Morphonotactic and phonotactic processing in German-speaking adults

Based on the theoretical framework of Dressler and Dziubalska-Kołaczyk (2006a,b), the Strong Morphonotactic Hypothesis will be tested. It assumes that phonotactics helps in decomposition of words into morphemes: if a certain sequence occurs only or only by default over a morpheme boundary and is thus a prototypical morphonotactic sequence, it should be processed faster and more accurately than a purely phonotactic sequence. Studies on typical and atypical first language acquisition in English, Lithuanian and Polish have shown significant differences between the acquisition of morphonotactic and phonotactic consonant clusters: Morphonotactic clusters are acquired earlier and faster by typically developing children, but are more problematic for children with Specific Language Impairment. However, results on acquisition are less clear for German. The focus of this contribution is whether and how German-speaking adults differentiate between morphonotactic and phonotactic consonant clusters and vowel-consonant sequences in visual word recognition. It investigates whether sub-lexical letter sequences are found faster when the target sequence is separated from the word stem by a morphological boundary than when it is a part of a morphological root. An additional factor that is addressed concerns the position of the target cluster in the word. Due to the bathtub effect, sequences in peripheral positions in a word are more salient and thus facilitate processing more than word-internal positions. Moreover, for adults the primacy effect most favors word-initial position (whereas for young children the recency effect most favors word- final position). Our study discusses effects of phonotactic vs. morphonotactic cluster status and of position within the word.

Sleep and information processing in individuals who have sustained a traumatic brain injury

Individuals who have sustained a traumatic brain injury (TBI) often complain of t roubl e sleeping and daytime fatigue but little is known about the neurophysiological underpinnings of the s e sleep difficulties. The fragile sleep of thos e with a TBI was predicted to be characterized by impairments in gating, hyperarousal and a breakdown in sleep homeostatic mechanisms. To test these hypotheses, 20 individuals with a TBI (18- 64 years old, 10 men) and 20 age-matched controls (18-61 years old, 9 men) took part in a comprehensive investigation of their sleep. While TBI participants were not recruited based on sleep complaint, the fmal sample was comprised of individuals with a variety of sleep complaints, across a range of injury severities. Rigorous screening procedures were used to reduce potential confounds (e.g., medication). Sleep and waking data were recorded with a 20-channel montage on three consecutive nights. Results showed dysregulation in sleep/wake mechanisms. The sleep of individuals with a TBI was less efficient than that of controls, as measured by sleep architecture variables. There was a clear breakdown in both spontaneous and evoked K-complexes in those with a TBI. Greater injury severities were associated with reductions in spindle density, though sleep spindles in slow wave sleep were longer for individuals with TBI than controls. Quantitative EEG revealed an impairment in sleep homeostatic mechanisms during sleep in the TBI group. As well, results showed the presence of hyper arousal based on quantitative EEG during sleep. In wakefulness, quantitative EEG showed a clear dissociation in arousal level between TBls with complaints of insomnia and TBls with daytime fatigue. In addition, ERPs indicated that the experience of hyper arousal in persons with a TBI was supported by neural evidence, particularly in wakefulness and Stage 2 sleep, and especially for those with insomnia symptoms. ERPs during sleep suggested that individuals with a TBI experienced impairments in information processing and sensory gating. Whereas neuropsychological testing and subjective data confirmed predicted deficits in the waking function of those with a TBI, particularly for those with more severe injuries, there were few group differences on laboratory computer-based tasks. Finally, the use of correlation analyses confirmed distinct sleep-wake relationships for each group. In sum, the mechanisms contributing to sleep disruption in TBI are particular to this condition, and unique neurobiological mechanisms predict the experience of insomnia versus daytime fatigue following a TBI. An understanding of how sleep becomes disrupted after a TBI is important to directing future research and neurorehabilitation.

