Psychology U2AOS2

Visual perception is the process of becoming consciously aware of visual stimuli as a result of the interactions between the visual sensory system, and the individual’s internal and external environments.

Biological. psychological. and social

Physical, physiological, neurological or genetic factors that are entirely internal.

Depth perception: ability to see three-dimensional space and accurately judge distances using environmental cues.

Retinal disparity: is a depth cue created by small differences between the image that reaches the right eye and the image that reaches the left eye

Convergence: involves both eyes simultaneously turning inwards as an object moves closer (within approximately 7m) in order to maintain focus on the object.

Convergence is controlled by muscles attached to the eyeball. When these muscles tense or relax, they feed information on eye position to the brain to help it judge distance.

Monocular cues: depth perception cues that rely on information from only one eye

Two types of monocular depth cues:

1.Accommodation

2.Pictorial cues

Accommodation: the changing shape of the lens to maintain focus on objects of varying distances. When the object is close the lens is more rounded. When the object is further away the lens flattens.

Pictorial cues: monocular cues present in two-dimensional (pictorial) images that allow the brain to perceive apparent three- dimensional depth

Linear perspective: The apparent convergence of parallel lines creates the impression of increasing distance.

The relative size of objects to one another in our visual field helps us to judge distance. If two similar objects cast different sized images on the retina, the object that casts the larger image is perceived to be closer, and the one that cast a smaller image is perceived to be further away.

Interposition (also known as overlap): When one object partially blocks another object it is perceived as being in front of and, therefore, closer than the object it covers

Texture gradient: We rely on the use of texture to judge how far away objects are. The closer we are, the greater the detail of texture we can see. When looking at a field up close, we can make out the individual blades of grass or flowers. The further away the field is, the less details we can see

Height in the visual field: In our visual field, the closer objects are to the horizon line, the further away they appear. This means that their height in the visual field helps us to determine their distance

Psychological factors: processes that operate at the individual level that impact the mental state and cognition of the individual, thereby influencing behaviours. 

Psychological factors include visual perception principles, context, motivation, past experiences and memory.

Visual perception principles: rules the brain applies automatically to organise and interpret visual stimuli in a consistent and meaningful way.


Context: refers to information (conditions or circumstances) that surrounds a stimulus that influences the perception of the stimulus. 

• Motivation: an internal state that activates, directs and sustains behaviour in relation to achieving a specific goal. Motivation can be either conscious or unconscious. It can influence how we interpret the world around us. It can be influenced by:
• physiological factors (e.g. pain, hunger and body temperature)
• psychological and emotional factors (e.g. your interests, priorities and mood).

Past experience: prior exposure to stimuli and previous life experiences create a tendency, or expectation, to interpret stimuli in the same way as similar previous stimuli.

Memory: when interpreting a new stimulus, memories of past experiences are retrieved and compared to the new stimulus to help. Humans recognise what they are looking at by combining current sensory stimuli with comparisons to images stored in memory.

Gestalt principles: rules used to organise separate elements of a visual stimulus into meaningful patterns or whole forms.

Figure–ground: applying an imaginary contour line to perceptually group and separate some features of a stimulus so that a part of the stimulus appears to stand out as an object (the figure) against a plainer background (the ground). 

Closure: mentally filling in the gaps in an incomplete figure by filling so that the figure has a consistent overall form.

Similarity: perceiving stimuli that have similar visual features (e.g. size, shape, colour or form) as belonging together and forming a meaningful whole.

Proximity: perceiving stimuli that are close together in space as belonging together and forming a meaningful whole.

Visual constancies: perception principles that allow us to view objects as unchanging in terms of their actual size, shape, brightness and orientation, even when there are changes to the image that the object casts on the retina

Culture: all the distinctive beliefs, values, customs, knowledge, art and language traditions that provide the basis of everyday social behaviours and that are handed down from one generation to the next. 

Culture influences how a person behaves, speaks and interacts with others. It also influences how we perceive our environment.