Cognitive neuroscience

This study investigates affect coding within the therapeutic relationship, by exploring the client's and therapist's perception of the relationship and the facial and vocal affect expressed by both parties. A sample of 14 therapy sessions each having 1800 data points was collected. The Working Alliance Inventory Short Form (WAI-S) and Real Relationship Inventory (RRI) were completed after each recorded session. The participants were therapists and clients at a university counseling center in South Florida. Data were analyzed using one-tailed t tests, descriptive statistics, scores from RRI and the WAI-S and percentages of negative, neutral and positive affect. Statistically significant relationships were found between seconds of therapist negative affect (t(13)= -2.065, p. <.05) and seconds of therapist neutral affect (t(13)= -1.959, p. <.05) for clients who dropped out of therapy. The seconds of negative affect coded for clients (t(13) = -1.396, p. >.05) was approaching statistical significance for clients who drop out of therapy. This study provides theoretical and empirical support for linking the presence of facial affect in the first session and its effects on the therapeutic relationship and thus client retention or drop out. The clinical implications of these findings are also discussed.

This study examined the topography of prefrontal molds of human endocasts using three-dimensional laser scanning and geographic information systems (GIS) in order to carry out intra-species comparisons. Overall brain topography can indicate when major reorganizational shifts in brain structure happened in our evolutionalry history, and these shifts may indicate major shifts in cognition and behavior. Endocasts are one of the sole sources of information about extinct hominin brains ; they reproduce details of the brain's external morphology. Analysis of endocast morphology has never been done using GIS methodology. The use of GIS helps to overcome previous obstacles in regards to endocast analysis. Since this methodology is new, this research focuses on only one species, Homo sapiens and the area of focus is narrowed to the frontal lobe, specifically Broca's cap. This area is associated with speech in humans and is therefore of evolutionary significance. The variability in lateralization of this feature was quantified.

Contemporary understanding of human visual spatial attention rests on the hypothesis of a top-down control sending from cortical regions carrying higher-level functions to sensory regions. Evidence has been gathered through functional Magnetic Resonance Imaging (fMRI) experiments. The Frontal Eye Field (FEF) and IntraParietal Sulcus (IPS) are candidates proposed to form the frontoparietal attention network for top-down control. In this work we examined the influence patterns between frontoparietal network and Visual Occipital Cortex (VOC) using a statistical measure, Granger Causality (GC), with fMRI data acquired from subjects participated in a covert attention task. We found a directional asymmetry in GC between FEF/IPS and VOC, and further identified retinotopically specific control patterns in top-down GC. This work may lead to deeper understanding of goal-directed attention, as well as the application of GC to analyzing higher-level cognitive functions in healthy functioning human brain.

Male C7BL/6J mice were implanted with bilateral dorsal CA1 guide cannulae. After confirming that intrahippocampal microinfusion of muscimol impaired hippocampal function, demonstrated by impaired performance in the Morris water maze, the influence of intrahippocampal muscimol was tested in the Novel Object Recognition paradigm. During a test session 24 h after the last habituation/sample session, mice were presented with one familiar object and one novel object. Successful retention of object memory was inferred if mice spent more time exploring the novel object than the familiar object. Results demonstrate that muscimol infused into dorsal CA1 region prior to the test session eliminates novel object preference, indicating that the hippocampus is necessary for the retrieval of this non-spatial memory - a topic that has garnered much debate. Understanding the similarities between rodent and human hippocampal function could enable future animal studies to effectively answer questions about diseases and disorders affecting human learning and memory.

