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2021 ◽  
Author(s):  
Danique Jeurissen ◽  
S Shushruth ◽  
Yasmine El-Shamayleh ◽  
Gregory D Horwitz ◽  
Michael N Shadlen

AbstractPerceptual decisions arise through the transformation of samples of evidence into a commitment to a proposition or plan of action. Such transformation is thought to involve cortical circuits capable of computation over time scales associated with working memory, attention, and planning. Neurons in the lateral intraparietal area (LIP) are thought to play a role in all of these functions, and much of what is known about the neurobiology of decision making has been influenced by studies of LIP and its network of cortical and subcortical connections. However a causal role of neurons in LIP remains controversial. We used pharmacological and chemogenetic methods to inactivate LIP in one hemisphere of four rhesus monkeys. Inactivation produced clear biases in decisions, but the effects dissipated despite the persistence of neural inactivation, implying compensation by other unaffected areas. Compensation occurs on a rapid times scale, within an experimental session, and more gradually, across sessions. The findings resolve disparate studies and inform interpretation of focal perturbations of brain function.


2021 ◽  
Vol 15 ◽  
Author(s):  
Seonghun Park ◽  
Do-Won Kim ◽  
Chang-Hee Han ◽  
Chang-Hwan Im

Neurocinematics is an emerging discipline in neuroscience, which aims to provide new filmmaking techniques by analyzing the brain activities of a group of audiences. Several neurocinematics studies attempted to track temporal changes in mental states during movie screening; however, it is still needed to develop efficient and robust electroencephalography (EEG) features for tracking brain states precisely over a long period. This study proposes a novel method for estimating emotional arousal changes in a group of individuals during movie screening by employing steady-state visual evoked potential (SSVEP), which is a widely used EEG response elicited by the presentation of periodic visual stimuli. Previous studies have reported that the emotional arousal of each individual modulates the strength of SSVEP responses. Based on this phenomenon, movie clips were superimposed on a background, eliciting an SSVEP response with a specific frequency. Two emotionally arousing movie clips were presented to six healthy male participants, while EEG signals were recorded from the occipital channels. We then investigated whether the movie scenes that elicited higher SSVEP responses coincided well with those rated as the most impressive scenes by 37 viewers in a separate experimental session. Our results showed that the SSVEP response averaged across six participants could accurately predict the overall impressiveness of each movie, evaluated with a much larger group of individuals.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ami Cohen ◽  
Kfir Asraf ◽  
Ivgeny Saveliev ◽  
Orrie Dan ◽  
Iris Haimov

AbstractThe ability to recognize emotions from facial expressions is essential to the development of complex social cognition behaviors, and impairments in this ability are associated with poor social competence. This study aimed to examine the effects of sleep deprivation on the processing of emotional facial expressions and nonfacial stimuli in young adults with and without attention-deficit/hyperactivity disorder (ADHD). Thirty-five men (mean age 25.4) with (n = 19) and without (n = 16) ADHD participated in the study. During the five days preceding the experimental session, the participants were required to sleep at least seven hours per night (23:00/24:00–7:00/9:00) and their sleep was monitored via actigraphy. On the morning of the experimental session, the participants completed a 4-stimulus visual oddball task combining facial and nonfacial stimuli, and repeated it after 25 h of sustained wakefulness. At baseline, both study groups had poorer performance in response to facial rather than non-facial target stimuli on all indices of the oddball task, with no differences between the groups. Following sleep deprivation, rates of omission errors, commission errors and reaction time variability increased significantly in the ADHD group but not in the control group. Time and target type (face/non-face) did not have an interactive effect on any indices of the oddball task. Young adults with ADHD are more sensitive to the negative effects of sleep deprivation on attentional processes, including those related to the processing of emotional facial expressions. As poor sleep and excessive daytime sleepiness are common in individuals with ADHD, it is feasible that poor sleep quality and quantity play an important role in cognitive functioning deficits, including the processing of emotional facial expressions that are associated with ADHD.


