R-3 Repository :: Browsing by Author "Dannemiller, James L."

Browsing by Author "Dannemiller, James L."

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A computational model of routine procedural memory
(2009) Tamborello, Franklin Patrick, II; Byrne, Michael D.; Kortum, Philip T.; Lane, David M.; Autry, Lynette S.; Dannemiller, James L.; Napier, Albert H.
Cooper and Shallice (2000) implemented a computational version of the Norman and Shallice's (1986) Contention Scheduling Model (CSM). The CSM is a hierarchically organized network of action schemas and goals. Botvinick and Plaut (2004) instead took a connectionist approach to modeling routine procedural behavior. They argued in favor of holistic, distributed representation of learned step co-occurrence associations. Two experiments found that people can adapt routine procedural behavior to changing circumstances quite readily and that other factors besides statistical co-occurrence can have influence on action selection. A CSM-inspired ACT-R model of the two experiments is the first to postdict differential error rates across multiple between-subjects conditions and trial types. Results from the behavioral and modeling studies favor a CSM-like theory of human routine procedural memory that uses discrete, hierarchically-organized goal and action representations that are adaptable to new but similar procedures.
An investigation of audiovisual speech perception using the McGurk effect
(2014-04-14) Basu Mallick, Debshila; Beauchamp, Michael S.; Dannemiller, James L.; Beier, Margaret E.; Schnur, Tatiana T.
Integrating information from the auditory and visual modalities is vital for speech perception. In this thesis, I describe two studies of audiovisual speech perception that make use of an audiovisual illusion known as the McGurk effect. In the McGurk effect, two different syllables presented simultaneously in auditory and visual modalities are fused and perceived as a novel syllable (McGurk & MacDonald, 1976). In the first study, we conducted a large-scale assessment of the McGurk effect across fourteen McGurk stimuli tested in up to 165 participants. This study revealed that McGurk perception is characterized by wide variability across stimuli. The second study investigated whether phonetic identification training could increase McGurk perception. This study showed that participants improved on the training task, but there was no increase in McGurk perception.
Chess Performance under Time Pressure: Evidence for the Slow Processes in Speed Chess
(2013-09-16) Chang, Yu-Hsuan; Lane, David M.; Oswald, Frederick L.; Dannemiller, James L.
An influential theory of chess skill holds that expertise in chess is not due to greater depth of search by experts but, rather, to the ability to recognize familiar patterns of pieces. Although there is evidence that experts search deeper than non-experts, the data are not consistent. In this thesis, I propose “key-position theory” which states that only in a small number of key positions is it necessary to search deeply and it is these positions that experts search deeper than non-experts. Study 1 found, consistent with key-position theory, that the distribution of moves times is extremely skewed with some moves taking much longer than others. This pattern was more pronounced for the stronger players. Study 2 found that the errors made by weaker players involved less search than the errors made by stronger players. These findings suggest that search is an important component of chess expertise.
Foraging memory: Retrieving words from one and from two semantic categories
(2008) Glaser, Daniel Shields; Dannemiller, James L.
Traditionally applied to an animal's search for food, the concept of foraging has been extended to include the search for information in such places as the Internet and libraries (Pirotti & Card, 1999). The premise behind the research reported here is that memory searching can also be construed as foraging. The goals of this investigation are to uncover mental factors that may affect memory production during memory search and to use this knowledge to guide a prediction of foraging production. Prior to testing, four such mental factors were identified: a time cost when producing an initial item from a different category (switch cost); a production benefit driven by a release of proactive interference (time-out benefit); a production cost caused by the additional mental load of executing an autonomous switching strategy (executive-decision cost); and sub-optimal allocation of time between categories. Experiment 1 tested whether switching between categories leads to a switch cost and/or time-out benefit by having subjects produce items from a category in a continuous three-minute block or multiple blocks that add to three minutes. Experiment 2 addressed the possibility of an "Executive-decision" cost by either allowing subjects to autonomously switch between categories or yoking them to another subject's switch schedule. Experiment 3 tested whether memory foragers divide their time optimally between categories. Data from the first experiment demonstrated that like external foraging, moving from category to category (patch to patch) results in a production downtime. These data also demonstrated that switching production between domains may lead to a time-out benefit. Experiment 2 showed that the execution of an autonomous switching strategy leads to less production then when switching is forced. The third experiment demonstrated that, unlike animals, humans do not have an innate sense of how to divide their time between patches (categories) to maximize gain. Our prediction was derived by having subjects produce category exemplars from a single category alone or from two categories at once. Data from single-category production trials as well as adjustments inspired by Experiment I through 3 were used to predict production from two categories. Though accurate, the flexibility of our prediction is limited. Research needed to allow for greater flexibility is discussed.
