Use this URL to cite or link to this record in EThOS:
Title: Cognitive theories and forensic applications : the pupillary correlates of familiar and unfamiliar face processing
Author: Elphick, Camilla
ISNI:       0000 0004 7657 5222
Awarding Body: University of Sussex
Current Institution: University of Sussex
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
This thesis used pupillometry to investigate whether pupils respond differently to faces that differ in familiarity. We aimed to see whether pupillometry measures cognitive processes involved in face processing, and whether it could be applied forensically. We started by evaluating three explanations for pupillary changes that occur when processing faces. The first was cognitive load (mental effort), because faces that have only been seen briefly are more difficult to recognise than well-known faces. The second was cognitive engagement (interest), because faces contain socially-important information. The third was memory strength (forensically applicable), as eyewitnesses have to recall a perpetrator's face in an attempt to identify them if they appear in a lineup. While pupillary responses reflected cognitive engagement to some extent, cognitive load best accounted for decreasing pupil sizes when learning new faces, and memory strength explained the pupillary changes seen in lineups. The theories all had some influence on pupil sizes, but their influence varied according to context, saliency, and the task at hand. Then we investigated whether pupillometry measured implicit recognition of a perpetrator in a lineup, and found that it did. Pupil sizes reflected memory strength in participants who believed their memory to be strong: there were differences in pupil sizes (between looking at the perpetrator and the distractors) in participants who identified him, but not in those who did not. The pupillary responses of participants who 'guessed' indicated that they were indeed guessing. There were no pupillary changes when the perpetrator was not in the lineup, even when participants misidentified a distractor. We concluded that pupillary responses are independent of explicit identification responses, and could be used forensically to support traditional measures of eyewitness identification and credibility.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: BF0242 Face perception