Nicoladie Tam, Ph.D., is a professor at University of North Texas. Her research areas include optical brain imaging, computational neuroscience, cognitive behavioral neuropsychology, neurophysiology, biomedical engineering, neuroprosthetics and robotics. Currently, her research projects include decoding brain signals to assist hands-free navigation of a wheelchair, emotional processing and decision-making analysis, social emotion in reciprocity, exercise neurophysiology, neurobiological basis of emotional functions, near infrared spectroscopy signal analysis, neural spike train analysis, and autonomous control robotics. Phone: +1-940-565-3261
Advances in Image and Video Processing, Feb 1, 2014
Motion-detection, edge-detection, and orientation-detection often require spatial
computation of... more Motion-detection, edge-detection, and orientation-detection often require spatial
computation of the light intensity difference between neighboring pixel cells. Pre-processing
the image at the retinal level can improve the computational efficiency when the parallel
processing can be achieved naturally by the spatial arrangement of the pixel-array. Pixel-arrays
that require spatial pre-processing computation have different geometric constraints than plain
pixel-arrays that do not require such local computation. Our analysis shows that geometric
optimization of pixel-arrays can be achieved by using hexagonal arrays over rectilinear arrays.
Hexagonal arrays improve the packing density, and reduce the complexity of the spatial
computation compared to rectilinear square and octagonal arrays. They also provide geometric
symmetry for efficient computation not only at the contiguous neighboring cell level, but also
at the higher-order neighboring cell level. The light intensity difference at the higher-order cell
level is used to compute the first-order and second-order time-derivatives for velocity and
acceleration detections of the visual scene, respectively. Thus, hexagonal arrays increase the
computational efficiency by using a symmetric configuration that allows pre-processing of
spatial information of the visual scene using hardware implementations that are repeatable in
all higher-order neighboring pixels.
We present a new spike train analysis technique based on interval difference statistics. The Join... more We present a new spike train analysis technique based on interval difference statistics. The Joint Cross Interval Difference (JCID) scatter plot is introduced to examine the dependency relationship between adjacent CIDs in a spike train allowing for inferences to be made about local cross train trends. Monotonically increasing, decreasing, constant, or alternatively varying CIDs will appear in separate quadrants in this JCID scatter plot. The method was applied to simulated spike trains in order to display the capabilities of this new technique. Repeated cross train trends between pairs of neurons can seen as clusters and bands of points in specific quadrants of this new scatter plot.
We introduced a multiple single-unit spike train analysis technique to deduce the burst "rin... more We introduced a multiple single-unit spike train analysis technique to deduce the burst "ring patterns in one neuron that are temporally correlated to the spike generation in another neuron. This analysis considers the contribution of temporal summation of burst "rings in one neuron that is correlated to the probability of spike "ring in another neuron. The result shows that the analysis can extract the number of spikes and the duration of burst pattern. 2001
Abstract: A theoretical analysis of the cumulative sum (CUSUM) technique for detecting a series o... more Abstract: A theoretical analysis of the cumulative sum (CUSUM) technique for detecting a series of time signals from noisy background is provided. The statistic using CUSUM-slope is introduced as a measure for capturing the average of signals within the time-window, in which the slope is computed. This provides a time-independent method for estimating the signal content within the time-window. The detection criterion is provided for different window-lengths. The results showed that this CUSUM-slope statistic is highly sensitive to the detection of subtle hidden trends in the data sequence with noise filtered even in very low signal-to-noise environment.
Having developed a computational model for emotional response (Emotional-Gain Model) [1-4] and a ... more Having developed a computational model for emotional response (Emotional-Gain Model) [1-4] and a model for fairness (Fairness-Equity Model) [5] that quantified emotional bias and fairness bias, we will address the gender difference between the perception of love. We employed the experimental paradigm called “ultimatum game ” to elicit emotional responses to the sharing of love and money. The experimental paradigm essentially asks human subjects to split a sum of money or love such that their emotional response to fairness can be assessed. The results showed that although male and female respond very similarly in their emotional perception and fairness perception, except for the subtle difference as revealed by our Emotional-Gain and Fairness-Equity Models. The results revealed that female tends to recognize the full spectrum of emotions (both positive and negative) while male tends to recognize the positive emotions more often than the negative emotions. Furthermore, female tends to...
The equivalence of an infinite series, such as (0.999... = 1) to a finite number is often not int... more The equivalence of an infinite series, such as (0.999... = 1) to a finite number is often not intuitively obvious to understand for most students. Yet, it is helpful to use an intuitive method to derive the equivalence that is familiar to most elementary school students. In this paper, a simple proof of the equality of 0.999... and 1 is provided by a non-traditional method using long division with an alternate quotient. This alternate method that uses long division to prove an infinite series of numbers can stimulate the imagination of students to use abstraction to understand the mathematical concept of infinity. This can be done without the use of geometric series.
Abstract: Toward understanding the role of emotion played in cognitive processing, an emotional m... more Abstract: Toward understanding the role of emotion played in cognitive processing, an emotional model has been proposed to quantify the computation involved in assessing the disparity between the expected and the actual outcomes. This study provides the experimental evidence to validate the above emotional model. In this model, emotion serves as an internal feedback to assess the disparity between the internal predicted outcomes and the actual (external) outcomes in reality. It predicts that emotion provides a feedback to reduce the discrepancy between the expected (subjective) reality and actual (objective) reality. The hypothesis for this model is that the intensity of emotional response is proportional to the disparity between the expected outcome and the actual outcome (i.e., gain/loss magnitude). Happiness is an emotional feedback that indicates the congruency between the predicted and actual outcomes. In order to validate this theoretical model of emotion, the classical Ultima...
In this study, we propose the use of phase space plot analysis to characterize coupling relations... more In this study, we propose the use of phase space plot analysis to characterize coupling relationships between two simultaneously recorded hemodynamic variables, i.e., oxyhemoglobin (oxy-Hb) and deoxy-hemoglobin (deoxy-Hb), using functional near-infrared spectroscopy (fNIRS). To demonstrate the validity of the proposed method, we analyze hemodynamic data recorded from human subjects performing an orthogonal movement task. Our results show that phase space plots can quantify the dynamic time-varying relationships between the two variables based on the trajectory of the loci of data points in the phase space plots. In particular, the location of the phase space plots in different quadrants provides a specific coupling relationship between the two hemodynamic variables. The orientation of the loci of points characterizes further the relationship between these two variables, which can be directly or inversely proportional. The locus of the trajectory along a straight line or an elliptica...
Advances in Image and Video Processing, Feb 1, 2014
Motion-detection, edge-detection, and orientation-detection often require spatial
computation of... more Motion-detection, edge-detection, and orientation-detection often require spatial
computation of the light intensity difference between neighboring pixel cells. Pre-processing
the image at the retinal level can improve the computational efficiency when the parallel
processing can be achieved naturally by the spatial arrangement of the pixel-array. Pixel-arrays
that require spatial pre-processing computation have different geometric constraints than plain
pixel-arrays that do not require such local computation. Our analysis shows that geometric
optimization of pixel-arrays can be achieved by using hexagonal arrays over rectilinear arrays.
Hexagonal arrays improve the packing density, and reduce the complexity of the spatial
computation compared to rectilinear square and octagonal arrays. They also provide geometric
symmetry for efficient computation not only at the contiguous neighboring cell level, but also
at the higher-order neighboring cell level. The light intensity difference at the higher-order cell
level is used to compute the first-order and second-order time-derivatives for velocity and
acceleration detections of the visual scene, respectively. Thus, hexagonal arrays increase the
computational efficiency by using a symmetric configuration that allows pre-processing of
spatial information of the visual scene using hardware implementations that are repeatable in
all higher-order neighboring pixels.
We present a new spike train analysis technique based on interval difference statistics. The Join... more We present a new spike train analysis technique based on interval difference statistics. The Joint Cross Interval Difference (JCID) scatter plot is introduced to examine the dependency relationship between adjacent CIDs in a spike train allowing for inferences to be made about local cross train trends. Monotonically increasing, decreasing, constant, or alternatively varying CIDs will appear in separate quadrants in this JCID scatter plot. The method was applied to simulated spike trains in order to display the capabilities of this new technique. Repeated cross train trends between pairs of neurons can seen as clusters and bands of points in specific quadrants of this new scatter plot.
We introduced a multiple single-unit spike train analysis technique to deduce the burst "rin... more We introduced a multiple single-unit spike train analysis technique to deduce the burst "ring patterns in one neuron that are temporally correlated to the spike generation in another neuron. This analysis considers the contribution of temporal summation of burst "rings in one neuron that is correlated to the probability of spike "ring in another neuron. The result shows that the analysis can extract the number of spikes and the duration of burst pattern. 2001
Abstract: A theoretical analysis of the cumulative sum (CUSUM) technique for detecting a series o... more Abstract: A theoretical analysis of the cumulative sum (CUSUM) technique for detecting a series of time signals from noisy background is provided. The statistic using CUSUM-slope is introduced as a measure for capturing the average of signals within the time-window, in which the slope is computed. This provides a time-independent method for estimating the signal content within the time-window. The detection criterion is provided for different window-lengths. The results showed that this CUSUM-slope statistic is highly sensitive to the detection of subtle hidden trends in the data sequence with noise filtered even in very low signal-to-noise environment.
