Recent theories suggest that speech disfluencies result from a disruption in the time-dependent processes of phonological and phonetic encoding (Howell & Au-Yeung, 2002; Karniol, 1995; Perkins, Kent, & Curlee, 1991; Postma & Kolk, 1993; Wingate, 1988). The purpose of this study was to examine the relationship between phonological complexity and disfluencies in the speech of preschool-age children. It was predicted that speech disfluencies would be more likely to occur in utterances with a higher degree of phonological complexity than in utterances with a lower degree of phonological complexity. Participants in this study were 12 monolingual English-speaking preschool-age children who stutter. Other than the diagnosis of stuttering, all 12 children exhibited normal speech, language, and hearing function. Each child was videotaped with a parent or guardian while engaged in a 30 minute free-play conversational interaction. Each of the participants utterances was examined to identify the presence of speech disfluencies. The presence of word-initial late-emerging consonants and consonant strings (LECi/CSi; Howell, Au-Yeung, & Sackin, 2000; Shriberg, 1993; Throneburg, Yairi, & Paden, 1994) and the Index of Phonetic Complexity (IPC; Jakielski, 2000) were utilized as metrics to identify a relationship between speech disfluencies and phonological complexity. Logistic regression was employed to determine the relationship between phonological complexity and disfluency for each child individually and to determine if a similar relationship existed for the group as a whole. While the results of initial analyses suggested that an utterance with a higher phonological complexity score was more likely to be disfluent than an utterance with a lower phonological complexity score, post-hoc analyses did not support this initial conclusion. The results of post-hoc analyses suggested that the initial results were confounded by the effect of utterance length. The best fit to the logistic regression model was achieved by utterance length (in number of words). The addition of phonological complexity did not add significantly to the regression model. The results of this study do not offer support to the contention that speech disfluency in young children is influenced by the phonological complexity of the utterance being produced (Howell et al., 2000; Weiss & Jakielski, 2001).

The view that impairments of attention may constitute an important factor underlying impaired language performance in aphasia has gained support in recent years. Aphasiologists taking this view have generally proceeded from resource allocation models of attention, with little or no attention given to alternative models. One alternative model of dual-task performance is the central bottleneck model, which proposes a single-channel limit at response selection or other central processing stages. The first purpose of the present experiments was to further examine the effects on word production of lexical frequency in the context of the psychological refractory period (PRP) dual-task method. The second purpose was to examine whether the reaction time (RT) patterns obtained under conditions promoting equal task emphasis are more consistent with the central bottleneck or central resource models. Three dual-task experiments were conducted using speeded picture naming and tone identification tasks presented at varying timulus onset asynchronies (SOAs). In experiment 1, lexical frequency affected primary-task naming and secondary-task tone identification RTs approximately equally. In experiment 2, lexical frequency affected secondary-task naming RTs similarly at all levels of SOA, after potentially confounding variables were taken into account. It was concluded that frequency-sensitive lexical processing in picture-naming participates in the central processing stage of the dual-task models under study. In the third experiment, the two tasks were presented in variable order and subjects were instructed to give equal attention to both. On tone-primary trials, tone RTs increased with decreasing SOA, a result consistent with the central resource model and inconsistent with the central bottleneck model, unless augmented by the assumption that particpants grouped responses on short SOA trials. Also, additional analyses restricted to those participants demonstrating a lexical frequency effect on the secondary naming task found that lexical frequency and SOA interacted on primary-task tone RTs such that tone responses preceding low-frequency naming responses were slower than those preceding high-frequency names. This further suggests that these subjects allocated more central processing capacity to the naming task on low-frequency trials. Comparison of results across the three experiments suggested that participants in Experiment 3 demonstrated less dual-task interference than predicted by either model.