Gender specific neural correlates of emotion and cognition
(2010) Lugar, Heather M.; Dannemiller, James L.
Evidence suggests that regions within the anterior cingulate cortex (ACC) are sensitive both to emotional and cognitive task demands. This experiment asked whether emotional and cognitive demands are processed separately by ventral and dorsal regions within the ACC, respectively. Results revealed significant individual variability between changes in anxiety and response times with practice during performance of a verb generation task. Correlational analyses of the functional magnetic resonance imaging (fMRI) data were inconclusive. However, exploratory analyses suggest that while the ventral and dorsal subdivisions of the medial prefrontal cortex, which encompasses the ACC, make specialized contributions to the processing of emotion and cognition, respectively, the two subdivisions also appear to interact. These analyses also suggest that there could be a difference in how women and men balance the competing demands of emotion and cognition that might be related to differences in self-concept and neural activity in the default mode network.
Genetic contributions to attentional response time slopes across repeated trials
(BioMed Central, 2015) Lundwall, Rebecca A.; Dannemiller, James L.
Background: Attention provides vital contribution to everyday functioning, and deficits in attention feature in many psychological disorders. Improved understanding of attention may eventually be critical to early identification and treatment of attentional deficits. One step in that direction is to acquire a better understanding of genetic associations with performance on a task measuring reflexive (exogenous) visual attention. Reflexive attention is an important component of overall attention because (along with voluntary selective attention) it participates in determining where attention is allocated and how susceptible to distractors the subject might be. The task that we used involves the presentation of a target that is preceded by one of several different types of cues (none, double, or single, either ipsilateral or contralateral to where the target subsequently appears). We used several different outcome measures depending on the cue presented. We have previously studied the relationship between selected genes and mean response time (RT). Here we report on the contributions of genetic markers to RT increases or decreases over the course of the task (linear trend in RT slope). Results: Specifically, we find that RT slope for a variety of reflexive attention outcome measures is dependent on DAT1 genotype. DRD4 was near significant for one outcome measure in the final (best) model. APOE, COMT, and DBH were not significant in any models. Conclusions: It is especially interesting that genotype predicts linear changes in RT across trials (and not just mean differences or moment-to-moment variability). DAT1 is a gene that produces a protein involved in the transport of dopamine from the synapse. To our knowledge, this is the first study that has associated neurotransmitter genotypes with RT slope on a reflexive attention experiment. The direction of these effects is consistent with genetic risk for attention deficit hyperactivity disorder (ADHD). That is, those with two risk alleles for ADHD (6R/6R on the DAT1 intron 8 VNTR) either got slower as the task progressed or had the least improvement. Those with no risk alleles (5R/5R) had the most improvement in RT as the task progressed.
Investigating contour integration using ideal observers, response classification, and natural image statistics
(2008) Hamel, Melanie Lunsford; Dannemiller, James L.
These analyses test the hypothesis that contour integration is distinct from simple, non-random pattern recognition, and that it can be studied fruitfully using a novel combination of methodologies. Real, human observers and ideal observers perform a classification task in which the two stimulus patterns are systematically corrupted by noise to determine the effect of that noise on observers' responses. This technique, response classification, is used to determine how observers use the available information in an array of line elements to discriminate between an aligned contour and a non-random (orthogonal) pattern. The comparison between performance of several ideal observers and the human observers reveals that template-matching models might not account entirely for the human observers' responses. Beyond showing that human observers perform the task using the local relations between neighboring elements, we also determine the circumstances under which grouped pairs of elements are integrated perceptually into more extended contours. These circumstances are related theoretically to co-occurrence statistics derived from natural images between pairs of small line elements using the parameters of distance, orientation difference, and direction. The complete set of analyses further our understanding of how humans perceive visual contour.
Is response time variability on an exogenous visual orienting task associated with specific genetic markers?
(2012) Lundwall, Rebecca A.; Dannemiller, James L.
Attention is a vital component of everyday functioning, and deficits in attention feature in many psychological disorders. Improved understanding of attention may eventually be critical to early identification and treatment of attentional deficits. One step in that direction is to acquire a better understanding of genetic associations with performance on a measure of reflexive visual attention. We have previously studied the relationship between selected genes and mean RT. This thesis reports on a new analysis of the same data which were used to examine mean differences but now examines the contributions of genetic markers to RT variability. I consider the relationship between mean RT and RT variability and account for other potential predictors of RT variability such as age, ethnicity, and sleepiness. I ask, after accounting for other reasons that RT variability might be increased in some subjects, does increased RT variability depend also on genotype?
