Agnieszka Pluta - Academia.edu (original) (raw)

Uploads

Papers by Agnieszka Pluta

Normal aging is associated with cognitive decline. Functions such as attention, information proce... more Normal aging is associated with cognitive decline. Functions such as attention, information processing, and working memory are compromised. It has been hypothesized that not only regional changes, but also alterations in the integration of regional brain activity (functional brain connectivity) underlie the observed agerelated deficits. Here, we examined the functional properties of brain networks based on spontaneous fluctuations within brain systems using functional magnetic resonance imaging. We hypothesized that functional connectivity of intrinsic brain activity in the ''default-mode'' network (DMN) is affected by normal aging and that this relates to cognitive function. Ten younger and 22 older subjects were scanned at ''rest,'' that is, lying awake with eyes closed. Our results show decreased activity in older versus younger subjects in 2 resting-state networks (RSNs) resembling the previously described DMN, containing the superior and middle frontal gyrus, posterior cingulate, middle temporal gyrus, and the superior parietal region. These results remain significant after correction for RSN-specific gray matter volume. The relevance of these findings is illustrated by the correlation between reduced activity of one of these RSNs and less effective executive functioning/processing speed in the older group.

Applied Neuropsychology: Adult, 2013

Three neuropsychological theories have been developed according to a possible existence of a simi... more Three neuropsychological theories have been developed according to a possible existence of a similar pattern of cognitive decline in elderly individuals and patients with brain damage. The respective neuropsychological theories attribute age-related deficits to: (a) dysfunction of the frontal lobes, (b) temporo-parietal dysfunction, or (c) decline of right-hemisphere functions. In the present study, we examined which of these theories best explains the cognitive patterns of normal elderly subjects older than 80 years of age (old elderly). Thirty normal old elderly subjects, 14 patients with subcortical vascular dementia, 14 with mild Alzheimer's disease, 15 with damage of the right hemisphere of the brain, and 20 young elderly controls participated. A test battery covering the main cognitive domains was administered to all participants. A hierarchical cluster analysis revealed five groups of individuals with different cognitive patterns across the whole sample. Old elderly subjects were assigned to four groups according to: (a) preserved overall cognitive performance, (b) processing speed decline, (c) attention decline, or (d) executive impairment. The results of the study are most congruent with models emphasizing frontal-lobe cortical-subcortical and fronto-parietal changes in old age. The results also indicate considerable heterogeneity in the cognitive patterns of normal old elderly adults.

Objective: To obtain images of auditory cortex activation in children by using functional magneti... more Objective: To obtain images of auditory cortex activation in children by using functional magnetic resonance imaging (FMRI). Methods: Seven healthy children (three girls and four boys), ages 6 to 10 years, were studied. Hearing evaluation was performed by puretone audiometry on the day of FMRI study. Brain imaging was performed on a commercial 1 . 6 T imager using a three-axis local gradient coil. During scanning the children were instructed to lie still and avoid any lip, eye, jaw, or other facial movements. Subjects were asked to listen to a standard text presented in on-off sequences. Functional images of the auditory cortex were acquired with FMRI technique. Functional imaging processing was done using cross-correlation techniques with a coefficient of 0.6 ( p c .ooO1). Results: k ctional correlation images of the auditory cortex activation were obtained in six of seven children after image processing. All children showed activation in the superior temporal gyrus, Heschl's gyrus, planum temporale, frontal lobe, and parietal regions. There was no significant difference in the number and percentage of activated pixels on right and left auditory cortices. Conclusions: Functional images of auditory cortex activation were obtained in healthy children following binaural text presentation. Consistent activation was observed in primary and secondary auditory cortices with no hemispheric dominance. FMRI characteristics of the auditory cortex activation in healthy children should be established in order to study those with hearing impairment. Rey Wonla: Magnetic resonance, functional, auditory cortex, children, FMRI.

