Sensory systems flexibly adapt their processing properties across a wide range of environmental and behavioral conditions. Such variable processing complicates attempts to extract mechanistic understanding of sensory computations. This is evident in the highly constrained, canonical Drosophila motion detection circuit, where the core computation underlying direction selectivity is still debated despite extensive studies. Here, I use the high temporal resolution method of in vivo whole-cell patch clamp electrophysiology to measure the filtering properties of neural inputs to the OFF motion-detecting T5 cell in Drosophila. I find state and stimulus dependent changes in the shape of these signals, which become more biphasic under specific conditions. Summing these inputs within the framework of a connectomic-constrained model of the circuit demonstrates that these changes in shape are sufficient to explain T5 responses to various motion stimuli. Thus, my stimulus and state dependent measurements reconcile motion computation with the anatomy of the circuit. These findings provide a clear example of how a basic circuit supports flexible sensory computation.

The brain is a complex system that seamlessly solves intricate problems with unprecedented efficiency. Part of the brain’s task is gathering sensory information from its environment, processing and representing it in a highly efficient manner. One of the key mechanisms used by sensory pathways is to process information by its context, disregarding redundancies and selectively focusing on novelty (deviance/change detection). A quantitative measure for how well the brain can detect novel stimuli is measured with the oddball paradigm and the mismatch negativity component (MMN). Deficits in context modulation and reduced MMN components are associated with mental disorders such as schizophrenia. Typically, oddball studies are done with coarse recording methods like EEG and MEG, and the network response dynamics underlying novelty detection is still unclear. In this work we used two-photon calcium imaging in awake mice listening to acoustic oddball stimuli, and recorded from large populations of neurons in primary and secondary auditory cortex (AC). We analyzed single cell and population representations of contextual information and found robust context modulation across all recorded AC regions. Responses to redundant stimuli were strongly suppressed while those to novel stimuli amplified. Furthermore, responses to identical stimuli in deviant, neutral, or redundant contexts were encoded by distinct populations of neurons, indicating an even stronger context encoding than seen in average population activity. Finally, we found that stimulus complexity also has an effect on where and to what extent context information is most robustly expressed. A2 was the most engaged in context processing for simple tones, while for complex frequency gratings A1 was doing novelty detection to the largest extent. My results provide a circuit basis for novelty detection in the auditory cortex, as a stepping stone to understand how processing of sensory stimuli is carried out by the brain.

Thesis (MA)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: his review examines the literature on the psychological impact of Kangaroo Mother Care (KMC) on the mother, infant, support personnel and other caretakers. The paper summarizes the findings of the KMC research and considers the implications of it in light of high numbers of premature and low birth weight infants in South Africa. The review briefly considers theories of bonding and attachment adopted in the research and theories on why KMC is effective. The psychological impact of one component of KMC, Skin-to-Skin Care (SSC), used primarily in developed countries to supplement traditional care, has been extensively researched. In contrast, much less research has explored the psychological impact of full KMC programmes in developing countries. Our understanding of the psychological impact of KMC therefore relies predominantly on research from a very different context to the one in which KMC is used. As SSC has been utilised very differently to KMC and in first world settings, it cannot offer mothers or their family reliable information on the psychological demands and benefits ofKMC. Findings: Although KMC appears to offer invaluable physiological benefits and assists in 'humanising' neonatal care in important ways, there is currently very little published research on the short or long-term psychological impact of KMC on the mother, infant, support personnel and other caretakers. On the whole, research findings on the psychological impact of KMC were not conclusive but indicate some positive outcomes for increased maternal sensitivity and confidence, developmental benefits for the infant and an improvement in the clarity of infants' cues and communication with caregiver. Findings on the psychological impact of KMC for support personnel and other caretakers such as the family of the infant are also not conclusive and indicate that more research is necessary. Further research is required regarding cross-cultural experiences of KMC; maternal experiences of depression, anxiety and ambivalence; long-term developmental and attachment outcomes for the infant and the possible preventative value of KMC for maternal and infant mental health. / AFRIKAANSE OPSOMMING: Hierdie hersiening ondersoek die literatuur aangaande die sielkundige uitwerking van Kangaroo Mother Care (KMC) op die ma, suigeling, ondersteunende personeel en ander opsigters. Die artikel is 'n opsomming van die uitspraak van KMC navorsing en oorweeg die gevolgtrekkings daarvan ten opsigte van die hoe getal vroeggebore en lae ligaamsgewig van suigelinge wat in Suid-Afrika gebore is. Die hersiening kyk kortliks na die teorie verbonde aan die binding en gehegtheid van die navorsing en teorie oor hoekom KMC doeltreffend is. Die sielkundige uitwerking van een onderdeel van KMC, Skin-to-Skin Care (SSC), wat meestal in gevorderde lande gebruik word om tradisionele versorg te verryk, is deeglik ondersoek. Inteendeel is ver minder navorsing op die sielkundige uitwerking van volle KMC programme in ontwikellende lande gedoen. Dus is ons begrip van die sielkundige uitwerking van KMC afhanklik op navorsing vanuit 'n ander konteks as die een waarin die eintlik gebruik is. SSC word baie anders benut as KMC, en in eerstewereldkontekste kan dit dus nie veel betroubare inligting op die sielkundige vereistes en voordele van KMC verskaf nie. Bevindings: Al kom dit voor dat KMC waardevolle sielkundige voordele verskaf en help in geboorte nasorg op belangrike maniere, is daar huidiglik baie min navorsing op druk oor die kort- of die langtermyn sielkundige uitwerking van KMC op die ma, suigeling, ondersteunende personeel en ander oppassers. In die algemeen, is die bevindings van navorsing oor die sielkundige uitwerking van KMC nie volkome nie, maar dui positiewe uitslae aan op verhoogde moederlike gevoelens en selfvertroue. Navorsing dui ook ontwikkelingsvoordele vir die suigeling, asook die bevordering van die duidelikheid van sy kommunikasie met die oppasser. Bevindings op die sielkundige uitwerking van KMC op die ondersteunende personeel en ander oppassers, byvoorbeeld familielede van die suigeling, is ook nie volkome nie, en dui die nodigheid van verdere navorsing aan. Verdere navorsing oor die kruiskulturele ervaring van KMC, moederlike ondervinding van moedeloosheid, angs en dubbelsinnigheid is benodig. Langtermyn ontwikkeling en gehegtigheidsake vir die suigeling en die moontlike voorkomende waarde van KMC vir moederlike en suigeling se geestelike gesondheid is ook wel benodig.

Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1992. / Includes bibliographical references (p. 101-104). / Potentially, health clubs can be rejuvenating and pleasant places. Unfortunately, many clubs in Boston are merely monotonous rooms stuffed into any available space downtown. Or, they are overwhelming, disorienting facilities sprawled out in suburban locales accessible only by car. The proposed site locates a facility at a T-stop. The health experience can be made more varied yet comprehensive by increasing users' awareness of sensory experiences in their surroundings. Movements, actions are grouped into a section according to what the body senses while engaged in an activity. These associations or common denominators assign particular qualities and characteristics to each section and make them distinguishable and different from one another. These juxtaposed differences provide contrast and variety needed to increase sensory awareness and stimulate the human body and mind. / by Amelia C. Jezierski. / M.Arch.

In Experiment I, I tested for the demonstration of Naming after presentation of Naming experiences that included an additional sensory experience (i.e., auditory non-speech stimulus) not presented during previous Naming studies. Probes were then conducted to test for the 4 dependent variables: 1) presence of listener half of Naming to visual stimuli, 2) the presence of the speaker half of Naming to visual stimuli, 3) the presence of the listener half of Naming to auditory non-speech stimuli, and 4) the presence of the speaker half of Naming to auditory non-speech stimuli. Following the first round of probes, all 6 participants demonstrated the listener half of Naming for visual stimuli, indicating that visual stimuli functioned as conditioned reinforcement for observing. In addition, following 3-4 probe sessions with the same set of stimuli, all participants emitted criterion-level responses for each of the four dependent variables. In Experiment II, using a multiple probe design across participants with participants who demonstrated conditioned reinforcement for observing visual stimuli, I tested whether repeated probes with sets of stimuli as an intervention would function to establish conditioned reinforcement for spoken and non-spoken auditory stimuli. In addition, I conducted two sets of probes during each pre and post- intervention probe session, one using a non-contrived stimuli set and another using a contrived stimuli set, to test whether there is a difference in the demonstration of Naming when assessed with non-contrived versus contrived stimuli. Results indicated overall increases in correct untaught listener and speaker responses during post-intervention probe sessions to novel sets of both contrived and non-contrived visual and auditory non-speech stimuli across all participants. In Experiment III, using a multiple probe design across participants, I tested the effects of the repeated probe procedure on the emergence of Naming for contrived visual and auditory stimuli, with 6 participants who demonstrated full Naming with non-contrived stimuli. During pre-intervention probes, all 6 participants demonstrated the listener half of Naming for contrived visual stimuli, but did not demonstrate the listener half of Naming for contrived auditory stimuli nor the speaker half of Naming for both contrived visual and auditory stimuli. Intervention was conducted in the same way as in Experiment II, but with only contrived stimuli sets. During post-intervention probes, all participants demonstrated criterion-level or close to criterion-level responding for untaught listener and speaker responses with a novel set of contrived visual and auditory stimuli. Results of the three studies combined suggested that simply having the listener component of Naming for visual stimuli and repeated exposures to visual and auditory stimuli may establish stimulus control for spoken and non-spoken contrived auditory stimuli. These increases in stimulus control are educationally significant, as they allow individuals to contact new stimuli in the environment, allowing for possibilities of learning multiple responses as well as multiple features of stimuli. Results also suggested that the demonstration of Naming with contrived stimuli may be a type of Naming cusp that is not necessarily present in individuals who demonstrate Naming with non-contrived stimuli. Educational implications of these findings, limitations, and future research are then discussed.

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No description available.

Thesis (M.A.)--York University, 2006. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 70-73). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://proquest.umi.com/pqdweb?index=0&did=1240699451&SrchMode=1&sid=15&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1195058296&clientId=5220

Thesis (M. Ed.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

Thesis (M.Sc.)--York University, 2005. Graduate Programme in Kinesiology and Health Science. / Typescript. Includes bibliographical references (leaves 72-82). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11836