The Reward Positivity (RewP) is a neurophysiological marker of reward sensitivity that has been found to be impacted in depression. However, there have been some mixed findings regarding the relationship between the RewP and depression, suggesting there are other factors which impact this relationship. The current study investigated how the demographic factors of sex, age, and socio-economic status might moderate the RewP-depression relationship, and examined if these effects generalize across three different inventories for symptoms of depression. 194 people were recruited by random digit dialing (55.2% male, mean age = 51.34 years, mean monthly income = $6625.95). They completed the SCID, HAM-D, and IDAS measures of depression, and an EEG session in which they did a random guessing task to elicit the RewP. We found that there was a trend-level interaction of a moderate effect size between symptoms of depression, age, and sex in predicting RewP amplitude. Further exploration of this interaction revealed that for females, there was an interactive effect between age and symptoms of depression, such that for younger females, increased symptoms of depression were associated with a blunted RewP, and lower symptoms of depression were associated with an enhanced RewP. These effects were specific to the SCID, but did not generalize to the HAM-D or IDAS. Moreover, there was no interactive effects between age and depression symptoms for males, nor did SES interact with depression and other demographic factors in predicting the RewP. This study provides evidence that demographic factors can impact the strength and nature of the relationships between the RewP and depression, and that future researchers might wish to over-sample younger females when investigating other moderating factors of the RewP in order to increase power.

The purpose of this thesis is to study how to overcome difficulties one typically encounters when solving non-negative inverse problems by standard Krylov subspace methods. We first give a theoretical background to the non-negative inverse problems. Then we concentrate on selected modifications of Krylov subspace methods known to improve the solution significantly. We describe their properties, provide their implementation and propose an improvement for one of them. After that, numerical experiments are presented giving a comparison of the methods and analyzing the influence of the present parameters on the behavior of the solvers. It is clearly demonstrated, that the methods imposing nonnegativity perform better than the unconstrained methods. Moreover, our improvement leads in some cases to a certain reduction of the number of iterations and consequently to savings of the computational time while preserving a good quality of the approximation.

The present study investigates the use of impoliteness in American presidential debates, analyzing whether the use of impoliteness strategies has increased, whether this varies depending on the candidate’s status as an incumbent or a challenger and if Donald Trump is an outlier when compared to his peers. To conduct this study, a total of 12 debates from the last 6 elections (2000-2020) were analyzed. The analysis used Culpeper’s (1996) framework as its base, specifically looking at the frequency and variability in the usage of face-attacks along with a set of output/micro-strategies from Garcia-Pastor (2008) typically used in the primary presidential debates as well as instances of overlaps and interruptions. The results showed, based on nearly all of the measured variables, that there was a significant increase in the 2016 and the subsequent 2020 debates when compared to the preceding ones. Furthermore, there were clear differences found in the incumbent presidents’ strategy choice and frequency when compared to their opponents as the former would typically be more defensive, using less impoliteness. Trump strayed from this established pattern by being vastly more aggressive than his incumbent predecessors. He additionally scored the highest in nearly all of the measured variables, this, in conjunction with the noticeable difference in his use of overlapping speech, as well as direct face-attacks, leads to the conclusion that he is an outlier in his use of impoliteness and a likely catalyst for the increase seen in the 2016-2020 debates.