2021 ◽  
Author(s):  
Charlotte Barot ◽  
Louise Chevalier ◽  
Lucie Martin ◽  
Véronique Izard

Many famous scientists have reported anecdotes where a new understanding occurred to them suddenly, in an unexpected flash. Do people generally experience such “Eureka” moments when learning science concepts, and how do these episodes relate to learning mechanisms? To address these questions, we developed a new paradigm where participants learned a mathematical concept in the lab, in a single experimental session. Participants were given 1 to 7 lessons introducing the concept of geodesic, which generalizes the common notion of straight line to straight trajectories drawn on curved surfaces. They were then tested on their understanding of geodesics in several tasks requiring increasing levels of generalization from the information taught in the lessons. Our findings indicate that insight experiences are common when learning mathematics, as such experiences were reported by about 61% of our participants. Moreover, the participants who experienced insights performed better in a generalization test where they needed to identify a type of geodesic that had not been presented in the lessons, and this, even after controlling for their confidence in their own understanding. Based on these findings, we suggest that concept learning involves mechanisms that generally are not accessible to introspection, except when the process reaches key computational steps and insights are triggered.


2021 ◽  
Author(s):  
Charlotte Barot ◽  
Louise Chevalier ◽  
Lucie Martin ◽  
Véronique Izard

Many famous scientists have reported anecdotes where a new understanding occurred to them suddenly, in an unexpected flash. Do people generally experience such “Eureka” moments when learning science concepts, and how do these episodes relate to learning mechanisms? To address these questions, we developed a new paradigm where participants learned a mathematical concept in the lab, in a single experimental session. Participants were given 1 to 7 lessons introducing the concept of geodesic, which generalizes the common notion of straight line to straight trajectories drawn on curved surfaces. They were then tested on their understanding of geodesics in several tasks requiring increasing levels of generalization from the information taught in the lessons. Our findings indicate that insight experiences are common when learning mathematics, as such experiences were reported by about 61% of our participants. Moreover, the participants who experienced insights performed better in a generalization test where they needed to identify a type of geodesic that had not been presented in the lessons, and this, even after controlling for their confidence in their own understanding. Based on these findings, we suggest that concept learning involves mechanisms that generally are not accessible to introspection, except when the process reaches key computational steps and insights are triggered.


Author(s):  
Velin Kralev ◽  
Radoslava Kraleva ◽  
Petia Koprinkova-Hristova

Data modeling and data processing are important activities in any scientific research. This research focuses on the modeling of data and processing of data generated by a saccadometer. The approach used is based on the relational data model, but the processing and storage of the data is done with client datasets. The experiments were performed with 26 randomly selected files from a total of 264 experimental sessions. The data from each experimental session was stored in three different formats, respectively text, binary and extensible markup language (XML) based. The results showed that the text format and the binary format were the most compact. Several actions related to data processing were analyzed. Based on the results obtained, it was found that the two fastest actions are respectively loading data from a binary file and storing data into a binary file. In contrast, the two slowest actions were storing the data in XML format and loading the data from a text file, respectively. Also, one of the time-consuming operations turned out to be the conversion of data from text format to binary format. Moreover, the time required to perform this action does not depend in proportion on the number of records processed.


2021 ◽  
Vol 15 ◽  
Author(s):  
Sara Invitto ◽  
Soheil Keshmiri ◽  
Andrea Mazzatenta ◽  
Alberto Grasso ◽  
Daniele Romano ◽  
...  

