Fractal characteristics of human parkinsonian neuronal spike trains

Rasouli, Golta; Rasouli, Mahta; Lenz, Frederick A.; Verhagen, Leo; Borrett, Donald S.; Kwan, Hon C.

doi:10.1016/j.neuroscience.2006.01.012

Cited by 27 publications

(16 citation statements)

References 33 publications

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“…In conclusion, whilst the spike train, taken as a whole, exhibited monofractal scaling behaviour [7], we observed that within the global scaling statistic, there was a detailed temporal organisation characterised by the presence or absence of subsequences of interspike intervals or alphabets. In other words, whilst scaling analyses provide a broad statistical indicator of the presence of persistent or anti-persistent dynamics [8], CGR is complementary in furnishing a more detailed specification of the "alphabets" of persistence or anti-persistence.…”

Section: Discussionmentioning

confidence: 65%

“…Conversely, the sparsely inhabited regions on the left side of the representation indicate a relative absence of the subsequence aad. Thus, the emergence of CGR patterns in GPi trains argues for the contention that within the more global framework of fractal dynamics [7], there is a fine local temporal structure consistent with the globally persistent dynamics in human pallidal neurons. In CGR of spike trains with scaling exponents closer to 0.5, however, there is a more diffuse distribution of points (Fig.…”

Section: Discussionmentioning

confidence: 97%

“…The data were collected from 14 patients whilst undergoing pallidotomy, as previously described [7,14,15]. Informed consent was obtained from all patients.…”

Section: Procedures and Collection Of Datamentioning

confidence: 99%

“…The scaling exponent characterising the monofractal property for each pallidal spike train was first computed as described previously [7]. Briefly, given the functional equation denoting the self-similar relation L(r) = kL(ar), where L is the fluctuations in ISIs measured at resolution r, a, a positive scale factor and k, a constant, a solution is the power-law relation L (r) = Ar α where the scaling exponent α is the self-similarity parameter and A a constant.…”

Section: Postoperative Analysismentioning

confidence: 99%

“…In a recent study, we observed that the interspike interval (ISI) time series from human internal pallidal (GPi) neurons exhibited scaling behaviour, thus characterising the fractal nature of a single GPi neuron as a nonlinear and nonequilibrium process in which the spike trains exhibit long-range correlation [7]. As most fractal analysis characterises the global patterns of average fluctuations as a function of resolution or size of the observation window [8], any fine temporal organisation would have been buried in the process.…”

Section: Introductionmentioning

confidence: 99%

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Chaos game representation of human pallidal spike trains

Rasouli

Lenz

et al. 2009

J Biol Phys

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Many studies have demonstrated the presence of scale invariance and long-range correlation in animal and human neuronal spike trains. The methodologies to extract the fractal or scale-invariant properties, however, do not address the issue as to the existence within the train of fine temporal structures embedded in the global fractal organisation. The present study addresses this question in human spike trains by the chaos game representation (CGR) approach, a graphical analysis with which specific temporal sequences reveal themselves as geometric structures in the graphical representation. The neuronal spike train data were obtained from patients whilst undergoing pallidotomy. Using this approach, we observed highly structured regions in the representation, indicating the presence of specific preferred sequences of interspike intervals within the train. Furthermore, we observed that for a given spike train, the higher the magnitude of its scaling exponent, the more pronounced the geometric patterns in the representation and, hence, higher probability of occurrence of specific subsequences. Given its ability to detect and specify in detail the preferred sequences of interspike intervals, we believe that CGR is a useful adjunct to the existing set of methodologies for spike train analysis.

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Section: Discussionmentioning

confidence: 65%

Section: Discussionmentioning

confidence: 97%

“…The data were collected from 14 patients whilst undergoing pallidotomy, as previously described [7,14,15]. Informed consent was obtained from all patients.…”

Section: Procedures and Collection Of Datamentioning

confidence: 99%

Section: Postoperative Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations