Week 5: Making and recognising faces

Introduction

Watch the following video in which Graham introduces this week.

Download this video clip.Video player: ou_futurelearn_psychology_vid_1013.mp4

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Transcript

GRAHAM PIKE

Welcome to week 5.

This week we are shifting direction and looking at the difficulties of describing a face. Psychology face recognition is my own area of research, which I've now been working on for more than 20 years.

Describing someone's face may sound easy, but most of us will find it difficult. Our two witnesses provided descriptions of the perpetrator's clothing, build, age and ethnicity, but they did not mention much about their faces. Clothing can be changed and stature, age and ethnicity are too generic to be used to identify a suspect. So how do the police obtain a useful description of a perpetrator's face?

We'll be looking at why it's so hard to describe a face in any detail, and explore the psychology of face recognition; what are our brains capable of doing, and what might disrupt our ability to recognise a face.

We'll also learn about the computer systems used by the police to construct a visual image of a suspect's face and how technological developments have been designed to make the most of psychological knowledge about human memory and face recognition. You'll then have an opportunity to try and recreate a face yourself using The Open University's very own online Photofit system.

You will hear from a person with a condition known as 'face blindness' and discover what it is like to be unable to recognise the faces of even your family and friends.

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Our two detectives were careful to get a description of the perpetrators in the initial statements they took from the witnesses. But what can the police do with this description?

Finding a potential suspect and then determining whether that suspect is the perpetrator by seeing whether they are identified by an eyewitness are incredibly important components of a police investigation.

The clothing worn by the perpetrator and general characteristics such as their sex, age, height and build can be very useful when searching for them immediately after the crime has been committed. However, it would obviously be immensely problematic to prosecute someone simply because they had the same jacket, or were the same age and height as the person who committed a crime! Instead, police investigations and criminal prosecutions rely on eyewitnesses recognising and describing the face of the perpetrator, which makes the face recognition abilities of the witness very important indeed.

This week you will be exploring the psychology of face recognition and description, and looking at why eyewitness misidentification is such a prevalent cause of wrongful convictions.

First, you will consider the assistance that a witness may give to the police by describing the identity of a perpetrator. The procedures that the police employ to elicit this help are system variables, and hence controllable. In some cases, where the available evidence does not suggest a suspect, the witness may be asked to search through mug-shot albums containing photographs of known offenders. Alternatively, a composite image of the perpetrator may be constructed with the help of the witness and this is then publicised in the media in the hope that someone familiar with the perpetrator will see the composite image and identify them.