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Behavioral states may be associated with distinct spatial patterns in electrocorticogram.

Panagiotides H, Freeman WJ, Holmes MD, Pantazis D - Cogn Neurodyn (2010)

Bottom Line: Moments of maximal spatial variance are shown to cluster by behavior.Comparisons between conditions using a permutation test reveal significantly different spatial patterns for each behavior.We conclude that ECoG recordings obtained on the cortical surface with optimal high spatial frequency resolution reveal distinct local spatial patterns that reflect different behavioral states, and we predict that similar patterns will be found in many if not most cortical areas on which a microgrid is placed.

View Article: PubMed Central - PubMed

ABSTRACT
To determine if behavioral states are associated with unique spatial electrocorticographic (ECoG) patterns, we obtained recordings with a microgrid electrode array applied to the cortical surface of a human subject. The array was constructed with the intent of extracting maximal spatial information by optimizing interelectrode distances. A 34-year-old patient with intractable epilepsy underwent intracranial ECoG monitoring after standard methods failed to reveal localization of seizures. During the 8-day period of invasive recording, in addition to standard clinical electrodes a square 1 × 1 cm microgrid array with 64 electrodes (1.25 mm separation) was placed on the right inferior temporal gyrus. Careful review of video recordings identified four extended naturalistic behaviors: reading, conversing on the telephone, looking at photographs, and face-to-face interactions. ECoG activity recorded with the microgrid that corresponded to these behaviors was collected and ECoG spatial patterns were analyzed. During periods of ECoG selected for analysis, no electrographic seizures or epileptiform patterns were present. Moments of maximal spatial variance are shown to cluster by behavior. Comparisons between conditions using a permutation test reveal significantly different spatial patterns for each behavior. We conclude that ECoG recordings obtained on the cortical surface with optimal high spatial frequency resolution reveal distinct local spatial patterns that reflect different behavioral states, and we predict that similar patterns will be found in many if not most cortical areas on which a microgrid is placed.

No MeSH data available.


Related in: MedlinePlus

Left Location of microgrid in a radiograph. Right Drawing of microgrid and its electrode arrangement
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Fig1: Left Location of microgrid in a radiograph. Right Drawing of microgrid and its electrode arrangement

Mentions: Fifty-two intracranial subdural clinical electrodes were placed over lateral and basal temporal regions of both hemispheres through temporal burr holes. Additionally, a microgrid array of 8 × 8 0.5 mm stainless steel wires spaced 1.25 mm apart was placed over a 1 cm2 cortical patch on the right anterior inferior temporal gyrus (Fig. 1). The interelectrode dimensions of the microgrid were established on the basis of knowledge of the spatial frequency spectrum of human EEG from the cortical surface (Freeman et al. 2000). More details of the electrode placement and microgrid design are available in Freeman et al. 2006a, which uses the same experimental data but a different set of behavioral moments, in order to investigate the power spectral density and phase of brain signals.Fig. 1


Behavioral states may be associated with distinct spatial patterns in electrocorticogram.

Panagiotides H, Freeman WJ, Holmes MD, Pantazis D - Cogn Neurodyn (2010)

Left Location of microgrid in a radiograph. Right Drawing of microgrid and its electrode arrangement
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3045495&req=5

Fig1: Left Location of microgrid in a radiograph. Right Drawing of microgrid and its electrode arrangement
Mentions: Fifty-two intracranial subdural clinical electrodes were placed over lateral and basal temporal regions of both hemispheres through temporal burr holes. Additionally, a microgrid array of 8 × 8 0.5 mm stainless steel wires spaced 1.25 mm apart was placed over a 1 cm2 cortical patch on the right anterior inferior temporal gyrus (Fig. 1). The interelectrode dimensions of the microgrid were established on the basis of knowledge of the spatial frequency spectrum of human EEG from the cortical surface (Freeman et al. 2000). More details of the electrode placement and microgrid design are available in Freeman et al. 2006a, which uses the same experimental data but a different set of behavioral moments, in order to investigate the power spectral density and phase of brain signals.Fig. 1

Bottom Line: Moments of maximal spatial variance are shown to cluster by behavior.Comparisons between conditions using a permutation test reveal significantly different spatial patterns for each behavior.We conclude that ECoG recordings obtained on the cortical surface with optimal high spatial frequency resolution reveal distinct local spatial patterns that reflect different behavioral states, and we predict that similar patterns will be found in many if not most cortical areas on which a microgrid is placed.

View Article: PubMed Central - PubMed

ABSTRACT
To determine if behavioral states are associated with unique spatial electrocorticographic (ECoG) patterns, we obtained recordings with a microgrid electrode array applied to the cortical surface of a human subject. The array was constructed with the intent of extracting maximal spatial information by optimizing interelectrode distances. A 34-year-old patient with intractable epilepsy underwent intracranial ECoG monitoring after standard methods failed to reveal localization of seizures. During the 8-day period of invasive recording, in addition to standard clinical electrodes a square 1 × 1 cm microgrid array with 64 electrodes (1.25 mm separation) was placed on the right inferior temporal gyrus. Careful review of video recordings identified four extended naturalistic behaviors: reading, conversing on the telephone, looking at photographs, and face-to-face interactions. ECoG activity recorded with the microgrid that corresponded to these behaviors was collected and ECoG spatial patterns were analyzed. During periods of ECoG selected for analysis, no electrographic seizures or epileptiform patterns were present. Moments of maximal spatial variance are shown to cluster by behavior. Comparisons between conditions using a permutation test reveal significantly different spatial patterns for each behavior. We conclude that ECoG recordings obtained on the cortical surface with optimal high spatial frequency resolution reveal distinct local spatial patterns that reflect different behavioral states, and we predict that similar patterns will be found in many if not most cortical areas on which a microgrid is placed.

No MeSH data available.


Related in: MedlinePlus