@article{pmid40177046,

title = {Performing a task with a friend does not change semantic processes but preparation: a social N400 and CNV event-related potential study},

author = {Sujata Sinha and Ashley Chau-Morris and Milena Kostova and J Bruno Debruille},

doi = {10.3389/fpsyg.2025.1475106},

issn = {1664-1078},

year  = {2025},

date = {2025-01-01},

journal = {Front Psychol},

volume = {16},

pages = {1475106},

abstract = {The N400 event-related potential (ERP) indexes the semantic processing of words. Recently, social N400 effects were reported: N400 amplitudes were found to be larger in the presence of a confederate. We tested whether this increase would be even larger in participants with friends (Pwfs). This was not the case: whether the words were coherent, incoherent or equivocal, N400s were not larger in Pwfs than in alones. According to the N400 inhibition hypothesis, the social N400 effects previously reported with confederates could then be due to the automatic sidelining of information that occurs when building a common ground with a stranger. Interestingly, contingent negative variations (CNVs) developed as the words had to be classified at the occurrence of an imperative stimulus that followed. PwFs had larger CNVs than alones, suggesting heightened preparation to this imperative stimulus. Unexpectedly, the larger this effect, the less confident PwFs were in their classifications. Given their higher levels of state anxiety before and after the experiment, it thus seems that the presence of someone else completing the same task, even if it is a friend, induces performance pressure, enhances anxiety and preparation, and diminishes self-confidence.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid38316943,

title = {Quantifying the effects of practicing a semantic task according to subclinical schizotypy},

author = {Mingyi Diao and Ilya Demchenko and Gifty Asare and Yelin Chen and J Bruno Debruille},

doi = {10.1038/s41598-024-53468-4},

issn = {2045-2322},

year  = {2024},

date = {2024-02-01},

journal = {Sci Rep},

volume = {14},

number = {1},

pages = {2900},

abstract = {The learning ability of individuals within the schizophrenia spectrum is crucial for their psychosocial rehabilitation. When selecting a treatment, it is thus essential to consider the impact of medications on practice effects, an important type of learning ability. To achieve this end goal, a pre-treatment test has to be developed and tested in healthy participants first. This is the aim of the current work, which takes advantage of the schizotypal traits present in these participants to preliminary assess the test's validity for use among patients. In this study, 47 healthy participants completed the Schizotypal Personality Questionnaire (SPQ) and performed a semantic categorization task twice, with a 1.5-hour gap between sessions. Practice was found to reduce reaction times (RTs) in both low- and high-SPQ scorers. Additionally, practice decreased the amplitudes of the N400 event-related brain potentials elicited by semantically matching words in low SPQ scorers only, which shows the sensitivity of the task to schizotypy. Across the two sessions, both RTs and N400 amplitudes had good test-retest reliability. This task could thus be a valuable tool. Ongoing studies are currently evaluating the impact of fully deceptive placebos and of real antipsychotic medications on these practice effects. This round of research should subsequently assist psychiatrists in making informed decisions about selecting the most suitable medication for the psychosocial rehabilitation of a patient.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid37961792,

title = {From jamais to déjà vu: The respective roles of semantic and episodic memory in novelty monitoring and involuntary memory retrieval},

author = {Louis Renoult and J Bruno Debruille},

doi = {10.1017/S0140525X23000158},

issn = {1469-1825},

year  = {2023},

date = {2023-11-01},

journal = {Behav Brain Sci},

volume = {46},

pages = {e373},

abstract = {Barzykowski and Moulin's model proposes that déjà vu and involuntary autobiographical memories are the result of a continuously active memory system that tracks the novelty of situations. Déjà vu would only have episodic content and concern interpretation of prior experiences. We argue that these aspects of the model would gain to be clarified and explored further and we suggest possible directions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid37773255,

title = {Finding normal-to-better neurocognitive indexes in individuals with schizotypal traits using a social role task},

author = {Mingyi Diao and Ilya Demchenko and Gifty Asare and Jingyan Quan and J Bruno Debruille},

