Neuroscience and Neurobiology Commons^™

A Conceptual Framework Of Computations In Mid-Level Vision, Jonas Kubilius, Johan Wagemans, Hans P. Op De Beeck

MODVIS Workshop

The goal of visual processing is to extract information necessary for a variety of tasks, such as grasping objects, navigating in scenes, and recognizing them. While ultimately these tasks might be carried out by separate processing pathways, they nonetheless share a common root in the early and intermediate visual areas. What representations should these areas develop in order to facilitate all of these higher-level tasks? Several distinct ideas have received empirical support in the literature so far: (i) boundary feature detection, such as edge, corner, and curved segment extraction; (ii) second-order feature detection, such as the difference in orientation or …

Binocular 3d Motion Perception As Bayesian Inference, Martin Lages, Suzanne Heron

MODVIS Workshop

The human visual system encodes monocular motion and binocular disparity input before it is integrated into a single 3D percept. Here we propose a geometric-statistical model of human 3D motion perception that solves the aperture problem in 3D by assuming that (i) velocity constraints arise from inverse projection of local 2D velocity constraints in a binocular viewing geometry, (ii) noise from monocular motion and binocular disparity processing is independent, and (iii) slower motions are more likely to occur than faster ones. In two experiments we found that instantiation of this Bayesian model can explain perceived 3D line motion direction under …

Object Recognition And Visual Search With A Physiologically Grounded Model Of Visual Attention, Frederik Beuth, Fred H. Hamker

MODVIS Workshop

Visual attention models can explain a rich set of physiological data (Reynolds & Heeger, 2009, Neuron), but can rarely link these findings to real-world tasks. Here, we would like to narrow this gap with a novel, physiologically grounded model of visual attention by demonstrating its objects recognition abilities in noisy scenes.

To base the model on physiological data, we used a recently developed microcircuit model of visual attention (Beuth & Hamker, in revision, Vision Res) which explains a large set of attention experiments, e.g. biased competition, modulation of contrast response functions, tuning curves, and surround suppression. Objects are represented by …

Presence-At-Hand, Eric Lyle Schultz

Graduate School of Art Theses

Abstract

The writing that follows is intended to provide a theoretical framework for the motives behind my practice. The primary concerns addressed are the reception, transmission, and physical shape of knowledge. I will discuss a human condition that exists as a byproduct of both the legacy of representation as well as the innate biology of the brain. I will argue that as a society we are governed by the residue of an extreme logic, and that this condition places severe margins on our potential for creative solutions. I will propose that our ability to create meaning is stifled by the …

Design, Programming, And User-Experience, Kaila G. Manca

Honors Scholar Theses

This thesis is a culmination of my individualized major in Human-Computer Interaction. As such, it showcases my knowledge of design, computer engineering, user-experience research, and puts into practice my background in psychology, com- munications, and neuroscience.

I provided full-service design and development for a web application to be used by the Digital Media and Design Department and their students.This process involved several iterations of user-experience research, testing, concepting, branding and strategy, ideation, and design. It lead to two products.

The first product is full-scale development and optimization of the web appli- cation.The web application adheres to best practices. It was …

The Perception Of Symmetry In Depth: Effect Of Symmetry Plane Orientation, Bart Farell

Biomedical and Chemical Engineering - All Scholarship

The visual system is sensitive to symmetries in the frontoparallel plane, and bilateral symmetry about a vertical axis has a particular salience. However, these symmetries represent only a subset of the symmetries realizable in three-dimensional space. The retinal image symmetries formed when viewing natural objects are typically the projections of three-dimensional objects—animals, for example—that have a symmetry in depth. To characterize human sensitivity to depth symmetry, experiments measured observers’ ability to discriminate stereo displays that were symmetrically distributed in depth and those that were asymmetrically distributed. Disparity values were distributed about one of four planes passing through the z-axis and …

Electrophysiological Changes Of N100 Latency And Amplitude In Healthy Participants Performing The Jitter Orientated Visual Integration Task: A Multi-Block Design Study, Fariya Naz

