Angelica Flores | Universidad Autonoma de Baja California (original) (raw)
Papers by Angelica Flores
Neuroscience Letters, 2008
The present report focuses on evaluating the neurocognitive consequences of the correct or incorr... more The present report focuses on evaluating the neurocognitive consequences of the correct or incorrect spatial prediction induced by a spatial cue. Positions in the vertical meridian were cued in order to evaluate the cognitive consequences in the processing of the validly (VC) or invalidly cued (IC) targets. The behavioural responses and the 64 EEG channel were recorded. The late endogenous event-related potential (ERP) induced by target stimuli in VC and IC targets were compared in voltage amplitude, voltage and current source density topographies. The P3a and a late positive complex, possibly P3b were increased in a statistically significant manner in the IC targets with regard to the VC targets. The previous result suggests that subjects prepare to accomplish the task upon specification of the cue, and when the IC target appeared it is treated as a low probability stimulus in a similar manner to deviant stimuli in odd-ball paradigms.
Neuroscience and Biobehavioral Reviews, 2011
The present review describes and analyzes several recent papers in which the processes of prepara... more The present review describes and analyzes several recent papers in which the processes of preparation, evaluation and changing a cue's predictive value on a trial-by-trial basis conform a cycle that permits behavior to be constantly updated. This approach is an extension of Joaquin Fuster's proposal of a "perception-action" cycle in which executive networks are constantly updated as a function of the trials' outcome. The presented results can also be considered in relation to the computational Bayesian brain framework proposed by Friston (2009). The present approach is based on human electrophysiological studies of Posner's central cue paradigm,…
Brain Research, 2008
In a spatial central cueing paradigm, positions in the horizontal meridian were cued to evaluate ... more In a spatial central cueing paradigm, positions in the horizontal meridian were cued to evaluate the neurocognitive processing of validly (V) and invalidly cued (I) targets. ERPs were obtained from 20 EEG channel recordings. Complex Morlet wavelets were applied for computing event-related spectral power (ERSP) modulations and inter-trial phase coherence (ITC). P3a and P3b responses were increased in a statistically significant manner in I targets with regard to V targets. This increase seems to be generated only by phase resetting without enhancement of spectral power. Comparing ERSP modulations between I and V target trials we found a major effect centred in the alpha range. The following results were obtained for invalid condition in relation to valid condition: 6-12Hz ERSP decrease topographically widespread over the scalp, starting around 450ms and peaking around 650ms; 10-14Hz ERSP increase peaking around 200ms at fronto-central electrodes; and 10-14Hz ERSP decrease occurring from 400 to 600ms at posterior electrodes. Therefore, the invalidity effect indeed produces salient changes in the stimulus related and ongoing neuronal activity leading to a brain state of comparative higher activity both excitatory and inhibitory with respect to the validly cued target processing. P3b Spectral power ITC Trial evaluation Invalid cue B R A I N R E S E A R C H X X ( 2 0 0 8 ) X X X -X X X ava i l a b l e a t w w w. s c i e n c e d i r e c t . c o m w w w. e l s ev i e r. c o m / l o c a t e / b r a i n r e s ARTICLE IN PRESS Please cite this article as: Digiacomo, M.R., et al., Wavelet analysis of the EEG during the neurocognitive evaluation of invalidly cued targets, Brain Res. (2008), Please cite this article as: Digiacomo, M.R., et al., Wavelet analysis of the EEG during the neurocognitive evaluation of invalidly cued targets, Brain Res. (2008),
Frontiers in Behavioral Neuroscience, 1970
ABSTRACT The brain rhythms are defined by frequency, topography and psychological reactivity. In ... more ABSTRACT The brain rhythms are defined by frequency, topography and psychological reactivity. In general there is agreement that such rhytms can be classified as, delta, theta, alpha, mu, beta and gamma rhythms upon these criteria. Children also show this general pattern, but there are some topographical and frequency changes with respect to adults. One possible way to define rhythms in a more quantitative way would be to explore data by means of factorial analysis and look for a separation of different frequencies. 48 subjects, 24 children (7-13 years) and 24 young adults (10-23) were recorded for a period of 3 minutes during spontaneous EEG activity. The power spectral density function was obtained for these recordings. Factorial analysis and mixed-model ANOVA (children and young adults as inter-subjects, and bands (delta, Theta, alpha and beta) and electrodes as whithin –subjects factors was computed. These analysis were performed on normalized and non-normalized spectral power. The ANOVA analysis showed that absolute frequency spectra of children presented a higher amplitude than those of young adults. The decrease of absolute amplitude with age was accompanied by an increase of relative amplitude in the beta band, indicating a shifting of spectrum to high frequency bands in adults with respect to young adults. The factorial analysis showed that delta, theta, alpha and beta bands can be segregated with three factors which explained more of the 80% of data variability. The factorial analysis was able to separate these bands in a quantitative manner in both groups. The present results suggested that frequency bands which have been defined by categorical criteria can also be defined quantitatively by factorial analysis. Moreover, the structure of EEG bands of the spontaneous EEG is already present in preadolescents children, with subtle differences in frequency, and high differences in absolute amplitude between both groups.
