A Frontal Neuropsychological Profile in Fitness to Drive Umberto León-Domínguez, Ignacio Solís-Marcos, Cristina Alejandra López-Delgado, Juan Manuel Barroso y Martín, José León-Carrión Accident Analysis and Prevention, 2020 Traffic accidents are a global concern due to the elevated mortality rates of both drivers and pedestrians. The World Health Organization declared 2011-2020 as the Decade of Action for Road Safety, endorsing initiatives to reduce traffic-related deaths. Yet, despite these incentives, fatal accidents still occur. Different studies have linked deficits in executive functions to risky driving attitudes and crashes. The present study focuses on demographic, cognitive and personality factors, related to the prefrontal cortex, that are characteristic of drivers prone to risky behavior behind the wheel. The penalty Points System was used to classify drivers as "safe", with no point loss over a two-year period, or "risky", with full point loss during the same interval. A neuropsychological assessment of prefrontal cognitive functions was carried out on each group to identify variables associated with safe and risky behavior. Neuropsychological indexes were obtained from a continuous performance task without cue (Simple Attention), a continuous performance task with cue (Conditioned Attention), the Tower of Hanoi test and the Neurologically-related Changes in Personality Inventory (NECHAPI). A Discriminant Analysis (DA) found that education level, reaction times in Simple and Conditioned Attention, learning errors in the Tower of Hanoi and vulnerability in the personality test, best predicted whether drivers were likely to be in the safe or risky group. Finally, a cross-validation analysis performed on the same sample correctly classified 87.5% of the drivers. These data suggest that prefrontal dysfunction contributes to risky behavior behind the wheel. The inclusion of cognitive programs to identify and train drivers with this propensity could reduce risky driving, and consequently, save lives on the road.
Safe driving and executive functions in healthy middle-aged drivers Umberto León-Domínguez, Ignacio Solís-Marcos, Elena Barrio-Álvarez, Juan Manuel Barroso y Martín, José León-Carrión Applied Neuropsychology Adult, 2017 The introduction of the point system driver’s license in several European countries could offer a valid framework for evaluating driving skills. This is the first study to use this framework to assess the functional integrity of executive functions in middle-aged drivers with full points, partial points or no points on their driver’s license (N = 270). The purpose of this study is to find differences in executive functions that could be determinants in safe driving. Cognitive tests were used to assess attention processes, processing speed, planning, cognitive flexibility, and inhibitory control. Analyses for covariance (ANCOVAS) were used for group comparisons while adjusting for education level. The Bonferroni method was used for correcting for multiple comparisons. Overall, drivers with the full points on their license showed better scores than the other two groups. In particular, significant differences were found in reaction times on Simple and Conditioned Attention tasks (both p-values < 0.001) and in number of type-III errors on the Tower of Hanoi task (p = 0.026). Differences in reaction time on attention tasks could serve as neuropsychological markers for safe driving. Further analysis should be conducted in order to determine the behavioral impact of impaired executive functioning on driving ability.
Recovery of cognitive function during comprehensive rehabilitation after severe traumatic brain injury J León-Carrión, M Domínguez-Morales, J Martín, U Leon-Dominguez Journal of Rehabilitation Medicine, 2012 OBJECTIVE To explore the course and timing of functional recovery in patients who have emerged from coma after undergoing severe traumatic brain injury. METHODS An observational study involving 19 patients with traumatic brain injury recovered from coma who underwent holistic, intensive and multidisciplinary neurorehabilitation. Daily performance in each cognitive function (long-term memory, short-term memory, orientation, calculation, attention, mental control, automation, and planning) was clinically scored and compared at admission and discharge. RESULTS The course of cognitive recovery after post-traumatic coma is not uniform, offering a curve with many ups, downs and plateaus. To achieve a good response and outcome nearing normalcy, a patient needs over 300 h of intensive rehabilitation. CONCLUSION The consolidation of functional recovery in patients with traumatic brain injury requires time and adequate training, and discharge is not recommended until cognitive improvement is established.
Efficient learning produces spontaneous neural repetition suppression in prefrontal cortex Jose León-Carrión, Meltem Izzetoglu, Kurtulus Izzetoglu, Juan Francisco Martín-Rodríguez, Jesús Damas-López, Juan Manuel Barroso y Martin, María Rosario Domínguez-Morales Behavioural Brain Research, 2010 Our study focuses on the physiological effects of repetition on learning and working memory using an adaptation of Luria's Memory Word-Task (LMWT). We assess the hemodynamic response in dorsolateral prefrontal cortex (DLPFC) of 13 healthy subjects while completing LMWT. Free word recalls were acquired at the beginning, middle and end of the task. Behavioral results showed that all subjects could recall the complete word list by the 10th trial, which was considered as successful task accomplishment. We observed an attenuation of stimulus-evoked neural activity in prefrontal neurons. Our findings show that the temporal integration of efficient verbal learning is mediated by a mechanism known as neural repetition suppression (NRS). This mechanism facilitates cortical deactivation in DLPFC once learning is successfully completed. This cortical reorganization is interpreted as a progressive optimization of neural responses to produce a more efficient use of neural circuits. NRS could be considered one of the natural mechanisms involved in the processes of memory learning.