While many speech errors can be generated at either a linguistic or motoric level of production, phonetically well formed sound-level serial order errors are generally assumed to result from disruption of phonologic encoding (PE) processes. An influential model of PE (Dell, 1986; Dell, Burger & Svec, 1997) predicts that speaking rate should affect the relative proportion of these serial order sound errors (anticipations, perseverations, exchanges). These predictions have been extended to, and have special relevance for persons with aphasia (PWA) because of the increased frequency with which speech errors occur and because their localization within the functional linguistic architecture may help in treatment management. Supporting evidence regarding the effect of speaking rate on phonological encoding has been provided by studies using young normal language (NL) speakers and computer simulations. Limited data exist at present for older NL users and no group data exist for PWA. The purpose of this study was to examine the effects of speech rate on the ratio of phonological sequencing errors (anticipation/exchange (AE), anticipation/perseveration) (AP)) and other error types (vocal reaction time and distortion) in non-brain-damaged individuals and in persons with aphasia who were without concomitant motor speech disorders. Sixteen NL users and 16 PWA performed a phonologically challenging (tongue twister) speech production task at their typical and two faster speaking rates. A significant effect of rate was obtained for the AP ratio but not for the other comparisons. Contrary to the predictions of the model, the AP ratio increased with faster speaking rates. There was also a significant effect of rate and group for the VRT measure. The results for the serial order error ratios did not provide support for the model derived predictions regarding the direction of change for error type proportions. However, the significant effect of rate for the AP ratio provided support that changes in speaking rate did affect phonological encoding. Additionally, the results suggest that the relationships among slow post-selection inhibition and normal residual activation functions postulated to create an increase in perseverations relative to anticipation serial order errors, needs to be reconsidered within the Dell, et al. (1997) model.

Language samples from 10 adults using an augmentative and alternative communication (AAC) system were analyzed for gender differences in performance measures. Participants (5 female; 5 male) were matched on device, access method, software, experience, age, and education. Each participant was asked to describe the "cookie theft" picture from the Boston Diagnostic Aphasia Examination (BDAE; Goodglass & Kaplan, 1983). The language samples were analyzed on the following two dependent variables: frequency of Semantic Compaction™ language representation use and average communication rate. A dependent samples t-test and the equivalent non-parametric matched-pair Wilcoxon tests were conduced on both variables. The effect size and the power were also calculated and used to support the following results. There was not a significant difference in the Semantic Compaction™ dependent variable, however there was a large effect size (d=1.11). A power analysis indicated a sample size consisting of 9 pairs (4 more males and 4 more females) would increase the power to 82%. Further research with an increased sample size of 9 pairs of participants may provide more support for the current finding in relation to the use of Semantic Compaction™. No significant difference was found between the average communication rates of the genders; however the presence of a female outlier was concluded to influence these results. A dependent samples t-test was conducted on the data excluding the pair containing the outlier. The results of the dependent samples t-test indicated a significant difference between the genders in the average communication rates. Overall, for both dependent variables, the majority of males were higher on the performance measures than their paired female participants. These observations support a need for future research addressing gender differences in individuals who use AAC. Clinical implications suggest that future research is needed to determine if intervention strategies need to accommodate for differences between genders in their ability to effectively use their device to communicate as fast as they are able. Caution needs to be used when interpreting and applying these results to this population due to the limitations (i.e., small sample size and lack of control of extraneous variable) of the current study.

Background: In 1990, Hough conducted a study investigating the role of theme organization on discourse comprehension in adults with right hemisphere brain damage (RHD). She reported that participants with RHD performed significantly worse when the theme of a narrative was delayed until the end, compared to when the theme was at the beginning. RHD participants also performed significantly worse on these tasks compared to participants with left hemisphere brain damage and normal controls. However, manipulations to delay the theme also resulted in narratives that lacked coherence and violated the rules of narrative structure. Aims: The current study examined if controlling for differences in coherence between original and delayed-theme narratives would eliminate discrepancies in comprehension in the two conditions. Methods & Procedures: Participants were 10 adults with unilateral RHD and five without brain damage. Participants listened to experimental and filler narratives. Experimental narratives consisted of original-theme narratives and delayed-theme narratives that were manipulated to delay the theme while maintaining story coherence. Filler narratives consisted of original-theme narratives and delayed-theme narratives that were not controlled for coherence. All narratives were followed by three yes/no questions pertaining to main ideas and details. Several ancillary tasks were also included to further classify participants and to analyze alternative explanations for performance. Outcomes & Results: Accuracy data revealed that as predicted, there was no significant difference in performance on experimental original-theme and delayed-theme narratives for the RHD group. There was a trend towards poorer comprehension of filler delayed-theme narratives compared to original-theme narratives. These results support the hypothesis that poor comprehension on delayed-theme narratives in Houghs study was a result of differences in coherence rather than theme organization. However, analysis of ancillary tasks revealed a significant correlation between estimated capacity for auditory working memory and performance on delayed-theme narratives. These results imply that even with coherence accounted for, delaying the theme of a narrative is more taxing on mental processing, thus decreasing comprehension in RHD participants with particularly low working memory capacity.