doi = {10.1038/s41537-023-00394-5},

issn = {2754-6993},

year  = {2023},

date = {2023-09-01},

journal = {Schizophrenia (Heidelb)},

volume = {9},

number = {1},

pages = {66},

abstract = {Schizophrenia patients make more errors and have longer reaction times (RTs) than healthy controls in most cognitive tasks. Deficits are also observed in subclinical participants having high scores on the schizotypal personality questionnaire (SPQ). They are accompanied by smaller amplitudes of the event-related brain potentials (ERPs) that index attention and semantic- and working-memory. These functions are thus thought to be impaired in individuals having various schizophrenia attributes (SzAs). Nevertheless, normal RTs were recently found in SzAs during a particular self-referential task where half of the stimuli were names of extraordinary social roles (e.g., genius). Each name (ordinary or extraordinary) was presented individually, and participants were asked to decide whether or not they would consider themselves performing the role at any moment of their lives. To further test an absence of cognitive deficits in this task, the ERPs elicited by names of social roles were also examined in 175 healthy participants. The absence of longer RTs in high- than in low-SPQs was replicated. Moreover, the ERPs of high SPQs had larger occipital N1s, larger P2s and larger occipital N400s than those of low SPQs while late positive potentials (LPPs) were of similar amplitudes. Such results are consistent with clinical observations of greater attention and faster processing of stimuli related to extraordinary/delusional beliefs. Further studies should test whether the cognitive deficits found in SzAs are due to the use of tasks and stimuli that are less within their focus of interest than within that of healthy controls.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid37537222,

title = {Unveiling the need of interactions for social N400s and supporting the N400 inhibition hypothesis},

author = {Sujata Sinha and Sarah Del Goleto and Milena Kostova and J Bruno Debruille},

doi = {10.1038/s41598-023-39345-6},

issn = {2045-2322},

year  = {2023},

date = {2023-08-01},

journal = {Sci Rep},

volume = {13},

number = {1},

pages = {12613},

abstract = {When participants (Pps) are presented with stimuli in the presence of another person, they may consider that person's perspective. Indeed, five recent ERP studies show that the amplitudes of their N400s are increased. The two most recent ones reveal that these social-N400 increases occur even when instructions do not require a focus on the other's perspective. These increases also happen when Pps know that this other person has the same stimulus information as they have. However, in all these works, Pps could see the other person. Here, we tested whether the interaction occurring with this sight is important or whether these social N400 increases also occur when the other person is seated a bit behind Pps, who are aware of it. All had to decide whether the word ending short stories was coherent, incoherent, or equivocal. No social N400 increase was observed: N400s elicited by those words in Pps who were with a confederate (n = 50) were similar to those of Pps who were alone (n = 51). On the other hand, equivocal endings did not elicit larger N400s than coherent ones but triggered larger late posterior positivities (LPPs), like in previous studies. The discussion focuses on the circumstances in which perspective-taking occurs and on the functional significance of the N400 and the LPP.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30662398,

title = {Mimicking Schizophrenia: Reducing P300b by Minimally Fragmenting Healthy Participants' Selves Using Immersive Virtual Reality Embodiment},

author = {Bernhard Spanlang and Birgit Nierula and Maud Haffar and J Bruno Debruille},

doi = {10.3389/fnhum.2018.00504},

issn = {1662-5161},

year  = {2018},

date = {2018-01-01},

journal = {Front Hum Neurosci},

volume = {12},

pages = {504},

abstract = {The most robust and clear biological index differentiating persons with schizophrenia from healthy controls is the drastic reduction of the amplitude of their P300b event-related brain potential (ERP). However, the cause of that reduction remains obscure. Nevertheless, the P300b belongs to the family of the late posterior positivities (LPPs) which are closely related to the consciousness of the meaning of the stimulus in the task e.g., the:  am seeing the target stimulus for which  have to respond. The fragmentation of the self present in schizophrenia, could thus be the cause. If this were true, then P300bs should be somewhat reduced in healthy participants when their self representations are temporarily and minimally fragmented. We tested this hypothesis by using the innocuous fragmentation of the self that occurs in virtual reality (VR). There, participants can have a fragment of their self in an avatar they feel embodied in, within a VR room, while having another fragment of their self in their real body in the real room where they know they are. Our participants were thus equipped with a head mounted display in which they viewed a virtual room where a female humanoid avatar was facing them. She was lifting her right hand in synchrony with the participants, in order to induce in them a feeling of embodiment. Stimuli were a frequent green- and a rare red-disk, the oddball stimulus, occurring over the right hand of the avatar. Participants had to perform a Go/NoGo task, lifting their right hand to the frequent green disk and repressing this action for the oddball red disk. In the syncMove block of trials the avatar was lifting her right hand synchronously with the participant, disturbing her self representation as confirmed by the debriefing session. In the noMove block, the avatar remained immobile. In the classic block, only the red and the green disk were displayed on a monochrome background, neither the room nor the avatar were shown. As predicted, P300bs were found to be smaller in the syncMove block than in the noMove- and the classic-block in participants who had the classically large P300b oddball effect between ERPs to the frequent and those to the rare stimuli. Reduced P300bs of schizophrenia could thus be partly due to self fragmentation. Results may also open an avenue of research to the functional significance of LPPs and the content of the consciousness indexed by these potentials.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}