University Scholar Projects

The present study investigated the differences in processing during visual integration in healthy adults. The visual N100 indexes early visual discrimination and in this case, was hypothesized to show differences in both latency and amplitude depending on the level of difficulty which corresponds to orientational jitter in a visual integration task. Four blocks with pseudo-random levels of jitter were presented to participants in the Jitter Oriented Visual Integration (JOVI) task. Results looking at the Oz channel showed significant reduction in amplitude in the visual N100 during the more difficult levels condition of the task. The multi-block design, originally expected to …

Prevalence Of Learned Grapheme-Color Pairings In A Large Online Sample Of Synesthetes, Nathan Withhoft, Jonathan Winawer, David M. Eagleman

Faculty, Staff and Students Publications

In this paper we estimate the minimum prevalence of grapheme-color synesthetes with letter-color matches learned from an external stimulus, by analyzing a large sample of English-speaking grapheme-color synesthetes. We find that at least 6% (400/6588 participants) of the total sample learned many of their matches from a widely available colored letter toy. Among those born in the decade after the toy began to be manufactured, the proportion of synesthetes with learned letter-color pairings approaches 15% for some 5-year periods. Among those born 5 years or more before it was manufactured, none have colors learned from the toy. Analysis of the …

Electrophysiological And Behavioral Working Memory Differences Between Musicians And Non-Musicians, Benjamin P. Richardson

All Master's Theses

The current study examines the P300 brainwave and working memory differences between musicians and non-musicians. Differences in aspects of recorded electrical brain activity have been used to quantify differences in updating processes of working memory possibly related to differences in amount of music experience. The current study is designed to partially replicate and enhance a method previously implemented in research describing how music experience may be associated with differences in visual processing as well auditory working memory and executive function. Behavioral data were collected using six standardized subtest measures of the TOMAL – II, followed by ERP recordings during a …

Reducing Subjectivity: Meditation And Implicit Bias, Diana M. Ciuca

CMC Senior Theses

Implicit association of racial stereotypes is brought about by social conditioning (Greenwald & Krieger, 2006). This conditioning can be explained by attractor networks (Sharp, 2011). Reducing implicit bias through meditation can show the effectiveness of reducing the rigidity of attractor networks, thereby reducing subjectivity. Mindfulness meditation has shown to reduce bias from the use of one single guided session conducted before performing an Implicit Association Test (Lueke & Gibson, 2015). Attachment to socially conditioned racial bias should become less prevalent through practicing meditation over time. An experimental model is proposed to test this claim along with a reconceptualization of consciousness …

Perceived Depth In Non-Transitive Stereo Displays, Bart Farell, Cherlyn J. Ng

Biomedical and Chemical Engineering - All Scholarship

The separation between the eyes shapes the distribution of binocular disparities and gives a special role to horizontal disparities. However, for one-dimensional stimuli, disparity direction, like motion direction, is linked to stimulus orientation. This makes the perceived depth of one-dimensional stimuli orientation dependent and generally non-veridical. It also allows perceived depth to violate transitivity. Three stimuli, A, B, and C, can be arranged such that A > B (stimulus A is seen as farther than stimulus B when they are presented together) and B > C, yet A ≤ C. This study examines how the visual system handles the depth of A, …

The Phenomenon Of Abstract Cognition Among Scholastic Chess Participants: A Case Study, Brent C. Laws

Electronic Theses and Dissertations

A qualitative investigation was conducted to explore the phenomenon of abstract cognition among a purposive sample of 5 secondary scholastic chess club participants. The case study enabled the researcher to explore the faculties of abstract cognition among students of contrasting skills and abilities in playing chess. The study also allowed for the consideration of potential visual-spatial, logical, academic, social competency and life benefits of chess play. Through analysis of interviews, chess simulations, blindfold chess play, and narration of chess lines and sequences, the investigator was able to extract meaning and code schemata into a holistic understanding of the phenomenon of …

Change Detection In Rhesus Monkeys And Humans, Deepna T. Devkar, Deepna T. Devkar

Dissertations and Theses (Open Access)