Empathy and Emotion Processing in Mild Head Injury and Sub-clinical Psychopathy

The current study sought to investigate the nature of empathic responding and emotion processing in persons who have experienced Mild Head Injury (MHI) and how this relationship between empathetic responding and head injury status may differ in those with higher psychopathic characteristics (i.e., subclinical psychopathy). One-hundred university students (36% reporting having a previous MHI) completed an Emotional Processing Task (EPT) using images of neutral and negative valence (IAPS, 2008) designed to evoke empathy; physiological responses were recorded. Additionally, participants completed measures of cognitive competence and various individual differences (empathy - QCAE; Reniers, 2011; Psychopathy - SRP-III, Williams, Paulhus & Hare, 2007) and demographics questionnaires. MHI was found to be associated with lower affective empathy and physiological reactivity (pulse rate) while viewing images irrespective of valence, reflecting a pattern of generalized underarousal. The empathic deficits observed correlated with the individual’s severity of injury such that the greater number of injury characteristics and symptoms endorsed by a subject, the more dampened the affective and cognitive empathy reactions to stimuli and the lower his/her physiological reactivity. Importantly, psychopathy interacted with head injury status such that the effects of psychopathy were significant only for individuals indicating a MHI. This group, i.e., MHI subjects who scored higher on psychopathy, displayed the greatest compromise in empathic responding. Interestingly, the Callous Affect component of psychopathy was found to account for the empathic and emotion processing deficits observed for individuals who report a MHI; in contrast, the Interpersonal Manipulation component emerged as a better predictor of empathic and emotion deficits observed in the No MHI group. These different patterns may indicate the involvement of different underlying processes in the manifestation of empathic deficits associated with head injury or subclinical psychopathy. It also highlights the importance of assessing for prior head injury in populations with higher psychopathic characteristics due to the possible combined/enhanced influences. The results of this study have important social implications for persons who have experienced a concussion or limited neural trauma since even subtle injury to the head may be sufficient to produce dampened emotion processing, thereby impacting one’s social interactions and engagement (i.e., at risk for social isolation or altered interpersonal success). Individuals who experience MHI in conjunction with certain personality profiles (e.g., higher psychopathic characteristics) may be particularly at risk for being less capable of empathic compassion and socially-acceptable pragmatics and, as a result, may not be responsive to another person’s emotional well-being.

The effects of manipulated augmented sensory feedback on error detection when using a touch screen

The purpose of the present study was to determine which augmented sensory modality would best develop subjective error-detection capabilities of learners performing a spatial-temporal task when using a touch screen monitor. Participants were required to learn a 5-digit key-pressing task in a goal time of 2550 ms over 100 acquisition trials on a touch screen. Participants were randomized into 1 of 4 groups: 1) visual-feedback (colour change of button when selected), 2) auditory-feedback (click sound when button was selected), 3) visual-auditory feedback (both colour change and click sound when button was selected), and 4) no-feedback (no colour change or click sound when button was selected). Following each trial, participants were required to provide a subjective estimate regarding their performance time in relation to the actual time it took for them complete the 5-digit sequence. A no-KR retention test was conducted approximately 24-hours after the last completed acquisition trial. Results showed that practicing a timing task on a touch screen augmented with both visual and auditory information may have differentially impacted motor skill acquisition such that removal of one or both sources of augmented feedback did not result in a severe detriment to timing performance or error detection capabilities of the learner. The present study reflects the importance of multimodal augmented feedback conditions to maximize cognitive abilities for developing a stronger motor memory for subjective error-detection and correction capabilities.

