U2 AOS2 Ch9 Perception

in the sense organs detect and respond to light, sound and chemical energy

The sensory receptors send electrochemical signals to specific sensory areas in the brain

• Sensation: physical reaction to a stimulus that is the same for everyone
• Reception: detection of stimulus energy by sensory receptor cells of the various sense organs
• Sensory receptors in the retina respond to light energy, and sensory receptors in your tongue respond to chemical energy

• Transduction: Converting stimulus energy into electrochemical energy that can be transmitted to the brain as neural impulses
• Transmission: sending the information form receptor sites to through neural pathways to specific sensory areas in the brain

Perception: a psychological activity that gives meaning to the stimuli our sense organs detect

• Perception occurs in the brain and involves cognitive processes, such as thinking, learning, memory and emotions
• Selection: the process of attending to certain sensory stimuli and excluding others

Organisation: the process of regrouping sensory stimuli to form a meaningful whole or pattern

• Lines and shape that make up a smiley face are grouped together so that they can be perceived as a whole
• Interpretation: the process in which information is given meaning to that it can be understood

Involves bringing together other incoming sensory information and existing knowledge (memories/experiences/emotional state) to make sense of information

• Bottom-up processing: when our sensory receptors, such as our eyes, receive sensory information and we do not rely on prior experience in order to interpret it 
• Top-down processing: used when the brain starts with an overall hypothesis about a stimulus and uses context and general knowledge to fill in any blanks

a voluntary (conscious) or involuntary (unconscious) tendency to focus awareness on a specific stimulus and ignore other stimuli

Attention filters out irrelevant information so we can focus on important information

• Internal stimuli: information or sensations originating from within our body
• External stimuli: information or sensations that originate outside our body

Sustained attention: focusing attention on an activity or stimulus over a prolonged period without being distracted by other stimuli

- Sustained attention deeply focuses your attention. It is most beneficial when learning something new

• EXAMPLES: 
• searching for something in your bag 
• watching a video from start to finish 
• completing a simple maths question 
• holding a conversation for a few minutes

Divided attention: (often referred to as multitasking): refers to rapidly switching the focus of your awareness between two (or more) sources of information so you can perform two (or more) tasks at the same time

• Selective attention: choosing to focus your awareness on a specific or limited range of stimuli while ignoring other stimuli
• - selective attention allows you to focus on the most important stimuli and ignore less important stimuli. This helps you to survive

• Controlled processes: conscious, voluntary actions or cognitive processes that require high level of attention and monitoring 
• Automatic processes: actions that require little conscious awareness or mental effort and do not interfere with performance on other activities  

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

Ability to see three-dimensional space and accurately judge distances using environmental cues

depth cues that require both eyes to work together and provide the brain with information about depth and distance

1. is a depth cue created by small differences between the image that reaches the right eye and the image that reaches the left eye - our eyes are approximately 6.5cm apart, each retina receives a slightly different image

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

depth perception cues that rely on information from only one eye

1. 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.

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

1. The apparent convergence of parallel lines creates the impression of increasing distance

2. 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 

3. When one object partially blocks another object it is perceived as being in front of and, therefore, closer than the object it covers

4. 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. 

EG) 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

5. 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

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

1. rules the brain applies automatically to organise and interpret visual stimuli in a consistent and meaningful way

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

1. 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)

2. When the contours are not clearly visible it is difficult to separate the figure from the background. This is called camouflage. (The figure and the background blend together).

3. Tendency to perceptually complete an incomplete figure by filling in an imaginary contour line so that the figure has a consistent overall form

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

5. Perceiving stimuli that are close together in space as belonging together and forming a meaningful whole

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

1. Recognising that an object’s actual size remains the same, even though the size of the image it casts on each retina changes

2. Shape constancy is the tendency to perceive an object as maintaining its shape despite the changing perspective from which it is observed

3. Perceive an object as maintaining it’s level of brightness in relation to it’s surroundings, despite changes in the amount of light being reflected from the object onto the retina

4. Perceived as being unchanged despite changes in the orientation of the object’s image on our retina

1. Refers to information (conditions or circumstances) that surrounds a stimulus that influences the perception of the stimulus

• 2. 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)

3. 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

the sensory experience of food or drink that is put into the mouth and perceived as flavour. 

Humans have five primary tastes: sour, sweet, bitter, salty and umami

1. Genetic make-up influences the amount of and composition of gustatory receptors on taste buds

2. Experience with taste begins in the womb.

Flavours are transmitted from the maternal diet to the amniotic fluid, which is swallowed by the foetus. The infant experiences flavour through their mother’s breast milk. This influences taste preferences and dietary choices made later in childhood

1. Memory of past food experiences helps create an expectation of a food’s taste. The smell or sight of a food triggers a memory that influences your perception of it, often before you have even tasted it.

2. Characteristics of packaging, such as how it feels (its texture and weight), how it sounds (the noise of a can or bottle being opened) and the colour of the serving bowls, influence the perception of the food’s taste

1. Visual appeal is a key element in food acceptance. We first look at our food or drink before consuming it, so our brain receives visual information before taste information

2. People from different cultures eat different foods and have different preferences for particular tastes.

Where families live, where their ancestors came from, and their socio-economic background can also influence people’s perception of food.

The values or beliefs a society attaches to food items also defines what families within a cultural group will eat.

1. a consistent misinterpretation of a visual stimulus

2. A disorder involving the loss or impairment of the ability to recognise familiar stimuli through the use of one or more senses, despite the senses functioning normally otherwise

3. A person with visual agnosia can see, but they cannot interpret what they see

4. occurs due to impairment at the first stage of visual processing. It is the inability to recognise visual stimuli such as shapes or forms of an object despite having no visual deficits

5. occurs due to impairment to the second stage of visual processing. It is the inability to recall information associated with an object, such as its name or what it is used for

6. (also known as face blindness) is the inability to recognise familiar faces (sometimes their own) or facial differences, and they cannot identify a person by name

a cognitive impairment where affected people fail to pay attention to, recognise or respond to stimuli located on one side of their body or in their visual space

• can result in: 
• - colliding with obstacles on their left (or right)
• - ignoring people situated on their left (or right)
• - eating food only from the left (or right) side of their plate