Visual working memory (VWM) is the temporary retention of visual information and a key component of cognitive processing. The classical paradigm for studying VWM and its encoding limitations has been change detection. Early work focused on how many items could be stored in VWM, leading to the popular theory that humans could remember no more than 4±1 items. More recently, proposals have suggested that VWM is a noisy, continuous resource distributed across virtually all items in the visual field, resulting in diminished memory quality rather than limited quantity. This debate about the nature of VWM has predominantly been studied with …

The New Normal: Goodness Judgments Of Non-Invariant Speech, Julia R. Drouin

Honors Scholar Theses

Previous research has found that perceptual learning, or normalizing the idiosyncratic phonemes of speech, causes a shift in speech sound category boundaries. The present study examined if perceptual learning was limited to the boundary or if also caused a shift in internal category structure. Seventeen individuals participated in three behavioral tasks to explicate this question. In the Lexical Decision task, participants were trained in either /s/-biasing or /ʃ/- biasing context. In the Goodness Judgment task, participants rated a continuum of sounds on perceived /s/ goodness using a designated scale. Finally, in the Phoneme Identification task, participants listened to the same …

Normal Acquisition Of Expertise With Greebles In Two Cases Of Acquired Prosopagnosia, Constantin Rezlescu, Jason J. S. Barton, David Pitcher, Bradley Duchaine

Dartmouth Scholarship

Face recognition is generally thought to rely on different neurocognitive mechanisms than most types of objects, but the specificity of these mechanisms is debated. One account suggests the mechanisms are specific to upright faces, whereas the expertise view proposes the mechanisms operate on objects of high within-class similarity with which an observer has become proficient at rapid individuation. Much of the evidence cited in support of the expertise view comes from laboratory-based training experiments involving computer-generated objects called greebles that are designed to place face-like demands on recognition mechanisms. A fundamental prediction of the expertise hypothesis is that recognition deficits …

Direct Control Of Visual Perception With Phase-Specific Modulation Of Posterior Parietal Cortex, Andrew Jaegle, Tony Ro

Publications and Research

We examined the causal relationship between the phase of alpha oscillations (9–12 Hz) and conscious visual perception using rhythmic TMS (rTMS) while simultaneously recording EEG activity. rTMS of posterior parietal cortex at an alpha frequency (10 Hz), but not occipital or sham rTMS, both entrained the phase of subsequent alpha oscillatory activity and produced a phase-dependent change on subsequent visual perception, with lower discrimination accuracy for targets presented at one phase of the alpha oscillatory waveform than for targets presented at the opposite phase. By extrinsically manipulating the phase of alpha before stimulus presentation, we provide direct evidence that the …

Perceived Depth In Non-Transitive Stereo Displays, Bart Farell, Cherlyn J. Ng

Biomedical and Chemical Engineering - All Scholarship

The separation between the eyes shapes the distribution of binocular disparities and gives a special role to horizontal disparities. However, for one-dimensional stimuli, disparity direction, like motion direction, is linked to stimulus orientation. This makes the perceived depth of one-dimensional stimuli orientation dependent and generally non-veridical. It also allows perceived depth to violate transitivity. Three stimuli, A, B, and C, can be arranged such that A > B (stimulus A is seen as farther than stimulus B when they are presented together) and B > C, yet A 6 C. This study examines how the visual system handles the depth of A, …

Examining The Intersection Of The Cognitive Advantages And Disadvantages Of The Bilingual Brain, Irina Rabkina

Scripps Senior Theses

Two conflicting findings characterize cognitive processing accompanying bilingualism. The “bilingual advantage” refers to improved cognitive performance for bilingual compared to monolingual participants. Most bilingual advantages fall under the umbrella of cognitive control mechanisms, most frequently demonstrated using the Stroop task and the Simon task (e.g., Bialystok, 2008; Coderre, Van Heuven, & Conklin, 2013). The “bilingual disadvantage,” on the other hand, refers to bilinguals’ diminished performance on tasks that require word retrieval or switching between languages. This study examined the intersection of the bilingual advantage and the bilingual disadvantage to investigate whether they stem from a single cognitive control process. The …

