Metacognitive accuracy predicts self-reported quality of life following traumatic brain injury.

OBJECTIVE: Metacognition and quality of life (QoL) are both adversely affected by traumatic brain injury (TBI), but the relation between them is not fully understood. As such, the purpose of this study was to determine the degree to which metacognitive accuracy predicts QoL in individuals with TBI. METHODS: Eighteen participants with moderate-to-severe TBI completed a stimulus-response task requiring the discrimination of emotions depicted in pictures of faces and then provided a retrospective confidence judgment after each response. Metacognitive accuracy was calculated using participants' response accuracy and confidence judgment accuracy. Participants also completed the Quality of Life After Brain Injury (QOLIBRI) questionnaire to assess QoL in various areas of functioning. RESULTS: Performance of a linear regression analysis revealed that higher metacognitive accuracy significantly predicted lower overall QoL. Additionally, higher metacognitive accuracy significantly predicted lower QoL related to cognition and physical limitations. CONCLUSION: The study results provide evidence of an inverse relation between metacognitive performance and QoL following TBI. Metacognitive changes associated with TBI and their relation to QoL have several clinical implications for TBI rehabilitation.

Variability of dot spread is overestimated.

Previous research has demonstrated that individuals exhibit a tendency to overestimate the variability of both low-level features (e.g., color, orientation) and mid-level features (e.g., size) when items are presented dynamically in a sequential order, a finding we will refer to as the variability overestimation effect. Because previous research on this bias used sequential displays, an open question is whether the effect is due to a memory-related bias or a vision-related bias. To assess whether the bias would also be apparent with static, simultaneous displays, and to examine whether the bias generalizes to spatial properties, we tested participants' perception of the variability of a cluster of dots. Results showed a consistent overestimation bias: Participants judged the dots as being more spread than they actually were. The variability overestimation effect was observed when there were 10 or 20 dots but not when there were 50 dots. Taken together, the results of the current study contribute to the ensemble perception literature by providing evidence that simultaneously presented stimuli are also susceptible to the variability overestimation effect. The use of static displays further demonstrates that this bias is present in both dynamic and static contexts, suggesting an inherent bias existent in the human visual system. A potential theoretical account-boundary effect-is discussed as a potential underlying mechanism. Moreover, the present study has implications for common visual tasks carried out in real-world scenarios, such as a radiologist making judgments about distribution of calcification in breast cancer diagnoses.

Task-irrelevant emotional faces impact BOLD responses more for prosaccades than antisaccades in a mixed saccade fMRI task.

Cognitive control allows individuals to flexibly and efficiently perform tasks by attending to relevant stimuli while inhibiting distraction from irrelevant stimuli. The antisaccade task assesses cognitive control by requiring participants to inhibit a prepotent glance towards a peripheral stimulus and generate an eye movement to the mirror image location. This task can be administered with various contextual manipulations to investigate how factors such as trial timing or emotional content interact with cognitive control. In the current study, 26 healthy adults completed a mixed antisaccade and prosaccade fMRI task that included task irrelevant emotional faces and gap/overlap timing. The results showed typical antisaccade and gap behavioral effects with greater BOLD activation in frontal and parietal brain regions for antisaccade and overlap trials. Conversely, there were no differences in behavior based on the emotion of the task irrelevant face, but trials with neutral faces had greater activation in widespread visual regions than trials with angry faces, particularly for prosaccade and overlap trials. Together, these effects suggest that a high level of cognitive control and inhibition was required throughout the task, minimizing the impact of the face presentation on saccade behavior, but leading to increased attention to the neutral faces on overlap prosaccade trials when both the task cue (look towards) and emotion stimulus (neutral, non-threatening) facilitated disinhibition of visual processing.

Visual bias could impede diagnostic accuracy of breast cancer calcifications.

