Facial typicality and attractiveness reflect an ideal dimension of face structure.

Face perception and recognition are important processes for social interaction and communication among humans, so understanding how faces are mentally represented and processed has major implications. At the same time, faces are just some of the many stimuli that we encounter in our everyday lives. Therefore, more general theories of how we represent objects might also apply to faces.

An Analysis of the External Validity of EEG Spectral Power in an Uncontrolled Outdoor Environment during Default and Complex Neurocognitive States.

Traditionally, quantitative electroencephalography (QEEG) studies collect data within controlled laboratory environments that limit the external validity of scientific conclusions. To probe these validity limits, we used a mobile EEG system to record electrophysiological signals from human participants while they were located within a controlled laboratory environment and an uncontrolled outdoor environment exhibiting several moderate background influences. Participants performed two tasks during these recordings, one engaging brain activity related to several complex cognitive functions (number sense, attention, memory, executive function) and the other engaging two default brain states.

Mental Effort and Information-Processing Costs Are Inversely Related to Global Brain Free Energy During Visual Categorization.

is a neurocognitive process that reflects the controlled expenditure of psychological information-processing resources during perception, cognition, and action. There is a practical need to operationalize and measure mental effort in order to minimize detrimental effects of mental fatigue on real-world human performance. Previous research has identified several neurocognitive indices of mental effort, but these indices are indirect measures that are also sensitive to experimental demands or general factors such as sympathetic arousal.

K-th Nearest Neighbor (KNN) Entropy Estimates of Complexity and Integration from Ongoing and Stimulus-Evoked Electroencephalographic (EEG) Recordings of the Human Brain.

Information-theoretic measures for quantifying multivariate statistical dependence have proven useful for the study of the unity and diversity of the human brain. Two such measures-integration, , and interaction complexity, -have been previously applied to electroencephalographic (EEG) signals recorded during ongoing wakeful brain states. Here, and were computed for empirical and simulated visually-elicited alpha-range (8-13 Hz) EEG signals.

Sustained engagement of attention is associated with increased negative self-referent processing in major depressive disorder.

This study investigated the link between self-reference and attentional engagement in adults with (n=22) and without (HC; n=24) Major Depressive Disorder (MDD). Event-related potentials (ERPs) were recorded while participants completed the Self-Referent Encoding Task (SRET). MDD participants endorsed significantly fewer positive words and more negative words as self-descriptive than HC participants.

The Effect of Electroencephalogram (EEG) Reference Choice on Information-Theoretic Measures of the Complexity and Integration of EEG Signals.

Converging evidence suggests that human cognition and behavior emerge from functional brain networks interacting on local and global scales. We investigated two information-theoretic measures of functional brain segregation and integration-interaction complexity C (X), and integration I(X)-as applied to electroencephalographic (EEG) signals and how these measures are affected by choice of EEG reference. C(X) is a statistical measure of the system entropy accounted for by interactions among its elements, whereas I(X) indexes the overall deviation from statistical independence of the individual elements of a system.

Attractiveness bias: A cognitive explanation.

According to cognitive averaging theory, preferences for attractive faces result from their similarity to facial prototypes, the categorical central tendencies of a population of faces. Prototypical faces are processed more fluently, resulting in increased positive affect in the viewer.

Licensing Novel Role-Governed Categories: An ERP Analysis.

Markman and Stilwell (2001) argued that many natural categories name roles in relational systems, and so they are role-governed categories. This view predicts instantiating a novel relational structure licenses the creation of novel role-governed categories. This paper supports this claim and helps to specify the mechanisms underlying this licensing.

Increased alpha band activity indexes inhibitory competition across a border during figure assignment.

Figure-ground assignment is thought to entail inhibitory competition between potential objects on opposite sides of a shared border; the winner is perceived as the figure, and the loser as the shapeless ground. Computational models and response time measures support this understanding but to date no online measure of inhibitory competition during figure-ground assignment has been reported. The current study assays electroencephalogram (EEG) alpha power as a measure of inhibitory competition during figure-ground assignment.

An examination of the association between chronic sleep restriction and electrocortical arousal in college students.

