FREE ELECTRONIC LIBRARY - Dissertations, online materials

Pages:   || 2 | 3 |

«A Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Science Approved April 2014 by the Graduate Supervisory ...»

-- [ Page 1 ] --

The Effects of Implied Motion Training on General Cortical Processing


Aresh Vasefi

A Thesis Presented in Partial Fulfillment

of the Requirements for the Degree

Master of Science

Approved April 2014 by the

Graduate Supervisory Committee:

Jose Nanez, Chair

Nicholas Duran

Thomas Keil

Arizona State University

May 2014


Current research has identified a specific type of visual experience that leads to faster cortical processing. Specifically, performance on perceptual learning of a directional-motion leads to faster cortical processing. This is important on two levels;

first, cortical processing is positively correlated with cognitive functions and inversely related to age, frontal lobe lesions, and some cognitive disorders. Second, temporal processing has been shown to be relatively stable over time. In order to expand on this line of research, we examined the effects of a different, but relevant visual experience (i.e., implied motion) on cortical processing. Previous fMRI studies have indicated that static images that imply motion activate area V5 or middle temporal/medial superior temporal complex (MT/MST+) of the visual cortex, the same brain region that is activated in response to real motion. Therefore, we hypothesized that visual experience of implied motion may parallel the positive relationship between real directional-motion and cortical processing. Seven subjects participated in a visual task of implied motion for 4 days, and a pre- and post-test of cortical processing. The results indicated that performance on implied motion is systematically different from performance on a dot motion task. Despite individual differences in performance, overall cortical processing increased from day 1 to day 4.



This Thesis would never have been written if not for the help of the following:

Dr. Jose E. Nanez Sr.

Daniel Zimmerman ii


Page Abstract

Acknowledgements….……………………………………………………………….…......ii Introduction………….………………………………………………………………..….....1 Methods


Material & Procedures



Footnotes….………………………………………………………………………………. 18 References…………………………………………………………………………….........19 Tables

Tables 1 - 3

Tables 4 - 7

Tables 8 & 9

Tables 10 & 11

Tables 12 - 14


Figures 1 - 3

Figures 4 & 5

Figures 6 & 7

Figures 8 & 9

–  –  –

Perceptual learning is broadly defined as improvement in sensory perception by way of training over time (Fahle, 2005). In addition, perceptual learning has been found to be highly specific to low-level features (i.e., contrast, direction, orientation, location, etc). For example, learning to discriminate motion in one location will not transfer to a location equal to and greater than 3 degrees away, which is within the primary visual cortex1. That is, neurons firing rate drops to baseline when location, direction, orientation of the stimuli is shifted (Fahle, 2005). Moreover, the high specificity suggests that cells in V1 integrate multiple low-levels features for more complex visual processing. For example, moving dots at 10 percent coherency (local motion) within randomly distributed dots will appear to move in one direction (global motion). Taken together, the integration suggests that V1 extracts great amount of information from single low-level features. The high specificity of perceptual learning has been empirically linked to a biological process of neuroplasticity, which is a functional (performance enhancement) and structural (increase in synaptic pathways) enhancement to novel changes in the environment. This neuro-biological process explains how we learn and adapt quickly and proficiently to new information in our environment (Fahle & Poggio, 2002).

Researchers have been exploring the generalizability of perceptual learning within low-level (e.g., change in location) and high-level visual processing (e.g., complex visual processing). For example, Crist, Kapadia, Westheimer, & Gilbert, (1997) found that performance in three-line bisection task2 transferred up to eight degrees from the training field, which is beyond the primary visual cortex. Furthermore, perceptual learning of coherent dot motion, where subjects discriminate direction of a specified group of dots

–  –  –

(high-level visual process). Very recent studies have indicated that perceptual learning of motion does not only lead to faster flicker perception, but also faster reading speed and better reading comprehension (Holloway, Nanez, & Seitz, under revision; Groth, (2013, unpublished MS thesis).