International Journal of Developmental Neuroscience, 2010
matter centered at the anterior cingulate cortex were determined using LC model. Participants com... more matter centered at the anterior cingulate cortex were determined using LC model. Participants completed 9 subtests of the California Computerized Assessment Package (CalCAP) to assess reaction time, working-memory, and attention. Correlations between age, imaging, and cognitive measures were determined (p < 0.05 significance).
Brain and Cognition, 2009
Objectives: The present study investigated the effect of age on task-specific preparatory activat... more Objectives: The present study investigated the effect of age on task-specific preparatory activation induced by a spatial cue using the central cue Posner's paradigm. The behavioral responses and the contingent negative variation (CNV) generated between S1 (the warning stimulus) and S2 (the imperative stimulus) were compared between 16 healthy children (8-13 years old) and 17 healthy young adults (18-23 years old). Methods: The EEG was recorded from 20 scalp sites of the International 10-20 system. The complete trial period included a central directional cue that was on for 300 m s and an attentive waiting period lasting 1360 m s. Finally, a peripheral target appeared, subtending a visual angle of 4.56°and situated 2.28°e ccentrically in the horizontal meridian. The early and late components of the CNV appearing in the period between cue and target were analyzed. Results: The CNV of children showed no contralateral cortical activation related to motor preparation. However, the young adults showed contralateral activation to the cue over motor areas. Both children and young adults showed cortical activation in posterior sensory areas, displaying a pattern of activation contralateral to the cue. Also, a positive parietal component appeared in children during the CNV period. Conclusions: These results suggest that the motor preparation system in children is less mature than the sensory preparatory system. The children may have used strategies and brain areas different from those of the young adults to prepare for stimuli and responses.
International Journal of Developmental Neuroscience, 2010
matter centered at the anterior cingulate cortex were determined using LC model. Participants com... more matter centered at the anterior cingulate cortex were determined using LC model. Participants completed 9 subtests of the California Computerized Assessment Package (CalCAP) to assess reaction time, working-memory, and attention. Correlations between age, imaging, and cognitive measures were determined (p < 0.05 significance).
Journal of Psychophysiology, 2011
This study analyzed the developmental trends of brain rhythms in a group of children and a group ... more This study analyzed the developmental trends of brain rhythms in a group of children and a group of young adults. Principal component analysis (PCA), ANOVA, as well as correlational and topographical analyses were applied to the power spectral density of spontaneous electroencephalography (EEG). Absolute and relative power data were analyzed. The PCA analysis allowed to define three sources of variability related to the classical EEG rhythms. The absolute power results showed that children have higher spectral power than young adults in all frequency bands. Relative power demonstrated that children have more spectral power in the lower frequency bands (delta and theta) while young adults have more spectral power in the higher frequency bands (alpha and beta). Scalp topography analysis showed similar distributions for the four EEG bands in both groups, although delta and theta differed slightly between age groups. Correlational and PCA analysis showed an inverse relationship between delta and alpha power during development. Posterior regions and lower frequency rhythms seem to mature earlier than other regions and frequencies.
The Open Neuroimaging Journal, 2008
In a spatial central cue Posner´s paradigm, positions in the vertical meridian were cued in order... more In a spatial central cue Posner´s paradigm, positions in the vertical meridian were cued in order to evaluate the neuro-cognitive consequences in the processing of validly cued (VC) and invalidly cued (IC) targets. Sixty-four EEG channels were recorded and analyzed showing that IC targets produced an enhanced P3 component with respect to VC targets. With the purpose of reinforcing the idea of increased activation during IC targets and to define the areas in which the increased activation would occur, source localization was applied to the ERPs. LORETA and single dipole localization showed that the early P3 presented a localization in the dorsal part of the anterior cingulate cortex (dACC), while the late P3 was fitted by single dipole more posterior than the early P3, and LORETA added a source in the parahippocampal gyrus in addition to the already activated dACC. LORETA results also showed a differential activation of the inferior frontal gyrus when IC targets were processed. The previous results suggest that subjects prepare to accomplish the task upon specification of the cue. Therefore, when the IC target appears, it induces the activation of the frontal cortex including areas related to the conflict monitoring system and to the processing of unexpected events. The IC targets also induce the revision of internal models about the task, possibly by activation of the temporo-mesial surface. All the obtained current source differences indicate that a higher brain activation during IC trials with respect to VC trials occurs.
