tone at the orthographic/phonological level during the early stages of word processing in Thai, we conducted a masked priming experiment-using both lexical decision and word naming tasks. For a given target word (e.g., ห้อง/hᴐ:ŋ2/, room), five priming conditions were created: (a) identity (e.g., ห้อง/hᴐ:ŋ2/), (b) same initial consonant, but with a different tone marker (e.g., ห่อง/hᴐ:ŋ1/), (c) different initial consonant, but with the same tone marker (e.g., ศ้อง/sᴐ:ŋ2/), (d) orthographic control (different initial consonant, different tone marker; e.g., ศ่อง/sᴐ:ŋ1/), and (e) same tone homophony, but with a different initial consonant and different tone marker (e.g., ธ่อง/t(h)ᴐ:ŋ2/). Results of the critical comparisons revealed that segmental information (i.e., consonantal information) appears to be more important than tone information (i.e., tone marker) in the early stages of visual-word processing in alphabetic, tonal languages like Thai. Thus, these findings may help constrain models of visual-word recognition and reading in tonal languages.

Testing the viability of webDMDX for masked priming experiments

The DMDX software package (Forster & Forster, 2003) is a Windows-based application that displays stimuli and records responses. Recent developments in this program have made it possible to deploy DMDX experiments over the Internet. This study evaluates the viability of the web-deployable implementation of DMDX, or webDMDX, for masked priming experiments. A lexical decision task (LDT) with masked repetition priming on high- and low-frequency words and an e/a letter detection task were conducted with both lab-based DMDX (labDMDX; Experiment 1) and webDMDX. The webDMDX experiments were run on lab computers (Experiments 2) and on different (unknown) hardware (Experiment 3). The labDMDX and webDMDX experiments yielded comparable results on the LDT. In the e/a-detection task, the only important difference observed among the tests was between the lab-based experiment (Experiment 1) and the first webDMDX experiment (Experiment 2), at the 50 ms display duration. However, after a minor change in keyword coding (Experiment 2 follow-up) and an adjustment to the millisecond-to-retrace conversion process (Experiment 3), the detection rates at all display durations were similar in both labDMDX and webDMDX. Taken together, these results indicate the utility of webDMDX for masked priming experiments as well as for other time-sensitive methodologies.

The influence of frequency across the time course of morphological processing: Evidence from the transposed-letter effect

The role that morphology plays in lexical access has been the subject of much debate, as has the influence of word frequency on morphological processing. The effect of frequency on morphological processing across the time course of lexical access was investigated using the transposed-letter effect. The results of two experiments (one masked-priming experiment and one eye-tracking experiment) outline a process in which morphological structure can be detected quickly and independently of frequency. The present study is also the first to show that transpositions that cross morpheme boundaries can be as disruptive as letter substitutions in inflected words, replicating earlier results with derived and compound words.

Visual processing of derivational morphology in children with developmental dyslexia: Insights from masked priming

ABSTRACTWe investigated whether children with dyslexia rely on derivational morphology during visual word recognition and how the semantic and form properties of morphemes influence this processing. We conducted two masked priming experiments, in which we manipulated the semantic overlap (Experiment 1) and the form overlap (Experiment 2) between morphologically related pairs of words. In each experiment, French dyslexic readers as well as reading-level matched and chronological-age matched children performed a lexical decision task. Significant priming effects were observed in all groups, indicating that their lexicon is organized around morpheme units. Furthermore, the dyslexics’ processing of written morphology is mainly influenced by the semantic properties of morphemes, whereas children from the two control groups are mainly influenced by their form properties.

Letter transpositions within and across morphemic boundaries: Is there a cross-language difference?

Research on the impact of letter transpositions that arise across morpheme boundaries has yielded conflicting results. These results have led to the suggestion that a cross-linguistic difference may exist in the recognition of Spanish and English words. In two masked-priming experiments run on separate groups of Spanish and English speakers, we tested this hypothesis by comparing the impacts of primes with letter transpositions that arose within morphemes or across morpheme boundaries on the recognition of identical or near-identical Spanish-English cognate targets. The results showed transposed-letter benefits in both Spanish and English that were not modulated by the position of the transposed letter in the prime stimulus. Our findings therefore add to the growing body of literature suggesting that the transposed-letter benefit is not affected by the position of the transposed letters relative to the morpheme boundary, and they dispel previous suggestions that there might be a genuine difference in orthographic coding across the Spanish and English writing systems.