Purpose: Diagnosing breast cancer based on the distribution of calcifications is a visual task and thus prone to visual biases. We tested whether a recently discovered visual bias that has implications for breast cancer diagnosis would be present in expert radiologists, thereby validating the concern of this bias for accurate diagnoses. Approach: We ran a vision experiment with expert radiologists and untrained observers to test the presence of visual bias when judging the spread of dots that resembled calcifications and when judging the spread of line orientations. We calculated visual bias scores for both groups for both tasks. Results: Participants overestimated the spread of the dots and the spread of the line orientations. This bias, referred to as the variability overestimation effect, was of similar magnitudes in both expert radiologists and untrained observers. Even though the radiologists were better at both tasks, they were similarly biased compared with the untrained observers. Conclusions: The results justify the concern of the variability overestimation effect for accurate diagnoses based on breast calcifications. Specifically, the bias is likely to lead to an increased number of false-negative results, thereby leading to delayed treatments.

The Z-Box illusion: dominance of motion perception among multiple 3D objects.

In the present article, we examine a novel illusion of motion-the Z-Box illusion-in which the presence of a bounding object influences the perception of motion of an ambiguous stimulus that appears within. Specifically, the stimuli are a structure-from-motion (SFM) particle orb and a wireframe cube. The orb could be perceived as rotating clockwise or counterclockwise while the cube could only be perceived as moving in one direction. Both stimuli were presented on a two-dimensional (2D) display with inferred three-dimensional (3D) properties. In a single experiment, we examine motion perception of a particle orb, both in isolation and when it appears within a rotating cube. Participants indicated the orb's direction of motion and whether the direction changed at any point during the trial. Accuracy was the critical measure while motion direction, the number of particles in the orb and presence of the wireframe cube were all manipulated. The results suggest that participants could perceive the orb's true rotation in the absence of the cube so long as it was made up of at least ten particles. The presence of the cube dominated perception as participants consistently perceived congruent motion of the orb and cube, even when they moved in objectively different directions. These findings are considered as they relate to prior research on motion perception, computational modelling of motion perception, structure from motion and 3D object perception.

Convolutional neural networks can decode eye movement data: A black box approach to predicting task from eye movements.

Previous attempts to classify task from eye movement data have relied on model architectures designed to emulate theoretically defined cognitive processes and/or data that have been processed into aggregate (e.g., fixations, saccades) or statistical (e.g., fixation density) features. Black box convolutional neural networks (CNNs) are capable of identifying relevant features in raw and minimally processed data and images, but difficulty interpreting these model architectures has contributed to challenges in generalizing lab-trained CNNs to applied contexts. In the current study, a CNN classifier was used to classify task from two eye movement datasets (Exploratory and Confirmatory) in which participants searched, memorized, or rated indoor and outdoor scene images. The Exploratory dataset was used to tune the hyperparameters of the model, and the resulting model architecture was retrained, validated, and tested on the Confirmatory dataset. The data were formatted into timelines (i.e., x-coordinate, y-coordinate, pupil size) and minimally processed images. To further understand the informational value of each component of the eye movement data, the timeline and image datasets were broken down into subsets with one or more components systematically removed. Classification of the timeline data consistently outperformed the image data. The Memorize condition was most often confused with Search and Rate. Pupil size was the least uniquely informative component when compared with the x- and y-coordinates. The general pattern of results for the Exploratory dataset was replicated in the Confirmatory dataset. Overall, the present study provides a practical and reliable black box solution to classifying task from eye movement data.

Examining the influence of different types of dynamic change in a visual search task.