Background: The Computerized Revised Token Test (CRTT) was recently developed to improve the reliability and accessibility of the Revised Token Test (RTT). The CRTT was standardized using a touchscreen monitor; however, for various reasons, clinicians may need to use a mouse for test administration. In general, research suggests that younger individuals who are familiar with computers are more accurate and prefer to use a mouse. However, this may not be the case for brain-damaged persons with physical limitations. Thus, comparable performance when different input devices are used cannot be assumed. Aims: The purpose was to investigate similarities and differences between participants performance on subtest and overall scores obtained from touchscreen versus mouse on the CRTT. The study also examined the test-retest reliability of the CRTT when different input devices were used and user preference. Methods & Procedures: Forty young, healthy adults participated in this study. All participants were native English speakers, and had no history of a speech, language, or learning disability. Participants passed a language screening, the Story Retell Procedure (SRP) (McNeil, Doyle, Park, Fossett, & Brodsky, 2002). Each participant took the CRTT with both modes of access, a mouse and a touchscreen, with their non-dominant hand. One-half (20) of the participants were administered both versions of the CRTT a second time. Additionally, all participants answered a preference questionnaire. Outcomes & Results: The results revealed that touchscreen overall scores were significantly higher than mouse scores. There were also significant differences on six of the ten subtests. The test-retest reliability for both versions was equivalent and not significantly different. The results indicated a significant preference for the touchscreen. Conclusions: While the touchscreen access method produced significantly higher subtest and overall CRTT scores than the mouse access method, along with equivalent reliability performance in this young normal participant population, it is not clear that it should be used as the preferred access method. If successful algorithms for equating the previously established psychometric data and normative sample derived from the touchscreen access method can be generated, then there will be no need to re-standardize the test.

Intraoral pressure waveforms of a learned volitional nonspeech task were compared to that of a parallel speech task in order to drawl inferences regarding a possible shared sensorimotor control mechanism. Similarities between the dependent variables at question (the percents of the increase and decrease interval involved in the total duration and the slopes of the increase and decrease interval) may provide preliminary evidence of a shared generalized motor program. The nonspeech task (which was devised as part of a larger study by Shaiman et al., 2004; 2006) reflected the goal and complexity of speech, by the incorporation of intraoral pressure targets and practiced, co-articulated gestures. Six subjects participated in the study. Subjects practiced the nonspeech task over two sessions, totaling to over 600 repetitions of the task, with KR regarding accuracy of reaching the pressure target provided for 65% of trials. Nonspeech retention data was gathered at the end of both practicing sessions. Parallel speech task data were then taken. The measures of the dependent variables were calculated by the division of the pressure waveform into three distinct intervals: the increase, plateau, and decrease interval. These intervals were automatically detected using a pressure waveform analysis program, which used the first derivative of the pressure signal to mark parts of the waveform. The means for the nonspeech retention data and the speech data were taken for each dependent variable. Univariate analysis revealed no significant difference between the speech and nonspeech condition for any of the four dependent variables (p<0.05). The finding of no significant difference for any of the four dependent variables may provide preliminary evidence for a shared generalized motor program for speech and nonspeech gestures. However, future research with data from additional subjects would assess this finding. Also, descriptive observations of waveform shape during the plateau interval indicate the need for further analysis of additional waveform measurements not analyzed in the current study, and also the need to control rate and precision of production in the future.

