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

Attentional Changes During Implicit Learning: Signal Validity Protects a Target Stimulus from the Attentional Blink

Participants in two experiments performed two simultaneous tasks: one, a dual-target detection task within a rapid sequence of target and distractor letters; the other, a cued reaction time task requiring participants to make a cued left/right response immediately after each letter sequence. Under these rapid visual presentation conditions, it is usually difficult to identify the second target when it is presented in close temporal proximity of the first target, a phenomenon known as the attentional blink. However, here, participants showed an advantage for detecting a target presented during the attentional blink if that target predicted which response cue would appear at the end of the trial. Participants also showed faster reaction times on trials with a predictive target. Both of these effects were independent of conscious knowledge of the target-response contingencies assessed by post-experiment questionnaires. The results suggest that implicit learning of the association between a predictive target and its outcome can automatically facilitate target recognition during the attentional blink, and therefore shed new light on the relationship between associative learning and attentional mechanisms.Australian Research Counci

Semantic radical consistency and character transparency effects in Chinese: an ERP study

BACKGROUND: This event-related potential (ERP) study aims to investigate the representation and temporal dynamics of Chinese orthography-to-semantics mappings by simultaneously manipulating character transparency and semantic radical consistency. Character components, referred to as radicals, make up the building blocks used dur...postprin

Motivating sustainable goal choices and providing effective feedback

Overconsumption of natural resources and the associated environmental hazards are one of today’s most pressing global issues. In the western world, individual consumption in homes and workplaces is a key contributor to this problem. Reflecting the importance of individual action in this domain, this thesis focuses on studying and influencing choices related to sustainability and energy consumption made by people in their daily lives. There are three main components to this work. Firstly, this thesis asserts that people frequently make ineffective consumption reduction goal choices and attempts to understand the rationale for these poor choices by fitting them to goalsetting theory, an established theoretical model of behavior change. Secondly, it presents two approaches that attempt to influence goal choice towards more effective targets, one of which deals with mechanisms for goal priming and the other of which explores the idea that carefully designed toys can exert influence on children’s long term consumption behavior patterns. The final section of this thesis deals with the design of feedback to support the performance of environmentally sound activities. Key contributions surrounding goals include the finding that people choose easy sustainable goals despite immediate feedback as to their ineffectiveness and the discussion and study of goal priming mechanisms that can influence this choice process. Contributions within the design of value instilling toys include a theoretically grounded framework for the design of such toys and a completed and tested prototype toy. Finally, contributions in designing effective and engaging energy consumption feedback include the finding that negative feedback is best presented verbally compared with visually and this is exemplified and presented within a working feedback system. The discussions, concepts, prototypes and empirical findings presented in this work will be useful for both environmental psychologists and for HCI researchers studying eco-feedback

Effects of Long-Term Memory on Visual Attention and Access to Visual Consciousness

