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

Multidimensional Approach to Implicit Bias and the Underlying Cognitive Mechanism

abstract: Social categories such as race and gender are associated by people with certain characteristics (e.g. males are angry), which unconsciously affects how people evaluate and react to a person of specific social categories. This phenomenon, referred to as implicit bias, has been the interest of many social psychologists. However, the implicit bias research has been focusing on only one social category at a time, despite humans being entities of multiple social categories. The research also neglects the behavioral contexts in which implicit biases are triggered and rely on a broad definition for the locus of the bias regulation mechanism. These limitations raise questions on whether the current bias reduction strategies are effective. The current dissertation sought to address these limitations by introducing an ecologically valid and multidimensional method. In Chapters 1 and 2, the mouse-tracking task was integrated into the implicit association task to examine how implicit biases were moderated in different behavioral contexts. The results demonstrated that the manifestation of implicit biases depended on the behavioral context as well as the distinctive identity created by the combinations of different social categories. Chapter 3 laid groundwork for testing working memory as the processing capacity for the bias regulation mechanism. The result suggested that the hand-motion tracking indices of working memory load could be used to infer the capacity of an individual to suppress the influence of implicit bias. In Chapter 4, the mouse-tracking paradigm was integrated into the Stroop task with implicit associations serving as the Stroop targets. The implicit associations produced various effects including the conflict adaptation effect, like the Stroop targets, which suggested that implicit associations and Stroop stimuli are handled by overlapping cognitive mechanisms. Throughout these efforts, the current dissertation, first, demonstrated that a more ecologically valid and multidimensional approach is required to understand biased behaviors in detail. Furthermore, the current dissertation suggested the cognitive control mechanism as a finer definition for the locus of the bias regulation mechanism, which could be leveraged to offer solutions that are more adaptive and effective in the environment where collaboration and harmony are more important than ever.Dissertation/ThesisDoctoral Dissertation Human Systems Engineering 201

The role of phonology in visual word recognition: evidence from Chinese

Posters - Letter/Word Processing V: abstract no. 5024The hypothesis of bidirectional coupling of orthography and phonology predicts that phonology plays a role in visual word recognition, as observed in the effects of feedforward and feedback spelling to sound consistency on lexical decision. However, because orthography and phonology are closely related in alphabetic languages (homophones in alphabetic languages are usually orthographically similar), it is difficult to exclude an influence of orthography on phonological effects in visual word recognition. Chinese languages contain many written homophones that are orthographically dissimilar, allowing a test of the claim that phonological effects can be independent of orthographic similarity. We report a study of visual word recognition in Chinese based on a mega-analysis of lexical decision performance with 500 characters. The results from multiple regression analyses, after controlling for orthographic frequency, stroke number, and radical frequency, showed main effects of feedforward and feedback consistency, as well as interactions between these variables and phonological frequency and number of homophones. Implications of these results for resonance models of visual word recognition are discussed.postprin

Interactive effects of orthography and semantics in Chinese picture naming

Posters - Language Production/Writing: abstract no. 4035Picture-naming performance in English and Dutch is enhanced by presentation of a word that is similar in form to the picture name. However, it is unclear whether facilitation has an orthographic or a phonological locus. We investigated the loci of the facilitation effect in Cantonese Chinese speakers by manipulating—at three SOAs (2100, 0, and 1100 msec)—semantic, orthographic, and phonological similarity. We identified an effect of orthographic facilitation that was independent of and larger than phonological facilitation across all SOAs. Semantic interference was also found at SOAs of 2100 and 0 msec. Critically, an interaction of semantics and orthography was observed at an SOA of 1100 msec. This interaction suggests that independent effects of orthographic facilitation on picture naming are located either at the level of semantic processing or at the lemma level and are not due to the activation of picture name segments at the level of phonological retrieval.postprin

Electrophysiological Studies of Visual Attention and of Emotion Regulation

Electrophysiological methods, such as electroencephalography (EEG) and electrocardiography (ECG), measure biological activity that allow us to infer underlying cognitive processes. In the first study, we use EEG to track feature-based attention (FBA), a form of visual attention that helps one detect objects with a particular color, motion, or orientation. We explore the use of SSVEPs, generated by flicker presented peripherally, to track attention in a visual search task presented centrally. Classification results show that one can track an observer’s attended color, which suggests that these methods may provide a viable means for tracking FBA in a real-time task. In the second study, we use cardiovascular measures to examine influences of the emotion regulation strategy of reappraisal. We examine cooperation and cardiovascular responses in individuals that were defected on by their opponent in the first round of an iterated Prisoner’s Dilemma. We find significant differences between the emotion regulation conditions using the biopsychosocial (BPS) model of challenge and threat, where participants primed with the reappraisal strategy were weakly comparable with a threat state of the BPS model and participants without an emotion regulation were weakly comparable with a challenge state of the BPS model. In the third study, we use EEG to study the chromatic sensitivity of FBA for color during a visual search task. We use SSVEP responses evoked through peripheral flicker to measure the spectral tuning of color detection mechanisms and how attentional selection is affected by distractor color. Our results find smaller responses for the distractor colors and suggest that feature-based attention to a particular color involves chromatic mechanisms that both enhance the response to a target and minimize responses to distractors