The dual system theory has been proposed to explain the systems of low- and high- level visual processing, and the interaction between the two levels (Milner & Goodale, 2007). According to the Milner and Goodale (2007), humans have two distinct, but mutually independent visual systems, which consist of visual streams for action (i.e., the dorsal stream) and perception (i.e., ventral stream). More specifically, when exposed to visual stimuli (i.e., moving dots), the information is carried from the ganglion cells within the retina to the magnocellualr pathways (large layer of cells within the lateral geniculate nucleus), then to the primary visual cortex for processing (V1). From V1, depending on the visual stimuli, the information travels through either the dorsal stream (“where pathway”) or the ventral stream (“what pathway”). If the stimulus is fast moving low-contrast dots, the information travels from V1 to the MT and parietal lobe for higherorder processing (e.g., where tasks like flicker perception, word decoding, reading comprehension are processed) via the dorsal stream. If subjects are instructed to identify an object that is presented at a slower rate with higher contrast, then the information is projected to the inferior temporal cortex through the ventral stream (Nealey & Maunsell, 1994).

In regards to our motion discrimination task, specifically, the neural properties of area MT provide the theoretical framework for the current study. Moreover, area MT has

–  –  –

decrease in neural activity when an observer is repeatedly exposed to the same direction of motion. In addition, area MT has demonstrated an increase in functional benefit when exposed to novel motion (Kohn, 2007; Ranganath & Rainer, 2003). Essentially, motion discrimination training that is randomly displayed throughout the experiment is structurally and functionally beneficial for area MT. In this paper, we are only interested in the neural correlates of V5 or medial temporal through the dorsal stream. The neural correlates of magnocallular pathway, MT/MST+, and the dorsal stream may provide the theoretical framework for the variables of interest in this paper. That is to say, the variables of interest include fast moving, low contrast, unidirectional-implied motion.

Each component of the variable is related to low-level and high-level visual processing.

Implied motion is broadly defined as static stimuli that imply motion due to dynamic features within the stimuli (Kourtzi & Kanwisher, 2000). For example, the image of a silhouette in Figure 1 is implying motion to the left with high leg-left, arched back, and extended arms. In contrast, the image of a woman in Figure 3 is motionless because she lacks the articulation in body posture needed to imply motion. Previous research has indicated that images resembling Figure 1 activate area MT/MST+ significantly higher than the images resembling Figure 3. Kourtzi and Kanwisher, (2000) argued that MT/MST+ is not the only brain region responsible for processing visual cues that imply motion; rather it is part of a larger network of brain regions that “mediate” the visual processing of motion. In addition, they reasoned that MT/MST+ sensitivity of implied motion are, in part, governed by a top-down influence. In other words, the adult brain has been exposed to similar animate objects (i.e., biological figure of a silhouette),

–  –  –

Resonance Imaging (fMRI) studies of implied motion following Kourtzi & Kanwisher, (2000) have confirmed the top-down influence, by showing neural correlates beyond MT/MST+. For example, researchers have found activation in superior temporal sulcus (STS; sensitive to dynamic biological forms), extrastriate body area (EBA; sensitive to body type), and pre-motor and motor cortex (sensitive to high degree of articulation) (Proverbio, Riva, & Zani, 2009; Jellema & Perrett, 2003). In addition, Fawcett, Hillebrand, & Singh, (2007) and Lorteije et al., (2006) found late activation (600 msms) in MT, suggesting the influence of higher-level processing. However, researchers also argue that activation of implied motion could be due to differences in low-level features (Lorteije et al., 2011; Pavan, Cuturi, Maniglia, Casco, & Campana, 2011).

The discrepancy regarding neural correlates of implied motion could be due to differences in experimental methodology (e.g., controlling for low level features, contrast, and timing). It is evident that there are no standardized methods of presenting implied motion in regards to timing and image properties (e.g., color, size, contrast, etc).

For example, the stimuli include, but are not limited to, grayscale images of (in)animate objects (Kourtzi, & Kanwisher, (2000); Jellema & Perrett 2003; Pavan, Cuturi, Maniglia, Casco, & Campana (2011), color images of (in)animate (Winawer, Huk, & Boroditsky, (2008), Fawcett, Hillebrand, & Singh, (2007); Holmes & Wolff, (2010), color images of hand in grasping movement (Urgesi, Moro, Candidi, & Aglioti, (2006), and cartoon images in articulated positions (Osaka, Matsuyoshi, Ikeda, & Osaka, (2010). In addition, the presentation of the stimuli varies as a function of experimenters’ parameter (i.e., motion perception, motor perception, and time perception) from approximately 25ms to

–  –  –

Winawer, Huk, & Boroditsky, (2008), Fawcett, Hillebrand, & Singh, (2007), Urgesi, Moro, Candidi, & Aglioti, (2006). Taken together, the image properties and the rate of presentation may influence different regions of the brain in a top-down process. For example, in a study by Proverbio, Riva, & Zani, (2009), participants were exposed to relatively bright (i.e., 47.88 cd/m2) and detailed colorful images of humans (e.g., athletic women running) presented at a rate of 1500 millisecond (ms) per frame. They found activation in MT, EBA, STS, pre-motor (BA-6), motor areas (BA-4), cingulate, and IF cortex. The method and features of the stimuli may, in part, explain the area of the brain that was activated in conjunction with area MT/MT+. In this paper, the properties of the stimuli and the rate of presentation were strategically chosen to reduce the influence of high-order processing on area MT/MST+.