In dieser Dissertation zeige ich anhand einer Reihe von Beispielen, wie das Langzeitgedächtnis die perzeptuelle Verarbeitung beeinflussen kann. Anhand einer Aufgabe zur visuellen Aufmerksamkeit verdeutliche ich, inwiefern episodische Erinnerungen perzeptuelle Distrakoreffekte reduzieren können. In Experiment 1 sollten Versuchspersonen zuvor gelernte Worte entweder ins Gedächtnis zu rufen oder die Erinnerung an die Worte zu unterdrücken. Anschließend mussten sie unter Zeitdruck neue, bisher nicht präsentierte Worte semantisch einordnen, wobei die Zielworte von den zuvor abgerufenen oder unterdrückten Worten flankiert waren. Da die flankierenden Worte für die semantische Entscheidungsaufgabe irrelevant und die Versuchspersonen instruiert worden waren, diese zu ignorieren, kann von einem perzeptuellen Distraktoreffekt ausgegangen werden. Distraktoreffekte waren für zuvor unterdrückte Gedächtnisinhalte im Vergleich zur abgerufenen Gedächtnisinhalten deutlich reduziert, was nahelegt, dass episodische Gedächtnisinhalte die Wahrnehmung beeinflussen. Auf dieser Erkenntnis aufbauend zeige ich in Experiment 2, wie die suppressionsinduzierte Reduktion der Verarbeitung von Distraktorreizen durch individuelle Differenzen maskiert werden kann. Schließlich wurden den Versuchspersonen in Experiment 3 in einer „Attentional-Blink“-Aufgabe unbekannte Objekte als zweites von zwei aufeinander folgenden Zielobjekten dargeboten. Versuchspersonen konnten Objekte, die mit einer neu gelernten semantischen Information assoziiert waren, besser erkennen als Objekte, die mit minimaler Information assoziiert waren. Dieser Effekt ging mit einer Modulation der ereigniskorrelierten Potenziale 100ms nach Erscheinen des Reizes einher. Diese Ergebnisse zeigen, dass Inhalte aus dem Langzeitgedächtnis Wahrnehmungsprozesse beeinflussen können und leisten damit einen weiteren Beitrag zur Erkenntnis, dass die Wahrnehmung gegenüber höheren Kognitionen nicht unabhängig ist.Numerous studies are emerging which suggest that long-term memories can influence early perceptual processing. Notwithstanding, these finding have come under fire from critics who view perceptual processing as independent of cognition. In this dissertation I demonstrate novel instances of long-term memory effects on perceptual processing, both in the context of an attentional task where I look at the extent to which episodic memory can reduce perceptual distraction and in a conscious detection task where I assess the effect of semantic knowledge on peoples ability to consciously detect briefly presented objects. In experiment one, participants retrieved or suppressed previously memorised words. Following this task, participants made speeded semantic judgments on novel target words that were flanked by the words that had previously undergone suppression or retrieval. Because the flanking words were irrelevant to the semantic judgment and were supposed to be ignored, any influence of their presence on semantic judgment speed can be taken as a marker of perceptual distraction. Results showed that the tendency for flankers to distract from target processing was markedly reduced if those flankers had undergone suppression. In experiment two, I expanded upon this finding by showing how this suppression-induced reduction in distractor processing can be masked by individual differences. Finally, in experiment three, I presented pictures of novel objects to participants as the second of two targets in an attentional blink paradigm. Results showed that participants were able to perceive objects associated with newly acquired semantic knowledge better than objects associated with minimal knowledge, a finding that was associated with a modulation of event-related brain potentials 100 msec after stimulus onset. Taken together, these experiments contribute to the growing body of evidence showing that information from long-term memory can influence perceptual processing

Learning empathy through virtual reality : Multiple strategies for training empathy-related abilities using body ownership Illusions in embodied virtual reality

Several disciplines have investigated the interconnected empathic abilities behind the proverb “to walk a mile in someone else’s shoes” to determine how the presence, and absence, of empathy-related phenomena affect prosocial behavior and intergroup relations. Empathy enables us to learn from others’ pain and to know when to offer support. Similarly, virtual reality (VR) appears to allow individuals to step into someone else’s shoes, through a perceptual illusion called embodiment, or the body ownership illusion. Considering these perspectives, we propose a theoretical analysis of different mechanisms of empathic practices in order to define a possible framework for the design of empathic training in VR. This is not intended to be an extensive review of all types of practices, but an exploration of empathy and empathy-related phenomena. Empathy-related training practices are analyzed and categorized. We also identify different variables used by pioneer studies in VR to promote empathy-related responses. Finally, we propose strategies for using embodied VR technology to train specific empathy-related abilities

