Examining Peripersonal Space: Representations Surrounding the Body and the Role of Threat Open Access

Hunley, Samuel Bennett (2017)

Permanent URL: https://etd.library.emory.edu/concern/etds/zw12z620p?locale=en
Published

Abstract

Extensive work across numerous scientific fields provides strong evidence that human and non-human primates maintain a representation of the space and objects immediately surrounding the body, a region that is known as peripersonal space, which plays a critical role in coordinating both defensive and non-defensive perception-action processes. Despite diligent research, many open questions remain regarding the nature of peripersonal space, its function, and its relation to other representations of space and the body. In this regard, the current dissertation makes two primary contributions. First, it reviews emerging findings and highlights important open questions. Second, it presents findings from a novel auditory time-to-contact paradigm, used to examine peripersonal space in front of and behind the body. Across three experiments, participants estimated the arrival time of approaching sounds that were either threatening or nonthreatening in nature. Initial results suggested an effect of perceived loudness. When controlling for this effect, participants consistently underestimated the arrival time of stimuli approaching from the front as compared to those approaching for the rear across both threatening and nonthreatening contexts, and they underestimated more for threatening stimuli as compared to nonthreatening stimuli. These findings suggest larger peripersonal space representations in front of the body relative to the rear for both threatening and nonthreatening contexts as well as larger peripersonal space representations in response to threatening stimuli. We discuss these findings in relation to the non-defensive and defensive functions of peripersonal space representations.

Table of Contents

1. Manuscript 1: A review of the peripersonal space literature: Emerging Findings and Unresolved Empirical Questions ...................................................1

a. Abstract........................................................................................................2

b. Introduction..................................................................................................3

c. Two functions of peripersonal space...........................................................4

i. Peripersonal space and its non-defensive function..........................4

ii. Peripersonal space and its defensive function.................................7

iii. One or two systems of peripersonal space?...................................11

1. Dissociating between these accounts.................................13

d. Distinguishing peripersonal space from other constructs..........................15

i. Peripersonal vs. personal space......................................................15

1. Considerations for future research.....................................18

2. Conclusions........................................................................20

ii. Peripersonal space and body representations.................................21

1. Conclusions........................................................................24

e. Open questions in peripersonal space research..........................................24

i. Individual differences in the flexibility of peripersonal space.......24

ii. How is peripersonal space represented around the body?.............27

f. Conclusions................................................................................................31

g. The current dissertation..............................................................................32

h. References..................................................................................................34

2. Manuscript 2: Examining peripersonal space around the body using auditory looming stimuli.....................................................................................................47

a. Abstract......................................................................................................48

b. Introduction................................................................................................49

i. The role of peripersonal space in non-defensive behaviors...........49

ii. The role of peripersonal space in defensive behaviors..................50

iii. Flexibility of peripersonal space....................................................51

1. Individual differences in the flexibility of peripersonal space……………………………………………………...52

iv. Spatial representations around the body........................................53

1. Individual differences in peripersonal space representations around the body..................................................................55

2. How do spatial representations surrounding the body vary under threatening and nonthreatening contexts?................55

v. The current paper...........................................................................57

c. Experiment 1..............................................................................................57

i. Introduction....................................................................................57

ii. Methods..........................................................................................60

1. Participants.........................................................................60

2. Apparatus and stimuli........................................................60

a. Auditory TTC task.................................................60

b. Psychological measure of trait anxiety..................62

c. Physical measures..................................................62

3. Procedure...........................................................................63

iii. Results............................................................................................63

1. Performance on the TTC task............................................63

a. Front versus rear performance...............................64

2. Trait anxiety.......................................................................65

3. Arm length.........................................................................66

iv. Discussion......................................................................................67

d. Experiment 2..............................................................................................69

i. Introduction....................................................................................69

ii. Methods..........................................................................................70

1. Participants.........................................................................70

2. Apparatus and stimuli........................................................70

a. Auditory TTC task.................................................70

b. Psychological measure of trait anxiety..................71

c. Physical measures..................................................72

3. Procedure...........................................................................72

iii. Results............................................................................................72

1. Performance on TTC task..................................................73

a. Front versus rear performance...............................73

2. Trait anxiety.......................................................................75

3. Arm length.........................................................................76

iv. Discussion......................................................................................76

e. Experiment 3..............................................................................................78

i. Introduction....................................................................................78

ii. Methods..........................................................................................79

1. Participants.........................................................................80

2. Apparatus and stimuli........................................................79

a. Auditory TTC task.................................................79

b. Psychological measure of trait anxiety..................81

c. Physical measures..................................................81

3. Procedure...........................................................................81

iii. Results............................................................................................82

1. Performance on TTC task..................................................82

a. Front versus rear performance...............................82

2. Trait anxiety.......................................................................84

3. Arm length.........................................................................84

iv. Discussion......................................................................................85

1. Consistent underestimation for front compared to rear trials....................................................................................86

2. An effect of threat?............................................................88

f. General discussion.....................................................................................89

i. Peripersonal space around the body...............................................89

ii. Larger peripersonal space representations in response to threatening targets..........................................................................92

iii. Trait anxiety and peripersonal space..............................................92

iv. Arm length and peripersonal space................................................93

v. Conclusions....................................................................................94

g. Concluding thoughts..................................................................................94

h. References..................................................................................................96

i. Supplemental Materials...........................................................................105

i. Supplemental Experiment 1.........................................................105

1. Introduction......................................................................105

2. Methods............................................................................105

a. Participants...........................................................105

b. Apparatus and stimuli..........................................105

i. Auditory stimuli.......................................105

ii. Perceived loudness ratings.......................105

c. Procedure.............................................................106

3. Results..............................................................................106

4. Discussion........................................................................108

ii. Supplemental Experiment 2.........................................................109

1. Introduction......................................................................109

2. Methods............................................................................109

a. Participants...........................................................109

b. Apparatus and stimuli..........................................109

i. Auditory stimuli.......................................109

ii. Threat rating.............................................110

iii. Perceived loudness ratings.......................110

c. Procedure.............................................................110

3. Results..............................................................................111

4. Discussion........................................................................113

About this Dissertation

Rights statement
  • Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.
School
Department
Degree
Submission
Language
  • English
Research Field
Keyword
Committee Chair / Thesis Advisor
Committee Members
Last modified

Primary PDF

Supplemental Files