Interestingly, implied motion is not limited to physical stimuli, but also nonphysical and imaginary stimuli (Saygin, McCullough, Alac, & Emmorey, (2010), Tartaglia, Bamert, Mast, & Herzog (2009); Tartaglia, Bamert, Herzog, & Mast, 2012).

For example, Saygin, McCullough, Alac, & Emmorey, (2010) found that motion sentences (i.e., sentences that include verbs) activated area MT+ at significantly higher rate than static sentences (e.g., sentence that does not describe action). Furthermore, there are two studies (Tartaglia, Bamert, Mast, & Herzog (2009); Tartaglia, Bamert, Herzog, & Mast, 2012) that examined the effects of perceptual training of imaginary stimuli on performance of real stimuli. More specifically, Tartaglia, Bamert, Mast, & Herzog (2009) showed that by instructing participants to imagine the offset of the middle line in a threeline bisection task2, improved performance on a bisection task with three physical lines.

–  –  –

and offset to the right (high frequency tone). Tartaglia, Bamert, Herzog, & Mast, (2012) successfully expanded on the three-line bisection task study through the examination of an imaginary motion discrimination task. Performance on imaginary motion discrimination task led to performance enhancement in real motion discrimination task. It has been empirically shown that multisensory feedback (audio or visual) increase performance in visual perception tasks (Seitz, Kim, & Shams, 2006). Based on pervious literature, multisensory feedback was utilized to enhance performance in implied motion training.

Although there is growing interest in neural correlates of implied motion, no study, to our knowledge, has examined the effects of implied motion, as a visual experience, on low- and high-level cortical processing. The goal of this paper is to expand on Seitz, Nanez, Holloway, & Watanabe’s, (2006) findings, through examination of implied motion training. They found that perceptual learning of directional-motion (i.e., visual experience) led to higher Critical Flicker Fusion Threshold (CFFT) (i.e., alteration of cortical processing). More specifically, functional change in motiondirection accompanied significant change in temporal processing of flicker perception, compared to control, non-coherent motion, and no-motion groups. Therefore, directional motion is an important visual cue that will be utilized in this study.

CFFT refers to a critical frequency of intermittent light (i.e., number of on and off flicker per second) that are perceived as steady continuous light to the human observer.

Previous research has indicated that CFFT is inversely correlated with frontal lobe lesions (Halstead, 1947); mental disorders (Saucer & Sweetbaum, 1958; Curran & Wattis, (2000)

–  –  –

Pages:   || 2 | 3 |

Similar works:

«When your water supply has a leak Code of practice for domestic properties Contents What this leaflet is about 3 Responsibility for water pipes 4 Finding leaks 5 Fixing leaks 6 Your water bill 8 Leak allowances if you’ve a water meter 9 Water meters 11 Using water wisely 13 If you wish to make a complaint 14 Contact information 12 2 When your water supply has a leak What this leaflet is about If you’re a private individual or organisation who owns a property that is used for domestic use,...»

«2014 Main Hall dimensions: Total seating: 1100/1229 seats 382 seats in the lower floor area/268 seats in the upper floor area (including 12 handicapped places) 18 boxes (total of 668 seats) 247 balcony seats 185 seats in the 2nd balcony 129 seats in the organ loft (not available for sale at PA events) Hall dimensions: 51 meters by 36 meters by 22 meters Acoustics: -acoustic designers: Artec Consultants Inc./Russell Johnson, New York, USA The audience area, the balconies and the stage have been...»

«Orientation for New Boy Scout Parents Training Summary The world of Boy Scouting can seem strange and confusing to new parents, even those who have been involved in Cub Scouting or who were Boy Scouts themselves. This brief orientation—actually a series of brief presentations that can be mixed and matched—is designed to draw new parents into the troop experience and give them the information they need to enjoy the program and help their sons succeed. Time Required Approximately 48 minutes...»

