Can you recognise these 3 famous upside down people?

What emotion are they feeling?

Turned round!

Who is this?

Who Is This?

Internal features of a face – we use these to recognise

familiar faces

eyes

brow

mouth

nose

External features of a face – we use these to recognise

unfamiliar facesheadshape

ears hair

Key concept: E-Fit

The Electronic Facial Identification Technique, commonly known as E-FIT, is a computerised method of synthesizing images to produce facial composites of the faces of suspects based on eyewitness descriptions.

Example police E-fit pictures

Sketch, E-fit, Evo-fit and actual face of the “Beast of Bozeat”

Can you recognise these two characters from Eastenders from

E-fits?

Eastenders example Efits

Can you identify the following famous Efits?

Brad Pitt

NicholasCage

Graham Norton

Michael Owen

Robbie Williams

Anthony (Ant) McPartlin

Now your turn…

Now your turn…

Bruce et al (1988) The importance of external and internal features in facial

recognition

• Aim: -To investigate the relative recognisability of internal (eyes, brows, nose and mouth) and external (head shape, hair and ears) features in facial recognition.

Why is face recognition important?

• Essential for safe social interaction and group existence as it informs us of the level of intimacy and familiarity with each other- friend? Stranger? Enemy?

• Humans have an innate attraction to faces. This helps to form attachment.

• Face recognition is found in other social animals like monkeys

• Errors in face-recognition can have catastrophic consequences i.e. eye witness testimony. 29

Procedure: -

• Experiment 1: - This was an independent measures design with three conditions.

• All The participants were given pictures of 10 celebrities, the task was to match the correct composite image (graphical representation of an eyewitness's memory of a face) to the celebrity from the 40 composites given.

• Group 1 were given complete composites, • Group 2 composites containing only internal features (eyes, nose,

mouth) • Group 3 external feature (head shape, hair and ears) composites. • Each face was clean shaven and spectacles were avoided.

Procedure: -

•Experiment 2: - This experiment used a photo array;

•The task was to identify the celebrity composites from the array.

•The task was made either easy or hard.

•Once again the composites were composed of either external or internal features.

Results: -

• Experiment 1: - 35% of whole composites and those of external features were sorted correctly, compared to only 19.5% of internal features.

•  

• Experiment 2: - External features were identified 42% of the time, compared to just 24% of internal features.

Conclusion: - • Participants performed at just above chance level for internal

features. • Participants performed equally well with both whole

composites and external features. • This shows that external features are more important for

facial recognition and that faces are processed holistically. • This has implications for facial reconstructions which involve

witnesses picking internal features from a book. • Newer face reconstruction software takes these finding into

account. E-fit or EvoFIT both change faces holistically.• This shows that external features are more important for

facial recognition and that faces are processed holistically.

What are the major issues with this study…?

Issues:

• Reliability– Used already well established (E-Fitt) methods of making

composites

– Laboratory experiment

• Generalisability– Celebrities

• Independent measures– Less demand characteristics

– Participant variables present

– Subjective

Debates:

• Usefulness– Can be applied to other environments– Newer face reconstruction software takes these finding into

account. E-fit (updates) or EvoFIT both change faces holistically.

Loftus

Weapon focus (1987)

Theories of interviewing witnesses

Background:

• Weapon focus refers to the concentration of a witnesses attention on a weapon which leads to them having difficulty recalling other details about the crime and identifying the offender.

• Previous research has shown that people fixate their gaze for longer, faster and more often on unusual or informative objects.

Aim:

• To provide support for the weapons focus effect when witnessing a crime.

• (however they were told it was about proactive interference – something you have learned in the past interferes with something you have learned in the future, old and new phone number)

Participants:

• 36 students from the university of Washington.

• Aged 18-31.

• Half were recruited through advertisements and paid $3.50.

• The other half were psychology students who participated for extra credit.

Procedure:• All participants were shown a series of 18 slides of

events in a Taco Time restaurant. • For both groups, the slides were same except for one

slide- the independent variable.• Control group: The second person in the queue hands

the cashier a cheque.• Experimental group: The same person pulls a gun on

the cashier.• The dependent variable was the recognition of that

individual, measured by a 20 item, multiple choice questionnaire.

• Participants were shown 12 pictures at random and asked to rate how confident they were of their identification on a scale of 1-6.

Results:

• Answers to the questionnaire about the slideshow showed no significant difference between the control and the experimental groups.

• In the control condition, 38.9% made a correct identification.

• In the experimental condition, only 11.1% made a correct identification.

• Eye fixation data showed an average fixation time of 3.72 seconds on the gun and 2.44 seconds on the cheque.

Conclusions:

• The participants spent longer looking at the weapon and therefore found it harder to identify the offender from the line-up.

Issues:

• Ecological validity– Not viewing a real event so little emotional attachment

from the participants

• Generalisability– All volunteers or students who are participating for

something- money or extra credit.– Wanting to please the experimenter

• Usefulness– How weapons can affect recognition

• Control group present– Results not due to chance

Debates:

• Individual vs Situational– What is present during an event can affect the ability to

identify offenders

• Ethnocentrism

Fisher and Geiselman

The cognitive interview

Background:

• The Cognitive interview is designed to take into account well known cognitive functions to avoid leading the witness.

• The interviewer gives the witness a series of instructions to reinstate the context of the original event and to search through their memory using a variety of retrieval methods.

Background:

• There are 4 main principles to the cognitive interview:– Interview similarity; memory of an event is enhanced when the

psychological environment of the interview is similar to that of the original event- external- weather- emotional and cognitive features.

– Focused retrieval; The interviewer is to generated focused concentration. There should be no interruption of the train of thought.

– Extensive retrieval; Encouraged to make as many retrieval attempts as possible and encouraged to try a variety of angles.

– Witness-compatible questioning; Successful retrieval reflects how compatible the questioning is with the witnesses unique mental representation.

Aim:

• To test the cognitive interview in the field.

Participants:

• 16 detectives from the Robbery Division of Dade County, Florida.

• All experienced in the first phase of the experiment.

Procedure:

• Detectives asked to record a selection of their next interviews using the standard techniques that they usually used.

• This took 4 months and 88 interviews were recorded, mostly related to snatches or robberies.

• Detectives then divided into two groups and one group was trained in the cognitive techniques- this was a group of 7 detectives, training was over four 60 minute sessions.

• Interviews by both groups were then recorded over the next 7 months.

• Interview recordings were analysed by a team at the University of California who were blind to the conditions.

Results:

• Cognitive Interview detectives elicited 47% more information than before and 63% more information than the untrained detectives.

• The time taken to interview witnesses was not significantly different, by Cognitive Interviews do take longer.

Conclusions:

• Cognitive interview techniques work by helping detectives to gain more information.

Issues:

• Generalisability– Only used 16 detectives from one area

• Ecological validity– In their normal, working environment

• Usefulness– Can help to train police to get more information from their

witnesses.

• Reliability– Data was analysed by another university– Single blind study

• Ethics– Witnesses had to relive the events of the crime

Debates:

• Ethnocentric– All detectives from Florida

• Individual vs Situational– The amount of information witnesses give depends on the

interview they have