Factors Affecting Perception » Bruner and Minturn Study

What you'll learn this session

Study time: 30 minutes

The concept of perceptual set and how it influences what we see
Details of Bruner and Minturn's classic 1955 study on perception
The methodology, findings and conclusions of the study
How expectations and context affect our interpretation of ambiguous stimuli
The strengths and limitations of the study
Real-world applications of perceptual set theory

Perceptual Set Theory and the Bruner and Minturn Study

When you look at something, do you always see exactly what's there? Or does what you expect to see influence what you actually perceive? In psychology, the way our brain selects and interprets information is fascinating - and it turns out we don't always see things as they really are!

Key Definitions:

Perception: The process of recognising, organising and making sense of information from our senses.
Perceptual set: A tendency to perceive things in a particular way based on expectations, motivations and past experiences.
Ambiguous stimulus: Something that can be interpreted in more than one way.

👀 What is Perceptual Set?

Perceptual set is like wearing invisible glasses that filter what we see. These "glasses" are shaped by our past experiences, current expectations, emotions, motivation and culture. They help us make quick sense of the world but can sometimes lead us to misinterpret what we're actually seeing.

🧠 Why is it Important?

Understanding perceptual set helps explain why different people can look at the same thing but see something completely different. It's relevant in many areas including eyewitness testimony, cultural misunderstandings and how we form impressions of other people.

The Bruner and Minturn Study (1955)

In 1955, Jerome Bruner and Leo Minturn conducted a classic experiment that demonstrated how context can influence what we perceive. Their study is one of the most famous investigations into perceptual set and has been included in psychology textbooks ever since.

Study Background

Jerome Bruner was an American psychologist who made significant contributions to cognitive psychology and educational psychology. He was interested in how our mental processes, like expectations and motivations, shape our perceptions.

The Experiment

Bruner and Minturn wanted to test how context affects our interpretation of ambiguous stimuli. They designed a clever experiment using a simple but ambiguous character that could be seen as either the letter 'B' or the number '13' depending on the context.

🔬 Aim

To investigate how context influences the perception of an ambiguous stimulus.

👥 Participants

A sample of adult participants (the exact number isn't specified in most accounts of the study).

📝 Design

Independent groups design with different contextual conditions.

Methodology

The researchers showed participants an ambiguous character that could be interpreted as either the letter 'B' or the number '13'. The character looked like this: 13 (but was presented in a way that made it ambiguous).

📄 Condition 1: Letter Context

One group of participants was shown a series of letters (like A, C, D) before being shown the ambiguous character. This created an expectation of seeing letters.

🔢 Condition 2: Number Context

Another group was shown a series of numbers (like 12, 14, 15) before seeing the same ambiguous character. This created an expectation of seeing numbers.

After viewing the context items, participants were shown the ambiguous character and asked to identify what they saw.

Findings

The results of the study clearly demonstrated the power of perceptual set:

Participants who saw letters first were more likely to perceive the ambiguous character as the letter 'B'.
Participants who saw numbers first were more likely to perceive the same character as the number '13'.

This showed that the context created a perceptual set that influenced how participants interpreted the ambiguous stimulus. Their expectations, primed by the context, guided their perception.

Case Study Focus: The 13/B Phenomenon

The ambiguous character in Bruner and Minturn's study is sometimes called the "13/B phenomenon" and has become a classic example in psychology. It demonstrates that perception isn't just about what our eyes see - it's about how our brain interprets visual information based on context and expectations. This is why optical illusions work - they exploit the brain's tendency to make assumptions based on context and past experience.

Conclusions

From this study, Bruner and Minturn concluded that:

Perception is not simply determined by the stimulus itself but is influenced by the context in which the stimulus appears.
Our expectations create a perceptual set that guides how we interpret ambiguous information.
We actively construct our perceptions rather than passively recording what's in front of us.

Evaluation of the Study

👍 Strengths

Simple but effective: The study used a simple design that clearly demonstrated the concept of perceptual set.
High control: By using the same ambiguous stimulus for all participants, differences in perception could be attributed to the context manipulation.
Real-world relevance: The findings help explain everyday phenomena where people interpret the same information differently.

👎 Limitations

Limited information: Details about sample size and participant demographics aren't widely reported.
Artificial task: The experimental task was somewhat artificial compared to real-world perception.
Cultural factors: The study doesn't address how cultural differences might affect perceptual set.

Real-World Applications

The concept of perceptual set demonstrated by Bruner and Minturn has important applications in many areas:

👮 Eyewitness Testimony

Witnesses may "see" what they expect to see rather than what actually happened, especially in stressful situations.

🎥 Advertising

Advertisers use context to influence how consumers perceive products and create positive associations.

🏫 Education

Teachers can help students overcome misleading perceptual sets to improve learning and critical thinking.

Modern Extensions

Since Bruner and Minturn's original study, researchers have expanded our understanding of perceptual set in several ways:

Studies have shown that emotional state can create a perceptual set (e.g., anxious people are more likely to perceive neutral faces as threatening).
Cultural background has been found to influence perceptual set, with people from different cultures sometimes literally seeing the same visual scenes differently.
Neuroscience research has begun to identify the brain mechanisms involved in how expectations shape perception.

Try It Yourself!

Look at this sequence: 12, 14, 16, ?

Now look at this one: A, C, E, ?

Now look at the character: B

Did you see it as a letter or a number? This is your perceptual set in action!

Summary

Bruner and Minturn's study demonstrated that our perception is not simply a passive recording of what's in front of us. Instead, our brain actively constructs our perceptions based on context and expectations. The study showed that when presented with an ambiguous stimulus, people tend to see what they expect to see based on the context.

This has important implications for understanding why people can look at the same thing but perceive it differently. It reminds us that perception is subjective and influenced by many factors including our past experiences, current context and expectations.

The next time you find yourself disagreeing with someone about what you both "saw," remember Bruner and Minturn - you might both be right from your own perceptual set!

🧠 Test Your Knowledge!