Sequential effects in continued visual search: Using fixation-related potentials to compare distractor processing before and after target detection

To search for a target in a complex environment is an everyday behavior that ends with finding the target. When we search for two identical targets, however, we must continue the search after finding the first target and memorize its location. We used fixation-related potentials to investigate the neural correlates of different stages of the search, that is, before and after finding the first target. Having found the first target influenced subsequent distractor processing. Compared to distractor fixations before the first target fixation, a negative shift was observed for three subsequent distractor fixations. These results suggest that processing a target in continued search modulates the brain's response, either transiently by reflecting temporary working memory processes or permanently by reflecting working memory retention

Rumination and Rebound from Failure: Investigating How Trait and State Forms of Ruminative Thought Influence Attention to Errors and the Ability to Correct Them in a Challenging Academic Environment

Rumination is a recurrent and repetitive manner of thinking that can be triggered by blockage of personally-relevant goals, creating a temporary state of abstract and evaluative self-focus that can also become a chronic trait-like style of responding to personal challenges. Despite claims that rumination helps down-regulate unwanted emotion, cope with problems, and lead to goal attainment, it often increases negative affect, interferes with problem solving, and exacerbates goal-state discrepancies, particularly for women. Given the pervasiveness of rumination and its potential impact on cognitive processes and emotional states, one important yet untested question is how it might impact individuals’ ability to remediate goal-state discrepancies caused by negative outcomes in an academically-relevant context. In this research program, we examine both trait and state rumination effects in a challenging verbal general knowledge test-feedback-retest paradigm, where first-test failures accrue (65%), but attention must be paid to corrective feedback in order to learn and later rebound from those failures at a surprise retest. Based on prominent cognitive models of rumination, such as the attentional scope model (Whitmer & Gotlib, 2013) and impaired disengagement hypothesis (Koster et al., 2011), individuals who ruminate exhibit a narrowed focus of attention on and impaired disengagement from negative self-referent information. Thus, we tested whether rumination would heighten and maintain focus on negative performance feedback (Aim 1) and therefore interfere with the ability to deploy attention toward learning opportunities that might facilitate remedial behavior (Aim 2). To assess attention processes, we employed both event-related potential (ERP; Study 1) and eye tracking (Study 3) techniques as covert and overt measures, respectively. To assess potential similarities and differences in trait and state rumination (Aim 3), we employed both an individual differences approach, utilizing a well-known self-report measure of trait rumination to predict measures of attention and learning (Studies 1-3), as well as an experimental approach, utilizing two different state rumination induction techniques, one from the clinical realm (Study 2) and the other from the social-cognitive realm (Study 3). Using state rumination induction methods not only afforded a more direct assessment of the causal relationship between rumination and the ability to learn and rebound from failure, but with each method rooted in a different area of research, such methods also permitted testing whether the effectiveness of a state rumination induction may depend on how well it overlaps with the domain of concerns related to the general knowledge task (i.e., academic). We also took participants’ gender into account, as rumination been linked with a host of ill effects on cognition and emotion particularly among women. In response to negative performance feedback, a maladaptive trait Brooding style of rumination sustained covert (i.e., internally-focused) attention to errors, as measured by the Late Positive Potential (LPP; Foti & Hajcak, 2010), but not overt (i.e., externally-oriented) attention, as indexed by gaze fixation duration metrics (e.g., Owens & Gibb, 2017). In response to corrective feedback, however, overt attention was impacted, with a brooding-like state of rumination attenuating visual fixation on learning-relevant information, but no apparent differences were found in covert measures of learning feedback (i.e., ERPs). Despite these effects on feedback processing, surprisingly, state and trait forms of Brooding rumination did not hinder error correction, though they worsened first-test memory performance. Trait Reflection, on the other hand, was found to consistently improve memory performance at first-test, with more mixed results at retest. Rumination effects among women were generally as predicted, while men exhibited null or unexpected effects. The implications of these findings are discussed with respect to how existing models of rumination might be updated to account for differences in internally-focused and externally-oriented attention in applied contexts

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

Scene Buildup From Latent Memory Representations Across Eye Movements

An unresolved problem in eye movement research is how a representation is constructed on-line from several consecutive fixations of a scene. Such a scene representation is generally understood to be sparse; yet, for meeting behavioral goals a certain level of detail is needed. We propose that this is achieved through the buildup of latent representations acquired at fixation. Latent representations are retained in an activity-silent manner, require minimal energy expenditure for their maintenance, and thus allow a larger storage capacity than traditional, activation based, visual working memory. The latent representations accumulate and interact in working memory to form to the scene representation. The result is rich in detail while sparse in the sense that it is restricted to the task-relevant aspects of the scene sampled through fixations. Relevant information can quickly and flexibly be retrieved by dynamical attentional prioritization. Latent representations are observable as transient functional connectivity patterns, which emerge due to short-term changes in synaptic weights. We discuss how observing latent representations could benefit from recent methodological developments in EEG-eye movement co-registration

Here’s Looking at You Kid: Preferential Attention to Same and Other Race Infant Faces Does Not Overcome the Other Race Effect

Given the attentional and motivational saliency of infant faces, triggered by a set of perceptual baby schema features, other-race infants may overcome the processing limitations associated with the Other Race Effect (ORE). Using an attentional bias paradigm, I found that while there was a same-race attentional bias for adult faces, there was no difference in attention bias between same- and other-race infants suggesting that other-race infants have the ability to overcome the attentional limitations associated with processing other-race faces. To directly measure the ORE, I used a recognition memory test to measure encoding differences between same- and other-race infant and adult faces. Regardless of age, same-race faces were better remembered than other-race faces. Further, regardless of race, adult faces were better remembered than infant faces, a finding consistent with an Other Age Effect. Results from the recognition task were validated with differences in Event Related Potentials which found that infant faces may not have been configurally processed as indexed by changes in the N170 and P2 components. However, evidence of infants’ saliency was marked by an increased response of the Late Positive Component (LPC), which supports the findings from the attention experiment. Taken together, these experiments suggest that the saliency of baby schema does not fully overcome the processing limitations of the ORE

