Michal Icht | Ariel University (original) (raw)

Papers by Michal Icht

Journal of Communication Disorders, 2014

Oro-facial and speech motor control disorders represent a variety of speech and language patholog... more Oro-facial and speech motor control disorders represent a variety of speech and language pathologies. Early identification of such problems is important and carries clinical implications. A common and simple tool for gauging the presence and severity of speech motor control impairments is oral-diadochokinesis (oral-DDK). Surprisingly, norms for adult performance are missing from the literature. The goals of this study were: (1) to establish a norm for oral-DDK rate for (young to middle-age) adult English speakers, by collecting data from the literature (five studies, N = 141); (2) to investigate the possible effect of language (and culture) on oral-DDK performance, by analyzing studies conducted in other languages (five studies, N = 140), alongside the English norm; and (3) to find a new norm for adult Hebrew speakers, by testing 115 speakers. We first offer an English norm with a mean of 6.2 syllables/s (SD = .8), and a lower boundary of 5.4 syllables/s that can be used to indicate possible abnormality. Next, we found significant differences between four tested languages (English, Portuguese, Farsi and Greek) in oral-DDK rates. Results suggest the need to set language and culture sensitive norms for the application of the oral-DDK task worldwide. Finally, we found the oral-DDK performance for adult Hebrew speakers to be 6.4 syllables/s (SD = .8), not significantly different than the English norms. This implies possible phonological similarities between English and Hebrew. We further note that no gender effects were found in our study. We recommend using oral-DDK as an important tool in the speech language pathologist's arsenal. Yet, application of this task should be done carefully, comparing individual performance to a set norm within the specific language. Learning outcomes: Readers will be able to: (1) identify the Speech-Language Pathologist assessment process using the oral-DDK task, by comparing an individual performance to the present English norm, (2) describe the impact of language on oral-DDK performance, and (3) accurately detect Hebrew speakers' patients using this tool.

Objectives. Occupational-related vocal load is an increasing global problem with adverse personal... more Objectives. Occupational-related vocal load is an increasing global problem with adverse personal and economic implications. We examined voice changes in real speaking situations during a single day, with and without vocal loading, aiming to identify an objective acoustic index for vocal load over a day. Methods. Call center operators (CCOs, n ¼ 27) and age-and gender-matched students (n ¼ 25) were recorded at the beginning and at the end of a day, with (CCOs) and without (students) vocal load. Speaking and reading voice samples were analyzed for fundamental frequency (F 0), sound pressure level (SPL), and their variance (F 0 coefficient of variation [F 0 CV], SPL CV). The impact of lifestyle habits on voice changes was also estimated. Results and conclusions. The main findings revealed an interaction, with F 0 rise at the end of the day for the students but not for the CCOs. We suggest that F 0 rise is a typical phenomenon of a day of normal vocal use, whereas vocal loading interferes with this mechanism. In addition, different lifestyle profiles of CCOs and controls were observed, as the CCOs reported higher incidence of dehydrating behaviors (eg, smoking, caffeine). Yet, this profile was not linked with voice changes. In sum, we suggest that F 0 rise over a day can potentially serve as an index for typical voice use. Its lack thereof can hint on consequent voice symptoms and complaints.

Journal of voice : official journal of the Voice Foundation, Jan 25, 2015

Occupational-related vocal load is an increasing global problem with adverse personal and economi... more Occupational-related vocal load is an increasing global problem with adverse personal and economic implications. We examined voice changes in real speaking situations during a single day, with and without vocal loading, aiming to identify an objective acoustic index for vocal load over a day. Call center operators (CCOs, n = 27) and age- and gender-matched students (n = 25) were recorded at the beginning and at the end of a day, with (CCOs) and without (students) vocal load. Speaking and reading voice samples were analyzed for fundamental frequency (F0), sound pressure level (SPL), and their variance (F0 coefficient of variation [F0 CV], SPL CV). The impact of lifestyle habits on voice changes was also estimated. The main findings revealed an interaction, with F0 rise at the end of the day for the students but not for the CCOs. We suggest that F0 rise is a typical phenomenon of a day of normal vocal use, whereas vocal loading interferes with this mechanism. In addition, different li...

