Common features of fluency-evoking conditions studied in stuttering subjects and controls: an H(2)15O PET study

We used H(2)15O PET to characterize the common features of two successful but markedly different fluency-evoking conditions -- paced speech and singing -- in order to identify brain mechanisms that enable fluent speech in people who stutter. To do so, we compared responses under fluency-evoking conditions with responses elicited by tasks that typically elicit dysfluent speech (quantifying the degree of stuttering and using this measure as a confounding covariate in our analyses). We evaluated task-related activations in both stuttering subjects and age- and gender-matched controls. Areas that were either uniquely activated during fluency-evoking conditions, or in which the magnitude of activation was significantly greater during fluency-evoking than dysfluency-evoking tasks included auditory association areas that process speech and voice and motor regions related to control of the larynx and oral articulators. This suggests that a common fluency-evoking mechanism might relate to more effective coupling of auditory and motor systems -- that is, more efficient self-monitoring, allowing motor areas to more effectively modify speech. These effects were seen in both PWS and controls, suggesting that they are due to the sensorimotor or cognitive demands of the fluency-evoking tasks themselves. While responses seen in both groups were bilateral, however, the fluency-evoking tasks elicited more robust activation of auditory and motor regions within the left hemisphere of stuttering subjects, suggesting a role for the left hemisphere in compensatory processes that enable fluency. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to: (1) compare brain activation patterns under fluency- and dysfluency-evoking conditions in stuttering and control subjects; (2) appraise the common features, both central and peripheral, of fluency-evoking conditions; and (3) discuss ways in which neuroimaging methods can be used to understand the pathophysiology of stuttering.     

Love, Suspense, Sex, and Violence: Men’s and Women’s Film Predilections, Exposure to Sexually Violent Media, and their Relationship to Rape Myth Acceptance

This investigation addressed the relationship between men’s and women’s predilections for film with a love story, suspense, or sex and violence theme and how that predilection related to rape myth acceptance (RMA). Also examined was how men’s and women’s predilections, as they related to RMA, were moderated by exposure to different levels of sexually violent media based on a true story. Finally, the relationship between traditional attitudes and film predilection, as well as the relationship between film predilection and attitudes toward film editing, were investigated. Results indicate that men prefer film with sex and violence significantly more than women do, whereas women prefer love stories significantly more than men do. Those with sex and violence film predilections are more accepting of RMA than those with love story or suspense predilections. Women’s film predilections and their relationship to RMA attitudes are moderated to an extent by exposure to sexually violent media based on a true story, whereas men’s attitudes remain unaffected. Finally, those with sex and violence film predilections are less in favor of film editing than are those with suspense or love story predilections. Theoretical explanations for the findings are discussed and their implications.     

Prosodic form and parsing commitments

This paper examines the question of whether there are effects of prosody on the syntactic parsing of temporarily ambiguous sentences containing complement verbs. It reports the results of five experiments employing cross-modal response tasks where the visually presented target word was either an appropriate or an inappropriate continuation in terms of the prosodic form of the preceeding auditory sentence fragment. Two experiments employing cross-modal naming only showed indications of sensitivity to syntactic and appropriateness manipulations when coupled with a simultaneous appropriateness judgment task. In contrast, the experiments employing cross-modal lexical decision showed greater sensitivity to syntactic and appropriateness effects. However, while the results from these studies replicated our earlier auditory parsing results and provided support for the suggestion that there are differences in visual and auditory parsing processes and for a constituent-based, minimal commitment type auditory parser, none of the studies demonstrated an effect of prosodic form on the parsing process.     

Phonological processing and lexical access in aphasia

This study explored the relationship between on-line processing of phonological information and lexical access in aphasic patients. A lexical decision paradigm was used in which subjects were presented auditorily with pairs of words or word-like stimuli and were asked to make a lexical decision about the second stimulus in the pair. The initial phonemes of the first word primes, which were semantically related to the real word targets, were systematically changed by one or more than one phonetic feature, e.g., cat-dog, gat-dog, wat-dog. Each of these priming conditions was compared to an unrelated word baseline condition, e.g., nurse-dog. Previous work with normals showed that even a nonword stimulus receives a lexical interpretation if it shares a sufficient number of phonetic features with an actual word in the listener's lexicon. Results indicated a monotonically decreasing degree of facilitation as a function of phonological distortion. In contrast, fluent aphasics showed priming in all phonological distortion conditions relative to the unrelated word baseline. Nonfluent aphasics showed priming only in the undistorted, related word condition relative to the unrelated word baseline. Nevertheless, in a secondary task requiring patients to make a lexical decision on the nonword primes presented singly, all aphasics showed phonological feature sensitivity. These results suggest deficits for aphasic patients in the various processes contributing to lexical access, rather than impairments at the level of lexical organization or phonological organization.     