It has been repeatedly demonstrated that when performing a visual search task, items can pop out of a display such that they are identified rapidly, independent of the number of distractors present. It has been less clear whether this type of pop-out is limited to static displays (e.g., images) or whether it can also occur in scenes containing movement, more akin to how we experience the real world. Recently, Jardine and Moore (Journal of Experimental Psychology: Human Perception and Performance, 42, 617-630, 2016) examined whether pop-out also occurs in displays consisting of dynamic motion - wherein items in the display rotated continuously until a critical frame that would elicit pop-out under static presentation conditions - and found that search was greatly impaired. It remains unclear, however, whether such impairment is exerted equivalently across all types of dynamic motions or if it is specific to orientation. In the present study, we replicate the original Jardine and Moore (Journal of Experimental Psychology: Human Perception and Performance, 42, 617-630, 2016) finding and extend this examination to another dimension - color change. We also explore whether search efficiency can be improved with dynamic context if aspects of the display become predictable. The results suggest that not all types of dynamic change impair search performance. Specifically, oddball color targets continue to pop out even when the items in the display are dynamic. Interestingly, adding predictable context did not aid search accuracy as expected, rather resulting in poorer performance. Taken together, the findings suggest that the influence of dynamic context on search performance is not absolute.

Object-based warping in three-dimensional environments.

Object-based warping is a powerful visual illusion wherein space between features within figural regions is regularly overestimated compared with those within ground regions. Originally, the effect was only examined in displays of two-dimensional (2D) stimuli. The present study sought to examine whether object-based warping persists in more naturalistic viewing conditions, where additional contextual cues are present. Stimuli were presented with either three-dimensional (3D) printed objects (Experiment 1) or 3D objects in virtual reality (Experiments 2-4). The testing metric was actual distance of features (dots) compared with estimated distances made by participants. Responses for the 3D printed stimuli were measured with replica dots on a slide ruler device. The virtual reality experiments collected responses either with a computer mouse or motion-tracked controller and included manipulations of object type, spatial separation, viewing distance of stimuli, and head motion. A standard warping effect in 3D was observed in all experiments, although the effect was not present in one condition that elicits warping in 2D (Occluded Rectangle). The final experiment resolves this discrepancy by reducing the multicomponent object (Occluded Rectangle) to a single component figure, while demonstrating the influence of depth cues on the warping effect under occlusion. Collectively, these experiments reveal that object-based warping is a powerful effect, even in naturalistic settings.

Gender and hometown population density interact to predict face recognition ability.

Several studies have found that individuals from small hometowns show diminished face recognition ability as compared with individuals from larger hometowns. We further this line of research by relating six measures of face recognition ability to hometown density. We predicted that the three face recognition ability measures which included a learning component would relate to hometown density whereas the three measures which did not include such a learning component would not. Instead, we found that none of the six measures related to hometown density. Interestingly, we found interactions between gender and hometown population density on many of these measures and on a general index of face recognition, with females from small hometowns outperforming males from small hometowns but no such differences in the large hometown group. In a follow-up re-analysis of a previous study, we found a similar interaction in one of two face recognition ability measures. Together, these results reveal a pattern of gender differences modulated by hometown population density. If indeed experience with faces in one's hometown influences face recognition ability, understanding these effects may require more than a quantification of the environment. Men and women growing up in the same environment likely have different experiences, which likely modulates effects on visual abilities.

The motion-induced contour revisited: Observations on 3-D structure and illusory contour formation in moving stimuli.

The motion-induced contour (MIC) was first described by Victor Klymenko and Naomi Weisstein in a series of papers in the 1980s. The effect is created by rotating the outline of a tilted cube in depth. When one of the vertical edges is removed, an illusory contour can be seen in its place. In four experiments, we explored which stimulus features influence perceived illusory contour strength. Participants provided subjective ratings of illusory contour strength as a function of orientation of the stimulus, separation between inducing edges, and the length of inducing edges. We found that the angle of tilt of the object in depth had the largest impact on perceived illusory contour strength with tilt angles of 20° and 30° producing the strongest percepts. Tilt angle is an unexplored feature of structure-from-motion displays. In addition, we found that once the depth structure of the object was extracted, other features of the display, such as the distance spanned by the illusory contour, could also influence its strength, similar to the notion of support ratio for 2-D illusory contours. Illusory contour strength was better predicted by the length of the contour in 3-D rather than in 2-D, suggesting that MICs are constructed by a 3-D process that takes as input initially recovered contour orientation and position information in depth and only then forms interpolations between them.