Memory (Hove, England), Jan 6, 2014

The production effect (PE) documents the advantage in memory performance for words that are read ... more The production effect (PE) documents the advantage in memory performance for words that are read aloud during study, rather than words that are read silently. Until now, the PE was examined in the visual modality, as the participants read the study words. In the present study, we extended the PE phenomenon and used the auditory modality at study. This novel methodology provides a critical test of the distinctiveness account. Accordingly, the participants heard the study words and learned them by vocal production (saying aloud) or by writing, followed by a free recall test. The use of the auditory modality yielded a memory advantage for words that were written during study over words that were vocally produced. We explain this result in light of the encoding distinctiveness account, suggesting that the PE is determined by the number of different encoding processes involved in learning, emphasising the essential role of active production.

Journal of child language, Jan 18, 2014

The 'Production Effect' (PE) refers to a memory advantage for items studied aloud over it... more The 'Production Effect' (PE) refers to a memory advantage for items studied aloud over items studied silently. Thus, vocalizing may serve as a mnemonic that can be used to assist learners in improving their memory for new concepts. Although many other types of mnemonic have been suggested in the literature, the PE seems especially appropriate for young children, as it does not involve literacy skills. The present study is a first investigation of the PE in children. In two experiments we tested five-year-olds in a PE paradigm using pictures of objects as stimuli. In Experiment 1, pictures of familiar objects were presented to be remembered, and in Experiment 2 we used pictures of unfamiliar objects (evaluating new vocabulary acquisition). In both experiments we showed a memory advantage for vocally produced words ('look and say') over other types of learning ('look', 'look and listen'), suggesting the PE as a prominent memory and learning tool.

Frontiers in psychology, 2014

The production effect is the difference in memory favoring words read aloud relative to words rea... more The production effect is the difference in memory favoring words read aloud relative to words read silently during study. According to a currently popular explanation, the distinctiveness of aloud words relative to silent words at the time of encoding underlies the better memory for the former. This distinctiveness is attributable to the additional dimension(s) of encoding for the aloud items that can be subsequently used during retrieval. In this study we argue that encoding distinctiveness is not the sole source of distinctiveness and that, in fact, there is an independent source of distinctiveness, statistical distinctiveness, which may or may not work in harmony with encoding distinctiveness in influencing memory. Statistical distinctiveness refers to the relative size of a subset of items marked by a(ny) unique property. Silently read words can carry statistical distinctiveness if they form a salient minority on the background of a majority of vocalized words. We show that, whe...

Clinical linguistics & phonetics, 2015

Oral-diadochokinesis (DDK) tasks are a common tool for evaluating speech disorders. Usually, thes... more Oral-diadochokinesis (DDK) tasks are a common tool for evaluating speech disorders. Usually, these tasks involve repetitions of non-words. It has been suggested that repeating real words can be more suitable for preschool children. But, the impact of using real words with elementary school children has not been studied yet. This study evaluated oral-DDK rates for Hebrew-speaking elementary school children using non-words and real words. The participants were 60 children, 9-11 years old, with normal speech and language development, who were asked to repeat "pataka" (non-word) and "bodeket" (Hebrew real word). Data replicate the advantage generally found for real word repetition with preschoolers. Children produced real words faster than non-words for all age groups, and repetition rates were higher for the older children. The findings suggest that adding real words to the standard oral-DDK task with elementary school children may provide a more comprehensive pictu...

Oro-facial and speech motor control disorders represent a variety of speech and language patholog... more Oro-facial and speech motor control disorders represent a variety of speech and language pathologies. Early identification of such problems is important and carries clinical implications. A common and simple tool for gauging the presence and severity of speech motor control impairments is oral-diadochokinesis (oral-DDK). Surprisingly, norms for adult performance are missing from the literature. The goals of this study were: (1) to establish a norm for oral-DDK rate for (young to middle-age) adult English speakers, by collecting data from the literature (five studies, N = 141); (2) to investigate the possible effect of language (and culture) on oral-DDK performance, by analyzing studies conducted in other languages (five studies, N = 140), alongside the English norm; and (3) to find a new norm for adult Hebrew speakers, by testing 115 speakers. We first offer an English norm with a mean of 6.2 syllables/s (SD = .8), and a lower boundary of 5.4 syllables/s that can be used to indicate possible abnormality. Next, we found significant differences between four tested languages (English, Portuguese, Farsi and Greek) in oral-DDK rates. Results suggest the need to set language and culture sensitive norms for the application of the oral-DDK task world-wide. Finally, we found the oral-DDK performance for adult Hebrew speakers to be 6.4 syllables/s (SD = .8), not significantly different than the English norms. This implies possible phonological similarities between English and Hebrew. We further note that no gender effects were found in our study. We recommend using oral-DDK as an important tool in the speech language pathologist's arsenal. Yet, application of this task should be done carefully, comparing individual performance to a set norm within the specific language.

