Latent inhibition (LI) is the attenuation in the acquisition of Pavlovian conditioning to a conditioned stimulus (CS) due to prior extensive exposure to that CS. It is assumed that LI is an animal model of attention in that animals learn to ignore the preexposed CS. The present series of experiments investigated the effects of selective serotonergic (5-HT) ligands known to increase 5-HT neurotransmission on LI using a conditioned emotional response (CER) procedure. In experiment 1, rats preexposed (PE) to 40 presentations of a tone CS acquired CER suppression more slowly than vehicle-treated nonpreexposed (NPE) animals, suggesting LI was obtained. Administration of 10 mg/kg fluoxetine (i.p.) did not influence CER acquisition in PE animals, suggesting that LI was not affected by fluoxetine. However, it was assumed that 40 CS presentations exerted a powerful LI effect, which might mask any effect of fluoxetine. Consequently, we assessed the effects of 5-HT ligands on LI following 10, rather than 40, CS preexposures. Under these conditions, both acute fluoxetine (experiment 2), and chronic (14 day) fluoxetine (experiment 3) administration, were found to augment LI. Experiment 4 suggested that acute administration of the 5-HT2 agonist DOI (2.5 mg/kg) also enhances LI. Experiment 5 revealed that 1 mg/kg 8-OH-DPAT did not influence LI, suggesting that postsynaptic 5-HT1a receptors are not involved in LI. These results suggest that enhancement of 5-HT neurotransmission enhance LI and that this effect is mediated, in part, through the 5-HT2 receptor subtype. The results are discussed within the context of the switching model of LI, which suggests that the effects of 5-HT are mediated through the modulation of the mesolimbic dopamine pathway.

Although aging is often believed to be linked to cognitive decline, some elderly humans maintain cognitive function that is comparable to young adults (Rowe, J. W. & Kahn, R. L., 1987). In rats, variations in cognitive performance due to age are frequently assessed in tests of spatial abilities such as the Morris water maze (Issa, A. M., Rowe, W., Gauthier, S., & Meaney, M. J., 1990; Quirion, R. et al., 1995; Aubert, I., Rowe, W., Meaney, M. J., Gauthier, S., & Quirion, R., 1995). BIBN 99, a highly specific M2 receptor antagonist, reverses impaired ACh release as well as the cognitive deficits of aged, impaired (AI) rats observed in the Morris water maze (Aubert, I., Rowe, W., Meaney, M. J., Gauthier, S., & Quirion, R., 1995; Quirion, R. et al., 1995). To further characterize the potential benefits of BIBN 99, we tested (AI), aged, cognitively unimpaired (AU) and young (Y) rats in an object recognition task (ORT) and pre-pulse inhibition of acoustic startle (PPI). Both groups of vehicle-treated aged animals demonstrated reduced exploratory activity in the ORT compared to Y vehicle-treated animals. However, pre-treatment with BIBN 99 (0.5mg/kg) increased overall exploration time in AI and AU animals while having no effect in the Y group. In contrast, BIBN 99 had no effect on PPI in any of the groups. While these results are inconclusive concerning support for the potential relevance of BIBN 99 in the treatment of cognitive disorders, further research is warranted.

No description available.

The nature of the rehearsal mechanism that supports short-term memory span (STM), and the role of lexical and semantic knowledge in list recall was evaluated. Forty university students (aged 17-29 years) recalled lists of words varied in syllable-length (SL), articulatory duration (AD), phonological similarity (PS), semantic relatedness (SR) and frequency of occurrence (FO). Auditory and visual presentation, vocal and picture-pointing recall, and concurrent articulation conditions were included. Nonword recall was evaluated using stimuli varied in SL and PS was also evaluated using a repetition task. Word length effects were found for word stimuli varied in SL but were absent or reversed for stimuli varied in AD. A non-articulatory basis for rehearsal is suggested. The influence of long-term semantic and lexical knowledge in recall is inconclusive due to a lack of SR. Nonword repetition ability reflects STM capacity in adult subjects and correlates with other measures of STM span.