How faces (and cars) may become special.

Recent reports have shown that individuals from small hometowns show relatively poor face recognition ability as measured by the Cambridge Face Memory Test or CFMT (Balas & Saville, 2015, 2017), suggesting that the number of faces present in an individual's visual environment relates to that individual's face recognition ability. We replicate this finding in a sample from a different region (Nebraska) and with more variable age distribution. We extend the study by using another test of face recognition ability that does not require learning over trials, and with non-face object recognition tests that share the learning format with the CFMT. We find no hometown effect in these other tests, although more power would be required to show the CFMT effect is significantly larger. We use the same dataset to explore whether experience with more faces and cars in larger hometowns leads to specialization of these abilities. We find strong and substantial support for the hypothesis that the recognition abilities for faces and for cars are more independent from general object recognition in people from larger hometowns. This suggests that experience may be critical to the specialization of these abilities.

Through the eyes of the beholder: Simulated eye-movement experience ("SEE") modulates valence bias in response to emotional ambiguity.

Although some facial expressions provide clear information about people's emotions and intentions (happy, angry), others (surprise) are ambiguous because they can signal both positive (e.g., surprise party) and negative outcomes (e.g., witnessing an accident). Without a clarifying context, surprise is interpreted as positive by some and negative by others, and this valence bias is stable across time. When compared to fearful expressions, which are consistently rated as negative, surprise and fear share similar morphological features (e.g., widened eyes) primarily in the upper part of the face. Recently, we demonstrated that the valence bias was associated with a specific pattern of eye movements (positive bias associated with faster fixation to the lower part of the face). In this follow-up, we identified two participants from our previous study who had the most positive and most negative valence bias. We used their eye movements to create a moving window such that new participants viewed faces through the eyes of one our previous participants (subjects saw only the areas of the face that were directly fixated by the original participants in the exact order they were fixated; i.e., Simulated Eye-movement Experience). The input provided by these windows modulated the valence ratings of surprise, but not fear faces. These findings suggest there are meaningful individual differences in how people process faces, and that these differences impact our emotional perceptions. Furthermore, this study is unique in its approach to examining individual differences in emotion by creating a new methodology adapted from those used primarily in the vision/attention domain. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The signature of undetected change: an exploratory electrotomographic investigation of gradual change blindness.

Neuroimaging-based investigations of change blindness, a phenomenon in which seemingly obvious changes in visual scenes fail to be detected, have significantly advanced our understanding of visual awareness. The vast majority of prior investigations, however, utilize paradigms involving visual disruptions (e.g., intervening blank screens, saccadic movements, "mudsplashes"), making it difficult to isolate neural responses toward visual changes cleanly. To address this issue in this present study, high-density EEG data (256 channel) were collected from 25 participants using a paradigm in which visual changes were progressively introduced into detailed real-world scenes without the use of visual disruption. Oscillatory activity associated with undetected changes was contrasted with activity linked to their absence using standardized low-resolution brain electromagnetic tomography (sLORETA). Although an insufficient number of detections were present to allow for analysis of actual change detection, increased beta-2 activity in the right inferior parietal lobule (rIPL), a region repeatedly associated with change blindness in disruption paradigms, followed by increased theta activity in the right superior temporal gyrus (rSTG) was noted in undetected visual change responses relative to the absence of change. We propose the rIPL beta-2 activity to be associated with orienting attention toward visual changes, with the subsequent rise in rSTG theta activity being potentially linked with updating preconscious perceptual memory representations. NEW & NOTEWORTHY This study represents the first neuroimaging-based investigation of gradual change blindness, a visual phenomenon that has significant potential to shed light on the processes underlying visual detection and conscious perception. The use of gradual change materials is reflective of real-world visual phenomena and allows for cleaner isolation of signals associated with the neural registration of change relative to the use of abrupt change transients.

A Generative Model of Cognitive State from Task and Eye Movements.

