Use of Mental Imagery in Psychotherapy: A Critical Review

The paper presents arguments in favor of the use of mental imagery for therapeutic purposes. Several existing imagery approaches to psychotherapy are critically examined and suggestions for future inquiry are offered. The intimate relation between imagery and the affective-somatic processes is stressed

Modification of Stimulation Seeking Behavior in Psychopaths using Hypnotic Sensory Imagery Conditioning

Recent theorizing has postulated that there exists for every individual an optimal level of arousal. Deviations from this optimal state produce discomfort which motivates behaviors aimed at remediation. Potential causes of underarousal include the attenuation of perceptual input and excessively rapid habituation to sensory input. Both of these processes have been linked dynamically to the psychopathic condition. Presumably, in the context of restricted opportunities for involvement in highly stimulating activities, the psychopathic individual attempts to alleviate the stress caused by chronic sensory deprivation through participation in illegal behaviors. The present investigation has attempted to clarify the dynamic picture with regards to psychopathy and the attenuation of sensation. It has further attempted to evaluate a therapeutic regimen designed to enhance the psychopath\u27s perceptual sensitivity and thereby reduce his excessive reliance on stimulation-seeking activities. Experimental psychopathic and non-psychopathic subjects from the Minnesota State Reformatory were exposed to a three-week sensory imagery conditioning program which employed both self-hypnosis and heterohypnosis in order to facilitate the relaxation response and conditioning effect. Subsequent evaluation was made of changes in repressive perceptual tendencies, stimulation-seeking behavior, internal- external locus of control, and psychopathic orientation. The results indicate that, among incarcerated subjects, repression does not appear to be a consistent distinguishing characteristic of psychopaths. The results further indicate that the experimental procedure is capable of fostering a less repressive perceptual style and a consequent diminution of stimulation-seeking activity, with these changes being generally more pronounced for the non-psychopathic subjects. The changes, however, tended to be either not enduring or did not generalize in a way which affected global measures of psychopathic orientation. An additional finding was that the extent of practice in autohypnosis tended to be unrelated in any consistent fashion to the changes observed. The results are discussed in terms of their implications for a psycho-dynamic theory of psychopathy, the appropriateness of the measures employed, possible modifications in the experimental procedure which might enhance change and facilitate accurate assessment, and recommendations for relevant future research

The Science of Disguise

Technological advances have made digital cameras ubiquitous, to the point where it is difficult to purchase even a mobile phone without one. Coupled with similar advances in face recognition technology, we are seeing a marked increase in the use of biometrics, such as face recognition, to identify individuals. However, remaining unrecognized in an era of ubiquitous camera surveillance remains desirable to some citizens, notably those concerned with privacy. Since biometrics are an intrinsic part of a person\u27s identity, it may be that the only means of evading detection is through disguise. We have created a comprehensive database of high-quality imagery that will allow us to explore the effectiveness of disguise as an approach to avoiding unwanted recognition. Using this database, we have evaluated the performance of a variety of automated machine-based face recognition algorithms on disguised faces. Our data-driven analysis finds that for the sample population contained in our database: (1) disguise is effective; (2) there are significant performance differences between individuals and demographic groups; and (3) elements including coverage, contrast, and disguise combination are determinative factors in the success or failure of face recognition algorithms on an image. In this dissertation, we examine the present-day uses of face recognition and their interplay with privacy concerns. We sketch the capabilities of a new database of facial imagery, unique both in the diversity of the imaged population, and in the diversity and consistency of disguises applied to each subject. We provide an analysis of disguise performance based on both a highly-rated commercial face recognition system and an open-source algorithm available to the FR community. Finally, we put forth hypothetical models for these results, and provide insights into the types of disguises that are the most effective at defeating facial recognition for various demographic populations. As cameras become more sophisticated and algorithms become more advanced, disguise may become less effective. For security professionals, this is a laudable outcome; privacy advocates will certainly feel differently

Articulatory-based Speech Processing Methods for Foreign Accent Conversion

The objective of this dissertation is to develop speech processing methods that enable without altering their identity. We envision accent conversion primarily as a tool for pronunciation training, allowing non-native speakers to hear their native-accented selves. With this application in mind, we present two methods of accent conversion. The first assumes that the voice quality/identity of speech resides in the glottal excitation, while the linguistic content is contained in the vocal tract transfer function. Accent conversion is achieved by convolving the glottal excitation of a non-native speaker with the vocal tract transfer function of a native speaker. The result is perceived as 60 percent less accented, but it is no longer identified as the same individual. The second method of accent conversion selects segments of speech from a corpus of non-native speech based on their acoustic or articulatory similarity to segments from a native speaker. We predict that articulatory features provide a more speaker-independent representation of speech and are therefore better gauges of linguistic similarity across speakers. To test this hypothesis, we collected a custom database containing simultaneous recordings of speech and the positions of important articulators (e.g. lips, jaw, tongue) for a native and non-native speaker. Resequencing speech from a non-native speaker based on articulatory similarity with a native speaker achieved a 20 percent reduction in accent. The approach is particularly appealing for applications in pronunciation training because it modifies speech in a way that produces realistically achievable changes in accent (i.e., since the technique uses sounds already produced by the non-native speaker). A second contribution of this dissertation is the development of subjective and objective measures to assess the performance of accent conversion systems. This is a difficult problem because, in most cases, no ground truth exists. Subjective evaluation is further complicated by the interconnected relationship between accent and identity, but modifications of the stimuli (i.e. reverse speech and voice disguises) allow the two components to be separated. Algorithms to measure objectively accent, quality, and identity are shown to correlate well with their subjective counterparts

Perception and Mitigation of Artifacts in a Flat Panel Tiled Display System

Flat panel displays continue to dominate the display market. Larger, higher resolution flat panel displays are now in demand for scientific, business, and entertainment purposes. Manufacturing such large displays is currently difficult and expensive. Alternately, larger displays can be constructed by tiling smaller flat panel displays. While this approach may prove to be more cost effective, appropriate measures must be taken to achieve visual seamlessness and uniformity. In this project we conducted a set of experiments to study the perception and mitigation of image artifacts in tiled display systems. In the first experiment we used a prototype tiled display to investigate its current viability and to understand what critical perceptible visual artifacts exist in this system. Based on word frequencies of the survey responses, the most disruptive artifacts perceived were ranked. On the basis of these findings, we conducted a second experiment to test the effectiveness of image processing algorithms designed to mitigate some of the most distracting artifacts without changing the physical properties of the display system. Still images were processed using several algorithms and evaluated by observers using magnitude scaling. Participants in the experiment noticed statistically significant improvement in image quality from one of the two algorithms. Similar testing should be conducted to evaluate the effectiveness of the algorithms on video content. While much work still needs to be done, the contributions of this project should enable the development of an image processing pipeline to mitigate perceived artifacts in flat panel display systems and provide the groundwork for extending such a pipeline to realtime applications