<p> Techniques to accurately measure situation awareness (SA) are important when designing systems that optimize operator performance. The two most prominent SA probe techniques vary based on screen visibility and situation pause during question presentation. The current study used four probe techniques based on all possible configurations of these factors. Air traffic control students controlled traffic in 10 scenarios that included all four probe techniques and a baseline no-probe condition across two degrees of automation. Probe questions varied on two levels of priority and specificity, creating four question types. Based on operator performance variations and subjective ratings, results support administration of probes with a visible screen and while the situation is paused. No method showed superior sensitivity to SA differences. Finally, the current study replicated findings that low priority information is offloaded to the environment and accessed as needed, supporting the situated approach towards SA.</p>

<p> This dissertation examined correlates of powerlessness, chronic homelessness (more than one-year homelessness), age, and gender, by analysis of the mental health (MH) and substance use (SU) service requests made by 699 people who attended a San Francisco, California homeless outreach event in May of 2005. People without homes (PWH) suffer MH and SU issues at a much higher rate than housed people, yet PWH who acknowledged they experienced MH and SU issues were least likely to request MH and SU services. PWH may have experienced chronic feelings of powerlessness, which resulted from marginalization. These chronic feelings of powerlessness contributed to a person's belief that his or her actions would produce no positive results. The concept of powerlessness may help explain PWH's reluctance to request MH and SU services. The author explored the relationship between chronicity of homelessness and requests for MH and SU services. Analyses showed that non-chronic PWH requested more MH services than those who were chronically homeless. However, this association was not seen when requests for SU services was examined. Additional analysis examining the relationship between service requests, age and gender did not result in significant findings. These findings provided support for the idea that powerlessness was an intrapersonal factor in PWH's choices to request or not request MH and SU services, based upon non-chronic homelessness and theoretically less exposure to powerlessness. These results assist in identifying intrapersonal factors influencing a person's experience in overcoming homelessness, providing an alternative to the current suggestion from the literature that services were unattractive to PWH.</p>

<p> This dissertation will discuss the research question, "What is the experience of providing therapy to sex abusers?" based on the results of a qualitative case study. A literature review will establish the preceding research related to sex abuse treatment. By filling a gap in previous research, this researcher seeks to encourage sex abuse treatment providers by authenticating their experiences, to provide valuable information to educators, as well as to inform legislators, the judiciary, and the general public about sex abuse treatment. Based on nine transcribed and analyzed interviews with providers of sex abuse treatment to adult male sex abusers who abuse children, this researcher discovered five themes and fourteen patterns within the providers' experiences. This study augments awareness of the field of sex abuse treatment as articulated by practicing providers.</p>

<p> This study has two parts: first, the development and execution of an abbreviated focusing-oriented dreamwork (FOD) treatment protocol for those with replicative PTSD nightmares, and second, an interpretative phenomenological analysis (IPA) of the experience of refugees who participated in the treatment. Participants included five clients from the Vancouver Association for the Survivors of Torture (VAST) who experienced clinically significant PTSD symptoms, including repetitive trauma-related nightmares. As a result of their participation in the FOD treatment, most experienced clinically significant reductions in PTSD symptoms, and their dreams began to change in specific ways, including a shift in the nature of the aggressor, dream ego actions, temporal and setting changes, and reduced fear responses within and after their nightmares. The fear responses in the dream content appear to relate directly to the physiological fight, flight or freeze responses the body initiates in response to threat. For those who are good candidates for the intervention, the FOD protocol appears to break the cycle of fear response and move the dreamer toward more empowered responses within dreaming and upon waking, and positively affect daytime functioning. </p>

Thesis (Ph.D.)--Pacific Graduate School of Psychology, 1995. / Source: Dissertation Abstracts International, Volume: 56-10, Section: B, page: 5806. Chair: Christine Zalewski.

Thesis (Ph.D.)--Pacific Graduate School of Psychology, 2002. / Source: Dissertation Abstracts International, Volume: 63-03, Section: B, page: 1594. Chair: Amy M. Wisniewski.