Early Development of Auditory-Verbal and Visual-Spatial Short-Term Memory: Age and Sex Effects

Memory is a multi-component cognitive ability to retain and retrieve information presented in different modalities. Research on memory development has shown that the memory capacity and the processes improve gradually from early childhood to adolescence. Findings related to the sex-differences in memory abilities in early childhood have been inconsistent. Although previous research has demonstrated the effects of the modality of stimulus presentation (auditory versus verbal) and the type of material to be remembered (visual/spatial versus auditory/verbal) on the memory processes and memory organization, the recent research with children is rather limited. The present study is a secondary analysis of data, originally collected from 530 typically developing Turkish children and adolescents. The purpose of the present study was to examine the age-related developments and sex differences in auditory-verbal and visual-spatial short-term memory (STM) in 177 typically developing male and female children, 5 to 8 years of age. Dot-Locations and Word-Lists from the Children's Memory Scale were used to measure visual-spatial and auditory-verbal STM performances, respectively. The findings of the present study suggest age-related differences in both visual-spatial and auditory-verbal STM. Sex-differences were observed only in one visual-spatial STM subtest performance. Modality comparisons revealed age- and task-related differences between auditory-verbal and visual-spatial STM performances. There were no sex-related effects in terms of modality specific performances. Overall, the results of this study provide evidence of STM development in early childhood, and these effects were mostly independent of sex and the modality of the task.

Electrophysiological and behavioural correlates of facial identity and expression perception deficits following a closed head injury /

A large variety of social signals, such as facial expression and body language, are conveyed in everyday interactions and an accurate perception and interpretation of these social cues is necessary in order for reciprocal social interactions to take place successfully and efficiently. The present study was conducted to determine whether impairments in social functioning that are commonly observed following a closed head injury, could at least be partially attributable to disruption in the ability to appreciate social cues. More specifically, an attempt was made to determine whether face processing deficits following a closed head injury (CHI) coincide with changes in electrophysiological responsivity to the presentation of facial stimuli. A number of event-related potentials (ERPs) that have been linked specifically to various aspects of visual processing were examined. These included the N170, an index of structural encoding ability, the N400, an index of the ability to detect differences in serially presented stimuli, and the Late Positivity (LP), an index of the sensitivity to affective content in visually-presented stimuli. Electrophysiological responses were recorded while participants with and without a closed head injury were presented with pairs of faces delivered in a rapid sequence and asked to compare them on the basis of whether they matched with respect to identity or emotion. Other behavioural measures of identity and emotion recognition were also employed, along with a small battery of standard neuropsychological tests used to determine general levels of cognitive impairment. Participants in the CHI group were impaired in a number of cognitive domains that are commonly affected following a brain injury. These impairments included reduced efficiency in various aspects of encoding verbal information into memory, general slower rate of information processing, decreased sensitivity to smell, and greater difficulty in the regulation of emotion and a limited awareness of this impairment. Impairments in face and emotion processing were clearly evident in the CHI group. However, despite these impairments in face processing, there were no significant differences between groups in the electrophysiological components examined. The only exception was a trend indicating delayed N170 peak latencies in the CHI group (p = .09), which may reflect inefficient structural encoding processes. In addition, group differences were noted in the region of the N100, thought to reflect very early selective attention. It is possible, then, that facial expression and identity processing deficits following CHI are secondary to (or exacerbated by) an underlying disruption of very early attentional processes. Alternately the difficulty may arise in the later cognitive stages involved in the interpretation of the relevant visual information. However, the present data do not allow these alternatives to be distinguished. Nonetheless, it was clearly evident that individuals with CHI are more likely than controls to make face processing errors, particularly for the more difficult to discriminate negative emotions. Those working with individuals who have sustained a head injury should be alerted to this potential source of social monitoring difficulties which is often observed as part of the sequelae following a CHI.

Investigative links between cognitive function and moderate-to-vigorous physical activity in elementary physical education

Research has noted both physical and psychosocial benefits when children participate in regular physical activity. Recent studies are indicating that there may also be academic benefits and that students may be more efficient learners with participation in physical activity. This study investigated the influence of acute moderate-to-vigorous physical activity on four cognitive functions: planning, attention, simultaneous processing, and successive processing. Three classes (59 students) were each tested twice using a balanced design (intervention, balance, and control groups). It was found that the intervention group had a large increase in planning abiHty (ES = 1.67) when compared to the balance (ES = .80) and control (ES = -.89) groups. On the three remaining cognitive functions, the intervention group showed effect sizes similar to that of the balance and control groups. These results indicate that improved planning after physical activity may playa role in improving student performance.

