Mehdi Purmohammad | University of Alberta (original) (raw)

Papers by Mehdi Purmohammad

Behavior Research Methods, 2025

The present study introduces the Persian Sentence Reading (PSR) Corpus, aiming to expand empirica... more The present study introduces the Persian Sentence Reading (PSR) Corpus, aiming to expand empirical data for Persian, an under-investigated language in research on oculomotor control in reading. Reading research has largely focused on Latin script languages with a left-to-right reading direction. However, languages with different reading directions, such as rightto-left and top-to-bottom, and particularly Persian script-based languages like Farsi and Dari, have remained understudied. This study pioneers in providing an eye movement dataset for reading Persian sentences, enabling further exploration of the influences of unique Persian characteristics on eye movement patterns during sentence reading. The core objective of the study is to provide data about how word characteristics impact eye movement patterns. The research also investigates the characteristics of the interplay between neighboring words and eye movements on them. By broadening the scope of reading research beyond commonly studied languages, the study aims to contribute to an interdisciplinary approach to reading research, exemplifying investigations through various theoretical and methodological perspectives.

Journal of Researches in Linguistics, 2022

The aim of this study was to investigate the role of construction similarity and verb tense in th... more The aim of this study was to investigate the role of construction similarity and verb tense in the construction of integrated syntactic representations in Persian and English bilinguals. Bilingual speakers aged 18 to 40 years (mean= 23 years old) fluent in Persian (as a mother tongue) and English (as a second language) attended in this study. We used the cross-language syntactic priming paradigm. The participants were first presented a sentence (prime sentence) in language A, which had a special syntactic construction such as the passive structure. Then the participants had to produce a sentence in language B (target sentence) in order to describe the target picture. If her/his production of sentences in language B is significantly influenced by the syntactic structure of the sentence that was first presented to her/him (i.e., s/he uses the same syntactic construction of the previous sentence), it is feasible to believe that crosslanguage syntactic priming occurred. In the present study, 4 experiments were designed in which the language of the prime sentence was Persian or English and the target language was either Persian or English. Also, in order to examine whether the syntactic representation is independent from the tense of the verb and whether syntactic priming is affected by whether tense of the verb stayed the same or differed between prime and target, the tense of the prime and target sentences was either the same or different in Experiments 2 and 4. The results showed that there were no cross-language priming effects in any linguistic directions (Persian to English and English to Persian). These results showed that structural differences in Persian and English languages are an influential factor in the occurrence of cross-language syntactic priming and, different word order of passive sentences prevents the occurrence of crosslanguage syntactic priming. The results from Experiments 2 and 4 also revealed that if the tense of the prime sentence is different or the same from the tense of the target sentence, cross-language syntactic priming did not occur.

Interdisciplinary Studies in English Language Teaching, 2023

Language selection in bilinguals is a multidimensional phenomenon. This paper aimed to adopt a mu... more Language selection in bilinguals is a multidimensional phenomenon. This paper aimed to adopt a multidisciplinary approach to investigate language selection in bilingual speech production. The present paper first reviews the sociolinguistic aspects of bilingual language choice, moves on to investigate the notion of language choice presented in the models of bilingual language production and comprehension, views different factors through a single window into the bilingual language selection, and finally examines language choice in dialogue. In this study, I examined neurolinguistics, psycholinguistic, and sociolinguistic models of bilingual language production in order to provide a better understanding of bilingual language selection. When language choice is formulated, information about language is included in the preverbal message at the conceptual level in order to channel the preverbal message into the intended language. This study suggests that as bilingual language selection is highly affected by the context, language tag specification is formulated outside the language system and the output is sent to the conceptualizer level where it is included in the preverbal message. Language cues may have various values depending on the linguistic context. In a bilingual mode or a dense (heavy) switch context, the value of language cues is not very high. I propose that information about language choice at the higher level of processing, language membership information, and language nodes at the lower level of processing construct a language information network that regulates bilingual language processing. Language selection in dialogue settings is also discussed. The present study suggests that bilinguals may not formulate a language choice for every utterance they produce during a course of dialogue or when there is a language history between the two participants.

