Thinking

Thinking, also known as “cognition”, is the way we respond to sensory perceptions of the world, process them and choose our responses. We do this with continual reference to long-term memory, using a short-term memory area for mental working that is also linked to conscious attention.

The brain organises incoming sensory information, processes it in the light of consciousness through attention and then initiates responses in the form of actions. At a higher level, the sensory, cognitive and motor functions of thinking are integrated together within the brain. Understanding the interaction between these is a basis for good product design.

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Most of the processes that underlie thinking occur in the brain, which forms part of the central nervous system, which in turn transmits sensations and sends signals to muscles through the spinal cord and nerves.

Biological studies have shown that different regions of the brain are specifically involved in different cognitive functions such as: attention, memory, vision, hearing, and movement initiation as well as coordination and speech. Many functions are also dispersed throughout the brain.

With age there is a general slowing of intentional action and reduction in capability for attention. The ability to recognize patterns is also reduced. There is an increased susceptibility to distraction whilst attending to a task, resulting in reduced capability for tasks that require two or more simultaneous functions.

Well-established memories and skills are unaffected with age, whereas the time required to learn new things, make decisions and respond to sensory information increases, as can the frequency of errors.

Degenerative brain disorders are more prevalent with age, examples of which include Parkinson’s and Alzheimer’s diseases. These affect memory, attention, movement, perception, reasoning and social interaction to varying degrees.

The brain serves many functions, a complete description of which are beyond the scope of this website. For understanding product interaction, the following are most significant

• Perceiving involves processing to convert low-level senses, such as light, shade and colour into high-level perceptions such as objects, faces, and an overall understanding of the environment
• Working memory describes the temporary storage used to process and rearrange all information with reference to perceptions of the current environment and long-term stored memories
• Long-term memory describes the processes through which information encountered repeatedly in working memory can be learnt, stored indefinitely, and retrieved
• Attention can consciously direct the focus of working memory towards specific things in the environment, and affects awareness of the environment by filtering out non-attended things; yet salient or intrusive events can also "grab" attention unconsciously
• Visual thinking is the ability to perceive and think about visual objects and spatial relationships in two and three dimensions
• Verbal thinking refers to the conversion of speech, words and symbols into language, and the use of language to store and categorise memories as linked episodes

Acting involves processing to convert general intentions and movements into specific actions, in the form of sequenced instructions to muscles

Perceiving is the the process by which the brain represents and interprets the information signals sent by the body’s sensory system. Sensory information is available from the eyes (vision); from the ears (hearing, balance) and from the skin, muscles and skeleton (touch, body-sense) for the brain to process into sounds, objects and surfaces, leading to an understanding of the current environment.

Low-level sensory information is briefly stored, while processing distinguishes and selects important features. For visual processing, information about shading, colour, motion and depth may be used to separate shapes from their background and identify objects. Recognition occurs when higher-level cognitive visual processing groups features into edges, clusters and patterns, then rotates and scales the image to match items in memory.

Some aspects of the environment may be perceived automatically, such as the use of light and shadow to form a perception of a three dimensional object. Visual illusions highlight instances where alternative interpretations of the perceived environment are possible.

Working memory allows us to reason about visual features and spatial relationships. Similar processing and representations are also involved in hearing to enable us to perceive speech, and to detect sounds in noisy environments. Our sense of where the body is within the environment results from the coordinated operation of all senses.

Working memory is used to manipulate and rearrange information within the span of attention. Information can originate from memory or from perception, and can be stored for up to 20 seconds before it decays. Information can be held in different forms, such as the verbal meaning of words (e.g. a word “house”), the visual or spatial content of attended material (e.g. “the shape of a house”) or its episodic context (e. g. “it's the place where I live”).

Attention and executive function refers to the execution of the processes that interface between long-term memory, working memory, perception and cognition; the number of different things that can be kept in working memory at once; and the choice and focus of information that is processed.

Working memory is known to be organised into “chunks” or items. This type of memory can be thought of as a rough working area for items being attended to. Examples of its use include remembering a phone number that’s being read out, or a list of words presented in a drop down menu, or where the objects on a table are in relation to each other.

The capacity of working memory is known to be limited to around 7 chunks or items, although the amount of information that can actually be simultaneously stored and processed depends on the form of the information, the way in which it is chunked together, and how the present information links together and with stored memories.

Long-term memories require learning and repetition to become fixed, but once stored they can last a long time and be retrieved by triggers or cues. Knowledge may be in different forms, such as remembering what things are; how to do something; or remembering linked episodes of verbal and visual interactions that occurred in the past. Prospective memory is remembering to do something in the future, such as checking that food left cooking is not burning.

Remembering that the perceptual cues in front of you are similar to a stored memory is called recognition, while remembering something stored in memory from different cues in front of you is called recall. Identifying whether you have seen someone’s face before requires recognition, while remembering their name takes longer because it requires recall.

Our general prior experience helps to realise that buttons should be pushed, and handles should be pulled, while specific experience with a product makes it easier to use in the future. The ability to use a new product is strongly dependent on how well it matches with these specific and general experiences. Our ability to learn decreases with age, so a product is likely to be difficult to use for an older person if it does not match up with their experiences when younger. Initial interaction with an unfamiliar product is characterised by frequent errors but this can improve if the product supports learning through feedback.