Completing the picture: the effects of video game practice on verbal and performance I.Q. scores in high functioning children

The strength and nature of the video game practice effect on tests of visual and perceptual skills were examined using high functioning Grades Four and Five students who had been tested with the WISC-R .for the purpose of gifted identification and placement. The control group, who did not own and .play video games on a sustained basis, and the experimental group, who did own a video game system and had some mastery of video games, including the -Nintendo game, "Tetris", were each composed of 18 juniorg:r;-ade students and were chosen from pre-existing conditions. The experimental group corresponded to the control group in terms of age, sex, and community. Data on the Verbal and Performance I.Q. Scores were· collected for both groups and the author was interested in the difference between the Verbal and Performance Scores within each group, anticipating a P > V outcome for the experimental group. The results showed a significant P > V difference in the experimental, video game playing group, as expected, but no significant difference between the Performance $cores of the control and experimental groups. The results, thus, indicated lower Verbal I.Q. Scores in the experimental group relat'ive to 'the control group.' The study conclu~ed that information about a sUbject's video game experience and "learhing style pref~rence is important for a clear interpretation of the Verbal and Performance I.Q. Scores of the WISC-R. Although the time spent on video game play may, 'indeed, increase P~rformance Scores relative to Verbal Scores for an individual, the possibilities exist that the time borrowed and spent away from language based activities may retard verbal growth and/or that the cognitive style associated with some Performance I.Q.subtests may have a negative effect on the approach to the tasks on the Verbal I.Q. Scale. The study also discussed the possibility that exposure to ,the video game experience, in pre-puberty, can provide spatial instruction which will result in improved spatial skills. strong spatial skills have been linked to improved performance and preference in mathematics, science, and engineering and it was suggested that appropriate video game play might be a way to involve girls more in the fields of mathematics and science.

Creativity and the working artist/teacher : the relationships

The purpose of this qualitative study was to understand the relationships between creativity and the working artist/teacher employed by an art college. The topic emerged from my job as an instructor at The Ontario College of Art which was used as the primary data resource and provided the highest caliber of professionals to chose from. Existent data were used to facilitate the study generated by the research of Cawelti, Rappaport, and Wood (1992). The data were generated by a group of 5 faculty members from The University of Northern Iowa, recognized for their expertise in the arts (a painter, a poet, a sculptor, a novelist, and a photographer). They were asked to respond to the following statement: "In as much detail as you like, list the things that you did, thought, or felt the last time you created an artistic product. II Cawelti, Rappaport, and Wood (1992) produced three models of the creative process, each building on the previous, with the resultant third,being in my opinion, an excellent illustration (text/visual) of the creative process. Model three (Appendix D) presented a "multi-dimensional view of the creative process: time, space, observatility, and consciousnessll (p. 90). Model three utilized a visual mapping device along the bottom of the page linked to text segments above. Both the visual and the text were interrelated so that they harmonized into a comprehensive "picture." The parti'cipants of this qualitative study were asked to consider model three from their professional perspective as artist/teachers. The interpretive sciences directed the methodology. The hermeneutic circle of continuous reflection from the whole to the part and back to the whole was an important aspect of the data analyses. Four members of the Foundation Department at The Ontario College of Art were the key participants. A series of conversational interviews was the primary source of data collection, this was augmented by observation, fie,ldnotes, and follow up telephone interviews. Transcripts of interviews were returned to participants for reflection and the telephone was used to discuss any additional -points raised. Analysis consisted of coding and organizing data according to emerging themes. These themes formed the basis for the narrative stories. The text of the narrative stories were given back to each participant for further comment. Revisions were made until both the researcher and the participants felt that the stories reflected reality. The resultant whole was critiqued from the researcher's perspective. The significance of this study was discussed as it pertains to the working artist/teacher and areas in need of further study are pointed out.