The perception of putative pheromones or social odors (PPSO) in humans is a widely debated topic because the published results seem ambiguous. Our research aimed to evaluate how cross-modal processing of PPSO and gender voice can affect the behavioral and psychophysiological states of the subject during a listening task with a bodily contact medium, and how these effects could be gender related. Before the experimental session, three embodied media, were exposed to volatilized estratetraenol (Estr), 5α-androst-16-en-3 α-ol (Andr), and Vaseline oil. The experimental session consisted in listening to a story that were transmitted, with a male or female voice, by the communicative medium via a Bluetooth system during a listening task, recorded through 64-active channel electroencephalography (EEG). The sense of co-presence and social presence, elicited by the medium, showed how the established relationship with the medium was gender dependent and modulated by the PPSO. In particular, Andr induced greater responses related to co-presence. The gender of the participants was related to the co-presence desire, where women imagined higher medium co-presence than men. EEG findings seemed to be more responsive to the PPSO–gender voice interaction, than behavioral results. The mismatch between female PPSO and male voice elicited the greatest cortical flow of information. In the case of the Andr–male voice condition, the trained model appeared to assign more relevance to the flow of information to the right frontotemporal regions (involved in odor recognition memory and social behavior). The Estr–male voice condition showed activation of the bilateral frontoparietal network, which is linked to cognitive control, cognitive flexibility, and auditory consciousness. The model appears to distinguish the dissonance condition linked to Andr matched with a female voice: it highlights a flow of information to the right occipital lobe and to the frontal pole. The PPSO could influence the co-presence judgements and EEG response. The results seem suggest that could be an implicit pattern linked to PPSO-related gender differences and gender voice.


2021 ◽  
Author(s):  
Andrea Fera

Abstract Here surprising results are shown demonstrating a workflow possibly able to exploit the discreet nature of interactions between high-energy electron beams and matter. Isolated protein constructs have been imaged after an original temperature-curing in vacuum, introduced recently for flash-frozen rigid biopolymers, and here applied to flash-frozen oligomers of viral origin. These results, if confirmed, may extend to plastics and bio-oligomers the access to atomic coordinates in one experimental session, when imaged by electron microscopy. Which is the case when imaging semiconductors or other solid materials, provided that the samples are not damaged by the interaction with accelerated electron beams in vacuum. Therefore, potentially, this workflow introduces the possibility of achieving atomic resolution in only one experiment with data only about one individual protein, maybe out of thermodynamic equilibrium. Such data are vital to understand protein-protein interactions. Finally, this workflow offers the possibility, new to cryo-electron microscopy samples, to store a sample indefinitely under liquid nitrogen for imaging the same molecules in more than one experimental session.


2021 ◽  
Author(s):  
Stéphanie B. Marion

To test the assumption that individuals who share a personal relationship are more likely to corroborate one another's false alibi than are strangers, 81 undergraduate students were provided the opportunity to either corroborate or refute a confederate's alibi for a suspected theft. In a 'friendship' condition, feelings of affiliation between the participant and the confederate were experimentally induced by increasing the perceived similarity between the pair, and by having the pair interact during a collaborative task. Later during the experimental session the confederate became a suspect for a mock crime and provided a false alibi that she was with the participant during the entire session. Contrary to what we hypothesized, participants in the 'stranger' condition were as likely to corroborate the false alibi as those who underwent friendship-enhancing activities. When the confederate acted in a highly suspicious manner, however, she was much less likely to have her false alibi corroborated by participant than when the confederate's behaviour was less suspicious. The results put into question our assumptions of what makes a credible witness and emphasizes the need for further empirical research on the behaviour of alibi corroboration.


2021 ◽  
Author(s):  
Stéphanie B. Marion

To test the assumption that individuals who share a personal relationship are more likely to corroborate one another's false alibi than are strangers, 81 undergraduate students were provided the opportunity to either corroborate or refute a confederate's alibi for a suspected theft. In a 'friendship' condition, feelings of affiliation between the participant and the confederate were experimentally induced by increasing the perceived similarity between the pair, and by having the pair interact during a collaborative task. Later during the experimental session the confederate became a suspect for a mock crime and provided a false alibi that she was with the participant during the entire session. Contrary to what we hypothesized, participants in the 'stranger' condition were as likely to corroborate the false alibi as those who underwent friendship-enhancing activities. When the confederate acted in a highly suspicious manner, however, she was much less likely to have her false alibi corroborated by participant than when the confederate's behaviour was less suspicious. The results put into question our assumptions of what makes a credible witness and emphasizes the need for further empirical research on the behaviour of alibi corroboration.


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