Review on solving the inverse problem in EEG source analysis

In this primer, we give a review of the inverse problem for EEG source localization. This is intended for the researchers new in the field to get insight in the state-of-the-art techniques used to find approximate solutions of the brain sources giving rise to a scalp potential recording. Furthermore, a review of the performance results of the different techniques is provided to compare these different inverse solutions. The authors also include the results of a Monte-Carlo analysis which they performed to compare four non parametric algorithms and hence contribute to what is presently recorded in the literature. An extensive list of references to the work of other researchers is also provided

Reliability of Upper Limb Pin-Prick Stimulation With Electroencephalography: Evoked Potentials, Spectra and Source Localization

In order for electroencephalography (EEG) with sensory stimuli measures to be used in research and neurological clinical practice, demonstration of reliability is needed. However, this is rarely examined. Here we studied the test-retest reliability of the EEG latency and amplitude of evoked potentials and spectra as well as identifying the sources during pin-prick stimulation. We recorded EEG in 23 healthy older adults who underwent a protocol of pin-prick stimulation on the dominant and non-dominant hand. EEG was recorded in a second session with rest intervals of 1 week. For EEG electrodes Fz, Cz, and Pz peak amplitude, latency and frequency spectra for pin-prick evoked potentials was determined and test-retest reliability was assessed. Substantial reliability ICC scores (0.76–0.79) were identified for evoked potential negative-positive amplitude from the left hand at C4 channel and positive peak latency when stimulating the right hand at Cz channel. Frequency spectra showed consistent increase of low-frequency band activity (< 5 Hz) and also in theta and alpha bands in first 0.25 s. Almost perfect reliability scores were found for activity at both low-frequency and theta bands (ICC scores: 0.81–0.98). Sources were identified in the primary somatosensory and motor cortices in relation to the positive peak using s-LORETA analysis. Measuring the frequency response from the pin-prick evoked potentials may allow the reliable assessment of central somatosensory impairment in the clinical setting

Reliability of Upper Limb Pin-Prick Stimulation With Electroencephalography : Evoked Potentials, Spectra and Source Localization

In order for electroencephalography (EEG) with sensory stimuli measures to be used in research and neurological clinical practice, demonstration of reliability is needed. However, this is rarely examined. Here we studied the test-retest reliability of the EEG latency and amplitude of evoked potentials and spectra as well as identifying the sources during pin-prick stimulation. We recorded EEG in 23 healthy older adults who underwent a protocol of pin-prick stimulation on the dominant and non-dominant hand. EEG was recorded in a second session with rest intervals of 1 week. For EEG electrodes Fz, Cz, and Pz peak amplitude, latency and frequency spectra for pin-prick evoked potentials was determined and test-retest reliability was assessed. Substantial reliability ICC scores (0.76-0.79) were identified for evoked potential negative-positive amplitude from the left hand at C4 channel and positive peak latency when stimulating the right hand at Cz channel. Frequency spectra showed consistent increase of low-frequency band activity (< 5 Hz) and also in theta and alpha bands in first 0.25 s. Almost perfect reliability scores were found for activity at both low-frequency and theta bands (ICC scores: 0.81-0.98). Sources were identified in the primary somatosensory and motor cortices in relation to the positive peak using s-LORETA analysis. Measuring the frequency response from the pin-prick evoked potentials may allow the reliable assessment of central somatosensory impairment in the clinical setting

Reliability of upper limb pin-prick stimulation with electroencephalography : evoked potentials, spectra and source localization

In order for electroencephalography (EEG) with sensory stimuli measures to be used in research and neurological clinical practice, demonstration of reliability is needed. However, this is rarely examined. Here we studied the test-retest reliability of the EEG latency and amplitude of evoked potentials and spectra as well as identifying the sources during pin-prick stimulation.We recorded EEG in 23 healthy older adults who underwent a protocol of pin-prick stimulation on the dominant and non-dominant hand. EEG was recorded in a second session with rest intervals of 1 week. For EEG electrodes Fz, Cz, and Pz peak amplitude, latency and frequency spectra for pin-prick evoked potentials was determined and test-retest reliability was assessed. Substantial reliability ICC scores (0.76–0.79) were identified for evoked potential negative-positive amplitude from the left hand at C4 channel and positive peak latency when stimulating the right hand at Cz channel. Frequency spectra showed consistent increase of low-frequency band activity (< 5 Hz) and also in theta and alpha bands in first 0.25 s. Almost perfect reliability scores were found for activity at both low-frequency and theta bands (ICC scores: 0.81–0.98). Sources were identified in the primary somatosensory and motor cortices in relation to the positive peak using s-LORETA analysis. Measuring the frequency response from the pin-prick evoked potentials may allow the reliable assessment of central somatosensory impairment in the clinical setting.peer-reviewe

Attitudes Towards the Diagnosis of Alzheimer's Disease Among Carers and Non-Carers

