Specific mechanisms underlying executive and emotional apathy: A phenotyping study.

Apathy is a behavioral symptom prevalent both in neuropsychiatric pathologies and in the healthy population. However, the knowledge of the cognitive and neural mechanisms underlying apathy is still very limited, even if clinical and fMRI data support the existence of three forms of apathy (executive, emotional, initiative). These forms could be explained by the alteration of specific mechanisms.

Initiative apathy trait underlies individual differences in the ability to anticipate and expend cognitive effort in cost-benefit decision-making tasks.

Initiative apathy is the most disabling form of apathy, prevalent both in neuropsychiatric pathologies and in the healthy population. This apathy has been specifically associated with functional abnormalities of the anterior cingulate cortex, a key structure underlying Effort-based Decision-Making (EDM). The main aim of the present study was to explore, for the first time, the cognitive and neural effort mechanisms of initiative apathy, by distinguishing the steps of effort anticipation and effort expenditure and the potential modulating effect of motivation.

Facing the pandemic and lockdown: an insight on mental health from a longitudinal study using diaries.

We conducted a longitudinal online study to examine attenuated psychotic symptoms (APS) over time in a sample of locked-down individuals. We used (i) questionnaires and (ii) the automatic analysis of the emotional content of narratives. Participants (N = 162) were recruited to complete an online survey 4 times between March and June 2020 (T1, T2, T3, T4).

Conjoint fluctuations of PFC-mediated processes and behavior: An investigation of error-related neural mechanisms in relation to sustained attention.

The ability to detect errors, which derives from the medial prefrontal cortex (mPFC), is crucial to maintain attention over a long period of time. While impairment of this ability has been reported in patients with sustained attention disruption, the role mPFC-mediated processes play in the intra-individual fluctuation of sustained attention remains an open question. In this context, we computed the variance time course of reaction time (RT) of 42 healthy individuals to distinguish intra-individual periods of low and high performance instability, assumed to represent optimal and suboptimal attentional states, when performing a sustained Go/NoGo task.

Investigation of electrophysiological precursors of attentional errors in schizophrenia: Toward a better understanding of abnormal proactive control engagement.

Impaired cognitive control has been associated with the occurrence of attentional errors in those with schizophrenia. However, the extent of altered proactive or reactive control underlying such errors is still unknown. Twenty-two patients with schizophrenia and 21 healthy matched controls performed a detection task (i.

Evidence of impaired proactive control under positive affect.

If it can be assumed that positive affect modulates cognitive control, the underlying mechanisms remain unclear. The main aim of this study was to investigate how positive affect influences proactive and reactive modes of control and to explore the temporal dynamic of this influence, in terms of its transient and/or sustained effects. We used the AX-continuous performance task, combined with event-related potentials (ERP) recording.

fMRI working memory hypo-activations in schizophrenia come with a coupling deficit between arousal and cognition.

Cognition has become a target for therapeutic intervention and favoring arousal could be a way to help patients. Working memory is an arousal dependent cognitive function. This study used functional MRI (fMRI) as a surrogate marker of working memory to evaluate the sensitivity of patients' hypoactive regions to arousal in a subpopulation of rehabilitated patients.

Correcting for the echo-time effect after measuring the cerebral blood flow by arterial spin labeling.

Purpose: To take into account the echo time (TE) influence on arterial spin labeling (ASL) signal when converting it in regional cerebral blood flow (rCBF). Gray matter ASL signal decrease with increasing TE as a consequence of the difference in the apparent transverse relaxation rates between labeled water in capillaries and nonlabeled water in the tissue (δR 2*). We aimed to measure ASL/rCBF changes in different parts of the brain and correct them.

Evidence for a role of the parafascicular nucleus of the thalamus in the control of epileptic seizures by the superior colliculus.

Purpose: The aim of this study was to investigate whether the nucleus parafascicularis (Pf) of the thalamus could be a relay of the control of epileptic seizures by the superior colliculus (SC). The Pf is one of the main ascending projections of the SC, the disinhibition of which has been shown to suppress seizures in different animal models and has been proposed as the main relay of the nigral control of epilepsy.

Methods: Rats with genetic absence seizures (generalized absence epilepsy rat from Strasbourg or GAERS) were used in this study.