Brain Research Bulletin, 2010
The influence of cerebral maturity on the neurocognitive evaluation of target stimuli that have b... more The influence of cerebral maturity on the neurocognitive evaluation of target stimuli that have been cued by a spatial directional central cue, which, validly or invalidly, indicates the spatial position of the upcoming target has been investigated. ERPs and behavioural responses were recorded in 18 children and 20 young adults. P3a and P3b amplitudes were analyzed in the valid and invalid trials to assess possible differences between children and young adults. Young adults showed more activation in anterior (P3a) and posterior (P3b) areas in the invalid than the valid condition, whereas children only showed greater activation in P3b. This may be due to the later maturation of the frontal cortex than the more posterior sites. Children also showed a greater P3 component amplitude and a topography shifting to occipital sites, irrespective of the experimental condition.
Brain Research Bulletin, 2007
The preparation for stimuli and responses in which the position and required finger to respond ar... more The preparation for stimuli and responses in which the position and required finger to respond are cued, produces the preparatory activation of the specific neural resources that are going to be needed for the completion of the task. The focus of the present report is to evaluate if the fronto-parietal networks activated in fMRI studies during endogenous attention are also activated during the CNV period using EEG recording. The behavioural responses and 64 EEG channels were recorded during an S1-S2 paradigm similar to Posner central cue paradigms. The LORETA analysis based in the averaging of the z-LORETA values showed that the Brodmann&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s areas with the highest activation during the CNV period were in the medial and superior frontal areas, fronto-parietal lateral areas (including the premotor cortex) and extrastriate visual cortex. These results suggest that in addition to the previously described activation in premotor-motor, posterior sensory and superior and medial frontal areas, the activation of fronto-parietal networks is a main contributor to the CNV, indicating the endogenous attentional effort during the CNV period.
Neuroscience Letters, 2008
The present report focuses on evaluating the neurocognitive consequences of the correct or incorr... more The present report focuses on evaluating the neurocognitive consequences of the correct or incorrect spatial prediction induced by a spatial cue. Positions in the vertical meridian were cued in order to evaluate the cognitive consequences in the processing of the validly (VC) or invalidly cued (IC) targets. The behavioural responses and the 64 EEG channel were recorded. The late endogenous event-related potential (ERP) induced by target stimuli in VC and IC targets were compared in voltage amplitude, voltage and current source density topographies. The P3a and a late positive complex, possibly P3b were increased in a statistically significant manner in the IC targets with regard to the VC targets. The previous result suggests that subjects prepare to accomplish the task upon specification of the cue, and when the IC target appeared it is treated as a low probability stimulus in a similar manner to deviant stimuli in odd-ball paradigms.
