scholarly journals Confidence in visual motion discrimination is preserved in individuals with schizophrenia

2020 ◽  
Vol 46 (1) ◽  
pp. E65-E73
Author(s):  
Nathan Faivre ◽  
Matthieu Roger ◽  
Michael Pereira ◽  
Vincent de Gardelle ◽  
Jean-Christophe Vergnaud ◽  
...  
Keyword(s):  
Visual Discrimination ◽  
Discrimination Task ◽  
Visual Motion ◽  
Discrimination Performance ◽  
Visual Discrimination Task ◽  
Task Execution ◽  
Bayesian Analyses ◽  
Narrative Assessment ◽  
Healthy Participants

Background: Metacognition is the set of reflexive processes that allows humans to evaluate the accuracy of their mental operations. Metacognitive deficits have been described in people with schizophrenia using mostly narrative assessment, and they have been linked to several key symptoms. Methods: We assessed metacognitive performance objectively by asking people with schizophrenia or schizoaffective disorder (n = 20) and matched healthy participants (n = 21) to perform a visual discrimination task and report their confidence in their performance. Metacognitive performance was defined as the adequacy between visual discrimination performance and confidence. Results: Bayesian analyses revealed equivalent metacognitive performance in the 2 groups, despite a weaker association between confidence and trajectory tracking during task execution among people with schizophrenia. We reproduced these results using an evidence accumulation model, which showed similar decisional processes in the 2 groups. Limitations: These results from a relatively small study sample cannot be generalized to other perceptual and nonperceptual tasks. To meet this purpose, ecological tasks are needed. As well, the role of antipsychotic medication and design deserves greater attention in the future. Conclusion: We found similar decisional and metacognitive capabilities between people with schizophrenia and healthy controls in a visual discrimination task.

scholarly journals Confidence in perceptual decision-making is preserved in schizophrenia

2019 ◽  
Author(s):  
Nathan Faivre ◽  
Matthieu Roger ◽  
Michael Pereira ◽  
Vincent de Gardelle ◽  
Jean-Christophe Vergnaud ◽  
...  
Keyword(s):  
Visual Discrimination ◽  
Discrimination Performance ◽  
Perceptual Decision Making ◽  
Task Execution ◽  
Bayesian Analyses ◽  
Functional Deficits ◽  
Evidence Accumulation ◽  
Narrative Assessment ◽  
Mental Operations ◽  
Healthy Participants

AbstractMetacognition is the set of reflexive processes allowing humans to evaluate the accuracy of their mental operations. Deficits in synthetic metacognition have been described in schizophrenia using mostly narrative assessment and linked to several key symptoms. Here, we assessed metacognitive performance by asking individuals with schizophrenia or schizoaffective disorder (N=20) and matched healthy participants (N = 21) to perform a visual discrimination task and subsequently report confidence in their performance. Metacognitive performance was defined as the adequacy between visual discrimination performance and confidence. Bayesian analyses revealed equivalent metacognitive performance in the two groups despite a weaker association between confidence and trajectory tracking during task execution among patients. These results were reproduced using a bounded evidence accumulation model which showed similar decisional processes in the two groups. The inability to accurately attune confidence to perceptual decisions in schizophrenia remains to be experimentally demonstrated, along with the way such impairments may underpin functional deficits.

Nonvisual Motor Learning Improves Visual Motion Perception: Evidence From Violating the Two-Thirds Power Law

2010 ◽  
Vol 104 (3) ◽  
pp. 1612-1624 ◽  
Author(s):  
I.A.M. Beets ◽  
F. Rösler ◽  
K. Fiehler
Keyword(s):  
Motor Learning ◽  
Velocity Profile ◽  
Power Law ◽  
Visual Discrimination ◽  
Discrimination Task ◽  
Visual Motion ◽  
Visual Discrimination Task ◽  
Control Group ◽  
Motor Training ◽  
Training Groups