ERP correlates of masked affective priming with emoticons

Emoticons seem to enrich computer-mediated communication by improving enjoyment, perceived richness and usefulness of information (Huang, Yen, & Zhang, 2008). Despite their extensive use over the last decades, the way emoticons affect subsequent emotional/cognitive processing is not fully understood. Here we conducted a masked priming experiment that explored the time course of the masked affective priming effect while recording event-related potentials. Type of prime (emoticon vs. word) and prime valence (positive vs. negative) were manipulated to assess their influence in the processing of positive/negative target words. Results showed a masked affective priming effect in early (N2) and late temporal windows (LPC). This effect was observed in early components for negative target words and in later components for positive target words. Furthermore, it was restricted to those targets preceded by emoticon primes. Thus, the processing of emoticons seems to be privileged when compared with the words to which they refer.

An investigation of the role of grapheme units in word recognition.

In most current models of word recognition, the word recognition process is assumed to be driven by the activation of letter units (i.e., that letters are the perceptual units in reading). An alternative possibility is that the word recognition process is driven by the activation of grapheme units, that is, that graphemes, rather than letters, are the perceptual units in reading. If so, there must be representational units for multiletter graphemes like CH and PH, which play a key role in this process. We examined this idea in four masked priming experiments. Primes were created by transposing, replacing entirely, or removing one component of either multiletter graphemes or two adjacent letters that each represented a grapheme, using both English and Spanish stimuli. In none of the experiments was there any evidence of differential priming effects depending on whether the two letters being manipulated formed a single grapheme or formed two separate graphemes. These data are most consistent with the idea that multiletter graphemes have no special status at the earliest stages of word processing and, therefore, that word recognition is, indeed, driven by the activation of units for individual letters.

Inflection and derivation in native and non-native language processing: Masked priming experiments on Turkish

Much previous experimental research on morphological processing has focused on surface and meaning-level properties of morphologically complex words, without paying much attention to the morphological differences between inflectional and derivational processes. Realization-based theories of morphology, for example, assume specific morpholexical representations for derived words that distinguish them from the products of inflectional or paradigmatic processes. The present study reports results from a series of masked priming experiments investigating the processing of inflectional and derivational phenomena in native (L1) and non-native (L2) speakers in a non-Indo-European language, Turkish. We specifically compared regular (Aorist) verb inflection with deadjectival nominalization, both of which are highly frequent, productive and transparent in Turkish. The experiments demonstrated different priming patterns for inflection and derivation, specifically within the L2 group. Implications of these findings are discussed both for accounts of L2 morphological processing and for the controversial linguistic distinction between inflection and derivation.

Early, equivalent ERP masked priming effects for regular and irregular morphology

Converging evidence from behavioral masked priming (Rastle & Davis, 2008), EEG masked priming (Morris, Frank, Grainger, & Holcomb, 2007) and single word MEG (Zweig & Pylkkänen, 2008) experiments has provided robust support for a model of lexical processing which includes an early, automatic, visual word form based stage of morphological parsing that applies to all derivationally affixed words. The mechanisms by which regularly (walked, birds) and irregularly (gave, geese) inflected forms are processed are less well established. We combine the masked priming paradigm with EEG recording to directly compare the ERPs evoked by regularly and irregularly inflected forms. We find equivalent N250 priming effects for both types of morphological complexity, which argues for rapid, form based morphological parsing of all morphologically complex word forms.

Masked Noncognate Priming across Farsi and English

In an attempt to test the prediction made by dual lexical model (Gollan, Forster, & Frost, 1997)regarding mental representation of non-cognate translation pairs (semantically similar translations) across languages with different scripts, non-cognate translation pairs were examined in a masked priming experiment across Farsi and English in L1-L2 and L2-L1direction. The results of the study showed a different pattern of priming for non-cognate as compared with Gollan et al study. The results of the study are discussed in terms of “entry opening “(Forster & Davis 1984; Davis, Schoknecht, & Carter, 1987) and Distributed Feature Model (De Groot ,1992).

Position Coding in Two-Digit Arabic Numbers

Digit position coding in two-digit Arabic numbers was examined in two masked priming experiments. In Experiment 1, participants had to decide whether the presented stimulus was a two-digit Arabic number (e.g., 67) or not (e.g., G7). Target stimuli could be preceded by a prime which (i) shared one digit in the initial position (e.g., 13-18), (ii) shared one digit but in a different position (83-18), and (iii) was a transposed number (81-18). Two unrelated control conditions, equalized in terms of the distance between primes and targets with the experimental conditions, were also included (e.g., 79-18). Results showed a priming effect only when prime and target shared digits in the same position. Experiment 2 employed a masked priming same-different matching task - a task that has been successfully employed in the literature on letter position coding. Results showed faster response times when prime and target shared digits - including the transposed-digit condition - relative to the control conditions. Thus, the identity of each digit in the early stages of visual processing is not associated with a specific position in two-digit Arabic numbers. We examine the implication of these findings for models of Arabic number processing.

