Peter J. Hills

Article / Updated 07-10-2023

Cognitive psychologists use the information processing model to explain cognition. This model assumes that human cognition is a lot like a computer and the way the human brain works is by processing information through a series of stages: Perception: Input stage. People need to encode information from the world in order to process it and then respond to it appropriately. In part, perception is guided by experience, which changes the way people see the world. If information is attended to, it’s transferred from perception to memory. Memory: Storage center. Information is stored in long-term memory and processed and used by short-term memory. All knowledge is stored in long-term memory. Thinking: A high-level cognitive function. Information from perception and memory is used to make decisions, to reason and to make deductions. Language: A high-level output stage of cognition. Often, the results of thinking need to be acted upon in terms of speaking or writing. The information processing model of cognition shows how information enters and leaves the mind.

Cheat Sheet / Updated 02-28-2022

Cognitive psychology is the study of all things to do with thinking. It’s the part of psychology that covers perception, attention, memory, knowledge, thinking, reasoning, decision-making and language. To study it, cognitive psychologists develop ingenious experiments that manipulate a small part of the cognitive system.

Article / Updated 12-29-2021

Lying is a deliberate attempt to mislead someone verbally or by conveying a false impression through body language. Cognitive psychologists are particularly interested in lying, because it’s a special kind of thought process: unusually, it’s not designed to communicate truthfully with other people. Normal thought and communication is based on trying to provide accurate information (for example, a textbook wouldn’t be much good if it was designed not to tell the truth). This difference makes lying an unusual process. People lie at least twice a day and in approximately one-fifth of all interactions lasting more than ten minutes. Men and women lie an equal amount, but women are slightly better at detecting lying (at least among their same-sex friends). Some people are more likely to lie than others (such as the manipulative and Machiavellian) and some are better at lying than others (the physically attractive and self-confident). Certain groups of people tend not to lie, such as people with a sense of social responsibility and those suffering from depression. Understanding the cognitive psychology of lying Although lying is quite frequent, cognitive psychologists have found that it’s a challenging process that demands a great deal of cognitive resources. Research consistently shows that lying takes longer than telling the truth — honest! The reason is that lying involves two stages: the decision to lie and then the construction of the lie. When someone asks a question to which a person may respond with a lie, the truth is more "active" in the mind of the liar than the lie (unless it’s a highly practiced lie — "We won’t raise taxes or cut benefits!"). Therefore, if the person decides to lie, he must suppress the truth, which requires cognitive effort. He must then search his memory to produce a lie, using logic to construct a believable one; he also requires a theory of mind (that is, he has to understand how someone else may see the world). Neuroscientists have discovered that when people are lying, different parts of the brain are active compared to when they’re recalling truthful events. Typically, when people are lying their pre-frontal cortex displays activity, which is the same brain region involved in high-level reasoning. Developing the ability to lie Given that lying depends on the liar’s theory of mind and his pre-frontal cortex, it’s no wonder that the ability to lie develops with age. The temptation resistance paradigm is a typical experiment employed to test children’s fibbing abilities. They’re left alone in a room with a tempting item (such as a chocolate cake or a toy) that the experimenter tells them not to touch. Most young children (under 4 years of age) can’t inhibit the behavior and they touch the object. When asked whether they touched the object, young children can’t verbalize a convincing lie — they’re too creative and may accidentally indicate the truth in their lie (for example, "a mysterious man entered the room and touched it"). This indicates that young children are less able to lie verbally than adults. The ability to lie develops in parallel with executive functions and theory of mind, and it tends to occur earlier than the ability to construct and maintain a believable lie. From about 7 years of age, children are able to maintain a lie. Lying in the animal kingdom Until relatively recent, biologists believed that animals were unable to lie. Work by psychologists, however, shows that many animal species can lie. In one example, researchers partially hid a grapefruit in a chimpanzee enclosure. They then showed the chimpanzees the empty grapefruit box. The chimpanzees were excited and went in search of the grapefruits as a group. They displayed no obvious detection of the grapefruit. But later in the day, one of the chimpanzees (when alone) went straight to where the grapefruit was buried, dug it up and ate it. Clearly it had seen the fruit earlier but didn’t want to reveal that it knew the location, because the others would try to steal it. Apes trained to use sign language, and who are tested in a similar way as the temptation resistance paradigm, lie in a similar manner to young children. In one classic example, a gorilla was told not to eat a particular fruit, and then the experimenter left the room. The gorilla promptly ate the fruit. When the experimenter returned, the gorilla denied eating the fruit. The limitations of the gorilla’s language mean that researchers will never know whether the gorilla could construct a believable lie as to what happened to the fruit, but it was clearly able to lie about eating it.

