Matching Items (5)

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Teleological Explanations of Nature Relate to Supernatural Agent Detection Among Theists and Atheists

Description

Humans are biased toward teleological explanations of natural phenomena. The promiscuous teleology account posits that this proclivity is rooted in the detection of supernatural agency behind the design of the natural world. This idea is supported by numerous positive correlations

Humans are biased toward teleological explanations of natural phenomena. The promiscuous teleology account posits that this proclivity is rooted in the detection of supernatural agency behind the design of the natural world. This idea is supported by numerous positive correlations of religious belief and agreement with teleological explanations of natural phenomena, but it is challenged by findings that non-believers often agree with them as well, suggesting the need for an adjudicating experiment. The current experiment tested whether considering similar teleological explanations of nature causes explicitly theistic and atheistic people to think about God, which would suggest that the teleological bias has roots in agency detection. Participants (N = 608) were randomly assigned to consider teleological explanations of either human-caused phenomena or natural phenomena, with the main prediction that considering the natural item set would make theists relatively faster to categorize God as real but make atheists relatively slower to categorize God as imaginary. The data did support this hypothesis, suggesting that people across the theistic belief spectrum automatically think of God when thinking about nature’s purpose, and thus the teleological bias might be rooted in the detection of supernatural agency. Implications for theories of teleology, study limitations, and potential future directions are discussed.

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2021

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Motivated Memory: Structural and Functional Neural Correlates

Description

Capacity limits of the human nervous system require important or rewarding information to be prioritized and encoded over less important or rewarding information. The present dissertation aims to identify structural and functional neural correlates of reward-motivated memory encoding. Chapter 1

Capacity limits of the human nervous system require important or rewarding information to be prioritized and encoded over less important or rewarding information. The present dissertation aims to identify structural and functional neural correlates of reward-motivated memory encoding. Chapter 1 reviews studies of reward-motivated memory encoding and their neural correlates, as well as the structure and function of dopaminergic midbrain circuits. Chapter 2 presents a study that utilizes electroencephalography (EEG) to determine which of two hypothesized processes underly the influence of reward value on episodic memory. One hypothesis is that value engages prefrontal executive control processes, so that valuable stimuli engage an elaborative rehearsal strategy that benefits memory. A second hypothesis is that value acts through the reward-related midbrain dopamine system to modulate synaptic plasticity in hippocampal and cortical efferents, thereby benefiting memory encoding. The results revealed that EEG signals thought to index dopamine-driven attention allocation were modulated by reward value and were positively correlated with individual differences in behavioral measures of memory prioritization. Chapter 3 employs diffusion-weighted magnetic resonance imaging (MRI) to dissociate heterogenous functional circuits of the midbrain reward system. The results comport with primate histology and show that midbrain circuits are differentially predictive of impulsivity and of attention-deficit hyperactivity disorder (ADHD). Chapter 4 presents a study that also employs diffusion-weighted MRI. The findings replicate Chapter 3 in dissociating heterogenous functional circuits of the midbrain reward system. Additionally, the structural integrity of midbrain-hippocampus circuits was quantified. Structural integrity of these circuits was positively correlated to behavioral measures of memory prioritization. These findings suggest that structural and functional measures of the dopaminergic reward system may underlie reward-motivated memory encoding in humans.

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Date Created
2021

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The Role of Knowledge Structures & Motivation on Problem Solving

Description

Individuals encounter problems daily wherein varying numbers of constraints require delimitation of memory to target goal-satisfying information. Multiply-constrained problems, such as compound remote associates, are commonly used to study this type of problem solving. Since their development, multiply-constrained problems have

Individuals encounter problems daily wherein varying numbers of constraints require delimitation of memory to target goal-satisfying information. Multiply-constrained problems, such as compound remote associates, are commonly used to study this type of problem solving. Since their development, multiply-constrained problems have been theoretically and empirically related to creative thinking, analytical problem solving, insight problem solving, intelligence, and a multitude of other cognitive abilities. Critically, in order to correctly solve a multiply-constrained problem the solver must have the solution available in memory and be able to target and access to that information. Experiment 1 determined that the cue – target relationship affects the likelihood that a problem is solved. Moreover, Experiment 2 identified that the association between cues and targets predicted inter- & intra-individual differences in multiply-constrained problem solving. Lastly, Experiment 3 found monetary incentives failed to improve problem solving performance likely due to knowledge serving as a limiting factor on performance. Additionally, problem solvers were shown to be able to reliably assess the likelihood they would solve a problem. Taken together all three studies demonstrated the importance of knowledge & knowledge structures on problem solving performance.

