scholarly journals Nonlinear transduction of emotional facial expression

2019 ◽  
Author(s):  
Katie Gray ◽  
Tessa R. Flack ◽  
Miaomiao Yu ◽  
Freya Lygo ◽  
Daniel H Baker
Keyword(s):  
Facial Expression ◽  
Complex Stimulus ◽  
Stimulus Contrast ◽  
Emotional Facial Expression ◽  
Facial Stimuli ◽  
Neural Representations ◽  
Stimulus Generation ◽  
External Stimuli ◽  
The Brain ◽  
Processing Steps

To create neural representations of external stimuli, the brain performs a number of processing steps that transform its inputs. For fundamental attributes, such as stimulus contrast, this involves one or more nonlinearities that are believed to optimise the neural code to represent features of the natural environment. Here we ask if the same is also true of more complex stimulus dimensions, such as emotional facial expression. We report the results of three experiments combining morphed facial stimuli with electrophysiological and psychophysical methods to measure the function mapping emotional expression intensity to internal response. The results converge on a nonlinearity that accelerates over weak expressions, and then becomes compressive for stronger expressions, similar to the situation for lower level stimulus properties. We further demonstrate that the nonlinearity is not attributable to the morphing procedure used in stimulus generation.

Consciousness and Emotional Facial Expression Recognition

2007 ◽  
Vol 21 (2) ◽  
pp. 100-108 ◽  
Author(s):  
Michela Balconi ◽  
Claudio Lucchiari
Keyword(s):  
Information Processing ◽  
Facial Expression ◽  
Facial Expressions ◽  
Facial Expression Recognition ◽  
Event Related Potential ◽  
Expression Recognition ◽  
Major Result ◽  
Emotional Facial Expression ◽  
Emotional Facial Expressions ◽  
Facial Stimuli

Abstract. In this study we analyze whether facial expression recognition is marked by specific event-related potential (ERP) correlates and whether conscious and unconscious elaboration of emotional facial stimuli are qualitatively different processes. ERPs elicited by supraliminal and subliminal (10 ms) stimuli were recorded when subjects were viewing emotional facial expressions of four emotions or neutral stimuli. Two ERP effects (N2 and P3) were analyzed in terms of their peak amplitude and latency variations. An emotional specificity was observed for the negative deflection N2, whereas P3 was not affected by the content of the stimulus (emotional or neutral). Unaware information processing proved to be quite similar to aware processing in terms of peak morphology but not of latency. A major result of this research was that unconscious stimulation produced a more delayed peak variation than conscious stimulation did. Also, a more posterior distribution of the ERP was found for N2 as a function of emotional content of the stimulus. On the contrary, cortical lateralization (right/left) was not correlated to conscious/unconscious stimulation. The functional significance of our results is underlined in terms of subliminal effect and emotion recognition.

scholarly journals A Review of Dynamic Datasets for Facial Expression Research

2016 ◽  
Vol 9 (3) ◽  
pp. 280-292 ◽  
Author(s):  
Eva G. Krumhuber ◽  
Lina Skora ◽  
Dennis Küster ◽  
Linyun Fou
Keyword(s):  
Facial Expression ◽  
Present Article ◽  
Facial Expressions ◽  
Temporal Dynamics ◽  
Future Directions ◽  
Facial Stimuli ◽  
Stimulus Generation ◽  
Key Dimensions

Temporal dynamics have been increasingly recognized as an important component of facial expressions. With the need for appropriate stimuli in research and application, a range of databases of dynamic facial stimuli has been developed. The present article reviews the existing corpora and describes the key dimensions and properties of the available sets. This includes a discussion of conceptual features in terms of thematic issues in dataset construction as well as practical features which are of applied interest to stimulus usage. To identify the most influential sets, we further examine their citation rates and usage frequencies in existing studies. General limitations and implications for emotion research are noted and future directions for stimulus generation are outlined.

scholarly journals Nonlinear transduction of emotional facial expression

2020 ◽  
Vol 170 ◽  
pp. 1-11
Author(s):  
Katie L.H. Gray ◽  
Tessa R. Flack ◽  
Miaomiao Yu ◽  
Freya A. Lygo ◽  
Daniel H. Baker
Keyword(s):  
Facial Expression ◽  
Emotional Facial Expression

scholarly journals Complex Activity and Short-term Memories in Reciprocally Connected Cerebral Organoids

2021 ◽  
Author(s):  
Tatsuya Osaki ◽  
Yoshiho Ikeuchi
Keyword(s):  
Human Brain ◽  
Three Dimensional ◽  
Oscillatory Activity ◽  
Cellular Functions ◽  
Complex Activity ◽  
Axonal Connections ◽  
Brain Organoid ◽  
External Stimuli ◽  
The Brain

AbstractMacroscopic axonal connections in the human brain distribute information and neuronal activity across the brain. Although this complexity previously hindered elucidation of functional connectivity mechanisms, brain organoid technologies have recently provided novel avenues to investigate human brain function by constructing small segments of the brain in vitro. Here, we describe the neural activity of human cerebral organoids reciprocally connected by a bundle of axons. Compared to conventional organoids, connected organoids produced significantly more intense and complex oscillatory activity. Optogenetic manipulations revealed that the connected organoids could re-play and recapitulate over time temporal patterns found in external stimuli, indicating that the connected organoids were able to form and retain temporal memories. Our findings suggest that connected organoids may serve as powerful tools for investigating the roles of macroscopic circuits in the human brain – allowing researchers to dissect cellular functions in three-dimensional in vitro nervous system models in unprecedented ways.

scholarly journals Task dependence of neural representations of global scene properties but not scene categories in the prefrontal cortex

2020 ◽  
Author(s):  
Yaelan Jung ◽  
Dirk B. Walther
Keyword(s):  
Prefrontal Cortex ◽  
Visual Cortex ◽  
Scene Perception ◽  
Sound Level ◽  
Task Context ◽  
Complex Scene ◽  
Neural Representations ◽  
Task Conditions ◽  
Scene Content ◽  
The Brain

AbstractNatural scenes deliver rich sensory information about the world. Decades of research has shown that the scene-selective network in the visual cortex represents various aspects of scenes. It is, however, unknown how such complex scene information is processed beyond the visual cortex, such as in the prefrontal cortex. It is also unknown how task context impacts the process of scene perception, modulating which scene content is represented in the brain. In this study, we investigate these questions using scene images from four natural scene categories, which also depict two types of global scene properties, temperature (warm or cold), and sound-level (noisy or quiet). A group of healthy human subjects from both sexes participated in the present study using fMRI. In the study, participants viewed scene images under two different task conditions; temperature judgment and sound-level judgment. We analyzed how different scene attributes (scene categories, temperature, and sound-level information) are represented across the brain under these task conditions. Our findings show that global scene properties are only represented in the brain, especially in the prefrontal cortex, when they are task-relevant. However, scene categories are represented in the brain, in both the parahippocampal place area and the prefrontal cortex, regardless of task context. These findings suggest that the prefrontal cortex selectively represents scene content according to task demands, but this task selectivity depends on the types of scene content; task modulates neural representations of global scene properties but not of scene categories.

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