In Persian, which adheres to an SOV word order, complement clauses or prepositional objects typic... more In Persian, which adheres to an SOV word order, complement clauses or prepositional objects typically follow the direct object in their conventional position. However, there is the potential to move this phrase to different positions within the sentence. However, this phrase can be moved to other positions in a sentence. Multiple explanations exist for this phenomenon. One such explanation is within Lexical-Functional Grammar, suggesting that the relocated constituent finds its place within lexical entries. More specifically, event-related potential (ERP) was used to investigate this processing in the centro-parietal part of the brain (for the for N400 and P600 components) following the Friedrici model of language comprehension (1995). This research aims to investigate how wh-complement displacement in Persian is processed within the verb's lexical entry using event-related potentials, rooted in the syntactic-semantic role structure. Specifically, this study focuses on the N400 central-anterior component, as introduced by Friedrich in the field of language processing in 1995. Given Persian's rich inflection, which permits various word orders, we examined four distinct positions for complement clauses in the sentences under study, constructing 50 sentences for each condition. These sentence conditions were thoughtfully designed based on consistent word length and syntactic category. To delve deeper into the verb's lexical entry, we presented sentences in a structured format on a display screen and provided comprehensive explanations to participants before the experiment. Participants were instructed to articulate words without any lip or facial movement. Brain responses were recorded as event-related potentials during reading and subsequently analyzed using MATLAB software with EEGlaB. The results reveal that complement clause displacement triggers distinct brain responses within the lexical entry of verbs, marked by an increased N400 amplitude in the central-anterior region when the complement clause is in its canonical position. These findings lead to the conclusion that the movement of the complementizer in Persian follows a Lexical-Functional grammar within the neurophysiological model put forth by by Friedrich's model of syntactic processing .The main conclusions to be drawn from these bits of evidence are the displacement of the Wh-complement in lexical entries of verb in Persian has a neurophysiological basis.

PLoS ONE, 2022

Introduction Linguistic disorders are one of the common problems in Alzheimer’s disease, which in... more Introduction
Linguistic disorders are one of the common problems in Alzheimer’s disease, which in recent years has been considered as one of the key parameters in the diagnosis of Alzheimer (AD). Given that changes in sentence processing and working memory and the relationship
between these two activities may be a diagnostic parameter in the early and preclinical stages of AD, the present study examines the comprehension and production of sentences and working memory in AD patients and healthy aged people.
Methods
Twenty-five people with mild Alzheimer’s and 25 healthy elderly people participated in the study. In this study, we used the digit span to evaluate working memory. Syntactic priming and sentence completion tasks in canonical and non-canonical conditions were used for evaluating sentence production. We administered sentence picture matching and crossmodal naming tasks to assess sentence comprehension.
Results
The results of the present study revealed that healthy elderly people and patients with mild Alzheimer’s disease have a significant difference in comprehension of relative clause sentences (P <0.05). There was no significant difference between the two groups in comprehension
of simple active, simple active with noun phrase and passive sentences (P> 0.05).
They had a significant difference in auditory and visual reaction time (P <0.05). Also there was a significant difference between the two groups in syntactic priming and sentence completion tasks. However, in non-canonical condition of sentence completion, the difference
between the two groups was not significant (P> 0.05).

Naqd-i Zabān va Adabīyyāt-i Khārijī, May 22, 2019

Investigating the Effect of Applying Brain-based Learning. . .

In this study, I report three experiments that examined whether words from one language of biling... more In this study, I report three experiments that examined whether words from one language of bilinguals can use the syntactic features form the other language, and how such syntactic co-activation might influence syntactic processing. In other words, I examined whether there are any cases in which an inherent syntactic feature a lexical item is inhibited and the syntactic feature that belongs to the other language is used, instead. In the non-switch condition in Experiments 1 and 2, Persian-English bilinguals described pictures using an adjective–noun string from the same language requested. In the switch condition, they used a noun and an adjective from the other language. In the switch condition in Experiment 3, participants used only the adjective of a noun phrase from the other language. The results showed that bilinguals may inhibit the activation of a word’s syntactic feature and use the syntactic property from the other language, instead [e.g., pirāhane (shirt-N) black]. As the combinatorial node (the node that specifies different kinds of syntactic structures in which a word can be used) of a used adjective retains activation at least temporarily, bilinguals are more likely to use the same combinatorial node even with an adjective from the other language. Cross-language syntactic interference increased in the switch conditions. Moreover, more inappropriate responses were observed when switching from bilinguals’ L2 to L1. The results also revealed that different experimental contexts may lead to different patterns of the control mechanism. The results will be interpreted in terms of Hartsuiker and Pickering’s (2008) model of syntactic representation.

