Attention and Consciousness
We are interested in exploring how our conscious perception is modulated by different attentional subsystems, such as spatial orienting, alerting, or executive control. By manipulating different attentional mechanisms and exploring their effects on conscious perception, we aim at better understanding how information is selected from our crowded environment to create our conscious experience (see Chica et al., 2012, Frontiers in Psychology).
We pay especial attention to the brain mechanisms subserving attention and consciousness interactions, and explore attentional mechanisms and conscious perception in brain damaged patients and in healthy controls using a variety of methods, such as functional Magnetic Resonance Imaging (fMRI), electroencephalographic recordings (EEG), and Transcranial Magnetic Stimulation (TMS).
We have demonstrated that conscious perception is facilitated by attentional orienting thanks to the activation of a distributed fronto-parietal network (Chica et al., 2013, Cerebral Cortex; Spagna et al., 2022, Cerebral Cortex); alerting and consciousness interact in a fronto-striatal network (Chica et al., 2016, Scientific Reports); and executive attention modulates conscious perception due to the activation of frontal structures such as the anterior cingulated cortex or the pre-SMA (Colás et al., 2018, Neuropsychologia; Martín Signes et al., 2021, Cortex).
Improving consciousness using a close-loop feedback training
In this project we aim at developing strategies to improve attentional modulations over perception, which can be of great interest for real-life activities in which errors are expected if attention fails. We are developing an algorithm that will use multivariate pattern analysis based on electroencephalographic (EEG) data to try to boost attentional effects over perception.
We will record EEG data while participants perform a difficult perceptual task. The EEG data will be use later to train a machine learning algorithm whose task is to predict the participants’ responses (i.e. correct and incorrect responses) from the recorded brain activity. Once the algorithm is trained with prerecorded data, it will be deployed on the computer where stimuli are being presented, so that the errors made by the participants can be detected even before they have reacted to the stimuli. Every time a possible error is detected by the algorithm, an alerting tone will be presented to the participants, which is well-known to improve performance by transiently increasing arousal.
Endogenous and exogenous attention
Orienting of attention in space can be controlled either endogenously (which is also known as top-down or voluntary attention), or exogenously, by external stimulation (bottom-up, involuntary stimulus-driven attention).
In this line of research, we explore the conditions where these two mechanisms are independent, produce different effects on information processing, and are supported by partially different brain regions.
We have largely explored the effects of both types of attention in the healthy population (see Chica et al., 2013, Behavioural Brain Research; Cobos et al., 2022, Quarterly Journal of Experimental Psychology), but also in patients with brain damage (see e.g. Bourgeois et al., 2013, Cortex; Bourgeois et al., 2015, Neuropsychologia). We have used TMS to explore the neural bases of both types of attention (Chica et al., 2011, Journal of Neuroscience; Martín-Arévalo et al., 2019, Cortex) and have discovered that endogenous and exogenous attention are implemented in partially overlapping, but different, brain regions.
In collaboration with Pom Charras (University of Montpellier) and Mariagrazia Capizzi (University of Montpellier and University of Granada) we are also exploring how different forms of attention to space and time can be independent or interactive processes.
Clinical Applications of Neuroscience: Locating Language Areas in Epileptic Patients and Restoring Speech in Paralyzed People
In collaboration with Dr. José Andrés González López (Dept. Signal Theory, Telematics and Communications, University of Granada), Pedro Macizo (Dept. Experimental Psychology, University of Granada), and the Epilepsy Unit from the Hospital Clínico Virgen de las Nieves de Granada, this project aims at localizing the brain areas involved in language processing from intracranial EEG data, with the clinical aim of preserving these regions during the resection of brain tissue in epileptic patients. A second aim of the project is to decode speech from the intracranial EEG data using state-of-the-art deep learning techniques (Gonzalez-Lopez et al., 2022, Proc. IberSPEECH).
White matter contributions to cognitive processes in the damaged and the healthy brain
Damage to localized brain regions can produce important impairments in both attention and consciousness. But damage to white matter pathways can also produce important deficits. The disconnections of a white matter fascicule connecting the parietal and the frontal lobe (the Superior Longitudinal Fascicule, SLF) has been demonstrated to cause hemispatial neglect, a syndrome characterized by significant impairments in both attention and consciousness.
Interesting, the integrity of white matter tracks in healthy individuals also correlates with their cognitive abilities. We have demonstrated that the integrity of the SLF in the healthy brain correlates with the activation of brain functional networks associated to attentional orienting and alerting (Chica et al., 2018, Brain Structure and Function). When using Transcranial Magnetic Stimulation in healthy participants, the integrity of the SLF also correlates with the TMS effects observed (Martín-Signes et al., 2017, Cerebral Cortex; Martín-Signes et al., 2019, Cortex; Martín-Signes et al., 2021, Cortex; Martín-Arévalo et al., 2019, Cortex).
Understanding the role of white matter connections in the healthy and damaged brain seems therefore essential in the study of attention and consciousness.
Development of conscious attention
In this project we will explore the neural basis of the development of conscious attention and its relationship to the establishment of anatomical and functional connections in the brain. We aim to test a sample of infants with a task that presents local and global sequences, which are broken on a percentage of trials. Local deviants relate to the detection of salient stimuli, whereas global deviants involve integrating information over longer periods. We will assess infants at two time points: in the first month and at 3-4 months of life. Infants will perform the “global-local” task while their brain activity is recorded using EEG. They will also participate in an MRI session to measure functional and anatomical connectivity between brain regions.
The development of conscious attention, and the brain mechanisms that support it, are transversal skills that will allow the development of executive control, rule learning in language or associative learning, among others. Therefore, EEG, anatomical and functional connectivity data from this project could serve in the near future as neural markers of problems in the development of these skills.