British Journal of Psychology, 2013

When words at study are divided into to-be-remembered and to-be-forgotten ones, people recall mor... more When words at study are divided into to-be-remembered and to-be-forgotten ones, people recall more of the former than of the latter in a surprise memory test for all words. In this study, we also tapped memory for word identity at study (forget or remember) by asking participants to reproduce in memory selected portions of the original words. We found word identity to be parasitic on word reproduction. As a result, there is a noted tendency to recall forget-words from study as remember-words in the memory test more than vice versa.

Attention, Perception, & Psychophysics, 2014

Sustained effects of emotion are well known in everyday experience. Surprisingly, such effects ar... more Sustained effects of emotion are well known in everyday experience. Surprisingly, such effects are seldom recorded in laboratory studies of the emotional Stroop task, in which participants name the color of emotion and neutral words. Color performance is more sluggish with emotion words than with neutral words, the emotional Stroop effect (ESE). The ESE is not sensitive to the order in which the two groups of words are presented, so the effect of exposure to emotion words does not extend to disrupting performance in a subsequent block with neutral words. We attribute this absence of a sustained effect to habituation engendered by excessive repetition of the experimental stimuli. In a series of four experiments, we showed that sustained effects do occur when habituation is removed, and we also showed that the massive exposure to negative stimuli within the ESE paradigm induces a commensurately negative mood. A novel perspective is offered, in which the ESE is considered a special case of mood induction.

Letters in Applied Microbiology, 1995

The phytopathogen Agrobacterium tumefaciens incites the production of crown-gall on a wide range ... more The phytopathogen Agrobacterium tumefaciens incites the production of crown-gall on a wide range of dicotyledonous plants. Gall formation is dependent upon indole-3-acetic acid (IAA) and cytokinin production by the transformed plant cells. Upon incubation of Agrobacterium tumefaciens C58 with the plant hormone indole-3-acetic acid (IAA), bacterial virulence on cucumber plants was stimulated up to tenfold. Stimulation was maximized after exposure of bacteria to 50 or 100 μg ml-1 IAA for 3 h. This was shown to be at the early log phase of bacterial growth.The authors suggest that the excretion of IAA by the transformed plant cells stimulates bacterial virulence mechanism(s) encoded by the Ti plasmid, the chromosome, or both.

Journal of Communication Disorders, 2014

Oro-facial and speech motor control disorders represent a variety of speech and language patholog... more Oro-facial and speech motor control disorders represent a variety of speech and language pathologies. Early identification of such problems is important and carries clinical implications. A common and simple tool for gauging the presence and severity of speech motor control impairments is oral-diadochokinesis (oral-DDK). Surprisingly, norms for adult performance are missing from the literature. The goals of this study were: (1) to establish a norm for oral-DDK rate for (young to middle-age) adult English speakers, by collecting data from the literature (five studies, N = 141); (2) to investigate the possible effect of language (and culture) on oral-DDK performance, by analyzing studies conducted in other languages (five studies, N = 140), alongside the English norm; and (3) to find a new norm for adult Hebrew speakers, by testing 115 speakers. We first offer an English norm with a mean of 6.2 syllables/s (SD = .8), and a lower boundary of 5.4 syllables/s that can be used to indicate possible abnormality. Next, we found significant differences between four tested languages (English, Portuguese, Farsi and Greek) in oral-DDK rates. Results suggest the need to set language and culture sensitive norms for the application of the oral-DDK task worldwide. Finally, we found the oral-DDK performance for adult Hebrew speakers to be 6.4 syllables/s (SD = .8), not significantly different than the English norms. This implies possible phonological similarities between English and Hebrew. We further note that no gender effects were found in our study. We recommend using oral-DDK as an important tool in the speech language pathologist's arsenal. Yet, application of this task should be done carefully, comparing individual performance to a set norm within the specific language. Learning outcomes: Readers will be able to: (1) identify the Speech-Language Pathologist assessment process using the oral-DDK task, by comparing an individual performance to the present English norm, (2) describe the impact of language on oral-DDK performance, and (3) accurately detect Hebrew speakers' patients using this tool.