Delta-alpha ratio correlates with level of recovery after neurorehabilitation in patients with acquired brain injury Jose Leon-Carrion, Juan Francisco Martin-Rodriguez, Jesus Damas-Lopez, Juan Manuel Barroso y Martin, Maria Rosario Dominguez-Morales Clinical Neurophysiology, 2009 OBJECTIVE To explore the relationship between three QEEG global indexes and their association with functional outcome after neurorehabilitation in non-acute acquired brain injury (ABI) patients (traumatic brain injury and stroke). METHODS Twenty-one adult ABI patients in post-acute phase were studied. Delta-alpha ratio (DAR), Power Ratio Index (PRI) and Mean Brain Symmetry Index (mBSI) were calculated from resting-state EEG taken at admission. These indexes and other clinical variables were correlated with functional recovery achieved after six months of neurorehabilitation. RESULTS DAR showed the highest strength of association with the functional outcome measure (rho=-0.65, P=0.002). The other QEEG indexes and clinical variables showed modest non-significant correlations. A posteriori group analysis showed higher DAR in patients with poor recovery as compared to good recovery patients. CONCLUSIONS Functional recovery after neurorehabilitation appears to be associated with a number of clinical and neurophysiological variables. Among the latter, the ratio between delta and alpha may play a significant role in predicting and monitoring functional rehabilitation outcome. SIGNIFICANCE Neurophysiological assessment of ABI patients may be an important tool in monitoring and predicting outcomes after neurorehabilitation.
The hemodynamics of cognitive control: The level of concentration of oxygenated hemoglobin in the superior prefrontal cortex varies as a function of performance in a modified Stroop task José León-Carrion, Jesús Damas-López, Juan Francisco Martín-Rodríguez, José Maria Domínguez-Roldán, Francisco Murillo-Cabezas, Juan Manuel Barroso y Martin, M. Rosario Domínguez-Morales Behavioural Brain Research, 2008 The purpose of this study was to establish the relationship between the hemodynamic response of prefrontal cortex (PFC) and individual differences in cognitive control, as measured by a color-word interference task. Twenty-five healthy volunteers were observed through functional near infrared spectroscopy (fNIRS) while performing a modified Stroop paradigm. Mean concentration levels of oxygenated hemoglobin (oxy-Hb) were correlated with behavioral performance in the conflict task. Those with shorter reaction times had higher levels of oxy-Hb concentration in superior dorsolateral PFC. Our results are the first to show a positive correlation between behavioral performance and oxy-Hb levels in superior dorsolateral PFC in a cognitive conflict task. These results suggest that the availability of oxygen in the superior PFC, possibly linked to an increase in metabolism, may be related to attention level and effectiveness of cognitive control.
Brain function in the minimally conscious state: A quantitative neurophysiological study J. Leon-Carrion, J.F. Martin-Rodriguez, J. Damas-Lopez, J.M. Barroso y Martin, M.R. Dominguez-Morales Clinical Neurophysiology, 2008 OBJECTIVE To explore possible EEG power spectrum and coherence differences between patients in minimally conscious state (MCS) and patients with severe neurocognitive disorders (SND), who show signs of awareness. We also try to find EEG cortical sources that differentiate between both conditions using LORETA source analysis. METHODS We studied 16 patients with traumatic brain injury (7 MCS, 9 SND; aged 18-49) and compared EEG power spectra, coherence, and LORETA sources at rest for both groups. RESULTS EEG power spectra revealed significant differences in the delta range of both conditions. Patients in MCS showed a notably increased power in this band, compared to SND patients. LORETA analysis showed that posterior sources of delta and theta frequencies had higher amplitude in MCS patients than in SND patients. Regarding fast frequencies, lower source magnitudes in temporal and frontal lobes were found for MCS patients. CONCLUSIONS Our results stress the importance of fronto-temporal-parietal associative cortices within the "awareness-regions" model. Our results also suggest a relation between excess of slow wave activity and diminished level of awareness in brain injury population. SIGNIFICANCE Neurophysiological correlates in brain damaged patients who are severely impaired could be used to assess the integrity of brain areas responsible for awareness.