Molecular Genetics and the Development of Reflexive Visual Attention
(2013-08-09) Lundwall, Rebecca; Dannemiller, James L.; Oswald, Frederick L.; Alford, John R.; Sereno, Anne B
This study elucidates genetic influences on the development of reflexive attention. Reflexive attention refers to processes that rapidly shift attention, typically from one location in space to another (such as to an object that appears suddenly or moves). Our previous work has shown that normal adults differ by genotype on a reflexive attention task (Lundwall, Guo & Dannemiller, 2012). The current study attempts to show that normal children show similar genotypic differences. Differences in reflexive attention by genotype are not certain because gene expression and experience differ in children compared to adults. However, understanding association by genotype could be important to the early identification and treatment of attention-related disorders commonly diagnosed in childhood (e.g., attention deficit disorder; ADHD). Here I follow-up with children (aged nine -16 years; N = 332) who participated as infants in visual attention studies (see Dannemiller, 2004). I investigate genetic associations with reflexive attention measures at both time points as well as associations with stress, health, and academic performance. The genetic markers (i.e., APOE, BDNF, CHRNA4, COMT, DRD4, HTR4, IGF2, MAOA, SLC5A7, SLC6A3, and SNAP25) are related to brain development and/or to the availability of neurotransmitters such as acetylcholine, dopamine, or serotonin. One of the more interesting findings is that markers on CHRNA4, DRD4, IGF2, and MAOA predict the trajectory of the development of reflexive attention from infancy to childhood. Another interesting finding is that, unlike with our previous study with adults where cost dim was most sensitive to individual differences, with this child sample cost bright (the response time cost of a single bright, contralateral pre-cue) was associated with markers on BDNF, MAOA, and SNAP25. These genes are associated with brain growth, neurotransmitters such as dopamine, and neurotransmitter release into the synapse, respectively. A specific marker (rs6323) on MAOA was associated with seven child attention-task outcomes. From these and related results, I conclude that individual differences in reflexive attention and its development are related to several genetic markers including dopaminergic genes (implicated in disorders of attention such as ADHD).
Object priming in the fusiform cortex: Exploring effects of task and visual similarity
(2010) Harvey, Denise Y.; Dannemiller, James L.
Neural priming for same and different exemplars and viewpoints of objects was examined in two experiments using functional magnetic resonance imaging. In line with previous studies, viewpoint- and exemplar-specific priming was observed in the right fusiform gyrus (RFG). In contrast to some studies, viewpoint- but not exemplar-abstract priming was observed in the left fusiform gyrus (LFG). In the first experiment, neither task-demands nor visual similarity affected priming in the LFG. However, the RFG, including an area specialized for processing faces (the fusiform face area) was sensitive to the visual similarity of exemplar pairs. The second experiment explored this unpredicted result, but did not replicate the visual similarity effects. Results suggest that RFG and LFG are differentially sensitive to changes in viewpoint and are unaffected by task demands or visual similarity.
Relative Salience of Emergent Features in Vision
(2013-11-26) Cragin, Anna; Pomerantz, James R.; Byrne, Michael D.; O'Callaghan, Casey; Dannemiller, James L.
What exactly are the ``parts'' that make up a whole object, and how and when do they group? The answer that is proposed hinges on Emergent Features: features that materialize from the configuration and that make the object more discriminable from other objects. EFs are not possessed by any individual part and are processed as or more quickly than are the properties of the parts. The present experiment focuses on visual discrimination of two-line configurations in an odd-quadrant task. Stimuli were created so as to isolate each EF in order to measure its contribution to speed of discrimination. Previous results suggest that the EFs most responsible for the variations in RT might be Lateral Endpoint Offset, Intersections, Parallelism, Connectivity, Terminator Count, Pixel Count, Closure, and Inside /Outside Relationship. The present study determined the boost or detriments in performance due to each EF and ranked them in terms of their relative salience. The most salient features were: Connectivity, Parallelism, Closure, Intersections, and Inside/Outside Relationship.
THE NEUROLOGICAL COMPONENTS OF METAMEMORY MONITORING: JOL ACCURACY IN YOUNGER AND OLDER ADULTS
(2012-09-05) Haber, Sara; Logan, Jessica M.; Beier, Margaret E.; Dannemiller, James L.; Grandy, Richard E.; Beauchamp, Michael S.