Predicting Inattentional Blindness with Pupillary Response in a Simulated Flight Task

Inattentional blindness (IB) is the failure of observers to notice the presence of a clearly viewable but unexpected visual event when attentional resources are diverted elsewhere. Knowing when an operator is unable to respond or detect an unexpected event may help improve safety during task performance. Unfortunately, it is difficult to predict when such failures might occur. The current study was a secondary data analysis of data collected in the Human and Autonomous Vehicle Systems Laboratory at NASA Langley Research Center. Specifically, 60 subjects (29 male, with normal or corrected-to-normal vision, mean age of 34.5 years (SD = 13.3) were randomly assigned to one of three automation conditions (full automation, partial automation, and full manual) and took part in a simulated flight landing task. The dependent variable was the detection/non-detection of an IB occurrence (a truck on the landing runway). Scores on the NASA-TLX workload rating scale varied significantly by automation condition. The full automation condition reported the lowest subjective task load followed by partial automation and then manual condition. IB detection varied significantly across automation condition. The moderate workload condition of partial automation exhibited the lowest likelihood of IB occurrence. The low workload full automation condition did not differ significantly from the manual condition. Subjects who reported higher task demand had increased pupil dilation and subjects with larger pupil dilation were more likely to detect the runway incursion. These results show eye tracking may be used to identify periods of reduced unexpected visual stimulus detection for possible real-time IB mitigation

Source Memory Revealed Through Eye Movements and Pupil Dilation

abstract: Current theoretical debate, crossing the bounds of memory theory and mental imagery, surrounds the role of eye movements in successful encoding and retrieval. Although the eyes have been shown to revisit previously-viewed locations during retrieval, the functional role of these saccades is not known. Understanding the potential role of eye movements may help address classic questions in recognition memory. Specifically, are episodic traces rich and detailed, characterized by a single strength-driven recognition process, or are they better described by two separate processes, one for vague information and one for the retrieval of detail? Three experiments are reported, in which participants encoded audio-visual information while completing controlled patterns of eye movements. By presenting information in four sources (i.e., voices), assessments of specific and partial source memory were measured at retrieval. Across experiments, participants' eye movements at test were manipulated. Experiment 1 allowed free viewing, Experiment 2 required externally-cued fixations to previously-relevant (or irrelevant) screen locations, and Experiment 3 required externally-cued new or familiar oculomotor patterns to multiple screen locations in succession. Although eye movements were spontaneously reinstated when gaze was unconstrained during retrieval (Experiment 1), externally-cueing participants to re-engage in fixations or oculomotor patterns from encoding (Experiments 2 and 3) did not enhance retrieval. Across all experiments, participants' memories were well-described by signal-detection models of memory. Source retrieval was characterized by a continuous process, with evidence that source retrieval occurred following item memory failures, and additional evidence that participants partially recollected source, in the absence of specific item retrieval. Pupillometry provided an unbiased metric by which to compute receiver operating characteristic (ROC) curves, which were consistently curvilinear (but linear in z-space), supporting signal-detection predictions over those from dual-process theories. Implications for theoretical views of memory representations are discussed.Dissertation/ThesisPh.D. Psychology 201

Top-down effects on early visual processing in humans: a predictive coding framework

An increasing number of human electroencephalography (EEG) studies examining the earliest component of the visual evoked potential, the so-called C1, have cast doubts on the previously prevalent notion that this component is impermeable to top-down effects. This article reviews the original studies that (i) described the C1, (ii) linked it to primary visual cortex (V1) activity, and (iii) suggested that its electrophysiological characteristics are exclusively determined by low-level stimulus attributes, particularly the spatial position of the stimulus within the visual field. We then describe conflicting evidence from animal studies and human neuroimaging experiments and provide an overview of recent EEG and magnetoencephalography (MEG) work showing that initial V1 activity in humans may be strongly modulated by higher-level cognitive factors. Finally, we formulate a theoretical framework for understanding top-down effects on early visual processing in terms of predictive coding

Estimation of overlapped Eye Fixation Related Potentials: The General Linear Model, a more flexible framework than the ADJAR algorithm

The Eye Fixation Related Potential (EFRP) estimation is the average of EEG signals across epochs at ocular fixation onset. Its main limitation is the overlapping issue. Inter Fixation Intervals (IFI) - typically around 300 ms in the case of unrestricted eye movement- depend on participants’ oculomotor patterns, and can be shorter than the latency of the components of the evoked potential. If the duration of an epoch is longer than the IFI value, more than one fixation can occur, and some overlapping between adjacent neural responses ensues. The classical average does not take into account either the presence of several fixations during an epoch or overlapping. The Adjacent Response algorithm (ADJAR), which is popular for event-related potential estimation, was compared to the General Linear Model (GLM) on a real dataset from a conjoint EEG and eye-tracking experiment to address the overlapping issue. The results showed that the ADJAR algorithm was based on assumptions that were too restrictive for EFRP estimation. The General Linear Model appeared to be more robust and efficient. Different configurations of this model were compared to estimate the potential elicited at image onset, as well as EFRP at the beginning of exploration. These configurations took into account the overlap between the event-related potential at stimulus presentation and the following EFRP, and the distinction between the potential elicited by the first fixation onset and subsequent ones. The choice of the General Linear Model configuration was a tradeoff between assumptions about expected behavior and the quality of the EFRP estimation: the number of different potentials estimated by a given model must be controlled to avoid erroneous estimations with large variances