Task interference effects in prospective memory

Prospective memory (PM), or remembering to remember, is biq it s i p pl ’s liv s a d PM misses might represent around half of daily memory failures according to recent research. In this thesis, several intention-related factors were investigated in order to clarify and elaborate our understanding of the effects of working memory (WM) and cognitive aging on prospective remembering, increase theoretical clarity regarding the dynamics of the monitoring processes in PM tasks, and investigate the interplay between two qualitatively different PM retrieval processes (i.e., spontaneous retrieval and monitoring). The overall approach was to examine how holding a particular intention affected ongoing task performance in a series of specifically devised laboratory studies of PM. The main findings of this thesis can be summarized as follows: First, encountering intention-related information boosted nonfocal PM performance for low, but not high, WM young adults, and did so without any additional cost to ongoing task performance (Experiment 1). Second, presenting intention-related information as distractor items improved PM performance for older, but not young adults (Experiments 2 and 3). The benefit was most likely due to distractor lures enhancing the salience of the target events and triggering spontaneous retrieval of the intention, or alternatively (or additionally), triggering (functional) monitoring in close proximity to the target events (Experiment 2). Third, practicing the ongoing activity prior to encoding the PM task enhanced nonfocal target detection for high WM young adults, but not for low WM young adults and older adults; practice probably allowed individuals to encode a more elaborate and detailed representation of the PM task (Experiment 4). Fourth, explicit information about target-defining features led to trial-by-trial modulations in task interference as a function of stimulus relevance for the nonfocal PM task. The effect was observed when relevant and irrelevant stimuli varied at random with no cuing (Experiments 5 and 6) and when presentation was blocked (Experiment 5), and was most likely associated with the action of top-down attentional control. Fifth, implicit information about the PM task demands also aff ct d pa ticipa ts’ ff t a d s cc ss i the PM task. Moreover, experience with the PM targets triggered local changes in attention allocation when actual demands were higher than expected (Experiment 7). And sixth, target repetition within a set boosted PM performance by stimulating retrieval through spontaneous retrieval processes, and optimized performance relative to when retrieval relied mostly on monitoring processes alone (Experiment 8). In summary, the present work uncovered several factors that have the potential to boost prospective remembering, as well as influence the extent to which monitoring processes are engaged and/or the type of processing required to support PM retrieval

Investigating priming, inhibition, and individual differences in visual attention

While much has been explored within the attentional control literature, questions still exist as to how attentional processing is modulated, and how different types of visual search paradigms can elucidate the underlying mechanisms involved in successful visual search. Throughout this dissertation, I will focus on the multifaceted aspects that come with the study of visual attention. After discussing visual attention I explore priming of pop out along two different dimensions. Specifically, using a rapid serial visual presentation design, I demonstrate that temporal and spatial priming interact along a similar mechanism. This result adds to the priming literature by demonstrating simultaneous multidimensional priming in our ability to efficiently process our visual environment. Next, I explore attentional distraction and psychophysical thresholds to examine whether an individual\u27s sensitivity to a visual feature can predict the individual\u27s magnitude of distraction by that feature. Results reveal that psychophysical thresholds are not sensitive enough to reflect a definite relationship between an individual\u27s baseline stimulus-driven sensitivity to visual features and the magnitude of distraction by those features. Finally, I explore the role of inhibition (using a stop signal paradigm) in individual differences in abilities to avoid distraction, and examine how working memory capacity influences target selection. Results failed to elucidate this relationship and further research is needed to uncover whether individual differences in avoiding distraction are subserved by either inhibitory processing, or working memory capacity. In conclusion, this dissertation uses various visual search paradigms to explore the interactions of stimulus-driven and goal-driven effects, to illuminate how individual differences inform models of attentional distraction, and to investigate how inhibiting a distractor modulates attentional processing

The Influence of Stereotype on Maintenance and Retrieval Errors: Does Working Memory Capacity Matter?

I explored the influence of stereotypes on performance in cognitive tasks as a function of individual differences in working memory capacity (WMC) in a multi-part study. First, I established that low and high WMC persons maintain equivalent knowledge of common racial stereotypes. Next, I tested whether stereotype-based responses in cognitive tasks that require controlled processing are influenced by individual differences in WMC. Given that stereotypical associations are automatic and cognitively efficient, I predicted that without sufficient resources to suppress these associations, persons with low relative to high WMC will be more susceptible to the influence of stereotype-consistent errors on tasks which have been demonstrated to induce performance differences in low and high WMC persons (Unsworth & Engle, 2007). Engaging WMC is not required in all cognitive tasks; thus, low and high WMC persons were not expected to perform differently on tasks that rely on more automatic processes. Results provided general support for predictions as persons with more inherently limited cognitive resources committed a higher number of stereotype-consistent errors when performing a maintenance task and accurately recalled fewer stereotype-consistent words when performing a retrieval task. However, persons completing inhibition and familiarity tasks, which are methodologically similar to the maintenance and retrieval tasks but involve less controlled cognitive processes, performed similarly regardless of WMC