Unconscious Priming Requires Early Visual Cortex At Specific Temporal Phases Of Processing, Marjan Persuh, Tony Ro

Publications and Research

Although examples of unconscious shape priming have been well documented, whether such priming requires early visual cortex (V1/V2) has not been established. In the current study, we used TMS of V1/V2 at varying temporal intervals to suppress the visibility of preceding shape primes while the interval between primes and targets was kept constant. Our results show that, although conscious perception requires V1/V2, unconscious priming can occur without V1/V2 at an intermediate temporal interval but not at early (5–25 msec) or later (65–125 msec) stages of processing. Because the later time window of unconscious priming suppression has been proposed to interfere …

Unconscious Processing Of Unattended Features In Human Visual Cortex, Tatiana Aloi Emmanouil, Philip Burton, Tony Ro

Publications and Research

Unconscious processing has been convincingly demonstrated for task-relevant feature dimensions. However, it is possible that the visual system is capable of more complex unconscious operations, extracting visual features even when they are unattended and task irrelevant. In the current study, we addressed this question by measuring unconscious priming using a task in which human participants attended to a target object's shape while ignoring its color. We measured both behavioral priming effects and priming-related fMRI activations from primes that were unconsciously presented using metacontrast masking. The results showed faster RTs and decreases in fMRI activation only when the primes were identical …

The Effect Of Visual Wulst Lesions And Trigeminal Nerve Sectioning On The Discrimination Of Magnetic Inclination In The Homing Pigeon (Columba Livia), Merissa Acerbi

Honors Projects

The ability of homing pigeons to return to their loft from unknown places has fascinated scientists for centuries. It is well established that homing pigeons, like migratory birds, posses an innate magnetic inclination compass to determine direction by measuring the angle between the magnetic field vector and the Earth's surface. Recent work has indicated that the avian magnetic compass is light mediated and appears to mediate magnetic information to the brain. This occurs via a visual pathway with processing in the visual Wulst area of the forebrain. There is, however, also evidence from other avian species that magnetic direction may …

Biological Motion And Gender Recognition: Visual Fixation On The Inversion Effect, Andrey P. Borisyuk, Rachel J. Garland, Alysse M. Feldman, Abigail R. Marchese

Science University Research Symposium (SURS)

Gender recognition of point-light animations replicated an inversion effect. Participants identified the gender of thirty-two (half upright and half inverted, half male and half female) moving point-light human figures. Male figures were more accurately recognized in upright animations whereas female figures were more accurately recognized in inverted animations. Eye gaze of both genders was identical in both the upright animations (predominantly waist and shoulders) and inverted animations (predominantly waist but more distributed across body parts).

Navigating The Diverse Dimensions Of Stereotypes, With Domain Specific Deficits: Processes Of Trait Judgments About Individuals With Disabilities, Christina G. Boardman

Scripps Senior Theses

Stereotype groups are interrelated. For example, in Australia, New Zealand, and the United States, racial minorities are referred to special education at a much higher rate than are majority racial groups (Tse, Lloyd, Petchkovsky, and Manaia, 2005; Harry, Arnaiz, Klingner, Sturges, 2008). The Stereotype Content Model describes stereotype relationships in terms of an interaction between competence and warmth. Warmth is the more consistent dimension. The nature of competence remains elusive (Fiske, Cuddy, and Glick, 2007; Fiske, Cuddy, Glick, and Xu, 2002). Knowledge of relationships between stereotype groups, which themselves may be effects of bias, could factor into observed competence effects. …

Change Detection Memory In Rhesus Monkeys And Humans, Lauren C. Elmore

Dissertations and Theses (Open Access)

Visual short-term memory (VSTM) is the storage of visual information over a brief time period (usually a few seconds or less). Over the past decade, the most popular task for studying VSTM in humans has been the change detection task. In this task, subjects must remember several visual items per trial in order to identify a change following a brief delay interval. Results from change detection tasks have shown that VSTM is limited; humans are only able to accurately hold a few visual items in mind over a brief delay. However, there has been much debate in regard to the …