Spoken language is produced with a great deal of variability with which listeners must be able to cope. One source of variation is coarticulation, which is due to articulatory planning and transitions between segments. Recently, the temporal features of coarticulation were investigated during a picture/spoken-word matching task by using spliced stimuli carrying either congruent or incongruent subphonemic cues at the CV juncture (Archibald & Joanisse, 2011). ERPs were recorded with attention paid to the phonological mapping negativity (PMN) (Connolly & Phillips, 1994; Newman & Connolly, 2004) – a prelexical response sensitive to violations of phonological expectations. Results found that the PMN varied in response to coarticulation violations and concluded that phonetic features in spoken words influence prelexical processing during word recognition. Using a written-/spoken-word paradigm, Arbour, 2012 controlled phonological shape by using onsets that were either fricatives or stops, hypothesizing that coarticulatory information would be differentially processed due to their temporal differences. Findings supported the PMN’s sensitivity to coarticulation but also showed that temporal and physical differences between onsets modulated the effect. These results raise the question of whether acoustic distance between vowels will modulate prelexical processing of speech as reflected by the PMN amplitude: the focus of the current study. Words were organized into minimal sets such that all onset/coda combinations appeared with each vowel provided that English words resulted. Vowels were one of /i, u, æ, ɑ/, maximizing acoustic distance (height and backness). Data from 20 subjects indicate that the PMN is sensitive to the degree of difference between the original and post-splice vowels. When the number of distinctive features changing is greater, the result is an earlier, more robust PMN. This suggests that the rate of speech recognition is not static but dynamic, and is dependent on likeness of subphonemic features. / Thesis / Master of Science (MSc)

Previous studies have found that behavioral and P300 responses to speech are influenced by linguistic cues in the stimuli. Research has found conflicting data regarding the influence of phonemic characteristics of stimuli in the mismatch negativity (MMN) response. The current investigation is a replication of the study designed by Tampas et al. (2005), which studied the effects of linguistic cues on the MMN response. This current study was designed to determine whether the MMN response is influenced by phonetic or purely acoustic stimuli, and to expand our knowledge of the scalp distribution of processing responses to within- and across-category speech and nonspeech stimuli. The stimuli used in this study consisted of within-category synthetic speech stimuli and corresponding nonspeech frequency glides. Participants consisted of 21 (11 male and 10 female) adults between the ages of 18 and 30 years. A same/different discrimination task was administered to all participants. Data from behavioral responses and event-related potentials (MMN and P300) were recorded. Results provided additional evidence that the MMN response is influenced by linguistic information. MMN responses elicited by the nonspeech contrasts had more negative peak amplitudes and longer latencies than MMN responses elicited by speech contrasts. Brain maps of t scores for speech vs. nonspeech contrasts showed significant differences in areas of cognitive processing for all contrast pairs over the left hemisphere near the temporal and parietal areas. The present investigation confirms that there are significant differences in the cortical processing of speech sounds vs. nonspeech sounds.

The mismatch negativity (MMN) response, a passively-elicited component of the auditory event-related potential (ERP), reflects preattentive identification of infrequent changes in acoustic stimuli. In the current study, the MMN response was examined closely to determine what extent natural speech sounds evoke the MMN. It was hypothesized that a significant MMN response results during the presentation of deviant stimuli from which spectral energy within formant bands critical to vowel identification has been removed. Localizations of dipoles within the cortex were hypothesized to yield information pertaining to the processing of formant-specific linguistic information. A same/different discrimination task was administered to 20 adult participants (10 female and 10 male) between the ages of 18 and 26 years. Data from behavioral responses and ERPs were recorded. Results demonstrated that the MMN may be evoked by natural speech sounds. Grand-averaged brain maps of ERPs created for all stimulus pairs showed a large preattentive negativity. Additionally, amplitudes of the MMN were greatest for pairs of auditory stimuli in which spectral energy not corresponding to formant frequencies was digitally eliminated. Dipoles reconstructed from temporal ERP data were located in cortical areas known to support language and auditory processing. Significant differences between stimulus type and reaction time were also noted. The current investigation confirms that the MMN response is evoked by natural speech sounds and provides evidence for a theory of preattentive formant-based processing of speech sounds.