Objectives. Occupational-related vocal load is an increasing global problem with adverse personal... more Objectives. Occupational-related vocal load is an increasing global problem with adverse personal and economic implications. We examined voice changes in real speaking situations during a single day, with and without vocal loading, aiming to identify an objective acoustic index for vocal load over a day. Methods. Call center operators (CCOs, n ¼ 27) and age-and gender-matched students (n ¼ 25) were recorded at the beginning and at the end of a day, with (CCOs) and without (students) vocal load. Speaking and reading voice samples were analyzed for fundamental frequency (F 0), sound pressure level (SPL), and their variance (F 0 coefficient of variation [F 0 CV], SPL CV). The impact of lifestyle habits on voice changes was also estimated. Results and conclusions. The main findings revealed an interaction, with F 0 rise at the end of the day for the students but not for the CCOs. We suggest that F 0 rise is a typical phenomenon of a day of normal vocal use, whereas vocal loading interferes with this mechanism. In addition, different lifestyle profiles of CCOs and controls were observed, as the CCOs reported higher incidence of dehydrating behaviors (eg, smoking, caffeine). Yet, this profile was not linked with voice changes. In sum, we suggest that F 0 rise over a day can potentially serve as an index for typical voice use. Its lack thereof can hint on consequent voice symptoms and complaints.

Journal of voice : official journal of the Voice Foundation, Jan 25, 2015

Occupational-related vocal load is an increasing global problem with adverse personal and economi... more Occupational-related vocal load is an increasing global problem with adverse personal and economic implications. We examined voice changes in real speaking situations during a single day, with and without vocal loading, aiming to identify an objective acoustic index for vocal load over a day. Call center operators (CCOs, n = 27) and age- and gender-matched students (n = 25) were recorded at the beginning and at the end of a day, with (CCOs) and without (students) vocal load. Speaking and reading voice samples were analyzed for fundamental frequency (F0), sound pressure level (SPL), and their variance (F0 coefficient of variation [F0 CV], SPL CV). The impact of lifestyle habits on voice changes was also estimated. The main findings revealed an interaction, with F0 rise at the end of the day for the students but not for the CCOs. We suggest that F0 rise is a typical phenomenon of a day of normal vocal use, whereas vocal loading interferes with this mechanism. In addition, different li...

Memory (Hove, England), Jan 6, 2014

The production effect (PE) documents the advantage in memory performance for words that are read ... more The production effect (PE) documents the advantage in memory performance for words that are read aloud during study, rather than words that are read silently. Until now, the PE was examined in the visual modality, as the participants read the study words. In the present study, we extended the PE phenomenon and used the auditory modality at study. This novel methodology provides a critical test of the distinctiveness account. Accordingly, the participants heard the study words and learned them by vocal production (saying aloud) or by writing, followed by a free recall test. The use of the auditory modality yielded a memory advantage for words that were written during study over words that were vocally produced. We explain this result in light of the encoding distinctiveness account, suggesting that the PE is determined by the number of different encoding processes involved in learning, emphasising the essential role of active production.

Journal of child language, Jan 18, 2014

The 'Production Effect' (PE) refers to a memory advantage for items studied aloud over it... more The 'Production Effect' (PE) refers to a memory advantage for items studied aloud over items studied silently. Thus, vocalizing may serve as a mnemonic that can be used to assist learners in improving their memory for new concepts. Although many other types of mnemonic have been suggested in the literature, the PE seems especially appropriate for young children, as it does not involve literacy skills. The present study is a first investigation of the PE in children. In two experiments we tested five-year-olds in a PE paradigm using pictures of objects as stimuli. In Experiment 1, pictures of familiar objects were presented to be remembered, and in Experiment 2 we used pictures of unfamiliar objects (evaluating new vocabulary acquisition). In both experiments we showed a memory advantage for vocally produced words ('look and say') over other types of learning ('look', 'look and listen'), suggesting the PE as a prominent memory and learning tool.

Frontiers in psychology, 2014

The production effect is the difference in memory favoring words read aloud relative to words rea... more The production effect is the difference in memory favoring words read aloud relative to words read silently during study. According to a currently popular explanation, the distinctiveness of aloud words relative to silent words at the time of encoding underlies the better memory for the former. This distinctiveness is attributable to the additional dimension(s) of encoding for the aloud items that can be subsequently used during retrieval. In this study we argue that encoding distinctiveness is not the sole source of distinctiveness and that, in fact, there is an independent source of distinctiveness, statistical distinctiveness, which may or may not work in harmony with encoding distinctiveness in influencing memory. Statistical distinctiveness refers to the relative size of a subset of items marked by a(ny) unique property. Silently read words can carry statistical distinctiveness if they form a salient minority on the background of a majority of vocalized words. We show that, whe...