The early eye tracking studies of Yarbus provided descriptive evidence that an observer's task influences patterns of eye movements, leading to the tantalizing prospect that an observer's intentions could be inferred from their saccade behavior. We investigate the predictive value of task and eye movement properties by creating a computational cognitive model of saccade selection based on instructed task and internal cognitive state using a Dynamic Bayesian Network (DBN). Understanding how humans generate saccades under different conditions and cognitive sets links recent work on salience models of low-level vision with higher level cognitive goals. This model provides a Bayesian, cognitive approach to top-down transitions in attentional set in pre-frontal areas along with vector-based saccade generation from the superior colliculus. Our approach is to begin with eye movement data that has previously been shown to differ across task. We first present an analysis of the extent to which individual saccadic features are diagnostic of an observer's task. Second, we use those features to infer an underlying cognitive state that potentially differs from the instructed task. Finally, we demonstrate how changes of cognitive state over time can be incorporated into a generative model of eye movement vectors without resorting to an external decision homunculus. Internal cognitive state frees the model from the assumption that instructed task is the only factor influencing observers' saccadic behavior. While the inclusion of hidden temporal state does not improve the classification accuracy of the model, it does allow accurate prediction of saccadic sequence results observed in search paradigms. Given the generative nature of this model, it is capable of saccadic simulation in real time. We demonstrated that the properties from its generated saccadic vectors closely match those of human observers given a particular task and cognitive state. Many current models of vision focus entirely on bottom-up salience to produce estimates of spatial "areas of interest" within a visual scene. While a few recent models do add top-down knowledge and task information, we believe our contribution is important in three key ways. First, we incorporate task as learned attentional sets that are capable of self-transition given only information available to the visual system. This matches influential theories of bias signals by (Miller and Cohen Annu Rev Neurosci 24:167-202, 2001) and implements selection of state without simply shifting the decision to an external homunculus. Second, our model is generative and capable of predicting sequence artifacts in saccade generation like those found in visual search. Third, our model generates relative saccadic vector information as opposed to absolute spatial coordinates. This matches more closely the internal saccadic representations as they are generated in the superior colliculus.

Human classifier: Observers can deduce task solely from eye movements.

Computer classifiers have been successful at classifying various tasks using eye movement statistics. However, the question of human classification of task from eye movements has rarely been studied. Across two experiments, we examined whether humans could classify task based solely on the eye movements of other individuals. In Experiment 1, human classifiers were shown one of three sets of eye movements: Fixations, which were displayed as blue circles, with larger circles meaning longer fixation durations; Scanpaths, which were displayed as yellow arrows; and Videos, in which a neon green dot moved around the screen. There was an additional Scene manipulation in which eye movement properties were displayed either on the original scene where the task (Search, Memory, or Rating) was performed or on a black background in which no scene information was available. Experiment 2 used similar methods but only displayed Fixations and Videos with the same Scene manipulation. The results of both experiments showed successful classification of Search. Interestingly, Search was best classified in the absence of the original scene, particularly in the Fixation condition. Memory also was classified above chance with the strongest classification occurring with Videos in the presence of the scene. Additional analyses on the pattern of correct responses in these two conditions demonstrated which eye movement properties successful classifiers were using. These findings demonstrate conditions under which humans can extract information from eye movement characteristics in addition to providing insight into the relative success/failure of previous computer classifiers.

Cerebral hemodynamics during scene viewing: Hemispheric lateralization predicts temporal gaze behavior associated with distinct modes of visual processing.

Systematic patterns of eye movements during scene perception suggest a functional distinction between 2 viewing modes: an ambient mode (characterized by short fixations and large saccades) thought to reflect dorsal activity involved with spatial analysis, and a focal mode (characterized by long fixations and small saccades) thought to reflect ventral activity involved with object analysis. Little neuroscientific evidence exists supporting this claim. Here, functional transcranial Doppler ultrasound (fTCD) was used to investigate whether these modes show hemispheric specialization. Participants viewed scenes for 20 s under instructions to search or memorize. Overall, early viewing was right lateralized, whereas later viewing was left lateralized. This right-to-left shift interacted with viewing task (more pronounced in the memory task). Importantly, changes in lateralization correlated with changes in eye movements. This is the first demonstration of right hemisphere bias for eye movements servicing spatial analysis and left hemisphere bias for eye movements servicing object analysis. (PsycINFO Database Record

All in the first glance: first fixation predicts individual differences in valence bias.