Development and characterization of concentric capillary nebulizer used in inductively coupled plasma analysis /

A simple, low-cost concentric capillary nebulizer (CCN) was developed and evaluated for ICP spectrometry. The CCN could be operated at sample uptake rates of 0.050-1.00 ml min'^ and under oscillating and non-oscillating conditions. Aerosol characteristics for the CCN were studied using a laser Fraunhofter diffraction analyzer. Solvent transport efficiencies and transport rates, detection limits, and short- and long-term stabilities were evaluated for the CCN with a modified cyclonic spray chamber at different sample uptake rates. The Mg II (280.2nm)/l\/lg 1(285.2nm) ratio was used for matrix effect studies. Results were compared to those with conventional nebulizers, a cross-flow nebulizer with a Scott-type spray chamber, a GemCone nebulizer with a cyclonic spray chamber, and a Meinhard TR-30-K3 concentric nebulizer with a cyclonic spray chamber. Transport efficiencies of up to 57% were obtained for the CCN. For the elements tested, short- and long-term precisions and detection limits obtained with the CCN at 0.050-0.500 ml min'^ are similar to, or better than, those obtained on the same instrument using the conventional nebulizers (at 1.0 ml min'^). The depressive and enhancement effects of easily ionizable element Na, sulfuric acid, and dodecylamine surfactant on analyte signals with the CCN are similar to, or better than, those obtained with the conventional nebulizers. However, capillary clog was observed when the sample solution with high dissolved solids was nebulized for more than 40 min. The effects of data acquisition and data processing on detection limits were studied using inductively coupled plasma-atomic emission spectrometry. The study examined the effects of different detection limit approaches, the effects of data integration modes, the effects of regression modes, the effects of the standard concentration range and the number of standards, the effects of sample uptake rate, and the effect of Integration time. All the experiments followed the same protocols. Three detection limit approaches were examined, lUPAC method, the residual standard deviation (RSD), and the signal-to-background ratio and relative standard deviation of the background (SBR-RSDB). The study demonstrated that the different approaches, the integration modes, the regression methods, and the sample uptake rates can have an effect on detection limits. The study also showed that the different approaches give different detection limits and some methods (for example, RSD) are susceptible to the quality of calibration curves. Multicomponents spectral fitting (MSF) gave the best results among these three integration modes, peak height, peak area, and MSF. Weighted least squares method showed the ability to obtain better quality calibration curves. Although an effect of the number of standards on detection limits was not observed, multiple standards are recommended because they provide more reliable calibration curves. An increase of sample uptake rate and integration time could improve detection limits. However, an improvement with increased integration time on detection limits was not observed because the auto integration mode was used.

Quadtree representation and compression of spatial data

Spatial data representation and compression has become a focus issue in computer graphics and image processing applications. Quadtrees, as one of hierarchical data structures, basing on the principle of recursive decomposition of space, always offer a compact and efficient representation of an image. For a given image, the choice of quadtree root node plays an important role in its quadtree representation and final data compression. The goal of this thesis is to present a heuristic algorithm for finding a root node of a region quadtree, which is able to reduce the number of leaf nodes when compared with the standard quadtree decomposition. The empirical results indicate that, this proposed algorithm has quadtree representation and data compression improvement when in comparison with the traditional method.