Magnetic Resonance Materials in Physics, Biology and Medicine, 2013

Introduction The objective of the presented study was to develop and evaluate a P300 experimental... more Introduction The objective of the presented study was to develop and evaluate a P300 experimental protocol for simultaneous registration of event-related potentials (ERPs) and functional MRI (fMRI) data with continuous imaging. It may be useful for investigating attention and working memory processes in specific populations, such as children and neuropsychiatric patients. Materials and methods Eleven children were investigated with simultaneous ERP-fMRI. To fulfill requirements of both BOLD and electroencephalographic signal registration, a modified oddball task was used. To verify the ERP-fMRI protocol we also performed a study outside the scanner using a typical two-stimuli oddball paradigm. Results Localization of the P300 component of ERPs partially corresponded with fMRI results in the frontal and parietal brain regions. FMRI activations were found in: middle frontal gyrus, insula, SMA, parietal lobule, thalamus, and cerebellum. Our modified oddball task provided ERP-fMRI results with high level of significance (EEG SNR = 35, fMRI p \ 0.05-Bonf.). ERPs obtained in the scanner were comparable with those registered outside the scanner, although some differences in the amplitude were noticed, mainly in the N100 component.

Normal aging is associated with cognitive decline. Functions such as attention, information proce... more Normal aging is associated with cognitive decline. Functions such as attention, information processing, and working memory are compromised. It has been hypothesized that not only regional changes, but also alterations in the integration of regional brain activity (functional brain connectivity) underlie the observed agerelated deficits. Here, we examined the functional properties of brain networks based on spontaneous fluctuations within brain systems using functional magnetic resonance imaging. We hypothesized that functional connectivity of intrinsic brain activity in the ''default-mode'' network (DMN) is affected by normal aging and that this relates to cognitive function. Ten younger and 22 older subjects were scanned at ''rest,'' that is, lying awake with eyes closed. Our results show decreased activity in older versus younger subjects in 2 resting-state networks (RSNs) resembling the previously described DMN, containing the superior and middle frontal gyrus, posterior cingulate, middle temporal gyrus, and the superior parietal region. These results remain significant after correction for RSN-specific gray matter volume. The relevance of these findings is illustrated by the correlation between reduced activity of one of these RSNs and less effective executive functioning/processing speed in the older group.

International Journal of Pediatric Otorhinolaryngology - INT J PED OTORHINOLARYNGOL, 2011

Objective: Aim of this study was to evaluate auditory cortex responses to chirp stimulation in pa... more Objective: Aim of this study was to evaluate auditory cortex responses to chirp stimulation in patients with partial deafness. Auditory cortex functioning is an important factor of successful rehabilitation after cochlear implantation, particularly in partially deafened patients who have to integrate the natural acoustic hearing with the electric one. This subject has not yet been properly recognized, especially regarding the auditory cortex' tonotopic organization in such patients.

Normal aging is associated with cognitive decline. Functions such as attention, information proce... more Normal aging is associated with cognitive decline. Functions such as attention, information processing, and working memory are compromised. It has been hypothesized that not only regional changes, but also alterations in the integration of regional brain activity (functional brain connectivity) underlie the observed agerelated deficits. Here, we examined the functional properties of brain networks based on spontaneous fluctuations within brain systems using functional magnetic resonance imaging. We hypothesized that functional connectivity of intrinsic brain activity in the ''default-mode'' network (DMN) is affected by normal aging and that this relates to cognitive function. Ten younger and 22 older subjects were scanned at ''rest,'' that is, lying awake with eyes closed. Our results show decreased activity in older versus younger subjects in 2 resting-state networks (RSNs) resembling the previously described DMN, containing the superior and middle frontal gyrus, posterior cingulate, middle temporal gyrus, and the superior parietal region. These results remain significant after correction for RSN-specific gray matter volume. The relevance of these findings is illustrated by the correlation between reduced activity of one of these RSNs and less effective executive functioning/processing speed in the older group.

Applied Neuropsychology: Adult, 2013

Three neuropsychological theories have been developed according to a possible existence of a simi... more Three neuropsychological theories have been developed according to a possible existence of a similar pattern of cognitive decline in elderly individuals and patients with brain damage. The respective neuropsychological theories attribute age-related deficits to: (a) dysfunction of the frontal lobes, (b) temporo-parietal dysfunction, or (c) decline of right-hemisphere functions. In the present study, we examined which of these theories best explains the cognitive patterns of normal elderly subjects older than 80 years of age (old elderly). Thirty normal old elderly subjects, 14 patients with subcortical vascular dementia, 14 with mild Alzheimer's disease, 15 with damage of the right hemisphere of the brain, and 20 young elderly controls participated. A test battery covering the main cognitive domains was administered to all participants. A hierarchical cluster analysis revealed five groups of individuals with different cognitive patterns across the whole sample. Old elderly subjects were assigned to four groups according to: (a) preserved overall cognitive performance, (b) processing speed decline, (c) attention decline, or (d) executive impairment. The results of the study are most congruent with models emphasizing frontal-lobe cortical-subcortical and fronto-parietal changes in old age. The results also indicate considerable heterogeneity in the cognitive patterns of normal old elderly adults.

