Factors Affecting Perception

Define perception and factors affecting perception

As we discussed above, perception and factors affecting perception can be defined as:

Stimulus factors affecting perception

Various stimulus factors can affect perception. These include:

• Intensity
  • The more intense something is, the more likely it is that it will be perceived. For example, people are more likely to perceive a loud noise rather than a quiet background noise.

• Changes
  • When driving in a car, there are constant changes in visual stimuli. So, what we see/perceive constantly changes.

• Magnitude
  • The larger the size of an object, the more likely it is to be seen/perceived.

• Repetition
  • Repetition increases our sensitivity to the stimuli. This means that we become more aware of stimuli because it has been perceived frequently.

Psychological factors affecting perception

Psychological factors that have been found to affect perception are:

Motivation

• We are more likely to perceive and see objects or aspects of objects that are of interest to us.

Emotion

• it is still debated how emotion affects perception. Generally, it is theorised that heightened states and emotions such as stress and anxiety can influence how much and what we perceive
• Sad or happy feelings can affect how stimuli are interpreted; when sad, we may notice events or situations that are more upsetting.

Expectation

• We have a tendency/bias to see things of how we expect to see them

Culture

• Social norms, rules, beliefs and standards set by the society/culture we live in can affect how stimuli are perceived. This can affect how we process and interpret information that is perceived.
• Culture affects the type of stimuli children are exposed to. For example, in western societies, children may be accustomed to colouring in 2D images and seeing pictures and cartoons of people and objects, so tend to draw them in a 2D format.

What research has investigated factors affecting perception?

Gilchrist and Nesberg (1952) and Bruner and Minturn (1995) carried out research to identify if various factors (motivation and expectations) affected perception.

The Gilchrist and Nesberg study of motivation

Gilchrist and Nesberg (1952) conducted research to see if hunger affected how people perceived food.

Procedure

The study involved 26 students who volunteered to take part in the study, and the sample was split into two groups

• Half were not allowed to eat for 20 hours before the start of the experiment, the experimental group

• The other half ate a normal amount of food before the start of the group, the control group

Both groups were shown an image for 15 seconds, and the screen would turn off. Additionally, participants were told that the same picture would be shown again for 15 seconds. However, it would look differently; they were told that the brightness had changed

Participants were told to adjust the brightness of the second image to match the first image that was presented to them

• This task was tested using a time-interval schedule: after lunchtime, after 6 hours and 20 hours

• All the images shown were pictures of food

Results

• The control group showed little difference in memory accuracy of the brightness of images
• The experimental group, as they became hungrier, judged the images to be brighter than they originally had been

From the results of the Gilchrist and Nesberg (1952) experiment, it can be concluded that motivation (in this case, hunger) can affect how we perception.

Evaluation

A strength of the study is that the study can be considered ecologically valid to a certain extent, as the experimental group did not actually eat for 20 hours. Therefore, participants actually would have been hungry. It is also easily replicated.

A weakness of the study is that it was carried out on a non-representative sample (only 20 students). Therefore, the results cannot be generalised to the wider population.

The Bruner and Minturn study of perceptual set

Bruner and Minturn (1995) carried out research to investigate if expectations affected perception.

Procedure

In this study, 24 students were recruited in the experiment. Participants were required to complete a recognition task (of numbers and letters). Letters or numbers were quickly flashed on a screen

Throughout the trials an ambiguous figure was shown, this means that it could have easily been interpreted as a 'B' or '13'

1. Group 1 was shown numbers before the ambiguous figure was shown
2. Group 2 was shown letters before the ambiguous figure was shown

Findings

Bruner and Minturn (1955) found that:

• 83% of Group 1 saw the ambiguous figure as the '13'.
• 92% of Group 2 saw the ambiguous figure as 'B'.
• The control group showed small differences in memory accuracy of the brightness of images
• The experimental group started seeing the images brighter than what was originally shown

From the results of Bruner and Minturn's (1995) experiment, it can be concluded that expectations affect how we perceive/interpret stimuli.

Evaluation