Showing papers by "Theodoros Marinis published in 2023"

Investigation of the properties and behaviour of ancient and newly constructed mudbricks from the ancient walls of Eleusis

Abstract: The paper presents the test results from the investigation of the nature and mechanical behaviour of mudbricks from the ancient mudbrick wall of Eleusis in Attica, Greece. The mudbrick wall remains preserved to date in the site of Eleusis are some of the largest preserved in Greece. Small fragments of mudbricks were taken to the laboratory for experimental investigation. Testing included index tests toclassify the soil material the mudbricks were made of, mineralogical analyses of their fines’ content, mechanical testing suitable for the nature of the materials and the ability to trim the samples without causing damage and measurements of suction on samples as they were obtained, further dried, or rewetted. The soil material used for ancient mudbrick construction was a silty sand to sandy silt with a small fraction clay content, with marginally plastic to non-plastic fines. Dry unit weight was found to be close to the dry unit weight of fresh mudbrick material after being compacted with a minimum compaction energy of only 45 kNm/m3 and left to dry to residual water content conditions. Similarly, field water content was found close to the residual water content of these recompacted soil samples. Consequently, unconfined compression strength was found very high corresponding to the residual water content condition, with similarly high cohesion obtained from direct shear tests and a very high yield stress under one-dimensional conditions of loading.

What Sentence Repetition Tasks Can Reveal about the Processing Effort Associated with Different Types of Code-Switching

Abstract: In this study, we explored the linguistic consolidation processes associated with bilingual processing using an experimental paradigm novel in bilingualism research, i.e., sentence repetition. We tested 46 L1-German L2-English bilinguals immersed in the L2 context. Firstly, we compared participants’ sentence repetition accuracy in single-language sentences and in sentences involving code-switches. Secondly, we investigated the processing cost associated with different types of code-switching, i.e., alternation, insertion, and dense code-switching. Finally, we assessed the following potential predictors of repetition accuracy: regular usage of different code-switching types, executive functions (working memory and inhibitory control), as well as relevant bilingualism variables (proficiency, dominance, and immersion). Our first finding was that bilinguals displayed reduced repetition accuracy in sentences involving code-switches compared to single-language sentences, but only when the single-language sentences were in the participants’ L1. This suggests that any processing costs associated with code-switching are modulated by bilinguals’ language background. Moreover, bilinguals’ poor performance in L2 compared to L1 single-language sentences, despite reporting high levels of L2 exposure frequency, highlights the importance of age of acquisition and dominance profiles for language processing. In terms of code-switching, our results revealed that bilinguals’ repetition accuracy differed across different types of code-switching. The processing effort associated with different types of code-switching in the sentence repetition task was primarily driven by the structural depth and the degree of mixing of the involved code-switch, i.e., dense forms of code-switching involving high levels of linguistic co-activation were harder to repeat than alternations involving unintegrated language switching. This effect partially converged with bilinguals’ sociolinguistic practices because bilinguals also reported lower exposure frequency to dense code-switching, but no direct correlations were observed at the level of individual differences. In terms of general cognitive functions, repetition accuracy was modulated by working memory but not by inhibitory control. By investigating this issue, we hope to contribute to our understanding of language processing in the face of cross-linguistic consolidation processes.

Language in autism: domains, profiles and co-occurring conditions

Abstract: This article reviews the current knowledge state on pragmatic and structural language abilities in autism and their potential relation to extralinguistic abilities and autistic traits. The focus is on questions regarding autism language profiles with varying degrees of (selective) impairment and with respect to potential comorbidity of autism and language impairment: Is language impairment in autism the co-occurrence of two distinct conditions (comorbidity), a consequence of autism itself (no comorbidity), or one possible combination from a series of neurodevelopmental properties (dimensional approach)? As for language profiles in autism, three main groups are identified, namely, (i) verbal autistic individuals without structural language impairment, (ii) verbal autistic individuals with structural language impairment, and (iii) minimally verbal autistic individuals. However, this tripartite distinction hides enormous linguistic heterogeneity. Regarding the nature of language impairment in autism, there is currently no model of how language difficulties may interact with autism characteristics and with various extralinguistic cognitive abilities. Building such a model requires carefully designed explorations that address specific aspects of language and extralinguistic cognition. This should lead to a fundamental increase in our understanding of language impairment in autism, thereby paving the way for a substantial contribution to the question of how to best characterize neurodevelopmental disorders.