A QEEG index of level of functional dependence for people sustaining acquired brain injury: The Seville Independence Index (SINDI) Jose Leon-Carrion, Juan Francisco Martin-Rodriguez, Jesus Damas-Lopez, Juan Manuel Barroso Y Martin, Maria Del Rosario Dominguez-Morales Brain Injury, 2008 Primary objective: To find an easy-to-use, valid and reliable tool for evaluating the level of functional dependence of an individual with brain damage who seeks a diagnosis of his/her functional dependence in daily activities. Methods: Eighty-one patients with acquired brain injury (ABI) in post-acute phase, 40 traumatic brain injury (TBI) and 41 cerebral vascular accident (CVA), were assessed using quantitative electroencephalography (QEEG) and grouped according to the FIM + FAM scale. Discriminant analysis was performed on QEEG variables to obtain a discriminant function with the best discriminative capacity between functionality groups. Results: Discriminant analysis showed classification accuracy of 100% in the training set sample and 75% in an external cross-validation sample; 100% sensitivity and 100% specificity were reached. Coherence measures were the most numerous variables in the function. Conclusions: These results point out that the discriminant function may be a useful tool in objective evaluations of patients seeking a diagnosis of their level of dependence and that it could be included in current functionality assessment protocols.
A lasting post-stimulus activation on dorsolateral prefrontal cortex is produced when processing valence and arousal in visual affective stimuli Jose León-Carrión, Juan Francisco Martín-Rodríguez, Jesús Damas-López, Kambiz Pourrezai, Kurtulus Izzetoglu, Juan Manuel Barroso y Martin, María Rosario Domínguez-Morales Neuroscience Letters, 2007 This paper introduces a new paradigm in the study of emotional processes through functional neuroimaging. We study whether the valence and arousal of visual stimuli influence neuroimaging of the evoked hemodynamic changes. Using functional near-infrared spectroscopy (fNIRS), we investigate evoked-cerebral blood oxygenation (CBO) changes in dorsolateral prefrontal cortex (DLPFC) during direct exposure to different emotion-eliciting stimuli ('on' period), and during the period directly following stimulus cessation ('off' period). We hypothesize that the evoked-CBO, rather than return to baseline after stimulus cessation, would show either overshoot or undershoot. The study includes 30 healthy subjects and a total of 9 stimuli, which consist of video-clips with different emotional content. The total sample of trials studied (270) is classified according to the valence and arousal ratings given by the subjects. Results show a more robust activation in DLPFC during the 'off' period than during the 'on' period, depending on the subjective degree of arousal given to the stimulus. Our findings provide the first fNIRS evidence showing that an increment in subjective arousal leads to activation in DLPFC which persists after stimulus cessation and this does not occur with non-arousing stimuli. Neuroimaging studies must consider the duration and affective dimensions of the stimulus as well as the duration of the scanning to specify how much of the recorded response is analyzed. Not accounting for this difference may contribute to confusion in the data interpretation.
Does dorsolateral prefrontal cortex (DLPFC) activation return to baseline when sexual stimuli cease?. The role of DLPFC in visual sexual stimulation Jose Leon-Carrion, Juan Francisco Martín-Rodríguez, Jesús Damas-López, Kambiz Pourrezai, Kurtulus Izzetoglu, Juan Manuel Barroso y Martin, M. Rosario Dominguez-Morales Neuroscience Letters, 2007 A fundamental question in human sexuality regards the neural substrate underlying sexually-arousing representations. Lesion and neuroimaging studies suggest that dorsolateral pre-frontal cortex (DLPFC) plays an important role in regulating the processing of visual sexual stimulation. The aim of this Functional Near-Infrared Spectroscopy (fNIRS) study was to explore DLPFC structures involved in the processing of erotic and non-sexual films. fNIRS was used to image the evoked-cerebral blood oxygenation (CBO) response in 15 male and 15 female subjects. Our hypothesis is that a sexual stimulus would produce DLPFC activation during the period of direct stimulus perception ("on" period), and that this activation would continue after stimulus cessation ("off" period). A new paradigm was used to measure the relative oxygenated hemoglobin (oxyHb) concentrations in DLPFC while subjects viewed the two selected stimuli (Roman orgy and a non-sexual film clip), and also immediately following stimulus cessation. Viewing of the non-sexual stimulus produced no overshoot in DLPFC, whereas exposure to the erotic stimulus produced rapidly ascendant overshoot, which became even more pronounced following stimulus cessation. We also report on gender differences in the timing and intensity of DLPFC activation in response to a sexually explicit visual stimulus. We found evidence indicating that men experience greater and more rapid sexual arousal when exposed to erotic stimuli than do women. Our results point out that self-regulation of DLPFC activation is modulated by subjective arousal and that cognitive appraisal of the sexual stimulus (valence) plays a secondary role in this regulation.
The attentional system in brain injury survivors José León-carrión, R. Rodriguez-duarte, J. M. Barroso-martin, F. Machuca, M. R. Dominguez-morales, F. Murillo, P. Forastero, M. A. Muñoz International Journal of Neuroscience, 1996
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