Objective: To obtain images of auditory cortex activation in children by using functional magneti... more Objective: To obtain images of auditory cortex activation in children by using functional magnetic resonance imaging (FMRI). Methods: Seven healthy children (three girls and four boys), ages 6 to 10 years, were studied. Hearing evaluation was performed by puretone audiometry on the day of FMRI study. Brain imaging was performed on a commercial 1 . 6 T imager using a three-axis local gradient coil. During scanning the children were instructed to lie still and avoid any lip, eye, jaw, or other facial movements. Subjects were asked to listen to a standard text presented in on-off sequences. Functional images of the auditory cortex were acquired with FMRI technique. Functional imaging processing was done using cross-correlation techniques with a coefficient of 0.6 ( p c .ooO1). Results: k ctional correlation images of the auditory cortex activation were obtained in six of seven children after image processing. All children showed activation in the superior temporal gyrus, Heschl's gyrus, planum temporale, frontal lobe, and parietal regions. There was no significant difference in the number and percentage of activated pixels on right and left auditory cortices. Conclusions: Functional images of auditory cortex activation were obtained in healthy children following binaural text presentation. Consistent activation was observed in primary and secondary auditory cortices with no hemispheric dominance. FMRI characteristics of the auditory cortex activation in healthy children should be established in order to study those with hearing impairment. Rey Wonla: Magnetic resonance, functional, auditory cortex, children, FMRI.

Magnetic Resonance Materials in Physics, Biology and Medicine, 2013

Introduction The objective of the presented study was to develop and evaluate a P300 experimental... more Introduction The objective of the presented study was to develop and evaluate a P300 experimental protocol for simultaneous registration of event-related potentials (ERPs) and functional MRI (fMRI) data with continuous imaging. It may be useful for investigating attention and working memory processes in specific populations, such as children and neuropsychiatric patients. Materials and methods Eleven children were investigated with simultaneous ERP-fMRI. To fulfill requirements of both BOLD and electroencephalographic signal registration, a modified oddball task was used. To verify the ERP-fMRI protocol we also performed a study outside the scanner using a typical two-stimuli oddball paradigm. Results Localization of the P300 component of ERPs partially corresponded with fMRI results in the frontal and parietal brain regions. FMRI activations were found in: middle frontal gyrus, insula, SMA, parietal lobule, thalamus, and cerebellum. Our modified oddball task provided ERP-fMRI results with high level of significance (EEG SNR = 35, fMRI p \ 0.05-Bonf.). ERPs obtained in the scanner were comparable with those registered outside the scanner, although some differences in the amplitude were noticed, mainly in the N100 component.

Normal aging is associated with cognitive decline. Functions such as attention, information proce... more Normal aging is associated with cognitive decline. Functions such as attention, information processing, and working memory are compromised. It has been hypothesized that not only regional changes, but also alterations in the integration of regional brain activity (functional brain connectivity) underlie the observed agerelated deficits. Here, we examined the functional properties of brain networks based on spontaneous fluctuations within brain systems using functional magnetic resonance imaging. We hypothesized that functional connectivity of intrinsic brain activity in the ''default-mode'' network (DMN) is affected by normal aging and that this relates to cognitive function. Ten younger and 22 older subjects were scanned at ''rest,'' that is, lying awake with eyes closed. Our results show decreased activity in older versus younger subjects in 2 resting-state networks (RSNs) resembling the previously described DMN, containing the superior and middle frontal gyrus, posterior cingulate, middle temporal gyrus, and the superior parietal region. These results remain significant after correction for RSN-specific gray matter volume. The relevance of these findings is illustrated by the correlation between reduced activity of one of these RSNs and less effective executive functioning/processing speed in the older group.

International Journal of Pediatric Otorhinolaryngology - INT J PED OTORHINOLARYNGOL, 2011

Objective: Aim of this study was to evaluate auditory cortex responses to chirp stimulation in pa... more Objective: Aim of this study was to evaluate auditory cortex responses to chirp stimulation in patients with partial deafness. Auditory cortex functioning is an important factor of successful rehabilitation after cochlear implantation, particularly in partially deafened patients who have to integrate the natural acoustic hearing with the electric one. This subject has not yet been properly recognized, especially regarding the auditory cortex' tonotopic organization in such patients.