«Interactive Sequence Discovery by Incremental Mining Ming-Yen Lin and Suh-Yin Lee* Department of Computer Science and Information Engineering National Chiao Tung University, Taiwan 30050, R.O.C. Abstract Sequential pattern mining has become a challenging task in data mining due to its complexity. Essentially, the mining algorithms discover all the frequent patterns meeting the user specified minimum support threshold. However, it is very unlikely that the user could obtain the satisfactory...»

«Exploring the Foundations of an Islamic Identity in a Global Context: A Study of the Nature and Origins of Cape Muslim Identity A thesis submitted to the Faculty of Humanities, Development & Social Sciences, in complete fulfillment of the requirements of the degree of Master of Arts by Abdul Taliep Baker Student Number: 200302457 School of Religion and Theology University of Kwazulu-Natal Howard College Campus, Durban Supervisor: Professor Suleman E. Dangor © 2009 DECLARATION The Registrar...»

«Plight of the Vanishing Songbirds A new study looks at the decline of forest-dwelling neotropical migratory birds by Maryalice Yakutchik Thud! It's startling — but hardly surprising — that the sound happens while I am poring over a new study addressing big questions that have divided the scientific community: Are migratory songbirds declining in numbers and, if so, why? The thud! jerks my attention away from work. I realize that a bird has just struck one of the two-story picture windows...»

«Underwater setting methods to minimise the accidental and incidental capture of seabirds by surface longliners Report on a prototype device developed by Akroyd Walshe Ltd SCIENCE FOR CONSERVATION: 66 P. Barnes and K.A.R. Walshe Published by Department of Conservation P.O. Box 10-420 Wellington, New Zealand 1 Science for Conservation presents the results of investigations by DoC staff, and by contracted science providers outside the Department of Conservation. Publications in this series are...»

«University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations 2015 RETROFIT OF LATTICED COMMUNICATION TOWERS Yuan Xue Follow this and additional works at: http://scholar.uwindsor.ca/etd Recommended Citation Xue, Yuan, RETROFIT OF LATTICED COMMUNICATION TOWERS (2015). Electronic Theses and Dissertations. Paper 5281. This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. These documents are...»

«Dpr nt f irnd a sincs ea me oM oa Nnoc e t c e Syncro n radiat n xht ro io ray tpo o graph o yf c al graph de c in ryst l o ic fets GaN SkrS o n aa i ne i nt D COA O T RL D SRAI N I E TT S S O Aalto University publication series DOCTORAL DISSERTATIONS 187/2014 Synchrotron radiation x-ray topography of crystallographic defects in GaN Sakari Sintonen A doctoral dissertation completed for the degree of Doctor of Science (Technology) to be defended, with the permission of the Aalto University...»

«Monthly Report of Gifu University July 2014 Vol.683 Gifu University Library Reopening Ceremony (July 1) Anniversary celebration event ·············································································· 01 A special lecture by Ms. Makiko Tanaka, a former Lower House member ········································ 05 Summer school for 2014 has started...»

«TWENTY GUIDELINES ON FORCED RETURN September 2005 1 TABLE OF CONTENT Preliminary Note. Twenty Guidelines of the Commitee of Ministers of the Council of Europe on Forced Return Preamble.. Chapter I – Voluntary return Guideline 1. Promotion of voluntary return Chapter II – The removal order Guideline 2. Adoption of the removal order Guideline 3. Prohibition of collective expulsion Guideline 4. Notification of the removal order Guideline 5. Remedy against the removal order Chapter III –...»

«BiBle Tales ages 18 and Up for g. richard BozarTh ◆ TUcson, arizona see sharp press Copyright © 2014 by G. Richard Bozarth. All rights reserved.For information contact: See Sharp Press P.O. Box 1731 Tucson, AZ 85702 www.seesharppress.com Bozarth, G. Richard. Bible tales for ages 18 and up : the Terminally Ill Sea Scrolls / by Richard Bozarth – Tucson, Ariz. : See Sharp Press, 2014. Contents : Introduction Creation Scroll Noah Scroll Ham Scroll Abram Scroll Tamar Scroll Exodus Scroll...»

<<  HOME   |    CONTACTS
2016 www.dissertation.xlibx.info - Dissertations, online materials

Materials of this site are available for review, all rights belong to their respective owners.
If you do not agree with the fact that your material is placed on this site, please, email us, we will within 1-2 business days delete him.