Moderate-to-severe traumatic brain injury (M/S TBI) can affect an individual's ability to perform daily tasks. For example, individuals with M/S TBI are more likely to commit errors on tasks such as making a meal or wrapping a present. The neural processes involved in such errors are poorly understood. Studies suggest that neurophysiologic markers of cognitive control and error processing may be helpful in gaining additional insight into errors on naturalistic action tasks. Unfortunately, previous experimental methods left a methodological gap which limited the use of neurophysiological markers in the study of naturalistic action. Several recent studies in healthy adults have suggested one method of bridging the gap by having individuals observe another person's errors. The current study was the first study to employ the method in a TBI population as a possible means of gaining additional insight into the detrimental effects of M/S TBI on the performance of naturalistic actions. In order to gain additional insight into the effects of M/S TBI on the completion of naturalistic tasks I used two neurophysiologic markers of cognitive control and error processing. They were the observer error related negativity (oERN) and the P300 components of the scalp-recorded event-related potential (ERP). I hypothesized that individuals with M/S TBI would demonstrate error-specific changes in the two oERN and P300 that would correlate with self-reported difficulties in daily functioning. The study consisted of two experiments. One compared 15 individuals with M/S TBI to 17 demographically similar healthy controls on an error related naturalistic action based picture task. The second compared an overlapping sample of 16 individuals with M/S TBI to 16 demographically similar controls as they watched a confederate complete the Erikson flanker task, a commonly used task in the study of electrophysiological markers. Accuracy (error vs. correct) and group (M/S TBI vs. control) effects were analyzed using 2 x 2 repeated measures ANOVAs on ERP amplitude and latency. Pearson product-moment correlations were calculated to evaluate the relationship between the P300 and oERN and measures of self-reported executive functioning (Frontal Systems Behavior Scale, FrSBe) and neuropsychological measures. Findings supported a difference between the control and M/S TBI groups in how errors were processed during the naturalistic actions based picture task. There was an interaction between group membership and response accuracy (error vs. correct) on P300 amplitude and P300 latency. Controls demonstrated reduced P300 amplitude and latency on error trials compared to correct trials. Individuals with M/S TBI did not demonstrate a significant difference between correct trials and error trials on P300 amplitude and latency. The amplitude and latency of the P300 were correlated with self-reported functional difficulties in individuals with M/S TBI but not control participants. A Fisher's r -- z analysis indicated that correlations differed significantly between groups; however, an outlier was identified in the correlational data. Removal of the outlier data led to non-significant results in the Fisher's r -- z analysis. Taken together, results of the picture task supplied evidence that for individuals with M/S TBI differences in neurophysiologic markers between groups could be explained by reduced adaptation to complexity or by possible deficits in a secondary error processing pathway for complex errors. Future research could focus on better defining the functional relationship between P300 amplitude and latency and increased errors in naturalistic actions following M/S TBI. Observation of the flanker task did not elicit oERN waveforms from either healthy controls or from individuals with M/S TBI. The results could be due to problems with the current task, but also raised some concerns about previous studies using the flanker task which employed a slightly different methodology requiring participants to count errors. The current study did not require participant to count errors. As a whole, the study supplied partial support for using electrophysiological markers of error processing to gain additional understanding increased errors in the performance of naturalistic actions following M/S TBI.

The human brain is highly responsive to (deviant) sounds violating an auditory regularity. Respective brain responses are usually investigated in situations when the sounds were produced by the experimenter. Acknowledging that humans also actively produce sounds, the present event-related potential study tested for differences in the brain responses to deviants that were produced by the listeners by pressing one of two buttons. In one condition, deviants were unpredictable with respect to the button-sound association. In another condition, deviants were predictable with high validity yielding correctly predicted deviants and incorrectly predicted (mispredicted) deviants. Temporal principal component analysis revealed deviant-specific N1 enhancement, mismatch negativity (MMN) and P3a. N1 enhancements were highly similar for each deviant type, indicating that the underlying neural mechanism is not affected by intention-based expectation about the self-produced forthcoming sound. The MMN was abolished for predictable deviants, suggesting that the intention-based prediction for a deviant can overwrite the prediction derived from the auditory regularity (predicting a standard). The P3a was present for each deviant type but was largest for mispredicted deviants. It is argued that the processes underlying P3a not only evaluate the deviant with respect to the fact that it violates an auditory regularity but also with respect to the intended sensorial effect of an action. Overall, our results specify current theories of auditory predictive processing, as they reveal that intention-based predictions exert different effects on different deviance-specific brain responses.