Young infants' generalization of emotional expressions: effects of familiarity

From birth, infants are exposed to a wealth of emotional information in their interactions. Much research has been done to investigate the development of emotion perception, and factors influencing that development. The current study investigates the role of familiarity on 3.5-month-old infants' generalization of emotional expressions. Infants were assigned to one of two habituation sequences: in one sequence, infants were visually habituated to parental expressions of happy or sad. At test, infants viewed either a continuation of the habituation sequence, their mother depicting a novel expression, an unfamiliar female depicting the habituated expression, or an unfamiliar female depicting a novel expression. In the second sequence, a new sample of infants was matched to the infants in the first sequence. These infants viewed the same habituation and test sequences, but the actors were unfamiliar to them. Only those infants who viewed their own mothers and fathers during the habituation sequence increased looking. They dishabituated looking to maternal novel expressions, the unfamiliar female's novel expression, and the unfamiliar female depicting the habituated expression, especially when sad parental expressions were followed by an expression change to happy or to a change in person. Infants are guided in their recognition of emotional expressions by the familiarity of their parents, before generalizing to others.     

On Ultrafilter Logic and Special Functions

Logics for generally were introduced for handling assertions with vague notions,such as generally, most, several, etc., by generalized quantifiers, ultrafilter logic being an interesting case. Here, we show that ultrafilter logic can be faithfully embedded into a first-order theory of certain functions, called coherent. We also use generic functions (akin to Skolem functions) to enable elimination of the generalized quantifier. These devices permit using methods for classical first-order logic to reason about consequence in ultrafilter logic.Presented by André Fuhrmann     

Suicidality in African American men: the roles of southern residence, religiosity, and social support

The rise in suicide by African Americans in the United States is directly attributable to the dramatic, nearly three-fold increase in suicide rates of African American males. Gibbs (1997) hypothesized high social support, religiosity, and southern residence are protective factors against suicidality for Black people. This hypothesis was tested among 5,125 participants from the National Comorbidity Survey; 299 were African American males. In this study we hypothesized that there would be significantly lower suicidality in the South, and social support and religiosity would mediate this relationship. Our results indicate that Southern region is indeed a significant predictor of suicidal symptoms in African American men, such that suicidal symptoms were lower in the South, but religiosity and social support did not account for this effect. Other potential mediators were also examined.     

The incremental validity of the MMPI-2: when does therapist access not enhance treatment outcome?

The present study examined whether therapist access to the Minnesota Multiphasic Personality Inventory (MMPI-2) predicted favorable treatment outcome, above and beyond other assessment measures. A manipulated assessment design was used, in which patients were randomly assigned either to a group in which therapists had access to their MMPI-2 data or to a group without therapist access to such information. Illness severity, improvement ratings, number of sessions attended, and premature termination were indicators of therapy outcome. Results indicated that therapist access to the MMPI-2 data did not add to the prediction of positive treatment outcome beyond that predicted by other measures in this setting. Findings from this initial study suggest that, compared with other resources, perhaps in clinical settings with an emphasis on diagnosis-based and evidence-based treatment, the MMPI-2 may not provide incrementally valid information. However, these effects warrant replication across different settings and samples. Guidelines for future studies are discussed.     

Automatic processing in spider phobia: implicit fear associations over the course of treatment

This study evaluates the cognitive model of anxiety by investigating treatment-related changes in automatic associations to evaluate schematic processing. Spider-phobic participants (n = 31) and healthy controls (n = 30) completed fear-based Implicit Association Tests (IATs), which are reaction-time measures that tap implicit associations without requiring conscious introspection. The specific tasks involved classifying pictures of snakes and spiders along with semantic categorizations (good vs.bad, afraid vs. unafraid, danger vs. safety, and disgusting vs. appealing). Phobic individuals were assessed before and after group-based exposure treatment and 2 months later, controls were assessed at matched time points. Results supported clinical applications for implicit fear associations, including prediction of phobic avoidance, and treatment sensitivity of the fear- and disgust-specific automatic associations.