Neuroscience and Biobehavioral Reviews, 2011
The present review describes and analyzes several recent papers in which the processes of prepara... more The present review describes and analyzes several recent papers in which the processes of preparation, evaluation and changing a cue&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s predictive value on a trial-by-trial basis conform a cycle that permits behavior to be constantly updated. This approach is an extension of Joaquin Fuster&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s proposal of a &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;perception-action&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; cycle in which executive networks are constantly updated as a function of the trials&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; outcome. The presented results can also be considered in relation to the computational Bayesian brain framework proposed by Friston (2009). The present approach is based on human electrophysiological studies of Posner&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s central cue paradigm,…
Brain Research, 2008
In a spatial central cueing paradigm, positions in the horizontal meridian were cued to evaluate ... more In a spatial central cueing paradigm, positions in the horizontal meridian were cued to evaluate the neurocognitive processing of validly (V) and invalidly cued (I) targets. ERPs were obtained from 20 EEG channel recordings. Complex Morlet wavelets were applied for computing event-related spectral power (ERSP) modulations and inter-trial phase coherence (ITC). P3a and P3b responses were increased in a statistically significant manner in I targets with regard to V targets. This increase seems to be generated only by phase resetting without enhancement of spectral power. Comparing ERSP modulations between I and V target trials we found a major effect centred in the alpha range. The following results were obtained for invalid condition in relation to valid condition: 6-12Hz ERSP decrease topographically widespread over the scalp, starting around 450ms and peaking around 650ms; 10-14Hz ERSP increase peaking around 200ms at fronto-central electrodes; and 10-14Hz ERSP decrease occurring from 400 to 600ms at posterior electrodes. Therefore, the invalidity effect indeed produces salient changes in the stimulus related and ongoing neuronal activity leading to a brain state of comparative higher activity both excitatory and inhibitory with respect to the validly cued target processing. P3b Spectral power ITC Trial evaluation Invalid cue B R A I N R E S E A R C H X X ( 2 0 0 8 ) X X X -X X X ava i l a b l e a t w w w. s c i e n c e d i r e c t . c o m w w w. e l s ev i e r. c o m / l o c a t e / b r a i n r e s ARTICLE IN PRESS Please cite this article as: Digiacomo, M.R., et al., Wavelet analysis of the EEG during the neurocognitive evaluation of invalidly cued targets, Brain Res. (2008), Please cite this article as: Digiacomo, M.R., et al., Wavelet analysis of the EEG during the neurocognitive evaluation of invalidly cued targets, Brain Res. (2008),
Frontiers in Behavioral Neuroscience, 1970
ABSTRACT The brain rhythms are defined by frequency, topography and psychological reactivity. In ... more ABSTRACT The brain rhythms are defined by frequency, topography and psychological reactivity. In general there is agreement that such rhytms can be classified as, delta, theta, alpha, mu, beta and gamma rhythms upon these criteria. Children also show this general pattern, but there are some topographical and frequency changes with respect to adults. One possible way to define rhythms in a more quantitative way would be to explore data by means of factorial analysis and look for a separation of different frequencies. 48 subjects, 24 children (7-13 years) and 24 young adults (10-23) were recorded for a period of 3 minutes during spontaneous EEG activity. The power spectral density function was obtained for these recordings. Factorial analysis and mixed-model ANOVA (children and young adults as inter-subjects, and bands (delta, Theta, alpha and beta) and electrodes as whithin –subjects factors was computed. These analysis were performed on normalized and non-normalized spectral power. The ANOVA analysis showed that absolute frequency spectra of children presented a higher amplitude than those of young adults. The decrease of absolute amplitude with age was accompanied by an increase of relative amplitude in the beta band, indicating a shifting of spectrum to high frequency bands in adults with respect to young adults. The factorial analysis showed that delta, theta, alpha and beta bands can be segregated with three factors which explained more of the 80% of data variability. The factorial analysis was able to separate these bands in a quantitative manner in both groups. The present results suggested that frequency bands which have been defined by categorical criteria can also be defined quantitatively by factorial analysis. Moreover, the structure of EEG bands of the spontaneous EEG is already present in preadolescents children, with subtle differences in frequency, and high differences in absolute amplitude between both groups.
International Journal of Developmental Neuroscience, 2010
matter centered at the anterior cingulate cortex were determined using LC model. Participants com... more matter centered at the anterior cingulate cortex were determined using LC model. Participants completed 9 subtests of the California Computerized Assessment Package (CalCAP) to assess reaction time, working-memory, and attention. Correlations between age, imaging, and cognitive measures were determined (p < 0.05 significance).
Brain and Cognition, 2009
Objectives: The present study investigated the effect of age on task-specific preparatory activat... more Objectives: The present study investigated the effect of age on task-specific preparatory activation induced by a spatial cue using the central cue Posner's paradigm. The behavioral responses and the contingent negative variation (CNV) generated between S1 (the warning stimulus) and S2 (the imperative stimulus) were compared between 16 healthy children (8-13 years old) and 17 healthy young adults (18-23 years old). Methods: The EEG was recorded from 20 scalp sites of the International 10-20 system. The complete trial period included a central directional cue that was on for 300 m s and an attentive waiting period lasting 1360 m s. Finally, a peripheral target appeared, subtending a visual angle of 4.56°and situated 2.28°e ccentrically in the horizontal meridian. The early and late components of the CNV appearing in the period between cue and target were analyzed. Results: The CNV of children showed no contralateral cortical activation related to motor preparation. However, the young adults showed contralateral activation to the cue over motor areas. Both children and young adults showed cortical activation in posterior sensory areas, displaying a pattern of activation contralateral to the cue. Also, a positive parietal component appeared in children during the CNV period. Conclusions: These results suggest that the motor preparation system in children is less mature than the sensory preparatory system. The children may have used strategies and brain areas different from those of the young adults to prepare for stimuli and responses.
