Hearing in the mind's ear: A PET investigation of musical imagery and perception

Neuropsychological studies have suggested that imagery processes may be mediated by neuronal mechanisms similar to those used in perception. To test this hypothesis, and to explore the neural basis for song imagery, 12 normal subjects were scanned using the water bolus method to measure cerebral blood flow (CBF) during the performance of three tasks. In the control condition subjects saw pairs of words on each trial and judged which word was longer. In the perceptual condition subjects also viewed pairs of words, this time drawn from a familiar song; simultaneously they heard the corresponding song, and their task was to judge the change in pitch of the two cued words within the song. In the imagery condition, subjects performed precisely the same judgment as in the perceptual condition, but with no auditory input. Thus, to perform the imagery task correctly an internal auditory representation must be accessed. Paired-image subtraction of the resulting pattern of CBF, together with matched MRI for anatomical localization, revealed that both perceptual and imagery. tasks produced similar patterns of CBF changes, as compared to the control condition, in keeping with the hypothesis. More specifically, both perceiving and imagining songs are associated with bilateral neuronal activity in the secondary auditory cortices, suggesting that processes within these regions underlie the phenomenological impression of imagined sounds. Other CBF foci elicited in both tasks include areas in the left and right frontal lobes and in the left parietal lobe, as well as the supplementary motor area. This latter region implicates covert vocalization as one component of musical imagery. Direct comparison of imagery and perceptual tasks revealed CBF increases in the inferior frontal polar cortex and right thalamus. We speculate that this network of regions may be specifically associated with retrieval and/or generation of auditory information from memory.

Hinterlands

The poems in Hinterlands are products of my interest in landscape. They feature complex territories that are constructs of the mind, emerging from the language of place. The term “existential territories” seems to fit my work because it suggests that the poems are products of language, spaces, and existential states coming together. The territories exist not as geographic places, but in the psyche, and their physical texture comes from using both the substantive quality of language and the ways language points to place. I do not think the resulting dream-like quality renders them unreal, but rather presents the adventure of navigating a reality unique to the world of the poem. Readers and the personae in these poems map themselves onto the world as the world maps itself onto them.

Mending The Mind With Dharma

Anxiety, depression, and tragedy are all unavoidable aspects of existence that we find ourselves grappling with at some point in our lives. In those darker moments we often look beyond ourselves for a means to cope with our struggles in the hopes of transcending into enhanced states of being. The world¿s religions have provided various answers to problems of mental and physical affliction. Across cultures and throughout history, numerous techniques for ¿mending the mind¿ have emerged, conditioned by a number of factors, including the normative values of a society as well as the scientific advances and technologies available for therapeutic application. Buddhism encompasses a broad tradition of beliefs, practices, and philosophies that, taken together, aim at eliminating suffering from the human experience. It is suggested that anyone who comes to understand and practice Buddhist teachings¿Dharma¿will rise out of the life of suffering and into a condition of awakening or nirvana. With this as an intended goal, a person who is unfulfilled in their life or who is experiencing feelings of depression will, it might be assumed, find great potential in turning to Buddhism as means for alleviation of these states. In contemporary western society, however, the most common route for eliminating emotional distress is to take antidepressant medication, which aims for immediate relief of the negative feelings and experiences that arise from depression. As I will argue, while this may be a successful approach to masking unwanted feelings, it in fact fails to treat the actual roots or cause of the undesirable experiences. Moreover, such a ¿therapeutic¿ approach lacks any aspect geared towards developing a consistently rewarding lifestyle. I will argue that the incorporation of Dharma¿both a set of ideas and as a form of practices¿into daily routines and modes of thinking provides the means for a balanced lifestyle, allowing the individual to relieve suffering and depression in a manner that the narrow scope of western medicine cannot provide.

Using Micro-Gravity Techniques to Map Alluvium Thickness and Pleistocene Location of the West Branch of the Susquehanna River Near Muncy, Pennsylvania

Laurentide glaciation during the early Pleistocene (~970 ka) dammed the southeast-flowing West Branch of the Susquehanna River (WBSR), scouring bedrock and creating 100-km-long glacial Lake Lesley near the Great Bend at Muncy, Pennsylvania (Ramage et al., 1998). Local drill logs and well data indicate that subsequent paleo-outwash floods and modern fluvial processes have deposited as much as 30 meters of alluvium in this area, but little is known about the valley fill architecture and the bedrock-alluvium interface. By gaining a greater understanding of the bedrock-alluvium interface the project will not only supplement existing depth to bedrock information, but also provide information pertinent to the evolution of the Muncy Valley landscape. This project determined if variations in the thickness of the valley fill were detectable using micro-gravity techniques to map the bedrock-alluvium interface. The gravity method was deemed appropriate due to scale of the study area (~30 km2), ease of operation by a single person, and the available geophysical equipment. A LaCoste and Romberg Gravitron unit was used to collect gravitational field readings at 49 locations over 5 transects across the Muncy Creek and Susquehanna River valleys (approximately 30 km2), with at least two gravity base stations per transect. Precise latitude, longitude and ground surface elevation at each location were measured using an OPUS corrected Trimble RTK-GPS unit. Base stations were chosen based on ease of access due to the necessity of repeat measurements. Gravity measurement locations were selected and marked to provide easy access and repeat measurements. The gravimeter was returned to a base station within every two hours and a looping procedure was used to determine drift and maximize confidence in the gravity measurements. A two-minute calibration reading at each station was used to minimize any tares in the data. The Gravitron digitally recorded finite impulse response filtered gravity measurements every 20 seconds at each station. A measurement period of 15 minutes was used for each base station occupation and a minimum of 5 minutes at all other locations. Longer or multiple measurements were utilized at some sites if drift or other externalities (i.e. train or truck traffic) were effecting readings. Average, median, standard deviation and 95% confidence interval were calculated for each station. Tidal, drift, latitude, free-air, Bouguer and terrain corrections were then applied. The results show that the gravitational field decreases as alluvium thickness increases across the axes of the Susquehanna River and Muncy Creek valleys. However, the location of the gravity low does not correspond with the present-day location of the West Branch of the Susquehanna River (WBSR), suggesting that the WBSR may have been constrained along Bald Eagle Mountain by a glacial lobe originating from the Muncy Creek Valley to the northeast. Using a 3-D inversion model, the topography of the bedrock-alluvium interface was determined over the extent of the study area using a density contrast of -0.8 g/cm3. Our results are consistent with the bedrock geometry of the area, and provide a low-cost, non-invasive and efficient method for exploring the subsurface and for supplementing existing well data.