Enrique Hortal

Dr. Enrique Hortal

Maastricht University, Maastricht, Limburg, The Netherlands
orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2015 in Neurocomputing
Verified
Journal Article
Closed access
Enrique HortalEnrique Hortal
Enrique Hortal
DPD. Planelles
D. Planelles
ACA. Costa
A. Costa
Eduardo IáñezEduardo Iáñez
Eduardo Iáñez
Andrés UbedaAndrés Ubeda
Andrés Ubeda
EFEduardo Buglioni Fernandez
Eduardo Buglioni Fernandez

29 July 2020 in British Journal of Educational Technology
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Journal Article
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PSPenelope J. Standen
Penelope J. Standen
DBDavid J. Brown
David J. Brown
MTMohammad Taheri
Mohammad Taheri
MTMaria J. Galvez Trigo
Maria J. Galvez Trigo
HBHelen Boulton
Helen Boulton
Enrique HortalEnrique Hortal
Enrique Hortal
Artificial intelligence tools for education (AIEd) have been used to automate the provision of learning support to mainstream learners. One of the most innovative approaches in this field is the use of data and machine learning for the detection of a student’s affective state, to move them out of negative states that inhibit learning, into positive states such as engagement. In spite of their obvious potential to provide the personalisation that would give extra support for learners with intellectual disabilities, little work on AIEd systems that utilise affect recognition currently addresses this group. Our system used multimodal sensor data and machine learning to first identify three affective states linked to learning (engagement, frustration, boredom) and second determine the presentation of learning content so that the learner is maintained in an optimal affective state and rate of learning is maximised. To evaluate this adaptive learning system, 67 participants aged between 6 and 18 years acting as their own control took part in a series of sessions using the system. Sessions alternated between using the system with both affect detection and learning achievement to drive the selection of learning content (intervention) and using learning achievement alone (control) to drive the selection of learning content. Lack of boredom was the state with the strongest link to achievement, with both frustration and engagement positively related to achievement. There was significantly more engagement and less boredom in intervention than control sessions, but no significant difference in achievement. These results suggest that engagement does increase when activities are tailored to the personal needs and emotional state of the learner and that the system was promoting affective states that in turn promote learning. However, longer exposure is necessary to determine the effect on learning.

17 October 2015 in Journal of NeuroEngineering and Rehabilitation
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Journal Article
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Enrique HortalEnrique Hortal
Enrique Hortal
DPDaniel Planelles
Daniel Planelles
FRFrancisco Resquin
Francisco Resquin
JCJosé M. Climent
José M. Climent
Jose M. AzorinJose M. Azorin
Jose M. Azorin
JPJose L. Pons
Jose L. Pons
As a consequence of the increase of cerebro-vascular accidents, the number of people suffering from motor disabilities is raising. Exoskeletons, Functional Electrical Stimulation (FES) devices and Brain-Machine Interfaces (BMIs) could be combined for rehabilitation purposes in order to improve therapy outcomes. In this work, a system based on a hybrid upper limb exoskeleton is used for neurological rehabilitation. Reaching movements are supported by the passive exoskeleton ArmeoSpring and FES. The movement execution is triggered by an EEG-based BMI. The BMI uses two different methods to interact with the exoskeleton from the user’s brain activity. The first method relies on motor imagery tasks classification, whilst the second one is based on movement intention detection. Three healthy users and five patients with neurological conditions participated in the experiments to verify the usability of the system. Using the BMI based on motor imagery, healthy volunteers obtained an average accuracy of 82.9 ± 14.5 %, and patients obtained an accuracy of 65.3 ± 9.0 %, with a low False Positives rate (FP) (19.2 ± 10.4 % and 15.0 ± 8.4 %, respectively). On the other hand, by using the BMI based on detecting the arm movement intention, the average accuracy was 76.7 ± 13.2 % for healthy users and 71.6 ± 15.8 % for patients, with 28.7 ± 19.9 % and 21.2 ± 13.3 % of FP rate (healthy users and patients, respectively). The accuracy of the results shows that the combined use of a hybrid upper limb exoskeleton and a BMI could be used for rehabilitation therapies. The advantage of this system is that the user is an active part of the rehabilitation procedure. The next step will be to verify what are the clinical benefits for the patients using this new rehabilitation procedure.