This study investigated the influences of prior discourse context and cumulative syntactic priming on readers predictions for verb subcategorizations. An additional aim was to determine whether cumulative syntactic priming has the same degree of influence following coherent discourse contexts as when following series of unrelated sentences. Participants (N = 40) read sentences using a self-paced, sentence-by-sentence procedure. Half of these sentences comprised a coherent discourse context intended to increase the expectation for a sentential complement (S) completion. The other half consisted of scrambled sentences. The trials in both conditions varied according to the proportion of verbs that resolved to an S (either 6S or 2S). Following each condition, participants read temporarily ambiguous sentences that resolved to an S. Reading times across the disambiguating and postdisambiguating regions were measured. No significant main effects or interactions were found for either region. However, the lack of significant findings for these analyses may have been due to low power. In a follow-up analysis, data from each gender were analyzed separately. For the data contributed by males, there were no significant findings. For the data contributed by females, the effect of coherence was significant (by participants but not by items) across the postdisambiguating region, and there was a marginally significant interaction (p =.05) between coherence and frequency across this region suggesting that discourse-level information may differentially influence the local sentence processing of female and male participant.

Aspergers Syndrome is an autism spectrum disorder in which patients generally exhibit average or above-average intelligence and linguistic ability, but considerable difficulty building social relationships. Its incidence has increased greatly since the 1990s. Also since the 1990s, personal computers have come into wide use as tools not only for work, but also for social communication (Baron, 1998). Computer-mediated communication (CMC) technologies, such as instant messaging (IM), have become very popular with the general public in this time frame. In order to determine whether IM will be a useful social tool for people with Aspergers, in this study, a corpus of IM conversations from volunteers both with and without Aspergers, conversing with their peers was collected and analyzed to identify patterns of use of standard English lexemes and characteristic IM lexemes. A lexeme is a minimal unit of semantic meaning, which usually corresponds roughly to a word. Emoticons (such as the smiley :-)), acronyms (such as lol), characteristic abbreviations (like probly for probably), and typed representations of non-uttered events (like *hugs you* or I hug you) are examples of characteristic IM lexemes. It was hypothesized that people with Aspergers would use significantly more standard English lexemes, and fewer lexemes that are unique to IM, per sent message than would be used by their neurotypical peers. Additionally, it was hypothesized that people with Aspergers would use fewer sent messages to complete an apparent thought than their neurotypical peers. Participants were recruited in already-acquainted pairs through a peer mentoring program for college students with autism and developmental disabilities. Conversational partners were matched based on their acquaintance with each other. Each Aspergers and neurotypical participant held one or two fifteen- to twenty-minute conversations using AOL Instant Messenger®. The conversations were recorded, transcribed and analyzed to compare the use of characteristic IM lexemes and structural aspects of each conversation. The lexemes were counted to determine their frequency in each whole conversation. The number of sent messages in each conversation, the number of sent messages per conversational turn, and the number of lexemes (both IM and standard English) per sent message were counted and compared. Results showed no significant differences between groups on any of the variables, or for the behavior of the control group between conditions, suggesting that people with Aspergers are likely to communicate in this medium in ways that are very similar to their neurotypical peers. Implications of this pilot data and potential directions for future research are discussed.

In normal hearing adults, acoustic context influences perception of speech in a spectrally contrastive manner. The aim of this study is to investigate whether typically developing children, aged 5 through 6 and 7 through 9 years, demonstrate phonetic context effects in a manner and extent similar to adults. By comparing the childrens responses to those of adults aged 18 to 28 years, it will be determined if the childrens use of phonetic context is limited by maturity. A total of 61 individuals participated in this study: 45 adults and 16 children. The participants listened to isolated vowels along the /ʌ/ to /ɛ/ acoustic continuum and indicated if they heard /ʌ/ or /ɛ/. They then listened to the same vowel continuum within a /d/-Vowel-/d/ syllable context and in a /b/-Vowel-/b/ syllable context. With each syllable presentation the participants identified the vowel sound that they heard. The participants responses were assessed for shifts in the vowel perceptual boundaries relative to consonant context. The results indicated that the older children and the adults exhibited a context effect, but as a group, the younger children did not exhibit the effect. However, some of the younger children presented an effect that was consistent with the Older Children and Adults.