Early diagnosis of dementia

The diagnosis of Alzheimer’s disease, the most frequent form of dementia, requires critical information provided by the neuropsychologist. There are neuropsychological specific tools that allow to establish a probable diagnosis of Alzheimer’s disease at an early stage. Several studies have revealed the importance of attentional and executive functions in the cognitive evaluation of patients with early dementia. The best diagnotic procedures combine therefore the assessment of episodic memory and executive functions, and we are interested in discovering the most sensitive ones.

Neuropsychology of epilepsy

We have investigated the cognitive functionning of patients with temporal lobe epilepsy (TLE) for some years. These patients typically present with long term memory difficulties, usually explained by an encoding impairment. We have also shown however that these deficits can not be linked to metamemory problems.  We are interested in carrying on with this research, and to study the same phenomena in children.

Child and adolescent neuropsychology

We are also interested in the cognitive profiles of some neurodevelopmental disorders like attention deficit disorder and the strategies that can be implemented to help the children and the families that encounter these difficulties.

Unexpected changes in an otherwise repeated or structured sequence generate behavioral distraction. Testament to the fundamental nature of behavioral deviance distraction, it is observed with auditory, visual and tactile task-irrelevant stimuli. On the basis of the evidence available to date, the functional mechanisms at play seem coherent across modalities. Behavioral distraction occurs when a sound violates the cognitive system’s predictions as long as this sound is presented as part of a stream of task-irrelevant stimuli conveying event information about the target. In such circumstances, attention orients to and away from the unexpected deviant stimulus, destabilizing the maintenance of the relevant task set and triggering the involuntary processing of its semantic features. The outcome of this processing can linger in immediate memory long enough to interact with the processing of the target, increasing distraction when deviant and target are incompatible, reducing it when they are compatible. While involuntary, deviance distraction is nevertheless subject to top-down modulation insofar as it is abolished when deviants are expected, when attentional resources are not available to be deployed toward the deviant, and when task-irrelevant stimuli are uninformative and do not assist goal-directed behavior. On the other hand, deviance distraction increases in old age (at least in the cross-modal oddball task), or when participants experience strong emotions (such as sadness). These effects might possibly result from a reduction in the orientation of attention towards deviance (especially in conditions reducing P3a), but also a difficulty in disengaging attention from the deviant and reactivating the relevant task set. Increasing evidence indicates that behavioral deviance distraction is not the mere by-product of the electrophysiological responses and appears to derive from distinct, high-level, mechanisms.

Some key findings

• Sounds distract us because they violate the predictions of our cognitive system, not because they are rare per se.

• Behavioral distraction by deviant sounds disappears when these do not predict the imminent occurrence of a target stimulus.

• Cognitive control reduces deviance distraction

• Deviant vibration stimuli produce deviance distraction in much the same way as deviant sounds

• Unexpected sounds undergo some involuntary semantic processing through two routes, one depending on attention capture, one purely automatic.

Physical exercise
Physical activity does not only have beneficial effects on health, it also enhances certain cognitive functions. As part of a project funded by the Spanish Ministry of Economy and Competitiveness, we are investigating how regular aerobic exercise affect cognition in a variety of cognitive tasks. We have a special interest in executive functions sustained by frontal cortical regions and are currently pursuing several lines of investigation in that area.

Key finding

• Young adults practicing regular physical activity show better inhibitory control and working memory performance
  

We study the relationship between emotions and attention in various paradigms (e.g., oddball tasks, ANT) and with a special interest in the impact of emotions on the processing of neutral stimuli (in contrast to most of past research in which emotionally-loaded or biologically relevant stimuli are typically used). Our work includes the testing of participants selected for presenting with a certain personality trait, the induction of emotional states, and work with patients with depression or anxiety disorders.

Some key findings

• Induced sadness and happiness increase deviance distraction

• Patients with anxiety disorders have a higher risk of response freezing in the face of deviant sounds

• Trait anxiety impairs executive control, state anxiety increases alerting and orienting

• Clinically anxious patients exhibit both an attentional control deficit and a greater difficulty in disengaging from irrelevant stimuli

We are interested in how aging affects cognition and are currently pursuing several lines of research in that area.

Aging and deviance distraction. It is established that with aging comes a reduction in the ability to inhibit irrelevant stimuli. However, it is not clear whether this conclusion also applies to the distraction caused by deviant sounds. Evidence shows that aging amplifies deviance distraction in tasks where irrelevant stimuli are auditory and target stimuli visual, but conclusions are mixed in tasks where both types of stimuli are auditory. Our work explores the role of sensory modalities in deviance distraction as a function of age, comparing young and older adults. We are also interested in examining whether factors found to mediate deviance distraction in young adults are also at work in older adults.

Some key findings

• Older adults exhibit twice as much deviance distraction as young adults in the cross-modal oddball task.

• Cognitive aging also increases post-deviance distraction (residual distraction observed on the trial following a deviant trial).

• In our ongoing work, older adults do not appear to show any increase in distraction when both target and irrelevant stimuli are auditory.