Clinical linguistics & phonetics, 2015

Oral-diadochokinesis (DDK) tasks are a common tool for evaluating speech disorders. Usually, thes... more Oral-diadochokinesis (DDK) tasks are a common tool for evaluating speech disorders. Usually, these tasks involve repetitions of non-words. It has been suggested that repeating real words can be more suitable for preschool children. But, the impact of using real words with elementary school children has not been studied yet. This study evaluated oral-DDK rates for Hebrew-speaking elementary school children using non-words and real words. The participants were 60 children, 9-11 years old, with normal speech and language development, who were asked to repeat "pataka" (non-word) and "bodeket" (Hebrew real word). Data replicate the advantage generally found for real word repetition with preschoolers. Children produced real words faster than non-words for all age groups, and repetition rates were higher for the older children. The findings suggest that adding real words to the standard oral-DDK task with elementary school children may provide a more comprehensive pictu...

Oro-facial and speech motor control disorders represent a variety of speech and language patholog... more Oro-facial and speech motor control disorders represent a variety of speech and language pathologies. Early identification of such problems is important and carries clinical implications. A common and simple tool for gauging the presence and severity of speech motor control impairments is oral-diadochokinesis (oral-DDK). Surprisingly, norms for adult performance are missing from the literature. The goals of this study were: (1) to establish a norm for oral-DDK rate for (young to middle-age) adult English speakers, by collecting data from the literature (five studies, N = 141); (2) to investigate the possible effect of language (and culture) on oral-DDK performance, by analyzing studies conducted in other languages (five studies, N = 140), alongside the English norm; and (3) to find a new norm for adult Hebrew speakers, by testing 115 speakers. We first offer an English norm with a mean of 6.2 syllables/s (SD = .8), and a lower boundary of 5.4 syllables/s that can be used to indicate possible abnormality. Next, we found significant differences between four tested languages (English, Portuguese, Farsi and Greek) in oral-DDK rates. Results suggest the need to set language and culture sensitive norms for the application of the oral-DDK task world-wide. Finally, we found the oral-DDK performance for adult Hebrew speakers to be 6.4 syllables/s (SD = .8), not significantly different than the English norms. This implies possible phonological similarities between English and Hebrew. We further note that no gender effects were found in our study. We recommend using oral-DDK as an important tool in the speech language pathologist's arsenal. Yet, application of this task should be done carefully, comparing individual performance to a set norm within the specific language.

British Journal of Psychology, 2013

When words at study are divided into to-be-remembered and to-be-forgotten ones, people recall mor... more When words at study are divided into to-be-remembered and to-be-forgotten ones, people recall more of the former than of the latter in a surprise memory test for all words. In this study, we also tapped memory for word identity at study (forget or remember) by asking participants to reproduce in memory selected portions of the original words. We found word identity to be parasitic on word reproduction. As a result, there is a noted tendency to recall forget-words from study as remember-words in the memory test more than vice versa.

Attention, Perception, & Psychophysics, 2014

Sustained effects of emotion are well known in everyday experience. Surprisingly, such effects ar... more Sustained effects of emotion are well known in everyday experience. Surprisingly, such effects are seldom recorded in laboratory studies of the emotional Stroop task, in which participants name the color of emotion and neutral words. Color performance is more sluggish with emotion words than with neutral words, the emotional Stroop effect (ESE). The ESE is not sensitive to the order in which the two groups of words are presented, so the effect of exposure to emotion words does not extend to disrupting performance in a subsequent block with neutral words. We attribute this absence of a sustained effect to habituation engendered by excessive repetition of the experimental stimuli. In a series of four experiments, we showed that sustained effects do occur when habituation is removed, and we also showed that the massive exposure to negative stimuli within the ESE paradigm induces a commensurately negative mood. A novel perspective is offered, in which the ESE is considered a special case of mood induction.

Letters in Applied Microbiology, 1995

The phytopathogen Agrobacterium tumefaciens incites the production of crown-gall on a wide range ... more The phytopathogen Agrobacterium tumefaciens incites the production of crown-gall on a wide range of dicotyledonous plants. Gall formation is dependent upon indole-3-acetic acid (IAA) and cytokinin production by the transformed plant cells. Upon incubation of Agrobacterium tumefaciens C58 with the plant hormone indole-3-acetic acid (IAA), bacterial virulence on cucumber plants was stimulated up to tenfold. Stimulation was maximized after exposure of bacteria to 50 or 100 μg ml-1 IAA for 3 h. This was shown to be at the early log phase of bacterial growth.The authors suggest that the excretion of IAA by the transformed plant cells stimulates bacterial virulence mechanism(s) encoded by the Ti plasmid, the chromosome, or both.