Frontal Lobe Function and Performance Monitoring following Total Sleep Deprivation

Imaging studies have shown reduced frontal lobe resources following total sleep deprivation (TSD). The anterior cingulate cortex (ACC) in the frontal region plays a role in performance monitoring and cognitive control; both error detection and response inhibition are impaired following sleep loss. Event-related potentials (ERPs) are an electrophysiological tool used to index the brain's response to stimuli and information processing. In the Flanker task, the error-related negativity (ERN) and error positivity (Pe) ERPs are elicited after erroneous button presses. In a Go/NoGo task, NoGo-N2 and NoGo-P3 ERPs are elicited during high conflict stimulus processing. Research investigating the impact of sleep loss on ERPs during performance monitoring is equivocal, possibly due to task differences, sample size differences and varying degrees of sleep loss. Based on the effects of sleep loss on frontal function and prior research, it was expected that the sleep deprivation group would have lower accuracy, slower reaction time and impaired remediation on performance monitoring tasks, along with attenuated and delayed stimulus- and response-locked ERPs. In the current study, 49 young adults (24 male) were screened to be healthy good sleepers and then randomly assigned to a sleep deprived (n = 24) or rested control (n = 25) group. Participants slept in the laboratory on a baseline night, followed by a second night of sleep or wake. Flanker and Go/NoGo tasks were administered in a battery at 1O:30am (i.e., 27 hours awake for the sleep deprivation group) to measure performance monitoring. On the Flanker task, the sleep deprivation group was significantly slower than controls (p's <.05), but groups did not differ on accuracy. No group differences were observed in post-error slowing, but a trend was observed for less remedial accuracy in the sleep deprived group compared to controls (p = .09), suggesting impairment in the ability to take remedial action following TSD. Delayed P300s were observed in the sleep deprived group on congruent and incongruent Flanker trials combined (p = .001). On the Go/NoGo task, the hit rate (i.e., Go accuracy) was significantly lower in the sleep deprived group compared to controls (p <.001), but no differences were found on false alarm rates (i.e., NoGo Accuracy). For the sleep deprived group, the Go-P3 was significantly smaller (p = .045) and there was a trend for a smaller NoGo-N2 compared to controls (p = .08). The ERN amplitude was reduced in the TSD group compared to controls in both the Flanker and Go/NoGo tasks. Error rate was significantly correlated with the amplitude of response-locked ERNs in control (r = -.55, p=.005) and sleep deprived groups (r = -.46, p = .021); error rate was also correlated with Pe amplitude in controls (r = .46, p=.022) and a trend was found in the sleep deprived participants (r = .39, p =. 052). An exploratory analysis showed significantly larger Pe mean amplitudes (p = .025) in the sleep deprived group compared to controls for participants who made more than 40+ errors on the Flanker task. Altered stimulus processing as indexed by delayed P3 latency during the Flanker task and smaller amplitude Go-P3s during the Go/NoGo task indicate impairment in stimulus evaluation and / or context updating during frontal lobe tasks. ERN and NoGoN2 reductions in the sleep deprived group confirm impairments in the monitoring system. These data add to a body of evidence showing that the frontal brain region is particularly vulnerable to sleep loss. Understanding the neural basis of these deficits in performance monitoring abilities is particularly important for our increasingly sleep deprived society and for safety and productivity in situations like driving and sustained operations.

Interpreting Quantifier Scope Ambiguity: Evidence of Heuristic First, Algorithmic Second Processing

The present work suggests that sentence processing requires both heuristic and algorithmic processing streams, where the heuristic processing strategy precedes the algorithmic phase. This conclusion is based on three self-paced reading experiments in which the processing of two-sentence discourses was investigated, where context sentences exhibited quantifier scope ambiguity. Experiment 1 demonstrates that such sentences are processed in a shallow manner. Experiment 2 uses the same stimuli as Experiment 1 but adds questions to ensure deeper processing. Results indicate that reading times are consistent with a lexical-pragmatic interpretation of number associated with context sentences, but responses to questions are consistent with the algorithmic computation of quantifier scope. Experiment 3 shows the same pattern of results as Experiment 2, despite using stimuli with different lexicalpragmatic biases. These effects suggest that language processing can be superficial, and that deeper processing, which is sensitive to structure, only occurs if required. Implications for recent studies of quantifier scope ambiguity are discussed.