Reproduction and long-term monitoring of drying of mudbricks and small mudbrick walls for the preservation of the ancient mudbrick wall of Eleusis

Abstract: The mudbrick wall remains preserved to date in the site of Eleusis are some of the largest preserved in Greece. Following an extensive investigation of the properties of existing mudbricks, material of similar properties from the archaeological site of Eleusis was used to reproduce mudbricks of similardensity with the ancient ones after drying with various concentrations of dry grass also from the archaeological site. Actual mudbricks were reproduced and brought to a final equilibrium condition under climatic conditions practically similar to those in Eleusis. Others were used to trim samples and measuremechanical properties to compare with original mudbricks, others were instrumented with suction and volumetric water content sensors in order to monitor mudbrick drying under climatic conditions and others in order to build small mudbrick walls with mortar from the same soil used to make the mudbricks. These small mudbrick walls included the mudbricks with internally installed suction and volumetric water content sensors and were also constructed with similar sensors in the mortar. This allowed monitoring of drying of the mortar until each whole mudbrick wall came to equilibrium and was then subjected to uniaxial compression under load control. Monitoring of mudbricks and mudbrick walls indicated that the higher the dry grass concentration, the higher the drying rate of the mudbricks; the lower the dry grass concentration the higher the probability of mudbrick cracking during drying; minimum required time for mudbrick and mudbrick wall drying for the particular soil used in the ancient mudbricks is not less than 5 weeks. Finally, uniaxial compression under load control on both samples trimmed from dried mudbricks and mudbrick walls indicated that uniaxial compression strength decreases with increasing dry grass concentration and mudbrick wall strength should be expected in the order of 70-80% that of the cubic samples trimmed from dried mudbricks and subjected to load rate control compression.

Development and validation of a task battery for verbal and non-verbal first- and second-order theory of mind

Abstract: This paper presents a new toolkit for assessing Theory of Mind (ToM) via performance in first and second-order false belief (FB) tasks. The toolkit includes verbal and non-verbal versions of first and second-order FB tasks; the verbal version is currently available in Greek and German. Scenarios in the toolkit are balanced for factors that may influence performance, like the reason for the FB (deception, change-of-location, unexpected content). To validate our toolkit, we tested the performance of neurotypical adults in the non-verbal and verbal versions in two studies: Study 1 with 50 native speakers of German and Study 2 with 50 native speakers of Greek. The data from both studies yield similar results. Participants performed well in all conditions, showing slightly more difficulties in the second- than first-order FB conditions, and in the non-verbal than the verbal version of the task. This suggests that the task is at the high end of the sensitive range for neurotypical adults, and is expected to be well inside the sensitive range for children and populations that have difficulties in ToM. Factors like deception and type of outcome in the video-scenarios did not influence the behavior of neurotypical adults, suggesting that the task does not have any confounds related to these factors. The order of presentation of the verbal and non-verbal version has an influence on performance; participants beginning with the verbal version performed slightly better than participants beginning with the non-verbal version. This suggests that neurotypical adults used language to mediate ToM performance and learn from a language-mediated task when performing a non-verbal ToM task. To conclude, our results show that the scenarios in the toolkit are of comparable difficulty and can be combined freely to match demands in future research with neurotypical children and autistic individuals, as well as other populations that have been shown to have difficulties in ToM. Differences between baseline and critical conditions can be assumed to reflect ToM abilities, rather than language and task-based confounding factors.

Using multiple measures of language dominance and proficiency in Farsi-English bilingual children

Abstract: This paper aims to identify effective means of measuring dominance and proficiency in bilingual children. Thirty-seven Farsi-English Heritage language speaking children from 6;1 to 11;6 were assessed on their vocabulary, morphosyntax, and narrative microstructure skills in both languages to address whether there is a difference between their proficiency in Farsi as a heritage and English as a majority language, how the scores on the vocabulary, morphosyntax, and narrative microstructure tasks relate to one another, and based on the results of each task in both languages if any of the children are at risk for a Developmental Language Disorder. Vocabulary was assessed using the LITMUS- Cross-Linguistic Lexical Task (CLT), morphosyntax using the LITMUS-Sentence Repetition (SR) tasks, and Narrative microstructure using the LITMUS-Multilingual Assessment Instrument for Narratives (MAIN). Individual language proficiency was identified via an in-depth profile analysis for each participant who looked at their performance on all experimental tasks in both languages. The data demonstrated that on the vocabulary and narrative tasks the participants were more dominant in English than in Farsi, while on the sentence repetition task there were no significant differences between the two languages. Correlation analyses showed that vocabulary scores were strongly correlated to the sentence repetition scores and the microstructure scores. The English and Farsi sentence repetition scores also correlated moderately with the microstructure scores within each language. Profile analysis showed that no child within the study scored < 1.5 or 2 standard deviations below the mean on more than two tasks in both languages. However, interesting patterns emerged indicating that some participants had a greater proficiency in one language vs. the other language. The results from this study showed that measuring language within a single domain (e.g., morphosyntax) is not enough to identify a bilingual child's language dominance and/or proficiency. Instead, an in-depth profile analysis and language assessments across various language domains need to be done in order to appropriately measure language dominance and proficiency. Consequently, this study supports the importance of measuring language across multiple domains in studies of bilingual children. The clinical significance of appropriately identifying language dominance and proficiency was also shown, as such information would allow clinicians to make more appropriate clinical decisions.