Because maximizing the learning of new material is a relevant concern for most individuals, understanding the specific processes involved could be beneficial for people of all ages. Both encoding and monitoring occur during the learning acquisition phase, yet monitoring accuracy and subsequent neural activation have been relatively ignored in the literature. The current research adapts a common metacognitive paradigm using Judgments of Learning (JOLs) to explore the neural differences in monitoring between younger (18-25) and older (65+) adults. Participants were asked to remember natural scenes and predict encoding success by providing a JOL response for each item. Participants were told to respond “will remember” if they believed they would remember that item on a later recognition memory test or “will forget” if they thought they would forget that item on a later recognition memory test. Actual memory performance was compared to predicted memory performance to provide a measure of monitoring accuracy. Individuals reported a JOL response for 150 intact (Easy) and 150 scrambled (Difficult) scenes while in a 3.0T fMRI scanner. Despite minimal differences in behavioral performance, there were several age-related neuroimaging findings of note. When compared to younger adults, older adults had decreases in medial temporal lobe (MTL) activation, as well as contralateral recruitment of the anterior cingulate. Most importantly, the present study also disambiguated structures related to encoding success (the right parahippocampus) and monitoring accuracy (the anterior cingulate). A novel account of neural structures that mediate monitoring is provided both across items varying in difficulty (Easy and Difficult) and across different age groups (Young and Old). Encoding and monitoring are important for learning acquisition and the present research provides the first account that successfully disambiguates the two processes. Results are discussed in reference to their educational implications on resource allocation during the learning of new material.
The priming effects of task irrelevant information
(2007) Boyer, Jennifer; Dannemiller, James L.
Much research has shown that information outside of awareness can be processed to some degree. Here we used overlapping pictures and words presented in a RSVP paradigm to examine the effect of semantic congruency in an unattended dimension on performance in an attended dimension. We hypothesized that if unattended information is processed, then by manipulating the congruency of the dimensions we may see facilitory or inhibitory effects on subject's responses to attended items. We found that when an unattended congruent word preceded a picture target by a lag of 2 items or 4 items, responses to that target picture were speeded compared to when the word was unrelated to the target. This finding suggests that the unattended information is being processed to the level at which it can influence behavior and that this processing lasts for an extended duration after the item is presented.
Top-down influences on crowding: The word superiority effect and attentional cuing
(2008) Boyer, Jennifer; Dannemiller, James L.
The goal of the current studies was to examine the influence of top-down mechanisms on the crowding effect. Crowding refers to the reduced ability to identify an object, typically a letter, when other objects in the periphery surround it spatially. We used crowding as a tool to examine the semantic contribution to word superiority effect and investigate the role that attentional cuing plays in both the crowding effect and the word superiority effect. In Experiments 2 and 3, we used a secondary task of either a lexical decision task or an additional letter identification task to assess priming from related crowded items, and found that semantics do not play a role in the word superiority effect. By controlling for letter sequence familiarity we found that words and pronounceable non-words produced comparable priming effects, suggesting that the word superiority effect results from pattern familiarity. In Experiments 4 and 5, we examined whether attentional cuing of crowded stimuli produces target enhancement, distracter suppression effects, or both. We found that neither endogenous nor exogenous cues produced distracter suppressions effects, but there was evidence for signal enhancement effects especially with word stimuli. The evidence suggests that exogenously and endogenously orienting attention interact with the word superiority effect such that they enhance the effect of context for words, but do so in different ways.
Visual Displays: The Continuing Investigations of the Highlighting Paradox
(2006) Tamborello, Franklin Patrick, II; Byrne, Michael D.; Lane, David M.; Dannemiller, James L.; Autrey, Lynette S.
Previous research has suggested that making certain items visually salient, or highlighting, can speed performance in a visual search task. But designers of interfaces cannot always easily anticipate a user's target, and highlighting items other than the
Visual influences on electrotactile processing: Localizing and sequencing crossmodal interactions
(2008) Johnson, Ruth M.; Dannemiller, James L.
Most research studies on crossmodal processing of visual and tactile modalities have found that vision enhances touch. Nevertheless, it is unclear whether vision increases tactile sensitivity or changes participants' response criteria for reporting touch. The following set of studies demonstrated that some experimental manipulations can lead to a small increase in tactile sensitivity; however, all experiments showed a consistently strong response bias to report feeling a touch with a concomitant visual stimulus. Further experiments sequenced the temporal processes associated with the visuotactile response bias and determined that greater visual influences on electrotactile processing occurred at smaller crossmodal asynchronies. A final experiment demonstrated that the reported electrotactile enhancement bias on light-present trials can be increased with transcranial magnetic stimulation (TMS) over the posterior parietal cortex 200 ms after visual and electrotactile stimuli presentation. Further research needs to be conducted to determine more precise cortical locations and temporal sequences of the crossmodal interactions between vision and touch.

Browsing by Author "Dannemiller, James L."

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