Few studies have reported direct effects of motor learning on visual perception, especially when using novel movements for the motor system. Atypical motor behaviors that violate movement constraints provide an excellent opportunity to study action-to-perception transfer. In our study, we passively trained blindfolded participants on movements violating the 2/3 power law. Before and after motor training, participants performed a visual discrimination task in which they decided whether two consecutive movements were same or different. For motor training, we randomly assigned the participants to two motor training groups or a control group. The motor training group experienced either a weak or a strong elliptic velocity profile on a circular trajectory that matched one of the visual test stimuli. The control group was presented with linear trajectories unrelated to the viewed movements. After each training session, participants actively reproduced the movement to assess motor learning. The group trained on the strong elliptic velocity profile reproduced movements with increasing elliptic velocity profiles while circular geometry remained constant. Furthermore, both training groups improved in visual discrimination ability for the learned movement as well as for highly similar movements. Participants in the control group, however, did not show any improvements in the visual discrimination task nor did participants who did not acquire the trained movement. The present results provide evidence for a transfer from action to perception which generalizes to highly related movements and depends on the success of motor learning. Moreover, under specific conditions, it seems to be possible to acquire movements deviating from the 2/3 power law.

The role of frontal and temporal lobes in visual discrimination task — depth ERP studies

1999 ◽  
Vol 29 (4) ◽  
pp. 339-350 ◽  
Author(s):  
M. Brázdil ◽  
I. Rektor ◽  
M. Dufek ◽  
P. Daniel ◽  
P. Jurák ◽  
...  
Keyword(s):  
Visual Discrimination ◽  
Discrimination Task ◽  
Visual Discrimination Task ◽  
Temporal Lobes

Activity of single neurons in the monkey amygdala during performance of a visual discrimination task

1992 ◽  
Vol 67 (6) ◽  
pp. 1447-1463 ◽  
Author(s):  
K. Nakamura ◽  
A. Mikami ◽  
K. Kubota
Keyword(s):  
Visual Stimulus ◽  
Visual Discrimination ◽  
Discrimination Task ◽  
Discharge Rate ◽  
Visual Stimuli ◽  
Delay Period ◽  
Visual Discrimination Task ◽  
Single Neurons ◽  
Visual Neurons ◽  
Human Faces

1. The activity of single neurons was recorded extracellularly from the monkey amygdala while monkeys performed a visual discrimination task. The monkeys were trained to remember a visual stimulus during a delay period (0.5-3.0 s), to discriminate a new visual stimulus from the stimulus, and to release a lever when the new stimulus was presented. Colored photographs (human faces, monkeys, foods, and nonfood objects) or computer-generated two-dimensional shapes (a yellow triangle, a red circle, etc.) were used as visual stimuli. 2. The activity of 160 task-related neurons was studied. Of these, 144 (90%) responded to visual stimuli, 13 (8%) showed firing during the delay period, and 9 (6%) responded to the reward. 3. Task-related neurons were categorized according to the way in which various stimuli activated the neurons. First, to evaluate the proportion of all tested stimuli that elicited changes in activity of a neuron, selectivity index 1 (SI1) was employed. Second, to evaluate the ability of a neuron to discriminate a stimulus from another stimulus, SI2 was employed. On the basis of the calculated values of SI1 and SI2, neurons were classified as selective and nonselective. Most visual neurons were categorized as selective (131/144), and a few were characterized as nonselective (13/144). Neurons active during the delay period were also categorized as selective visual and delay neurons (6/13) and as nonselective delay neurons (7/13). 4. Responses of selective visual neurons had various temporal and stimulus-selective properties. Latencies ranged widely from 60 to 300 ms. Response durations also ranged widely from 20 to 870 ms. When the natures of the various effective stimuli were studied for each neuron, one-fourth of the responses of these neurons were considered to reflect some categorical aspect of the stimuli, such as human, monkey, food, or nonfood object. Furthermore, the responses of some neurons apparently reflected a certain behavioral significance of the stimuli that was separate from the task, such as the face of a particular person, smiling human faces, etc. 5. Nonselective visual neurons responded to a visual stimulus, regardless of its nature. They also responded in the absence of a visual stimulus when the monkey anticipated the appearance of the next stimulus. 6. Selective visual and delay neurons fired in response to particular stimuli and throughout the subsequent delay periods. Nonselective delay neurons increased their discharge rates gradually during the delay period, and the discharge rate decreased after the next stimulus was presented. 7. Task-related neurons were identified in six histologically distinct nuclei of the amygdala.(ABSTRACT TRUNCATED AT 400 WORDS)

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