Having developed a computational model for emotional response (Emotional-Gain Model) [1-4] and a ... more Having developed a computational model for emotional response (Emotional-Gain Model) [1-4] and a model for fairness (Fairness-Equity Model) [5] that quantified emotional bias and fairness bias, we will address the gender difference between the perception of love. We employed the experimental paradigm called “ultimatum game ” to elicit emotional responses to the sharing of love and money. The experimental paradigm essentially asks human subjects to split a sum of money or love such that their emotional response to fairness can be assessed. The results showed that although male and female respond very similarly in their emotional perception and fairness perception, except for the subtle difference as revealed by our Emotional-Gain and Fairness-Equity Models. The results revealed that female tends to recognize the full spectrum of emotions (both positive and negative) while male tends to recognize the positive emotions more often than the negative emotions. Furthermore, female tends to...
The equivalence of an infinite series, such as (0.999... = 1) to a finite number is often not int... more The equivalence of an infinite series, such as (0.999... = 1) to a finite number is often not intuitively obvious to understand for most students. Yet, it is helpful to use an intuitive method to derive the equivalence that is familiar to most elementary school students. In this paper, a simple proof of the equality of 0.999... and 1 is provided by a non-traditional method using long division with an alternate quotient. This alternate method that uses long division to prove an infinite series of numbers can stimulate the imagination of students to use abstraction to understand the mathematical concept of infinity. This can be done without the use of geometric series.
Abstract: Toward understanding the role of emotion played in cognitive processing, an emotional m... more Abstract: Toward understanding the role of emotion played in cognitive processing, an emotional model has been proposed to quantify the computation involved in assessing the disparity between the expected and the actual outcomes. This study provides the experimental evidence to validate the above emotional model. In this model, emotion serves as an internal feedback to assess the disparity between the internal predicted outcomes and the actual (external) outcomes in reality. It predicts that emotion provides a feedback to reduce the discrepancy between the expected (subjective) reality and actual (objective) reality. The hypothesis for this model is that the intensity of emotional response is proportional to the disparity between the expected outcome and the actual outcome (i.e., gain/loss magnitude). Happiness is an emotional feedback that indicates the congruency between the predicted and actual outcomes. In order to validate this theoretical model of emotion, the classical Ultima...
In this study, we propose the use of phase space plot analysis to characterize coupling relations... more In this study, we propose the use of phase space plot analysis to characterize coupling relationships between two simultaneously recorded hemodynamic variables, i.e., oxyhemoglobin (oxy-Hb) and deoxy-hemoglobin (deoxy-Hb), using functional near-infrared spectroscopy (fNIRS). To demonstrate the validity of the proposed method, we analyze hemodynamic data recorded from human subjects performing an orthogonal movement task. Our results show that phase space plots can quantify the dynamic time-varying relationships between the two variables based on the trajectory of the loci of data points in the phase space plots. In particular, the location of the phase space plots in different quadrants provides a specific coupling relationship between the two hemodynamic variables. The orientation of the loci of points characterizes further the relationship between these two variables, which can be directly or inversely proportional. The locus of the trajectory along a straight line or an elliptica...
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Papers by Nicoladie Tam
computation of the light intensity difference between neighboring pixel cells. Pre-processing
the image at the retinal level can improve the computational efficiency when the parallel
processing can be achieved naturally by the spatial arrangement of the pixel-array. Pixel-arrays
that require spatial pre-processing computation have different geometric constraints than plain
pixel-arrays that do not require such local computation. Our analysis shows that geometric
optimization of pixel-arrays can be achieved by using hexagonal arrays over rectilinear arrays.
Hexagonal arrays improve the packing density, and reduce the complexity of the spatial
computation compared to rectilinear square and octagonal arrays. They also provide geometric
symmetry for efficient computation not only at the contiguous neighboring cell level, but also
at the higher-order neighboring cell level. The light intensity difference at the higher-order cell
level is used to compute the first-order and second-order time-derivatives for velocity and
acceleration detections of the visual scene, respectively. Thus, hexagonal arrays increase the
computational efficiency by using a symmetric configuration that allows pre-processing of
spatial information of the visual scene using hardware implementations that are repeatable in
all higher-order neighboring pixels.
computation of the light intensity difference between neighboring pixel cells. Pre-processing
the image at the retinal level can improve the computational efficiency when the parallel
processing can be achieved naturally by the spatial arrangement of the pixel-array. Pixel-arrays
that require spatial pre-processing computation have different geometric constraints than plain
pixel-arrays that do not require such local computation. Our analysis shows that geometric
optimization of pixel-arrays can be achieved by using hexagonal arrays over rectilinear arrays.
Hexagonal arrays improve the packing density, and reduce the complexity of the spatial
computation compared to rectilinear square and octagonal arrays. They also provide geometric
symmetry for efficient computation not only at the contiguous neighboring cell level, but also
at the higher-order neighboring cell level. The light intensity difference at the higher-order cell
level is used to compute the first-order and second-order time-derivatives for velocity and
acceleration detections of the visual scene, respectively. Thus, hexagonal arrays increase the
computational efficiency by using a symmetric configuration that allows pre-processing of
spatial information of the visual scene using hardware implementations that are repeatable in
all higher-order neighboring pixels.