Browsing by Subject "Priming"

Now showing 1 - 4 of 4
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    21st Century media effects: choice, predispositions, and their impact on agenda setting and priming.
    (2009-12) Holmes, Justin Whitely
    In the past 25 years, we have seen a massive shift to communication technologies that allow increased choice of content for citizens. Using an experiment, this study explores the relationship between individual differences, increased choice, and media effects such as agenda setting and priming. It finds that increased choice greatly attenuates both attention to political news and subsequent priming and framing effects.
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    Is metamemory implicit? evidence of priming and antipriming in individuals with and without traumatic brain injury.
    (2009-07) Ramanathan, Pradeep
    Implicit memory refers to the phenomenon of prior exposure to a stimulus influencing cognitive processing on subsequent exposure to that stimulus, irrespective of one's awareness of such influence. Metamemory refers to the presumably explicit act of making judgments about one's memory. Theories vary regarding possible relationships between implicit memory and metamemory, with mixed findings of previous research. Some researchers argue that there is no relationship, that metamemory does not rely on input from implicit memory only on explicit memory (Hart, 1965; Koriat, 1995), while others argue that metamemory is driven only by implicit processes (Reder & Schunn, 1996). Still others argue that the metamemory system relies on input from both implicit and explicit memory (Vernon & Usher, 2003). To date, no study has examined whether subliminal masked priming and antipriming can influence individuals' metamemory judgments of learning (JOLs). The present study independently varies subliminal masked priming conditions (using baseline, prime, and antiprime conditions) and observes the influence on participants' immediate and delayed JOLs and relative predictive accuracy, in a paired associate learning task. This study also examines long term repetition priming and antipriming (measured in a visual object identification task) to determine whether the magnitudes of these effects correlate with those found in the paired associate learning task. Both neurologically normal individuals and those with traumatic brain injury (TBI) participated in this study. Metamemory deficits are common after TBI. Thus, inclusion of this clinical population in the present study is critical in evaluating whether or not such individuals' metamemory judgments can be influenced by, or correlated with, priming or antipriming. Furthermore, to date, no study has examined antipriming among TBI survivors; therefore their participation in the visual object identification task will shed light on antipriming in that population, and will provide a perceptual implicit memory benchmark against which to compare any findings of implicit metamemory. Results demonstrate no main effect of subliminal masked priming and antipriming on participants' metamemory judgments for JOL ratings, predictive accuracy (gamma correlation), or response times for judgments of the likelihood of future recall of target words. However, there was a trend towards an interaction effect of priming and JOL timing (i.e.: immediate vs. delayed), such that JOLs made immediately after study were higher for the primed items than for the baseline or antiprimed items. In contrast, antipriming did significantly influence explicit recall, with slowing of explicit recall response times for antiprimed target words, relative to word-pairs in the baseline condition. Difference scores between JOL ratings and recall accuracy reflected overconfidence among TBI survivors, and good calibration among controls. There was a significant decrease in the overconfidence of TBI survivors for antiprimed items. However, much of this lowering was caused by an increase in recall accuracy for antiprime items. In the visual object identification task, antipriming was robustly observed for both participant groups; there was significant slowing observed for responses to antiprimed items. Finally, a mild positive correlation between the degree of priming for visual object identification and the degree of priming of relative predictive accuracy in the paired associate learning task was found across participants. The present research finds weak evidence for the role of implicit memory, in the form of masked priming and antipriming, in JOLs and relative predictive accuracy in paired associate learning. Future research providing masked priming stimuli immediately prior to the solicitation of JOLs may address possible attenuation of such effects which may have occurred in the present study. Additionally, using numbers from the JOL rating scale as subliminal stimuli may shed additional light on the type of representation taken as input by the metamemory system. Finally, exploration of long term priming and antipriming of metamemory in the TBI population should be undertaken to determine whether or not there is a priming benefit to metamemory judgments through supraliminal implicit memory.
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    Mass media campaigns and conversation: testing short-term and long-term priming effects of topic-related conversation on conversational participants.