Reinforcement Learning in Individuals at Risk for Alzheimer\u27s Disease

Explicit memory is the hallmark of impairment in Alzheimer’s disease (AD) while implicit memory has mixed task-dependent results. Models of memory processes have posited that hippocampal function is sensitive to reinforcement learning (RL), which involves both explicit and implicit memory. The hippocampus is also vital for the transfer of learned associations to novel situations. Nevertheless, RL paradigms have been underutilized in assessing memory processes in individuals at risk for AD, which may aid in early identification of cognitive decline. Thirty-six apolipoprotein-E (APOE) genotyped older adults (Male n=8; Mage=80; Meducation=15 years) performed word stem completion, word recognition, and RL tasks. The RL task was comprised of an RL phase, an implicit testing phase, and explicit recognition component. Group comparisons were made based on low risk (APOE ε4-; n=16) vs. high risk (APOE ε4+; n=20) for AD. A series of mixed ANOVAs based on task performance indicated that risk groups did not differ on EM measures (RL, word recognition, and RL recognition). However, high risk participants exhibited significantly poorer IM performance (RL testing and word stem) than the low risk group, p = .03. The pattern of results in the present study was counter to prediction in that risk groups did not differ on explicit memory measures, which was strongly supported by existing literature. However, the exhibited performance of poorer implicit memory in the high risk group is consistent with results implicating the hippocampus in the application learned associations to novel environments. RL paradigms may offer high sensitivity for assessing preclinical decline

Acute Exercise and Creativity: Embodied Cognition Approaches

This dissertation manuscript is the culmination of three years of research examining several unique, exercise-induced mechanisms underlying creativity. This collection of work addresses historical and current empirical concepts of creativity in a narrative review, providing recommendations for future research. Several reviews follow this introduction, highlighting the proposed effects of exercise on creativity, putative mechanisms for creativity, and the effects of exercise and embodied manipulations on creative behavior. Multiple experiments utilizing moderate-intensity exercise as a theoretical stimulus for higher-order cognitions were conducted to investigate associations between exercise and creativity, which lead to the final dissertation experiment. The dissertation experiment was the first to provide statistically significant evidence for acute, moderate-intensity treadmill exercise coupled with anagram problem-solving to prime subsequent RAT completion compared to a non-exercise, priming only condition. We emphasize that the additive effects of exercise plus priming may be a viable strategy for enhancing verbal convergent creativity. Future research is warranted to explore a variety of priming effects on the relationship between exercise, embodied interventions, and creativityThis dissertation manuscript is the culmination of three years of research examining several unique, exercise-induced mechanisms underlying creativity. This collection of work addresses historical and current empirical concepts of creativity in a narrative review, providing recommendations for future research. Several reviews follow this introduction, highlighting the proposed effects of exercise on creativity, putative mechanisms for creativity, and the effects of exercise and embodied manipulations on creative behavior. Multiple experiments utilizing moderate-intensity exercise as a theoretical stimulus for higher-order cognitions were conducted to investigate associations between exercise and creativity, which lead to the final dissertation experiment. The dissertation experiment was the first to provide statistically significant evidence for acute, moderate-intensity treadmill exercise coupled with anagram problem-solving to prime subsequent RAT completion compared to a non-exercise, priming only condition. We emphasize that the additive effects of exercise plus priming may be a viable strategy for enhancing verbal convergent creativity. Future research is warranted to explore a variety of priming effects on the relationship between exercise, embodied interventions, and creativit

Social cognitive and neural mechanisms of food choice under the influence of food-related information

