Cognition and Perception Commons^™

Examining Age-Related Enhancement Of Multisensory Gain: The Role Of Sensory Decline And Inverse Effectiveness, Laura C. Schneeberger

Electronic Thesis and Dissertation Repository

Older adults experience a greater benefit from multisensory integration than their younger counterparts, but it is unclear why. One hypothesis is that age-related sensory decline weakens unisensory stimulus effectiveness, producing a boost in multisensory gain through inverse effectiveness. Many previous studies present stimuli at the same intensity for both younger and older adults (i.e., stimulus-matched), as opposed to accounting for each participant’s unique perceptual ability (i.e., perception-matched). This makes it difficult to discern the source of age-related differences in multisensory gain. Through a combination of stimulus-matched and perception-matched tasks, I found that older adults exhibit enhanced multisensory gain at low …

Does Optic Flow Provide Information About Actions?, Hannah Masoner

Dissertations

Optic flow, the pattern of light generated in the visual field by motion of objects and the observer’s body, serves as information that underwrites perception of events, actions and affordances. This visual pattern informs the observer about their own actions in relation to their surroundings, as well as those of others. This study explored the limits of action detection for others as well as the role of optic flow. First-person videos were created using camera recordings of the actor’s perspective as they performed various movements (jumping jacks, jumping, squatting, sitting, etc.). In three experiments participants attempted to detect the action …

Does Optic Flow Provide Information About Actions?, Hannah Masoner

Dissertations

Optic flow, the pattern of light generated in the visual field by motion of objects and the observer’s body, serves as information that underwrites perception of events, actions and affordances. This visual pattern informs the observer about their own actions in relation to their surroundings, as well as those of others. This study explored the limits of action detection for others as well as the role of optic flow. First-person videos were created using camera recordings of the actor’s perspective as they performed various movements (jumping jacks, jumping, squatting, sitting, etc.). In three experiments participants attempted to detect the action …

Increment And Decrement Effects In Motion Induced Blindness, Sofia C. Lombardo

Honors Theses and Capstones

Motion induced blindness (MIB) refers to the perceptual disappearance of a stationary stimulus in the presence of a motion mask. The current study investigated the degree to which afterimages affect MIB inhibition when measured as a contrast detection threshold in a modified replication of White et al. (2020). Adult participants (N = 3) with normal or corrected-to-normal eyesight completed a series of target detection tasks while viewing a standard MIB stimulus with the motion mask removed that consisted of increment versus decrement inducer and target components. A univariate ANOVA data analysis procedure revealed a significant afterimage effect (Scheffé p < 0.0253) on contrast detection threshold was found for targets presented at an interstimulus interval of 500 ms. This effect was stronger for decrement targets compared to increment targets in the decrement inducer conditions. Based on a comparison with previous research in which the MIB effect was found to endure across interstimulus intervals up to 15500 ms, the current findings indicate that afterimages do not significantly influence contrast detection thresholds for MIB. Further research is necessary for determining the strength and duration of afterimage effects on contrast detection thresholds in MIB that may be caused by interaction with the motion mask.

The Temporal Dynamics Of Ensemble Perception, Michael L. Epstein

Dissertations, Theses, and Capstone Projects

The striking disparity between the subjective richness of experience and the considerable limitations of perceptual processing has emerged as an essential, enduring question in both vision science and philosophy of mind. A potential solution to this issue is ensemble perception: the ability for the visual system to compute the statistical summaries of object groups, effectively compressing an otherwise overwhelming amount of information. Previous work has supported that ensemble statistics can be perceived quickly and accurately for a wide range of object features. This has motivated models of ensemble perception as an early process in vision, providing an initial sense of …

Mapping The Spatial And Temporal Dynamics Of Visual Percepts Elicited By A Non-Invasive Brain Stimulation Technique, Kelly Webster

Dissertations, Theses, and Capstone Projects

While many of us rely on vision to interact with and experience the world, for people with damage or disease to the eye or visual cortex, experience through this modality is extremely limited. Brain and retinal stimulation devices show exciting promise for restoring vision, but little is understood about where and when vision percepts can be induced through stimulation. Using a non-invasive brain stimulation technique called transcranial magnetic stimulation (TMS), we characterized the spatial and temporal dynamics of perception induced through brain stimulation. In the first set of experiments, we explore the importance of higher visual and non-visual areas vs. …

Electrophysiological Correlates Of Visual Object Category Formation In A Prototype-Distortion Task, Stephanie Marie Long