The auditory system is able to recognize auditory objects and is thought to form predictive models of them even though the acoustic information arriving at our ears is often imperfect, intermixed, or distorted. We investigated implicit regularity extraction for acoustically intact versus disrupted six-tone sound patterns via event-related potentials (ERPs). In an exact-repetition condition, identical patterns were repeated; in two distorted-repetition conditions, one randomly chosen segment in each sound pattern was replaced either by white noise or by a wrong pitch. In a roving-standard paradigm, sound patterns were repeated 1–12 times (standards) in a row before a new pattern (deviant) occurred. The participants were not informed about the roving rule and had to detect rarely occurring loudness changes. Behavioral detectability of pattern changes was assessed in a subsequent behavioral task. Pattern changes (standard vs. deviant) elicited mismatch negativity (MMN) and P3a, and were behaviorally detected above the chance level in all conditions, suggesting that the auditory system extracts regularities despite distortions in the acoustic input. However, MMN and P3a amplitude were decreased by distortions. At the level of MMN, both types of distortions caused similar impairments, suggesting that auditory regularity extraction is largely determined by the stimulus statistics of matching information. At the level of P3a, wrong-pitch distortions caused larger decreases than white-noise distortions. Wrong-pitch distortions likely prevented the engagement of restoration mechanisms and the segregation of disrupted from true pattern segments, causing stronger informational interference with the relevant pattern information

Die Hegelsche Wissenschaft der Logik gilt zurecht als das grundlegende, wenn auch komplexeste und dunkelste Werk Hegels. In ihr entfaltet Hegel den begrifflich-methodischen Hintergrund seines Systems mit dem Anspruch, eine spekulative Metaphysik zu etablieren. Dafür spielt eine wichtige Rolle der Reflexionsbegriff, der explizit in der Wesenslogik zur Darstellung kommt und als die Natur der Reflexion, als die immanente Reflexion von Reflexion in Anderes und Reflexion in sich, charakterisiert wird. Die Reflexion als objektive Reflexion bezieht sich einerseits auf die selbstbezügliche Negativität, die in ihrem vollständigen Sinne die einheitliche Struktur der negativen Selbstbeziehung ausmacht, und andererseits auf den Widerspruch, der die selbstbezügliche Negativität zur Natur hat und selber als der sich aufhebender Widerspruch die Reflexionseinheit als Grund bildet; diese Reflexionseinheit hat jene einheitliche Struktur der negativen Selbstbeziehung in sich. Solche Reflexion bringt das Sein zur Darstellung als das, was es in Wahrheit ist, nämlich als Selbstsein im Anderssein, das für Hegel der Begriff bzw. das Subjekt ist. Wenn das Sein sich als das Selbstsein im Anderssein erweist, kann die Selbstbewegung des Begriffs selbst ermöglicht werden, die Hegel in seiner Wissenschaft der Logik in Anspruch nimmt. Ohne das Verständnis dafür, wie die Begriffe der Negativität, des Widerspruchs und der Reflexion bei Hegels System sich zueinander verhalten, könnte man nicht genau die Wissenschaft der Logik verstehen. / Hegel’s Science of Logic is considered to be a fundamental, but at the same time the most complex and difficult, work of Hegel. He has developed in this work the conceptual and methodic background of his system, claiming that he tries to establish a speculativ metaphysics. The concept of reflexion plays an important role in this project. The concept of reflexion is explained in the Logic of Essence and the nature of reflexion is charaterized as the immanent reflexion of the reflexion in the other and in itself. The reflexion as the objektive reflexion is related, on the one hand, with the self-related negation, which makes up the unified structure of the negative self-relation, on the ohter hand, with the contradiction, whose nature lies in the self-related negativity. The contradiction builds up the unity of reflexion as the ground(Grund), because it must sublime (aufheben) itself. The unity of reflexion has the unified structure of the negative self-relation in itself. Such reflexion describes the being as what it truly is, namely as the self-being in the other-being. This means for Hegel the concept or the subject. If the being proves itself as the self-being in the other-being, the self-movement of concept itself becomes possible through it. The self-movement of concept was an aim of Hegel in his Science of Logik. Without unstanding the reciprocal relations between the concept of negation, contradiction and reflexion in the system of Hegel, we cound never exactly understand the Science of Logic.