International Journal of Developmental Neuroscience, 2010
matter centered at the anterior cingulate cortex were determined using LC model. Participants com... more matter centered at the anterior cingulate cortex were determined using LC model. Participants completed 9 subtests of the California Computerized Assessment Package (CalCAP) to assess reaction time, working-memory, and attention. Correlations between age, imaging, and cognitive measures were determined (p < 0.05 significance).
Journal of Psychophysiology, 2011
This study analyzed the developmental trends of brain rhythms in a group of children and a group ... more This study analyzed the developmental trends of brain rhythms in a group of children and a group of young adults. Principal component analysis (PCA), ANOVA, as well as correlational and topographical analyses were applied to the power spectral density of spontaneous electroencephalography (EEG). Absolute and relative power data were analyzed. The PCA analysis allowed to define three sources of variability related to the classical EEG rhythms. The absolute power results showed that children have higher spectral power than young adults in all frequency bands. Relative power demonstrated that children have more spectral power in the lower frequency bands (delta and theta) while young adults have more spectral power in the higher frequency bands (alpha and beta). Scalp topography analysis showed similar distributions for the four EEG bands in both groups, although delta and theta differed slightly between age groups. Correlational and PCA analysis showed an inverse relationship between delta and alpha power during development. Posterior regions and lower frequency rhythms seem to mature earlier than other regions and frequencies.
The Open Neuroimaging Journal, 2008
In a spatial central cue Posner´s paradigm, positions in the vertical meridian were cued in order... more In a spatial central cue Posner´s paradigm, positions in the vertical meridian were cued in order to evaluate the neuro-cognitive consequences in the processing of validly cued (VC) and invalidly cued (IC) targets. Sixty-four EEG channels were recorded and analyzed showing that IC targets produced an enhanced P3 component with respect to VC targets. With the purpose of reinforcing the idea of increased activation during IC targets and to define the areas in which the increased activation would occur, source localization was applied to the ERPs. LORETA and single dipole localization showed that the early P3 presented a localization in the dorsal part of the anterior cingulate cortex (dACC), while the late P3 was fitted by single dipole more posterior than the early P3, and LORETA added a source in the parahippocampal gyrus in addition to the already activated dACC. LORETA results also showed a differential activation of the inferior frontal gyrus when IC targets were processed. The previous results suggest that subjects prepare to accomplish the task upon specification of the cue. Therefore, when the IC target appears, it induces the activation of the frontal cortex including areas related to the conflict monitoring system and to the processing of unexpected events. The IC targets also induce the revision of internal models about the task, possibly by activation of the temporo-mesial surface. All the obtained current source differences indicate that a higher brain activation during IC trials with respect to VC trials occurs.
Brain Research Bulletin, 2010
The influence of cerebral maturity on the neurocognitive evaluation of target stimuli that have b... more The influence of cerebral maturity on the neurocognitive evaluation of target stimuli that have been cued by a spatial directional central cue, which, validly or invalidly, indicates the spatial position of the upcoming target has been investigated. ERPs and behavioural responses were recorded in 18 children and 20 young adults. P3a and P3b amplitudes were analyzed in the valid and invalid trials to assess possible differences between children and young adults. Young adults showed more activation in anterior (P3a) and posterior (P3b) areas in the invalid than the valid condition, whereas children only showed greater activation in P3b. This may be due to the later maturation of the frontal cortex than the more posterior sites. Children also showed a greater P3 component amplitude and a topography shifting to occipital sites, irrespective of the experimental condition.
Brain Research Bulletin, 2007
The preparation for stimuli and responses in which the position and required finger to respond ar... more The preparation for stimuli and responses in which the position and required finger to respond are cued, produces the preparatory activation of the specific neural resources that are going to be needed for the completion of the task. The focus of the present report is to evaluate if the fronto-parietal networks activated in fMRI studies during endogenous attention are also activated during the CNV period using EEG recording. The behavioural responses and 64 EEG channels were recorded during an S1-S2 paradigm similar to Posner central cue paradigms. The LORETA analysis based in the averaging of the z-LORETA values showed that the Brodmann&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s areas with the highest activation during the CNV period were in the medial and superior frontal areas, fronto-parietal lateral areas (including the premotor cortex) and extrastriate visual cortex. These results suggest that in addition to the previously described activation in premotor-motor, posterior sensory and superior and medial frontal areas, the activation of fronto-parietal networks is a main contributor to the CNV, indicating the endogenous attentional effort during the CNV period.