Number perception, its neural basis and its relationship to how numerical stimuli are presented have been challenging research topics in cognitive neuroscience for many years. A primary question that has been addressed is whether the perception of the quantity of a visually presented number stimulus is dissociable from its early visual perception. The present study examined the possible influence of visual quality judgment on quantity judgments of numbers. To address this issue, volunteer adult subjects performed a mental number comparison task in which two-digit stimulus numbers (Arabic number format), among the numbers between 31 and 99 were mentally compared to a memorized reference number, 65. Reaction times (RTs) and neurophysiological (i.e. electroencephalographic (EEG) data) responses were acquired simultaneously during performance of the two-digit number comparison task. In this particular quantity comparison task, the number stimuli were classified into three distance factors. That is, numbers were a close, medium or far distance from the reference number (i.e., 65). In order to evaluate the relationship between numerical stimulus quantity and quality, the number stimuli were embedded in varying degrees of a typical visual noise form, known as "salt and pepper noise" (e.g., the visual noise one perceives when viewing a photograph taken with a dusty camera lens). In this manner, the visual noise permitted visual quality to be manipulated across three levels: no noise, medium noise (approximately 60% degraded visual quality from nonoise), and dense noise (75% degraded visual quality from no-noise).

This dissertation studies the neural basis of song, a universal human behavior. The relationship of words and melodies in the perception of song at phonological, semantic, melodic, and rhythmic levels of processing was investigated using the fine temporal resolution of Electroencephalography (EEG). The observations reported here may shed light on a ubiquitous human experience and also inform the discussion of whether language and music share neural resources or recruit domain-specific neural mechanisms. Experiment 1 was designed to determine whether words and melody in song are processed interactively or independently. Participants listened to sung words in which the melodies and/or the words were similar or different, and performed a same/different task while attending to the linguistic and musical dimensions in separate blocks of trials. Event-Related Potentials and behavioral data converged in showing interactive processing between the linguistic and musical dimensions of sung words, regardless of the direction of attention. In particular, the N400 component, a well-established marker of semantic processing, was modulated by musical melody. The observation that variations in musical features affect lexico-semantic processing in sung language was a novel finding with implications for shared neural resources between language and music. Experiment 2 was designed to explore the idea that well-aligned text-settings, in which the strong syllables occur on strong beats, capture listeners' attention and help them understand song lyrics. EEG was recorded while participants listened to sung sentences whose linguistic stress patterns were well-aligned, misaligned, or had variable alignment with the musical meter, and performed a lexical decision task on subsequently presented visual targets.

The human prefrontal cortex (PFC) is associated with complex cognitive behaviors such as planning for the future, memory for serial order, social information processing and language. Understanding how the PFC has changed through time is central to the study of human neural evolution. Here we investigate the expansion of the PFC by measuring relative surface area of the PFC in Pan troglodytes and Homo sapiens. Magnetic resonance images (MRI's) from 8 preserved chimpanzee brains (3 male and 5 female adults) were segmented and measured. The results of this study indicate that there are gross anatomical differences between the chimpanzee and human prefrontal cortex beyond absolute size. The lower surface area to volume ratio in PFC of the chimpanzee when compared to a human indicates less gyral white matter in this region and thus, less associative connectivity. This anatomical evidence of a difference corresponds with the lesser cognitive complexity observed in chimpanzees.

The success of the music therapy profession has been well established, though the healing properties of music are not yet fully understood. Clinical observations show the medicinal value of music therapy; however, it is challenging to quantify music's beneficial effects. Examining music therapy's effectiveness in treating neurological disorders can possibly help to better validate this profession. However, music therapy is a multidisciplinary field, and perhaps we must come to a better understanding of how the various disciplines relate to one another. Music has the power to modulate our emotions. Neurological studies involving music therapy might help to uncover the connection between our emotional states and our physical health. To truly understand the success of music therapy, we must further study the role of emotions in the healing process. Future examinations of the emotional factor in music therapy may hold the key to a better understanding of how music affects us.

DNA methylation, the addition of a methyl group to the 5' position of DNA cytosines (5mC), is generally associated with transcriptional repression during early embryo formation ; however, in the adult brain, it is dynamically regulated and plays an important role in the formation and maintenance of memory. Very recently, it has been hypothesized that DNA hydroxymethylation, the addition of a hydroxyl group to methylated cytosines (5mC), serves as an intermediate in the DNA demethylation pathway. GIven its recent discovery, the role of DNA hydroxymethylation in memory has not yet been explored. In this study, we developed an immunofluorescent triple labeling protocol in order to begin examining the involvement of 5mC and 5hmC in neurons activated by consolidation of a contextual memory associated with methamphetamine in the brain's reward center, the nucleus accumbens.