The goal of the present thesis was to investigate the production of code-switched utterances in b... more The goal of the present thesis was to investigate the production of code-switched utterances in bilinguals’ speech production. This study investigates the availability of grammatical-category information during bilingual language processing. The specific aim is to examine the processes involved in the production of Persian-English bilingual compound verbs (BCVs). A bilingual compound verb is formed when the nominal constituent of a compound verb is replaced by an item from the other language. In the present cases of BCVs the nominal constituents are replaced by a verb from the other language. The main question addressed is how a lexical element corresponding to a verb node can be placed in a slot that corresponds to a noun lemma. This study also investigates how the production of BCVs might be captured within a model of BCVs and how such a model may be integrated within incremental network models of speech production. In the present study, both naturalistic and experimental data wer...

Biannual Journal of Contemporary Psychology, 2019

This study aimed to develop a computational model for recognition of emotion in Persian text as a... more This study aimed to develop a computational model for recognition of emotion in Persian text as a supervised machine learning problem. We considered Pluthchik emotion model as supervised learning criteria and Support Vector Machine (SVM) as baseline classifier. We also used NRC lexicon and contextual features as training data and components of the model. One hundred selected texts including political-social newspaper editorials were used to test the model (real terms). Also in this study, the "support vector machine" algorithm was used as the learning classifier and four indicators of accuracy, accuracy, f-score and recall were used to evaluate the model. The results show that the efficiency of the model in detecting different emotions varies from 79% to 98% and mean presision of the model for all classes was 84%. Using all indexes, the classifier showed more performance in joy category than other 7 types. The results of this study show that using emotion-based approach, supervised learning and minimal contextual features can be useful in automatic identification of emotions. It also showed that a combination of lexical resource and contextual features can be used as learning base for a SVM model.

Brain and Language, 2019

Patients with completely locked-in syndrome (CLIS) are incapable of any voluntary muscle movement... more Patients with completely locked-in syndrome (CLIS) are incapable of any voluntary muscle movement and do not have any means of communication. Recently functional near infrared spectroscopy (fNIRS) based brain computer interface (BCI) has been successfully used to enable communication with these patients. The developed fNIRS-BCI system relies on the intactness of language comprehension in these patients in all dimensions of language. Interwoven language and motor cortex in brain, and lack of muscular activity in long run, can cause language attrition due to complete immobility in CLIS patients. In this study we have investigated effects of semantic content of sentences presented to a CLIS patient on the performance of the BCI system during a YES/NO paradigm. Comparison of communication success rate in BCI classification between different semantic categories indicate that semantic content of sentences presented to a CLIS patient can affect the BCI performance. Affected concepts are mostly associated with executive words. These findings can be beneficial towards development of more reliable communication device for patients in CLIS. In addition, these results may assist in elucidating the cognitive changes in completely paralyzed patients with the passage of time since the onset of total immovability.

Function and Disability Journal, Feb 10, 2019

Background: In cognitive linguistics, the key factor in understanding of the abstract and metapho... more Background: In cognitive linguistics, the key factor in understanding of the abstract and metaphorical concepts is the individuals' embodied experiences sensed by their body. Therefore, a better understanding of abstract concepts requires healthy senses and feelings. Hearing impairment leads to disorders in understanding abstract concepts. The present study is aimed to investigate the differences between 5 to 7 year-old Persian-speaking hearing-impaired children and their normal counterparts in terms of understanding embodied conceptual metaphors. Methods: The present study was conducted on twenty 5 to 7 year-old Persian-speaking children with moderate to severe hearing impairment. The study investigated the participants' understanding of abstract concepts when using embodied metaphors in four sensory-motor organs (the eyes, ears, hands and legs) through conducting a researcher-made task including both audio and audio-visual sections. The results of the hearing-impaired children were compared with the performance of 200 normal children. Results: The findings of the present study indicated a significantly lower mean score of hearing-impaired children compared to their normal peers. The mean score of hearing-impaired participants was 9.6, while their normal counterparts scored 24.51. Moreover, it was indicated that the performance of 6 to 7 year-old hearing-impaired children was better than the 5 to 6 year-old children. Conclusion: Despite the quick reception through hearing aids, hearing-impaired children are unable to understand abstract and metaphorical concepts although they have an acceptable language competence unless receiving a direct professional training to understand the metaphors. The hearing-impaired children tend to interpret the metaphorical concepts literally and fail to understand the abstract metaphorical concepts. The findings of the present study clearly revealed the necessity of designing a cognitive rehabilitation protocol dedicated to the abstract concepts.