Food is the fuel of life. As such food stimuli are intensively processed by the human brain and the consequences of these processes, resulting in our food choice, have an essential impact on our life. Research suggested that food choice is largely guided by predominantly learned preference, and is likely to be influenced by information regarding the food (e.g., nutritional value) as well as by learned beliefs and associations (e.g., between a given food and its health value). This project aims at understanding at both behavioral and neural levels how these non-physiological factors might influence the food/drink choice and how they can be modified to improve our choice. Chapter 1 includes the literature review on 1) how semantic information influences implicit/explicit associations toward food/drink, 2) the predictive validity implicit/explicit associations on food/drink choice, 3) the behavioral and neural evidence of changing associations, choices, and impulsivity control toward food/drink by implementing a conditioning paradigm (e.g. evaluative conditioning). The motivation and the objectives of my Ph.D. project are also presented here. Chapter 2 contains Study 1 (Experiment 1 and 2). The first aim of the thesis is to understand how the association between a certain food and different concepts may guide our choices. This is addressed in Experiment 1 where I investigated how our choices can be predicted by preference and/or implicit associations between different constructs of interest (e.g., social status) and coffee and/or tea. People\u2019s self-report preference, implicit and explicit associations between different social constructs and tea/coffee were measured. Results based on 22 Italian healthy adults indicate that they possess strong implicit associations between tea and low social status, and this association significantly predicted choice of tea. The second aim of the thesis is to investigate whether the associations between food/drink and certain constructs can be changed through a classical learning paradigm, evaluative conditioning (EC), in which the associations between target drinks/food and food-related information was manipulated. This approach allowed us to investigate a possible strategy of intervention that could improve drink/food choices. This is addressed in Experiment 2 whereby a within-subject design is employed with participants going through both EC-condition and control condition. Results based on 68 healthy adults show that the implicit associations between tea and high-social-status, as well as the preference towards tea, significantly increase after EC. Most importantly, the difference in implicit associations across conditions significantly predict the difference in choices of tea between conditions, indicating that changes in implicit associations determine changes in choice. Chapter 3 is dedicated to the third aim which is to identify the neural mechanisms underlying the changes in association after EC between foods and the concepts of healthiness and sustainability. To this end changes in neural markers were related to changes in food choice as well as personal eating habits and individual difference in restraint eating and impulsive behavior. In Study 2, I experimentally strengthened the association between the concept of unhealthiness/unsustainability and heavily-processed food, and between healthiness/sustainability and minimally-processed food. A semantic congruency task combined with the Electroencephalography (EEG) technique was used to investigate changes in neural activity of the N400 in incongruent trials. Results on 18 healthy adults derived by comparing neural signatures of incongruent trials between conditions demonstrated that the magnitude of the N400 in left dorsal lateral prefrontal cortex (DLPFC) for minimally-processed high-calorie food significantly increased after EC. Thus, EC can be considered as an effective method to strengthen the semantic association between foods and a given concept, indexed by the change of neural signature tracking the semantic conflict. This increased magnitude also positively correlated with the Barratt Impulsiveness Scale score, indicating that the more impulsive a person is, the greater the change in magnitude of the N400. Chapter 4 is devoted to address the fourth aim of the thesis that is to understand whether control of impulsivity over unhealthy food choice can be improved through the evaluative priming (EP) that is a variation of EC used in Study 2. Thus in Study 3, 15 healthy adults went through a pre-EP and a post-EP test including a Go/NoGo task combined with EEG. During EP, an increased subjective liking was found for Minimally-Processed Low-Calorie food images in evaluative block. For GNG tasks, at neural level, the averaged amplitude at left DLPFC for food images with evaluative priming was more negative in post-EP than in pre-EP GNG task. More negative N200 amplitudes were consistently found at left DLPFC in post-EP GNG task for Heavily-Processed Low-Calorie food as well as for Minimally-Processed Low-Calorie food. The behavioral and neural evidence showed the improvement of self-control towards food stimuli through evaluative priming. The possible role of left dorsal lateral prefrontal region in online value modulation and in integrating the stimulus feature with related information was identified, suggesting the self-control process based on deliberated thinking with symbolic representations and information operations. In Chapter 5 I summarized and discussed the main findings of my thesis. In short, my project provides the basic roadmap for understanding how food/drink related information affects cognitive and neural underpinnings of food/drink choices. Indeed, choices can be improved through modifying associations between food/drink and related information and thus healthy diets are encouraged. These results provide a potentially interesting research avenue well as possible interventions to modify and improve food/drink choices that could possibly be applied to individuals with eating disorders