29 September 2014 in Sensors
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DPDaniel Planelles
Daniel Planelles
Enrique HortalEnrique Hortal
Enrique Hortal
ÁCÁlvaro Costa
Álvaro Costa
Andrés UbedaAndrés Ubeda
Andrés Ubeda
Eduardo IáñezEduardo Iáñez
Eduardo Iáñez
Jose M. AzorinJose M. Azorin
Jose M. Azorin
This paper presents a methodology to detect the intention to make a reaching movement with the arm in healthy subjects before the movement actually starts. This is done by measuring brain activity through electroencephalographic (EEG) signals that are registered by electrodes placed over the scalp. The preparation and performance of an arm movement generate a phenomenon called event-related desynchronization (ERD) in the mu and beta frequency bands. A novel methodology to characterize this cognitive process based on three sums of power spectral frequencies involved in ERD is presented. The main objective of this paper is to set the benchmark for classifiers and to choose the most convenient. The best results are obtained using an SVM classifier with around 72% accuracy. This classifier will be used in further research to generate the control commands to move a robotic exoskeleton that helps people suffering from motor disabilities to perform the movement. The final aim is that this brain-controlled robotic exoskeleton improves the current rehabilitation processes of disabled people.

26 April 2016 in PLOS ONE
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ÁCÁlvaro Costa
Álvaro Costa
Eduardo IáñezEduardo Iáñez
Eduardo Iáñez
Andrés UbedaAndrés Ubeda
Andrés Ubeda
Enrique HortalEnrique Hortal
Enrique Hortal
ADAntonio J. Del-Ama
Antonio J. Del-Ama
Jose M. AzorinJose M. Azorin
Jose M. Azorin
Rehabilitation techniques are evolving focused on improving their performance in terms of duration and level of recovery. Current studies encourage the patient’s involvement in their rehabilitation. Brain-Computer Interfaces are capable of decoding the cognitive state of users to provide feedback to an external device. On this paper, cortical information obtained from the scalp is acquired with the goal of studying the cognitive mechanisms related to the users’ attention to the gait. Data from 10 healthy users and 3 incomplete Spinal Cord Injury patients are acquired during treadmill walking. During gait, users are asked to perform 4 attentional tasks. Data obtained are treated to reduce movement artifacts. Features from δ(1 − 4Hz), θ(4 − 8Hz), α(8 − 12Hz), β(12 − 30Hz), γlow(30 − 50Hz), γhigh(50 − 90Hz) frequency bands are extracted and analyzed to find which ones provide more information related to attention. The selected bands are tested with 5 classifiers to distinguish between tasks. Classification results are also compared with chance levels to evaluate performance. Results show success rates of ∼67% for healthy users and ∼59% for patients. These values are obtained using features from γ band suggesting that the attention mechanisms are related to selective attention mechanisms, meaning that, while the attention on gait decreases the level of attention on the environment and external visual information increases. Linear Discriminant Analysis, K-Nearest Neighbors and Support Vector Machine classifiers provide the best results for all users. Results from patients are slightly lower, but significantly different, than those obtained from healthy users supporting the idea that the patients pay more attention to gait during non-attentional tasks due to the inherent difficulties they have during normal gait. This study provides evidence of the existence of classifiable cortical information related to the attention level on the gait. This fact could allow the development of a real-time system that obtains the attention level during lower limb rehabilitation. This information could be used as feedback to adapt the rehabilitation strategy.

24 August 2016 in International Journal of Neural Systems
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Journal Article
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Enrique HortalEnrique Hortal
Enrique Hortal
Andrés UbedaAndrés Ubeda
Andrés Ubeda
Eduardo IáñezEduardo Iáñez
Eduardo Iáñez
Jose M. AzorinJose M. Azorin
Jose M. Azorin
EFEduardo Buglioni Fernandez
Eduardo Buglioni Fernandez