Objective: The deleterious neurocognitive effects of laboratory-controlled short-term sleep deprivation are well-known. The present study investigated neurocognitive changes arising from chronic sleep restriction outside the laboratory.

Methods: Sleep patterns of 24 undergraduates were tracked via actigraphy across a 15-week semester.

Sleep and sadness: exploring the relation among sleep, cognitive control, and depressive symptoms in young adults.

Background: Sleep disturbance is a common feature of depression. However, recent work has found that individuals who are vulnerable to depression report poorer sleep quality compared to their low-risk counterparts, suggesting that sleep disturbance may precede depression. In addition, both sleep disturbance and depression are related to deficits in cognitive control processes.

Beauty is in the ease of the beholding: a neurophysiological test of the averageness theory of facial attractiveness.

Hundreds of studies have shown that people prefer attractive over unattractive faces. But what is an attractive face, and why is it preferred? Averageness theory claims that faces are perceived as being attractive when their facial configuration approximates the mathematical average facial configuration of the population. Conversely, faces that deviate from this average configuration are perceived as being unattractive.

Neurobehavioral correlates of the rapid formation of the symbolic control of visuospatial attention.

Prior research suggests that nonpredictive symbolic central cues can produce nonvoluntary shifts of endogenous attention when associations between cues and spatial locations are overlearned during cognitive development. The present ERP study extends this research by first showing that overlearned cue-spatial location associations necessary to support nonvoluntary attentional orienting can be rapidly formed in adult humans. A second experiment indicates that the nonvoluntary orienting formed by such rapid learning is semireflexive (amenable to top-down influence) rather than reflexive (resistant to top-down influence).

Neurophysiological evidence for the influence of past experience on figure-ground perception.

A fundamental aspect of perceptual organization entails segregating visual input into shaped figures presented against shapeless backgrounds; an outcome termed "figure-ground perception" or "shape assignment." The present study examined how early in processing past experience exerts an influence on shape assignment. Event-related potential (ERP) measures of brain activity were recorded while observers viewed silhouettes of novel objects that differed in whether or not a familiar shape was suggested on the outside-the groundside-of their bounding edges (experimental versus control silhouettes, respectively).

An ERP examination of the different effects of sleep deprivation on exogenously cued and endogenously cued attention.

Background: Behavior and neuroimaging studies have shown selective attention to be negatively impacted by sleep deprivation. Two unresolved questions are (1) whether sleep deprivation impairs attention modulation of early visual processing or of a later stage of cognition and (2) how sleep deprivation affects exogenously versus endogenously driven selective attention.

Study Objectives: To investigate the time course and different effects of sleep deprivation on exogenously and endogenously cued selective attention.

Theta EEG dynamics of the error-related negativity.

Objective: The error-related negativity (ERN) is a response-locked brain potential (ERP) occurring 80-100ms following response errors. This report contrasts three views of the genesis of the ERN, testing the classic view that time-locked phasic bursts give rise to the ERN against the view that the ERN arises from a pure phase-resetting of ongoing theta (4-7Hz) EEG activity and the view that the ERN is generated - at least in part - by a phase-resetting and amplitude enhancement of ongoing theta EEG activity.

Methods: Time-domain ERP analyses were augmented with time-frequency investigations of phase-locked and non-phase-locked spectral power, and inter-trial phase coherence (ITPC) computed from individual EEG trials, examining time courses and scalp topographies.

EEG phase synchrony differences across visual perception conditions may depend on recording and analysis methods.

Objective: (1) To investigate the neural synchrony hypothesis by examining if there was more synchrony for upright than inverted Mooney faces, replicating a previous study; (2) to investigate whether inverted stimuli evoke neural synchrony by comparing them to a new scrambled control condition, less likely to produce face perception.

Methods: Multichannel EEG was recorded via nose reference while participants viewed upright, inverted, and scrambled Mooney face stimuli. Gamma-range spectral power and inter-electrode phase synchrony were calculated via a wavelet-based method for upright stimuli perceived as faces and inverted/scrambled stimuli perceived as non-faces.