Concepts
We have learnt four reasons for visual illusions. Which visual rule in perception can be used to explain the Muller-lyer illusion?
The misinterpretations of depth cues
In Kunst-Wilson & Zajonc's study (1980), researchers showed participants a set of pictures of meals on screen and then changed the brightness of the pictures and showed them the pictures again.
True or False?
False.
Gilchrist and Nesberg (1952): how motivation affects perception.
Kunst-Wilson & Zajonc's study (1980): recognition and perception study.
Match this statement with the name and researchers of the study:
People from different cultural backgrounds may focus on different aspects of the same visual scene, leading to different ways of perceiving it.
Nisbett & Miyamoto (2005) → Culture and perception study in 2005
Match this statement with the name and researchers of the study:
Participants were asked to recognise a broken letter B for three times when the letter B were placed in different list series.
Bruner and Minturn's perceptual set study (1955)
What is Gibson's direction theory of perception?
Gibson’s direct theory of perception argues that we can perceive the world directly through information available in the environment, without needing to rely on complex mental processes such as inference, memory or interpretation.
吉布森的直接知觉理论认为，我们能够直接通过环境中存在的信息来感知周围世界，而不需要依赖复杂的心理推理、记忆或解释过程。
Which study was done by Nisbett & Miyamoto (2005) in terms of perceptual set?
The study testing the relationship between perception and the enviroment people grow up with (culture and perception study)
Say one limitation of Nisbett and Miyamoto's culture and perception study.
1. low ecological validity
2. Nisbett and Miyamoto’s research may be criticised for cultural differences being difficult to separate from other factors, such as education, familiarity with particular visual stimuli, and previous experiences.
Because our perceptual system has matched something about them to features of other people we already like.
In terms of perception, say one difference between Gibson and Gregory.
ibson argued that perception is direct and relies on information available in the environment, whereas Gregory argued that perception involves unconscious inference, using prior knowledge and experience to interpret sensory information.
A study claims that what we expect to see can influence how we interpret an ambiguous stimulus.
Which study has a conclusion from above? Who are the researchers?
Bruner & Minturn's perceptual set study done in1955 → testing how Expectation can direct perception and cause a perceptual set
In Gilchrist and Nesberg’s (1952) study, hungry participants were found to perceive food-related pictures as brighter.
Apart from hunger, identify ONE extraneous variable or factor that could have influenced the results. Explain why?
Previous experience with food 食物相关的个人经历
Participants who have strong positive associations with food may respond differently to food-related pictures, regardless of hunger.
Food preferences 食物偏好
Participants may pay more attention to pictures of foods they like, which could influence their responses.
Time since the last meal 距离上次进餐的时间
Two participants who report being hungry may differ in their actual level of hunger.
Mood and emotional state 情绪状态
Participants who feel stressed, tired or happy may process visual information differently.
Visual acuity 视力
Participants with different levels of visual acuity may perceive brightness differently.
Lighting conditions 环境光线
Differences in screen brightness or room lighting may affect how bright the pictures appear.
Individual differences in brightness perception 个体对亮度的感知差异
Some participants may naturally rate images as brighter than others, irrespective of hunger.
Demand characteristics 实验需求特征
Participants may guess that the study concerns hunger and food, then unconsciously or deliberately alter their responses.
Attention and concentration 注意力与专注程度
Hungry participants might focus more on food-related pictures, potentially affecting their brightness judgements.
In Kunst-Wilson and Zajonc's recognition and perception study (1980), one weakness is that if the researchers use pictures of spiders, the exposure to spiders may cause participants' fear of spiders.
True or False? Why?
False.
•Important: Subliminal exposure does not automatically cause fear. Responses depend on factors such as the stimulus, the person's previous experiences, and the experimental conditions. A brief presentation of a spider, for example, does not necessarily make someone afraid of spiders.
Say one limitation and one ethical issue of the visual cliff study conducted by Gibson.
1. Low ecological validity (limited generalisability to real-life situations)
2. Informed consent
One study has links to research into fear responses. For example, people can be shown pictures of things that people fear of at subliminal exposure.
Explain what is subliminal exposure and how can subliminal exposure be linked with fear?
Kunst-Wilson and Zajonc's recognition and perception study (1980).
Subliminal exposure refers to presenting a stimulus so briefly or weakly that a person cannot consciously identify or recognise it, even though their brain may still process some information about it.
阈下暴露（subliminal exposure） 是指将某种刺激呈现得非常短暂或微弱，以至于个体无法有意识地识别它，但大脑仍可能对其中的一部分信息进行加工。
How might subliminal exposure reduce fear?
1. Repeated exposure: A person is briefly exposed to an image of something they fear, such as a spider, without consciously recognising it.
2. Reduced threat response: In some circumstances, processing a feared stimulus without fully experiencing or anticipating the threat might influence the brain's emotional response.
3. Potential reduction in fear: If repeated experiences change how the stimulus is processed, the person's fear response might decrease. However, this effect is not guaranteed, and subliminal exposure alone is not an established treatment for phobias.
In the Kunst-Wilson and Zajonc's recognisiton and perception study, why were the shapes presented very briefly rather than for long enough for participants to see them clearly?
The shapes were presented very briefly to limit participants’ conscious awareness of them. The researchers wanted to investigate whether participants could develop a preference for previously seen shapes even when they could not consciously recognise them.
研究者短暂呈现图形，是为了限制参与者对图形的有意识觉察。他们想研究：即使参与者无法有意识地识别之前看过的图形，是否仍然会更喜欢这些图形。
Link the study done by Bruner and Minturn's testing perceptual set with the Gibson's direct theory.
Explain in your own words: how this study may challenage Gibson's theory.
Bruner and Minturn’s study (1955) can challenge Gibson’s direct theory because it suggests that perception is influenced by our expectations and previous experiences, rather than being based only on information directly available in the environment.