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Date Created
2021

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Top Versus Bottom Saliency Bias in Object and Scene Perception

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Research has demonstrated observers have a generic bias for top saliency in object identification, such that random shapes appear more similar to ones that share the same tops versus same bottoms (Chambers et al., 1999). These findings are consistent with

Research has demonstrated observers have a generic bias for top saliency in object identification, such that random shapes appear more similar to ones that share the same tops versus same bottoms (Chambers et al., 1999). These findings are consistent with the idea that in nature, the tops of most important objects and living things tend to be the most informative locations with respect to intentionality and functionality, leading observers to favor attending to top. Yet, such a bias also may imply a generic downward vantage bias, suggesting that unlike natural objects, the more informative aspects of scenes tend to lie below their horizon midpoints. In two experiments, saliency bias was investigated for objects and scenes with both information-balanced and naturalistic stimuli. Experiment 1 replicates and extends the study of the top-saliency effect for information-balanced objects. Here 91 participants made 80 similarity judgments between an information-balanced object and two comparison objects that contain either the same top or the same bottom. Participants also made 80 similarity judgments of information-balanced scenes in which the coordinates of the vertices of the random shapes were replaced with little objects to create a scene. Experiment 2 extends Chambers et al. (1999) by examining top-saliency bias in naturalistic object perception when 91 participants made similarity judgments between a photographed test object and two comparison objects which contain either the same top or the same bottom. Experiment 2 also tests the idea of a downward vantage bias by predicting that naturalistic scenes will be judged more similar when the portions that lie below the horizon are identical versus when the portions above are the same. Results of the two experiments confirm that observers tend to assume a downward vantage when viewing pictures of objects and objects within scenes, which supports that saliency varies as a function of the informative aspect of the visually attended component.

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2021

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An Experimental Evaluation of the Influence of Transcranial Direct Current Stimulation to the Trigeminal Nerve on Attention and Arousal

Description

Sustained attention, the ability to concentrate on a stimulus or task over a prolonged period, is essential for goal pursuit and fulfillment. Sustained attention failures can have catastrophic consequences, underscoring the importance of understanding the mechanisms that underlie variability in

Sustained attention, the ability to concentrate on a stimulus or task over a prolonged period, is essential for goal pursuit and fulfillment. Sustained attention failures can have catastrophic consequences, underscoring the importance of understanding the mechanisms that underlie variability in sustained attention, and developing interventions targeting these mechanisms to reduce such failures. A growing body of research implicates the brainstem locus coeruleus (LC) as a core modulator of attention and arousal. Activation of LC afferents, such as the trigeminal nerve, may indirectly modulate the LC. The altered LC activity could theoretically be tracked via well-established psychological and physiological indicators of attention and arousal, such as performance, self-reports of attention state, and pupillary activity during attention tasks. The present study tests the hypothesis that continuous transcranial direct current stimulation (tDCS) over the trigeminal nerve of the face improves attentional state, attentional performance, and pupillary reactivity via indirect modulation of the LC. Participants received 2 mA of anodal or cathodal stimulation or sham stimulation over the dorsolateral prefrontal cortex while completing the Psychomotor Vigilance Task. Participants occasionally reported on their attentional state. Pupillary activity was recorded continuously throughout the task. To compare patterns of attention task performance, frequency of task-unrelated thoughts, and pupillary activity across time by stimulation condition, linear mixed-effects models were implemented.
The results replicate the complex interplay between attentional state, attentional performance, and pupillary activity reported in the literature. Specifically, a ubiquitous pattern of performance deterioration was observed, which coincided with an increase in task-unrelated thoughts and reduced pretrial and task-evoked pupil responses. However, tDCS over the face did not produce significant effects compared to the sham condition in attention task performance, proportion of task-unrelated thoughts, and pupillary activity that would indicate LC modulation. This study addresses the causal relations between LC activity, attentional state, attentional performance, and pupillary reactivity that are still poorly understood in human subjects. The findings reported here support the dominant theory of the role of the LC in attentional processes but fail to support hypotheses suggesting that tDCS of the trigeminal nerve influences activity of the LC and indicators of LC activity.

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Date Created
2022