Background The primary focus of studies on preferences regarding the disclosure of Alzheimer’s disease diagnoses has been the preferences of AD-carers. Relatively few studies have investigated such preferences in other groups, nor have the reasons behind such preferences been widely or systematically investigated. Objectives To provide some preliminary data on AD-disclosure preferences among non-carer older adults and to compare this data to that of AD-carers; to investigate reasons underlying disclosure preference among carers and non AD-carers, and; to explore the level of AD knowledge among carer and non-carer samples and investigate its relationship with disclosure preferences. Methods Participants were 20 elderly adults who were not caring for a relative with AD, and 16 older adults who were caring for an AD relative. Participants completed a modified AD knowledge test and a test designed to measure the reasons for and against disclosure of an AD diagnosis. Results AD knowledge among AD carers was significantly higher than among non-carers. Views about disclosure of AD diagnoses did not differ between groups though generally opinions were pro-disclosure (at least 85% of the overall sample opted for disclosure). No significant differences were found when preferences for disclosure for oneself versus a significant other were compared. Similar reasons for disclosure were given by carers and non-carers, and included factors such as the persons’ right to know their diagnosis. Conclusions Older Australians overwhelmingly supported disclosure of AD diagnoses, whether or not they had previously been through the diagnostic process

Paternal postnatal depressive symptoms, infant sleeping and feeding behaviors, and rigid parental regulation: a correlational study

Paternal postnatal depression (PND) is now recognized as a serious and prevalent problem, associated with poorer well-being and functioning of all family members. Aspects of infant temperament, sleeping and feeding perceived by parents as problematic are associated with maternal PND, however, less is known about paternal PND. This study investigated depressive symptoms (Edinburgh postnatal depression scale (EPDS)) in 219 fathers of infants aged from 1 to 24 weeks (median 7.0 weeks). Infant predictor variables were sleeping problems, feeding problems and both mother and father reported temperament. Control variables were partner’s support, other support and life events. Rigidity of parenting beliefs regarding infant regulation was also measured as a potential moderating factor. Infant feeding difficulties were associated with paternal depressive symptoms, subsuming the variance associated with both sleep problems and temperament. This relationship was not moderated by regulation beliefs. It was concluded that infant feeding is important to fathers. Fathers of infants with feeding difficulties may not be able to fulfill their idealized construction of involved fatherhood. Role incongruence may have an etiological role in paternal PND

Disconfirmed expectations of infant behaviours and postnatal depressive symptoms among parents

Objectives: A number of studies have examined the relationship between disconfirmed expectations about early parenthood and postnatal depressive symptoms. Most have focused on primiparous women, yet new fathers and multiparous parents also develop depressive symptoms following childbirth. The current study examined whether primiparous and multiparous mothers' and fathers' antenatal expectations about infant feeding and sleeping behaviours were consistent with their later experiences and whether disconfirmed expectations were associated with postnatal depressive symptoms. Method: Thirty-five mothers and 24 fathers in Brisbane Australia completed questionnaires during the third trimester of pregnancy and again in the first 16 weeks post-delivery. Results: Parents' expectations of infant behaviours were matched or exceeded by their postnatal experience. Discrepancies between antenatal expectations and postnatal experiences were not associated with parity or severity of depressive symptoms in the early postnatal period. Conclusion: Primiparous and multiparous parents typically held realistic expectations of infant sleeping and feeding behaviours relative to their postnatal experience. A small group of parents held less favourable antenatal expectations which may be an adaptive cognitive strategy used to protect parents against negative postnatal experience. Implications of these findings for research and clinical practice are discussed

Attitudes towards the diagnosis of Alzheimer’s disease carers and non-carers

Background \ud The primary focus of studies on preferences regarding the disclosure of Alzheimer’s disease diagnoses has been the preferences of AD-carers. Relatively few studies have investigated such preferences in other groups, nor have the reasons behind such preferences been widely or systematically investigated. \ud \ud Objectives \ud To provide some preliminary data on AD-disclosure preferences among non-carer older adults and to compare this data to that of AD-carers; to investigate reasons underlying disclosure preference among carers and non AD-carers, and; to explore the level of AD knowledge among carer and non-carer samples and investigate its relationship with disclosure preferences.\ud \ud Methods \ud Participants were 20 elderly adults who were not caring for a relative with AD, and 16 older adults who were caring for an AD relative. Participants completed a modified AD knowledge test and a test designed to measure the reasons for and against disclosure of an AD diagnosis. \ud \ud Results \ud AD knowledge among AD carers was significantly higher than among non-carers. Views about disclosure of AD diagnoses did not differ between groups though generally opinions were pro-disclosure (at least 85% of the overall sample opted for disclosure). No significant differences were found when preferences for disclosure for oneself versus a significant other were compared. Similar reasons for disclosure were given by carers and non-carers, and included factors such as the persons’ right to know their diagnosis.\ud \ud Conclusions \ud Older Australians overwhelmingly supported disclosure of AD diagnoses, whether or not they had previously been through the diagnostic process