The Role Of Corticothalamic Feedback On The Response Dynamics Of Thalamic Neurons
Funder
National Health and Medical Research Council
Funding Amount
$351,852.00
Summary
A fundamental question in neuroscience is how the brain selectively processes sensory information to generate a reliable representation of the world. Positioned in the centre of the brain, the thalamus plays a key role in sensory processing. This project investigates how the interaction between thalamus and cortex shapes the selection and gating of sensory information. This is a fundamental question in basic neuroscience with the potential to increase our knowledge about attentional deficits.
Functional Interactions Between Primate Cortical Areas In Tasks Involving Attention And Short-term Memory
Funder
National Health and Medical Research Council
Funding Amount
$267,280.00
Summary
To navigate and operate in the cluttered and dynamic sensory world around us, our brains need to be able to attend to specific objects or features in the environment, identify them and also know where they exist at any one instant of time, prior to performing the appropriate action. The attention, memory, decision and motor components involved in this process possibly involve a variety of cortical areas and neuronal operations. The special primate preparation we have developed permits us to eluc ....To navigate and operate in the cluttered and dynamic sensory world around us, our brains need to be able to attend to specific objects or features in the environment, identify them and also know where they exist at any one instant of time, prior to performing the appropriate action. The attention, memory, decision and motor components involved in this process possibly involve a variety of cortical areas and neuronal operations. The special primate preparation we have developed permits us to elucidate at a neuronal level many of these brain mechanisms. By recording neuronal activities in two different cortical areas simultaneously as the monkey performs a memory task that he has been trained on, we will test the following ideas: (1) A cortical region in the dorsal, parietal stream directs spatial attention by gating other visual areas to process only a selected region of the visual world (2) A region in the ventral, temporal stream directs attention to specific features in the visual world by gating earlier cortical areas (3) The parietal cortical areas that mediate intention for action hold the relevant information in working memory till it is forwarded to the more anterior premotor areas. These experiments have the potential to reveal the basic neuronal scheme that underpins functions such as attention, visual recognition and memory, which are impaired in many neurological disorders.Read moreRead less
Effects Of Electromagnetic Radiation On Visual Processing
Funder
National Health and Medical Research Council
Funding Amount
$299,564.00
Summary
We are increasingly surrounded by devices such as mobile phones and wireless networks. The effect of this electromagnetic radiation on human physiology is still largely unknown. Recent research has shown increases in "alpha-wave" electrical activity in the human brain after exposure to mobile phone radiation, but no effect has yet been shown on human mental processes. We plan to explore the effects of the electromagnetic environment on human visual processing, using sensitive techniques that wil ....We are increasingly surrounded by devices such as mobile phones and wireless networks. The effect of this electromagnetic radiation on human physiology is still largely unknown. Recent research has shown increases in "alpha-wave" electrical activity in the human brain after exposure to mobile phone radiation, but no effect has yet been shown on human mental processes. We plan to explore the effects of the electromagnetic environment on human visual processing, using sensitive techniques that will help reveal the underlying brain processes.Read moreRead less
Mechanisms And Pathways Leading To Saccadic Suppression In Primate Brain
Funder
National Health and Medical Research Council
Funding Amount
$858,086.00
Summary
Only the central few degrees of the visual field are viewed in high resolution. Consequently, the eyes must be pointed at targets of interest using saccadic eye movements. Each saccade generates potentially disturbing image motion but this is never perceived: saccadic suppression. This project aims to characterise the neural basis of saccadic suppression using modern techniques. As a result, a prime question in Neuroscience for over 100 years can now be answered.
Signals And Noise: A Study Of The Neurocognitive Mechanisms Underpinning Habituation To Noise In Normal And Damaged Hearing
Funder
National Health and Medical Research Council
Funding Amount
$408,938.00
Summary
McLachlan and Wilson recently published the first model of hearing that combines brain structure with function. This model postulates that recognition mechanisms initiate first, and then regulate the processing of other features. This project will investigate whether recognition mechanisms enable the auditory system to adapt to repetitive (background) noise by predicting and inhibiting responses to these sounds, and any changes in these mechanisms that may accompany hearing damage and tinnitus.