Attention is thought to be a function of working memory. It can be consciously directed towards specific tasks, or it can be ‘grabbed’ by a distracting event such as a flashing light or the sound of one's name. This can be advantageous, to direct a person's attention towards a warning or impending hazard, or can be a distraction if a flashing light disrupts attention away from the task at hand.

For each individual, attention can be overloaded if too many things have to be kept in mind at once, in which case items or tasks may be forgotten. For example, if a person attempts to cook while having a conversation or reading, it is likely that something will be forgotten or an action will be missed.

Working memory performance is also affected by the time taken to process incoming sensory information, and to decide on, and implement, the required response. For example, when driving a car, incoming sensory information is continually processed in the form of road hazards, signs, and information from the vehicle. If the user cannot process and respond to the incoming information fast enough, then newly arriving information passes unnoticed, or existing information is lost.

Working memory has limited overall resources which are divided amongst separate visual and verbal modes, each of which use their own storage.

Visual thinking is the ability to perceive and think about visual objects and spatial relationships in two and three dimensions. Some key functions are

• Filtering and extracting information from the low-level sensory information the eyes receive, to identify and group objects
• Relating objects and icons to each other according to their spatial position, for example understanding the relationship between the control knobs and the burner positions on a cooker
• Rotating drawings, symbols or text in two dimensions, or objects in three dimensions
• Grouping objects according to properties such as their shape, colour or spatial alignment
  

Visual thinking and other processes develop a perception of shape, using colour, shading, depth and motion. Shapes are then matched to objects in our visual memories. Buttons that share similar functions on a calculator have been designed so that they are perceived as part of the same visual group, thereby making the calculator easier to use.

Verbal thinking refers to the conversion of speech, words and symbols into meaningful constructs, and the use of established semantic knowledge (what things are) stored in long term memory.

Semantic memory holds words and their meanings, the relationships between words and more complex structures such as language, grammar, rules and knowledge. These elements are constructed and utilised through processes of relating, reasoning, and categorising that are thought to be carried out in working memory as a result of executive processing.

In order to understand speech and printed material, low-level auditory and visual processing must first separate the sounds and letters from the background. Higher-level processing, under the control of attention, can then operate on the word sounds and text objects to generate words that are held in working memory. These processes use separate auditory and visual stores.

Executive processes in working memory then interface with long-term memory to enable the meaning of words to be understood. Retrieved episodic memories further contextualise how, where and when these words were encountered. High-level thinking can then use memories of how to do things to generate speech or writing by the initiation of low-level muscular actions.

• Use shapes, colours and alignment to assist visual grouping of features that share some kind of similarity, thereby reducing the time and working memory required to locate a desired feature
• Align controls in a spatial orientation that matches the devices they affect, or provide an obvious link between controls and the corresponding devices
• Consider the increased demand on spatial ability if left and right are used to represent up and down (or vice versa), and avoid this situation wherever possible
• Use the visual form of the device to help users understand what areas they can interact with, and the correct way to interact with them
• Try to use simple language, and supplement textual information with images and icons
• Be wary of potential problems that can result if multiple actions have to be completed within a certain time period
• Try to ensure that attention is only required to be directed in one place at any one time

• Use structure to assist memory and learning
• Reduce the number of information chunks that need to be kept in mind at any given time, and try not to exceed 5 as the best practice
• Where hierarchy is used, ensure the current location within the overall hierarchy is always evident and try not to exceed three levels
• Assist learning and recall through distinctive spatial positions for menu options, and be wary of the potential confusion if these positions change
• Provide an obvious mechanism that allows users to get back to their previous location or home when navigating any menu structure
• Consider the memory implication of unseen content if scrolling is required to obtain more menu items
• Support learning by ensuring that all possible actions generate suitable feedback that guides the user
• Try to ensure all actions are easily and immediately reversible, and try to constrain the availability of actions that would result in undesirable or irreversible outcomes

The thinking ability level is calculated using this table, which considers the number of disabilities from the list below

Thinking disabilities

• Often loses track of what is being said in the middle of a conversation
• Thoughts tend to be muddled or slow
• Often gets confused about what time of day it is
• Cannot watch a 30 minute TV programme all the way through, and tell someone what it was about
• Cannot read a short newspaper article
• Cannot write a short letter to someone without help
• Cannot count well enough to handle money
• Cannot remember a message and pass it on correctly
• Often forgets to turn things off, such as fires, cookers or taps
• Often forgets the names of friends and family that are seen regularly
• Often forgets what was supposed to be doing in the middle of something

No demand: The user is not required to do things similar to any of the tasks listed below.

Low demand: The user is required to do things similar to 4 of the tasks below.

Moderate demand: The user is required to do things similar to 7 of the tasks below.

High demand: The user is required to do things similar to 11 of the tasks below.

• Hold a conversation without losing track of what is being said
• Think clearly, without muddling thoughts
• Tell the time of day, without any confusion
• Watch a 30 min. TV programme, and tell someone what it was about
• Read a short newspaper article
• Write a short letter to someone without help
• Count well enough to handle money
• Remember a message and pass it on correctly
• Remember to turn things off, such as fires, cookers or taps
• Remember the names of friends / family that are seen regularly
• Do something without forgetting what the task was whilst in the middle of it