    (2009-08) Wirtz, John Garfield
    This dissertation investigates how participating in a topic-related conversation (i.e., a conversation focused on a specific event-related topic) may create short-term and long-term priming effects. In the case of topic-related conversations occurring prior to message exposure, it was expected that those conversations would function as a priming task and influence how subsequent mass media messages were evaluated. In the case of long-term engagement in topic-related conversation, it was expected that frequency of topic-related conversations and topic-related media use would predict current and future topic-related behavior. The dissertation presents the results of three studies that test hypotheses suggested by this line of reasoning. In Study 1, the basic hypothesis was that topic-related conversation would act as a priming task and influence how ensuing mass media messages would be evaluated. Consistent with what was predicted, prior topic-related conversation did influence how subsequent stimuli (i.e., two anti-binge drinking public service announcements) were evaluated. Study 2 was informed by the active-self account of prime-to-behavior effects (Wheeler, DeMarree & Petty, 2007, 2008). The study tested multiple hypotheses, including whether self-monitoring (Snyder, 1974) moderated the topic-related conversation--message evaluation relation and whether a measure of the active self-concept mediated the topic-related conversation--message evaluation relation. Consistent with what was predicted, self-monitoring did moderate the topic-related conversation--target stimulus evaluation relation. However, the hypothesis that scores from a measure of the active self-concept would mediate the topic-related conversation--target stimulus evaluation relation was not supported. Study 3 examined some longer-term effects of topic-related conversation. Influenced by prior research indicating that media use and conversation about the news can predict political participation (e.g., McLeod, Schuefele & Moy, 1999), the hypotheses for this study proposed that topic-related conversation about exercise and exercise-related media use would predict concurrent and future exercise-related behavior. Analyses indicated that at Time 1 increases in overall television use were associated with decreases in exercise, while increases in exercise-related conversation were associated with increases in exercise. A second analysis indicated that higher levels of sports television viewing and exercise-related conversation at Time 1 were associated with higher levels of exercise behavior at Time 2.
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    Neuromodulation Using Primed Paired Associative Stimulation
    (2017-10) Frost, Kate
    Purpose: Neuroplasticity governs mechanisms of cortical reorganization, adaptation and recovery following neural injury. Paired associative stimulation (PAS) alters neuroplasticity by pairing peripheral nerve and cortical stimuli which induces spike-timing-dependent-like plasticity. Preceding a principal bout of PAS that intends to weight plasticity in one direction (e.g. facilitatory) with a priming bout of PAS that intends to weight plasticity in the opposite direction (e.g. suppressive) may deploy homeostatic synaptic mechanisms resulting in a greater change from baseline corticospinal excitability. Exploring principles of homeostatic synaptic plasticity using all combinations of priming and principal suppressive PAS (PASLTD), facilitatory PAS (PASLTP) and sham PAS (PASSHAM), this study explores the efficacy of primed PAS as a method of neuromodulation and investigates a relationship between individual characteristics and response to PAS. Methods: Thirty-one healthy individuals were randomized into and completed one of two experiments. Experiment 1 (n=15, age 23.60 ± 2.33 years) investigated priming of PASLTD using a cross-over of the following four interventions separated by at least one-week washouts: 1. PASSHAM→PASLTD; 2. PASLTP→PASLTD; 3. PASLTD→PASLTD; 4. PASSHAM→PASSHAM. Experiment 2 (n=16, age 22.25 ± 2.28 years) investigated priming of PASLTP using a similar four-intervention cross-over of 1. PASSHAM→PASLTP; 2. PASLTD→PASLTP; 3. PASLTP→PASLTP; 4. PASSHAM→PASSHAM. The primary outcome for both experiments was the average peak-to-peak amplitude of 20 motor evoked potentials (MEPs) recorded at baseline and 0, 10, 20, 30, 40, 50 and 60 minutes following intervention. Secondary outcomes included presence of the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and the latency of MEPs collected using an anterior-posterior current flow across the central sulcus. Results: In Experiment 1, the PASLTP→PASLTD intervention produced a significant increase from baseline corticospinal excitability. Nonresponders had a significantly higher presence of the BDNF Val66Met polymorphism. In Experiment 2, no intervention produced a significant change from baseline excitability. Priming did not convert individual nonresponders to responders for any PAS intervention. Discussion: Our results highlight the complexity of synaptic plasticity and the difficulty in harnessing mechanisms of plasticity to augment neuromodulation strategies. Individual characteristics may influence response to PASLTD and optimal protocols may need to be established for stratified groups.