The Role Of Dopamine And Other Neuromodulators As Light Signals In The Inner Retina: A Link To Night Blindness Disorders
Funder
National Health and Medical Research Council
Funding Amount
$250,250.00
Summary
Although most human activities can be performed at night as efficiently as during daytime due to the use of artificial light, normal function of the circuits underlying night vision is critical. For example, when driving at night in a poorly illuminated road where the region illuminated by the headlights is processed by the cone circuit that serves daylight in the retina whilst the peripheral areas are processed by the rod driven nighttime circuit. Impairment of night vision and of the dark-ligh ....Although most human activities can be performed at night as efficiently as during daytime due to the use of artificial light, normal function of the circuits underlying night vision is critical. For example, when driving at night in a poorly illuminated road where the region illuminated by the headlights is processed by the cone circuit that serves daylight in the retina whilst the peripheral areas are processed by the rod driven nighttime circuit. Impairment of night vision and of the dark-light switch can have fatal consequences. Night blindness is a symptom characterised by reduced vision in the dark and slow adaptation to dim light. Some congenital night blindness disorders are caused by mutations in the photoreceptor calcium channels which mediate signal transmission. Additionally, patients treated with neuroleptics, a group of drugs which affect the dopaminergic system, suffer night vision disorders. Dopamine acts as a light signal in the retina. AII amacrine cells are pivotal neurones for night vision segregating two channels (ON and OFF) which convey visual information. AII cells are modulated by dopamine and thus, represent interesting targets to study the role of dopamine in the dark-light switch. Much is know about the action of dopamine on transmission of ON signals channelled by AII cells. However, its action on the OFF channel is largely unknown. We believe that some night vision disorders originate by imbalance in the dopaminergic system in the retina and its effects on AII cells. We will test our hypothesis by studying the modulatory effect of dopamine on calcium dependent signal transmission between AII cells and their partners in the OFF channel. Our hypothesis will be further tested by using animal models in which dopamine receptor function is altered. The results of these studies will provide us with an invaluable model to understand the physiological basis of the dark-light switch and of the role of dopamine in night vision disorders.Read moreRead less
Discovery Early Career Researcher Award - Grant ID: DE180100433
Funder
Australian Research Council
Funding Amount
$365,058.00
Summary
Cortical layer specific functional imaging of the human brain. This project aims to record layer specific cortical activity in humans by leveraging ultra-high field magnetic resonance imaging. It expects to yield robust techniques for the general analysis of neuroimaging-based, layer-specific measurements. This project will progress the fields of cognitive neuroscience and neuroimaging as well as bring the field of neuroimaging closer to that of neurophysiology and thus facilitate collaboration ....Cortical layer specific functional imaging of the human brain. This project aims to record layer specific cortical activity in humans by leveraging ultra-high field magnetic resonance imaging. It expects to yield robust techniques for the general analysis of neuroimaging-based, layer-specific measurements. This project will progress the fields of cognitive neuroscience and neuroimaging as well as bring the field of neuroimaging closer to that of neurophysiology and thus facilitate collaboration among researchers.Read moreRead less
Cochlear Type II Neurons In Contralateral Suppression
Funder
National Health and Medical Research Council
Funding Amount
$459,434.00
Summary
Sound in one ear affects hearing in the other ear. This contralateral suppression is important for hearing attention and protection from noise damage. We will test the hypothesis that cochlear type II sensory neurons provide the sensory input for this process using models where neuronal development is altered, or the neurons are removed. The study addresses hearing disability in society, facilitating cochlear prosthesis development and the understanding of hearing loss.
Organization and Plasticity of Visual Processing in a Miniature Brain. To recognise objects a brain must have an internal representation of most likely object appearance. Two ways in which brains may posses this information include a hard wired template system, and/or the neuroplasticity to learn novel objects. Recent investigations on honeybee vision show that this animal can learn to recognise very difficult objects, although currently we do not know how the miniaturised bee brain manages thes ....Organization and Plasticity of Visual Processing in a Miniature Brain. To recognise objects a brain must have an internal representation of most likely object appearance. Two ways in which brains may posses this information include a hard wired template system, and/or the neuroplasticity to learn novel objects. Recent investigations on honeybee vision show that this animal can learn to recognise very difficult objects, although currently we do not know how the miniaturised bee brain manages these tasks. This project will reveal changes that occur in the processing of visual objects by the bee's brain with increasing experience, with potential applications including robotics or building interfaces between sensors and biological systems.Read moreRead less