PSYC1001 Lecture Notes - Lecture 5: Eyewitness Memory, Lie Detection, Blood Pressure
19 May 2018
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Emotions applied – eyewitness memory, lie detection, physiological measures
Applications of emotion and memory research
• Forensic investigations - attempt to reconstruct past event
• Physical evidence (hair, fibres, DNA)
o Collecting, preserving and interpreting physical evidence done by forensic scientists
o Avoid contamination
o Physical evidence often circumstantial
• Eyewitness evidence (memory and ID)
o Typically collected by non-specialists in human memory
o Protocols for collecting, preserving and interpreting ev not incorporated scientific
psychological research to extent that it could
o Often directly links suspect to crime
o Memory is not a veridical record of an event, affected by many factors
Memory and emotion/arousal
3 stages
• Acquisition/encoding
o Witness' perceptions at time of event
• Storage
o Witness stores memory to avoid forgetting
• Retrieval
o Witness retrieves information from storage when needed
Human memory evidence
• Can be critical to an investigation
• Can be very influential
• Vulnerable to contamination
• Must handle with care
Memory test
• Examples suggest emotional arousal is detrimental to memory
o Assassination of JF Kennedy Jr
• Highly emotional event
• Trivial memory error in relation to crime
o Martin VR 2001
• Tony Martin english former convicted murder
• Inconsistency between account and forensic evidence
• Emotional arousal could lead to forgetfulness
o Stephen Lawrence murder
• Stabbing
• Witnesses struggled to remember perpetrators
• Stress and forgetfulness link?
Emotional arousal - transient state, temporary
o Stimulation of an acute state of emotion induced by exposure to a specific current event
o Comprising of
• Cognitive appraisal of emotionally arousing stimuli
• Changes in physiological activity in brain and body
• Cognitive appraisals
find more resources at oneclass.com
find more resources at oneclass.com
o Researchers promote notion of cognitive appraisal as a crucial factor in experiencing
emotion
o Appraisal theories help account for
• Why people experience emotions in some situations but not others
• Individual differences in emotional arousal
• Emotions in memory
o Emotions help people adapt to their environment
o Enable individuals to detect and engage with beneficial stimuli and avoid harmful stimuli
o Remember emotion-eliciting events
o Emotional arousal can have enhancing and impairing effect on memory
• Selective attention towards emotional stimuli
o Images of phobia related items detected significantly faster than non-emotional stimuli
in visual search task (Ohman et al 2001)
o Eye tracking data indicated a bias to look at left hand images first when presented with
pairs of images, but bias overcome when emotionally arousing image presented to right
of neutral image (LaBar et al. 2000)
• Found once attention drawn towards emotional stimuli, appears to become
fixated
o Eyeblinks = normal reflexive reactions to sudden noises, but not observed when startling
tone sounded during first 800ms of viewing emotional pictures, but observed for neutral
pictures. Emotional stimuli receive an attentional advantage (Levenston et al. 2000)
• Relationship between emotional arousal and memory
o Hard to define terms: stress, emotional arousal and trauma
• Should they be defined in terms of feelings, the situation, consequences or bodily
reactions
o Problems with manipulating realistic emotion in the lab setting
• Experimental conditions
Screen clipping taken: 6/06/2017 9:28 PM
• Archival data analysis
▪ Yuille & Cutshall 1986
▪ 13 witnesses of street shooting interviewed by police after incident and by
researched month later
▪ Witnesses provided stress rating on a 7 point scale
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Emotions applied eyewitness memory, lie detection, physiological measures. 3 stages: acquisition/encoding, witness" perceptions at time of event. Storage: witness stores memory to avoid forgetting, retrieval, witness retrieves information from storage when needed. Human memory evidence: can be critical to an investigation, can be very influential, vulnerable to contamination, must handle with care. Inconsistency between account and forensic evidence: stephen lawrence murder. Found once attention drawn towards emotional stimuli, appears to become fixated: eyeblinks = normal reflexive reactions to sudden noises, but not observed when startling tone sounded during first 800ms of viewing emotional pictures, but observed for neutral pictures. Emotional stimuli receive an attentional advantage (levenston et al. 2000: relationship between emotional arousal and memory, hard to define terms: stress, emotional arousal and trauma. Should they be defined in terms of feelings, the situation, consequences or bodily reactions: problems with manipulating realistic emotion in the lab setting, experimental conditions.
