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Frames of Reference for Gaze Saccades Evoked During Stimulation of Lateral Intraparietal Cortex
, 2007
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You might find this additional information useful... Supplemental material for this article can be found at:
Auditory saccades from different eye positions in the monkey: implications for coordinate transformations
- J Neurophysiol., Vol
, 2004
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from different eye positions in the monkey: implications for
Mid-latency AEP Response in Blind 113 Mid-latency Auditory Evoked Potential Response Revealed as an Evidence of Neural Plasticity in Blind Individuals
"... Abstract There is a general impression that visually blind individuals show an exceptionally better perception of other sensory modalities such as hearing, touch and smell sensations. In this study, we intended to compare the mid-latency auditory evoked potential response (MLAEP) or Middle latency ..."
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Abstract There is a general impression that visually blind individuals show an exceptionally better perception of other sensory modalities such as hearing, touch and smell sensations. In this study, we intended to compare the mid-latency auditory evoked potential response (MLAEP) or Middle latency Response (MLR) to get an idea of the activity pattern of auditory thalamus and cortex between 30 visually handicapped subjects and 30 normal sighted subjects. The results showed a decrease in many of the MLR wave latencies, but highly significant for the wave Pa (P value <0.002). This fact can be reflected as an evidence of existence of crossmodal neuroplasticity. We also inferred that there are significant gender differences with latencies shorter in males than females (P value <0.02) in the blind subjects group which could be attributed to their rehabilitation training.
Human Motor Control Section, and
"... We have used positron emission tomography (PET) to measure regional cerebral blood flow (rCBF) in sighted and congenitally blind subjects performing auditory localization tasks. During scanning, the spectral and binaural cues of localized sound were reproduced by a sound system and delivered via hea ..."
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We have used positron emission tomography (PET) to measure regional cerebral blood flow (rCBF) in sighted and congenitally blind subjects performing auditory localization tasks. During scanning, the spectral and binaural cues of localized sound were reproduced by a sound system and delivered via headphones. During tasks that required auditory localization both the sighted and blind subjects strongly activated posterior parietal areas. In addition, the blind subjects activated association areas in the right occipital cortex, the foci of which were similar to areas previously identified in visual location and motion detection experiments in sighted subjects. The blind subjects, therefore, demonstrated visual to auditory crossmodal plasticity with auditory localization activating occipital association areas originally intended for dorsal-stream visual processing.
Cerebral Cortex doi:10.1093/cercor/bhn207 Motor-Related Signals in the Intraparietal Cortex Encode Locations in a Hybrid, rather than Eye-Centered Reference
, 2008
"... The reference frame used by intraparietal cortex neurons to encode locations is controversial. Many previous studies have suggested eye-centered coding, whereas we have reported that visual and auditory signals employ a hybrid reference frame (i.e., a combination of head- and eye-centered informatio ..."
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The reference frame used by intraparietal cortex neurons to encode locations is controversial. Many previous studies have suggested eye-centered coding, whereas we have reported that visual and auditory signals employ a hybrid reference frame (i.e., a combination of head- and eye-centered information) (Mullette-Gillman et al. 2005). One possible explanation for this discrepancy is that sensory-related activity, which we studied previously, is hybrid, whereas motor-related activity might be eye centered. Here, we examined the reference frame of visual and auditory saccaderelated activity in the lateral and medial banks of the intraparietal sulcus (areas lateral intraparietal area [LIP] and medial intraparietal area [MIP]) of 2 rhesus monkeys. We recorded from 275 single neurons as monkeys performed visual and auditory saccades from different initial eye positions. We found that both visual and auditory signals reflected a hybrid of head- and eye-centered coordinates during both target and perisaccadic task periods rather than shifting to an eye-centered format as the saccade approached. This account differs from numerous previous recording studies. We suggest that the geometry of the receptive field sampling in prior studies was biased in favor of an eye-centered reference frame. Consequently, the overall hybrid nature of the reference frame was overlooked because the non--eye-centered response patterns were not fully characterized.
REPRESENTATION OF OBJECT-CENTERED SPACE BY NEURONS OF THE SUPPLEMENTARY EYE FIELD
, 2005
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Cognitive Neural Prosthetics: Brain Machine Interfaces Based in Parietal Cortex
, 2005
"... The term “cybernetics” was coined by Norbert Weiner in 1947 in his book Cybernetics: or, Control and Communication in the Animal and the Machine. His foresight in this work predicted the ever closer interaction between the products of electrical engineering and biology. In the 1970s the notion of fu ..."
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The term “cybernetics” was coined by Norbert Weiner in 1947 in his book Cybernetics: or, Control and Communication in the Animal and the Machine. His foresight in this work predicted the ever closer interaction between the products of electrical engineering and biology. In the 1970s the notion of fusion between man and machine was popularized in the TV series The Six Million Dollar Man, where Col. Steve Austin is saved from certain paraplegia by bioengineering, becoming the first [albeit fictional] bionic man. Since then there has been a continuing fascination with the notion of physical integration between man and machine. The recent surge of progress in the field of Brain Machine Interfaces has brought what was once considered a castle in the sky down to a reality that may be achieved in our lifetimes.
Though there are many limitations to overcome, the study of the brain from an engineering perspective, that is, with the intent of applying the neural information rather than merely characterizing it, provides for new and better understandings of both the biological and technical problems at hand. We not only get better ideas of the accuracy and limitations of neural information, but are given a means of understanding dynamics that may not have been observable previously, such as how the brain changes with the use of BMIs. Chapter 2 sets up the BMI problem and demonstrates a proof of concept of a BMI using data from a former experiment showing that spikes in the Parietal Reach Region (PRR) are tuned to planned reach direction. Chapter 3 documents the instantiation of such a BMI and its effect on neural coding. Chapter 4 shows that non-spiking neural data, the Local Field Potential (LFP), can also be used for BMI control. The results of the experiments outlined in Chapters 3 and 4 give rise to questions about the nature of learning and neural adaptation in the Parietal Cortex. Chapter 5 looks at some preliminary results on the relationship between motivation, timing of spikes and LFPs, and spike timing dependent plasticity (STDP), and presents a model to inspire further experiments. Chapter 6 briefly describes the importance of these experiments in the context of neural prosthetics and neuroscience in general.