Surprised expressions are interpreted as negative by some people, and as positive by others. When compared to fearful expressions, which are consistently rated as negative, surprise and fear share similar morphological structures (e.g. widened eyes), but these similarities are primarily in the upper part of the face (eyes). We hypothesised, then, that individuals would be more likely to interpret surprise positively when fixating faster to the lower part of the face (mouth). Participants rated surprised and fearful faces as either positive or negative while eye movements were recorded. Positive ratings of surprise were associated with longer fixation on the mouth than negative ratings. There were also individual differences in fixation patterns, with individuals who fixated the mouth earlier exhibiting increased positive ratings. These findings suggest that there are meaningful individual differences in how people process faces.

Functional Transcranial Doppler Ultrasound for Measurement of Hemispheric Lateralization During Visual Memory and Visual Search Cognitive Tasks.

Functional transcranial Doppler ultrasound (fTCD) is a noninvasive sensing modality that measures cerebral blood flow velocity (CBFV) with high temporal resolution. CBFV change is correlated to changes in cerebral oxygen uptake, enabling fTCD to measure brain activity and lateralization with high accuracy. However, few studies have examined the relationship of CBFV change during visual search and visual memory tasks. Here a protocol to compare lateralization between these two similar cognitive tasks using fTCD is demonstrated. Ten healthy volunteers (age 21±2 years) were shown visual scenes on a computer and performed visual search and visual memory tasks while CBFV in the bilateral middle cerebral arteries was monitored with fTCD. Each subject completed 40 trials, consisting of baseline (25 s), calibration (variable), instruction (2.5 s), and task (20 s) epochs. Lateralization was computed for each task by calculating the bilateral CBFV envelope percent change from baseline and subtracting the right side from the left side. The results showed significant lateralization ( ) of the visual memory and visual search tasks, with memory reaching lateralization of 1.6% and search reaching lateralization of 0.5%, suggesting that search is more right lateralized (and therefore may be related to "holistic" or global perception) and memory is more left lateralized (and therefore may be related to local perception). This method could be used to compare cerebral activity for any related cognitive tasks as long as the same stimulus is used in all tasks. The protocol is straightforward and the equipment is inexpensive, introducing a low-cost high temporal resolution technique to further study lateralization of the brain.

Which way is which? Examining symbolic control of attention with compound arrow cues.

Spatial symbols can generate attentional biases toward peripheral locations compatible with the symbol's meaning. An important question concerns how one symbol is selected when competing symbols are present. Studies examining this issue for spatially distinct symbols have suggested that selection depends on the task goals. In the present study, we examined whether the influence of competing symbolic stimuli (arrows) at different levels of structure on attentional control also depends on the task goals. Participants made simple detection responses to a peripheral target preceded by a spatially uninformative compound arrow (global arrow composed of local arrows). In addition, participants were required to perform a secondary task in which they matched the orientation of the global arrow (global task) or the location of a uniquely colored local arrow (local task) to a test display presented immediately following a detection response. When the global and local arrows pointed at opposite locations, a local cueing effect emerged in the local task, and a global cueing effect in the global task, indicating that the task goals influenced the selection of the level of structure. However, when the local level was spatially neutral (global arrow, local rectangles), a cueing effect was observed independent of task, and when the global level was spatially neutral (global rectangle, local arrows), a cueing effect was observed in the local task only, suggesting that global processing was obligatory and local processing optional. These findings suggest that attentional effects triggered by the global level are more strongly reflexive than those triggered by the local level.