Text-Speak processing

Chapman University Orange, United States of America There has been a steady shift from more traditional means of communication (e.g., hand written letters) to more electronically based (e.g., text messaging) (Crystal, 2008). This shift in communication style has influenced both civilian and military occupations (Turkoski, 2009; Finomore, et al., 2010). The current study investigated whether text-speak (method for shortening words or phrases) provides semantic value. A text-speak proficiency scale was also created in order to determine if the extent of text-speak use correlates with behavioral performance. Eighty-seven university students completed a masked priming experiment coupled with an 8-item text-speak scale. The masked priming experiment yielded significant priming indicating that text-speak primes are semantically meaningful, because they facilitate responding to their word counterpart even when the prime is processed unconsciously. The 8-item scale yielded a correlation between willingness to use text speak and magnitude of priming. These findings suggest that the 8-item scale may be useful in assessing text-speak behavior and aid in a better understanding of the role of text-speak proficiency and performance.

Effects of lexical status and morphological complexity in masked priming: An ERP study

Two masked priming experiments examined behavioural and event-related potential responses to simplex target words (e.g., flex) preceded by briefly presented, masked, derived word primes (flexible-flex), complex nonword primes formed by an illegal combination of the target word and a real suffix (flexify-flex), and simplex nonword primes formed by adding a nonsuffix word ending to the target (flexint-flex). Subjects performed a lexical decision task. Behavioural results showed that all prime types significantly facilitated target recognition. Priming effects were reflected in the electrophysiological data by reduced N250 and N400 amplitudes, and these priming effects were statistically equivalent for the three types of prime. The strong priming effects found with simplex primes in the present study, compared with prior research, are thought to be due to the combination of targets always being completely embedded in prime stimuli plus the reduced lexical inhibition that arises with nonword primes. In line with prior behavioural research, however, there was evidence for differential priming effects as a function of prime type in the N400 ERP component in Experiment 2, with greater priming effects for derived and pseudocomplex primes relative to simplex primes at lateral posterior electrode sites.

Decomposition of prefixed words in Russian.

I examined the nature of morphological decomposition in a series of masked-priming experiments with Russian prefixed nouns. In Experiments 1A and 1B, I tested 3 types of prime-target pairs in which the prime was a morphologically simple word, and a facilitation was found when the prime and the target were truly morphologically related (e.g., narost [outgrowth] and rost [growth] are morphologically related via the prefix na- [on]) or apparently morphologically related (e.g., priton [den] and ton [tone] seem to be morphologically related via the prefix pri- [toward], but this relation is false) but not when the relation was purely orthographic (e.g., kumir [idol] and mir [peace]; ku- is not an existing prefix of Russian). These results suggest that all orthographic forms that can be exhaustively parsed into a prefix and a stem are decomposed into (apparent) constituent morphemes during their retrieval from the lexicon. This early segmentation process is driven by morpho-orthographic but not by morphosemantic considerations and applies even for derived forms that are more frequent than their stem.

The masked priming toolbox: an open-source MATLAB toolbox for masked priming researchers

The Masked Priming Toolbox is an open-source collection of MATLAB functions that utilizes the free third-party PsychToolbox-3 (PTB3: Brainard, Spatial Vision, 10, 433-436, 1997; Kleiner, Brainard & Pelli, Perception, 36, 2007; Pelli, Spatial Vision, 10, 437-442, 1997). It is designed to allow a researcher to run masked (and unmasked) priming experiments using a variety of response devices (including keyboards, graphics tablets and force transducers). Very little knowledge of MATLAB is required; experiments are generated by creating a text file with the required parameters, and raw and analyzed data are output to Excel (as well as MATLAB) files for further analysis. The toolbox implements a variety of stimuli for use as primes and targets, as well as a variety of masks. Timing, size, location, and orientation of stimuli are all parameterizable. The code is open-source and made available on the Web under a Creative Commons License.

Through the looking-glass: Mirror reading

At early stages of object identification we process correctly oriented and mirrored versions of an object similarly. However, in letter and word perception, such tolerance to mirror reversals is harmful for efficient reading. Do readers successfully develop blindness mechanisms for mirror-letters and words? We conducted two masked priming experiments while recording participants' electrophysiological brain responses to briefly presented primes including mirror-letters (Experiment 1) or to shortly presented mirror-words (Experiment 2). Results showed that the human visual word recognition system is not totally blind to mirror-letters and mirror-words, since the early stages of processing mirror-letters and mirror-words produced effects on target word recognition that were highly similar to the effects produced by identical primes (N250 component). In a posterior stage of processing (N400 epoch), the effect of mirror-letters and mirror-words was different from the effect of identical primes, even though reversed primes still elicited N400 priming effects different from unrelated primes. These results demonstrate that readers perceive mirror-letters and words as correct at initial stages of word recognition, and that the visual word recognition system's neural representation is grounded on basic principles that govern object perception.