Graduate Theses and Dissertations

In perceptual learning studies, participants engage in extensive training in the discrimination of visual stimuli in order to modulate perceptual performance. Much of the literature in perceptual learning has looked at the induction of the reorganization of low-level representations in V1. However, much remains to be understood about the mechanisms behind how the adult brain (an expert in visual object categorization) extracts high-level visual objects from the environment and categorically represents them in the cortical visual hierarchy. Here, I used event-related potentials (ERPs) to investigate the neural mechanisms involved in object representation formation during a hybrid visual search and prototype …

Object Permanence In Asian Elephants (Elephas Maximus), Dalia Miller

Theses and Dissertations

This study investigated object permanence in Asian elephants (Elephas maximus) using visible and invisible test paradigms with single and multiple object displacements. Elephants were predicted to succeed, demonstrating a capacity for object permanence and for using vision in a cognitive task. Study outcomes supported these predictions.

Correspondence Between Haptic And Visual Perception Of Stand-On-Ability: Do Hills Look As Steep As They Feel?, Jonathan Kenealy Doyon

Master's Theses

Vision and haptics play a central role in perceiving environmental layout to guide action. Hajnal, Wagman, Doyon, and Clark (2016) demonstrated that visual perception of stand-on-ability is accurate compared to action capabilities, whereas haptic perception of stand-on-ability reliably underestimates action capabilities. This finding contradicts Gibson’s (1979) theory of equivalence in perceptual systems, which suggests that perception should be equivalent regardless of modality. Previous comparisons of visual and haptic perception tested the modalities in isolation. The current experiment directly compares visual to haptic perception of stand-on-ability by using one perceptual system to estimate the other. Observers viewed a surface set to …

The Effect Of Auditory Stimuli On Visual Time-To-Contact Perception, Chelsea L. Rugel

Senior Honors Projects, 2010-2019

Previous research has demonstrated that auditory and visual stimuli have individual effects on the accuracy of a person’s estimation of time-to-contact (TTC), the time at which two objects collide. Prior findings also suggest that there is cross-modal interference between vision and audition; however, this phenomenon has never been studied in a TTC situation. (Driver & Spence, 1998; Ichikawa & Masskura, 2006; Roseboom, Kawabe, & Nishida, 2013) In this study we attempted to fill in this research gap by examining the effect of auditory speed cues over visual speed cues in a two-dimensional TTC scenario, and by determining if an object’s …

Seeing With Sound: Investigating The Behavioural Applications And Neural Correlates Of Human Echolocation, Jennifer L. Milne

Electronic Thesis and Dissertation Repository

Some blind humans use the reflected echoes from self-produced signals to perceive their silent surroundings. Although the use of echolocation is well documented in animals such as bats and dolphins, comparatively little is known about human echolocation. The overarching goal of the work presented in this thesis was to shed light on some of the basic functions of human echolocation, including the perception of the shape, size, and material. I addressed these aspects of echolocation using behavioural psychophysics and neuroimaging.

In Chapter 2 I show that blind echolocators were able to accurately identify the shape of 2D objects, but that …

Are Visual Texture-Selective Areas Recruited During Haptic Texture Discrimination?, Samantha K. Podrebarac

Electronic Thesis and Dissertation Repository

Shape and texture provide cues to object identity, both when objects are explored using vision and via touch (haptics). Visual shape information is processed within the lateral occipital complex (LOC), while texture is processed in medial regions of the collateral sulcus (CoS). Evidence indicates that the LOC is consistently recruited during both visual and haptic shape processing. We used functional magnetic resonance imaging (fMRI) to examine whether 'visual' texture-selective areas are similarly recruited when observers discriminate texture via touch. We used a blocked design in which participants attended to either the texture or shape of a number of 3-dimensional (3D) …

Eye Contact Perception At Distances Up To Six Meters, Daniel L. Scarl

Dissertations and Theses

Common experience suggests that most people can tell whether they are being looked at by another person who is about 8 m away. However, the results of past experiments, which used distances of no more than about 3 m, have implied that this cannot be done if the person looked at (Receiver) judges only by the iris-sclera configuration of the person looking (Sender). This is true even if eye contact is defined simply as identifying on-face gazes (FGs). It has been suggested that in everyday experience eye contact is accompanied by cues other than iris position, and that these non-iris-position …

Ames Trapezoid Illusion: A New Model, Daniel Robert Kelly

Dissertations and Theses

Current explanations for the Ames Trapezoid Illusion are based upon the the absence of cues: the illusion is said to occur at chance. A review of recent literature showed that: (a) the illusion varies in frequency as a function of target shape (b) that the dominant cue to reduce the frequency of the illusion is the variant in retinal height. Based upon the dominance of this cue a new model was presented. Following this model it was hypothesized that observers viewing partial rotation when the target produces the greatest difference in the retinal height of the ends would determine the …