Common And Distinct Mechanisms Of Cognitive Flexibility In Prefrontal Cortex, Chobok Kim, Nathan F. Johnson, Sara E. Cilles, Brian T. Gold

Neuroscience Faculty Publications

The human ability to flexibly alternate between tasks represents a central component of cognitive control. Neuroimaging studies have linked task switching with a diverse set of prefrontal cortex (PFC) regions, but the contributions of these regions to various forms of cognitive flexibility remain largely unknown. Here, subjects underwent functional brain imaging while they completed a paradigm that selectively induced stimulus, response, or cognitive set switches in the context of a single task decision performed on a common set of stimuli. Behavioral results indicated comparable reaction time costs associated with each switch type. Domain-general task-switching activation was observed in the inferior …

Locus Of Control And The Age Difference In Free Recall From Episodic Memory, Paul Amrhein, Judith K. Bond, Derek Hamilton

Department of Psychology Faculty Scholarship and Creative Works

The authors investigated the relation of locus of control (LOC) to age differences in free-recall memory performance. Older and younger participants completed P. C. Duttweiler's (1984) Internal Control Index (ICI) and subsequently performed free-recall memory tasks. Compared with the younger participants, the older participants exhibited poorer recall with more intrusions and uncorrected repetition errors as well as reduced categorical clustering. For the older participants with less internal LOC, recall proportion and item-pair associative recall clustering were lower than for the older participants with more internal LOC. By contrast, the younger participants did not exhibit any LOC effects in their recall …

The Neuroscientific Study Of The Self: Methodological And Theoretical Challenges, Cynthia J. Najdowski, Samuel E. Winer

Psychology Faculty Scholarship

Neuroscientific research methods, such as brain imaging techniques, have increasingly been applied to social cognitive research efforts and, in particular, to the study of the self. In this essay we discuss the ability of such research to shed light on the emergent, dynamic psychological phenomenon of self. Although neuroscientific tools can be useful for gaining general knowledge about associated underlying structures, a careful consideration of the methodological and theoretical issues discussed herein is necessary to avoid simplifying or reifying the self.

Examining Neurophysiological Evidence Of Age-Related Interactions Of Sensory And Cognitive Processes During Speech Processing, Cady Kristen Block

Psychology Theses & Dissertations

The present study sought to examine the contribution of sensory and cognitive factors on speech processing as evidenced by ERP measures and to find support for the Sensory Cognitive Interaction Theory (SCIT) and the Effortfulness Hypothesis in that older adults. who experience sensory deficits with normal aging. must put forth increased effort during early sensory stages of speech processing that may compromise subsequent semantic performance and recall of information. In the present investigation. younger and older adults performed a sentence verification task at low and high presentation levels (PL). Accuracy and response time to sentence verifications were assessed along with …

Maintenance Of Visual Stability In The Human Posterior Parietal Cortex, Erik Chang, Tony Ro

Publications and Research

Visual stability refers to our stable visuospatial perceptions despite the unstable visual input caused by saccades. Functional neuroimaging results, studies on patients with posterior parietal cortex (PPC) lesions, and single-unit recordings in the lateral intraparietal sulcus of primates indirectly suggest that the PPC might be a potential locus of visual stability through its involvement with spatial remapping. Here we directly explored the role of the PPC in visual stability by applying transcranial magnetic stimulation (TMS) while participants performed a perisaccadic displacement detection task. We show that TMS over the PPC but not a frontal control site alters sensitivity to displacement …

Effects Of Age On Motor Preparation And Restructuring, Paul Amrhein, Noreen Goggin, George Stelmach

Department of Psychology Faculty Scholarship and Creative Works

Age-related decrements in motor plan restructuring were investigated. In this experiment, older and younger adults performed a discrete aiming task that involved responses that were precued and responses that were modified at the time of an imperative signal. On 75% of the trials, the precue specified the response-stimulus (valid trials) with respect to the movement parameters of the arm (left or right) and direction (toward or away). On the remaining 25% of the trials, the response-stimulus was different from the precue (invalid trials) in that the subject was required to modify a planned movement by changing the arm to be …