Article / Updated 03-26-2016

Understanding long-term memory is essential in cognitive psychology. Long-term memory isn’t a unitary structure ‒ many different types of memory exist, which can independently be damaged due to brain injury. Research suggests the existence of the following different types of memory: Episodic memory: A conscious declarative (verbalisable) memory store for recent events that have occurred. Autobiographic memory: A declarative memory for all life events that have happened to you, usually important ones that are highly personal and emotional. Semantic memory: A declarative memory for all facts that you’ve accumulated throughout your lifetime. Procedural memory: An unconscious non-declarative memory for every skill or behaviour that you have. Priming: A non-declarative memory store due to the repetition of information and its effect on behaviour and perception. Associative learning: A non-declarative memory for unconscious associations formed between things and conditioned learning (learning based on linking two stimuli ‒ such as light and sound ‒ together sometimes with a reward). Non-associative learning: A non-declarative memory store for habits. The different types of long-term memory.

Article / Updated 03-26-2016

Humans are thinking animals and cognitive psychologists are aware that people make decisions all the time. These decisions can be trivial (what should I have as a snack?) or much more life-changing (should I marry my current boyfriend?). Humans don’t appear to be that rational and use a number of mental shortcuts (called heuristics) to help them make decisions (quite often badly): Availability heuristic: People make decisions based on how easy they find thinking of examples or outcomes, which leads to poor decisions if only certain information is easily available. Anchoring: People often make decisions based on the piece of information they’re presented with first. Ignoring the base-rate: People tend to ignore base-rate statistical information (that is, information about the frequency of particular events occurring), because it complicates the decision-making process. Familiarity heuristic: People’s decisions are biased due to past experience. These experiences influence how they make decisions, instead of focusing on the novelty of the current situation (see figure for an example where familiarity and experience can impact people’s ability to solve a problem). Recognition heuristic: People make decisions based on their recognition memory. When they see something they recognise, they’re likely to believe that it’s better or more common than something they don’t recognise. A problem to solve that’s often affected by people’s familiarity with the objects. You’re given a box of drawing pins (thumb tacks), a candle and a book of matches. Your task is to fix the candle to a wall. Tip: think beyond your assumptions about these items’ normal uses.

Article / Updated 03-26-2016

Short-term memory is memory for things currently in mind. It’s the active state of memory in cognitive psychology, like the RAM on a computer. According to the working memory model of British psychologists Alan Baddeley and Graham Hitch, different types of short-term memory exist: Phonological loop: The inner ear. This system comprises the phonological store, a short-term store for sounds, and an articulatory rehearsal mechanism, which is where sounds are repeated for a short time to keep them active in memory. Visuospatial sketchpad: The inner eye. This system comprises the visual cache, a store for mental images, and an inner scribe, which is a mechanism that plans sequences of actions. Episodic buffer: This system binds and integrates information into discrete pieces. The brain stores new discoveries and information by linking together how something looks with other sensory information and anything already known about it. Central executive: Like a computer’s central processing unit. It directs the resources of the remaining parts of working memory. It focuses attention on a particular task, switches attention between tasks and divides attention between tasks. The working memory model of short-term memory.

Article / Updated 03-26-2016

Cognitive psychology can provide insight in how people create new words. Language is a human form of communication ‒ it’s highly complex, creative, spontaneous and constantly changing. When people create new words, they usually do so in a consistent way such that new words fit with the grammatical structure. The following rules and findings apply to how new words and phrases (see figure for how to generate new insults!) are created: Inflectional morphology: In English, adding an ‘-s’ to the end of a word automatically makes it plural, even if the word is new or has never been pluralised before: for example, the made-up animal ‘wug’ would be pluralised to ‘wugs’. Derivational morphology: When words are created taking the name of someone or something and using that to describe something similar: for example ‘Corbynistas’ to represent followers of the politician Jeremy Corbyn. Combining words: Two words can be linked together that have never previously been linked together in order to form a new concept: for example ‘keyboard’ is the combination of ‘key’ and ‘board’. Creating new open-class words: Open-class words are nouns, verbs and adjectives, which people can easily create when the need arises. For example, ‘tweeting’ is a new word created from the social media device Twitter. Creating new closed-class words: Closed-class words are functional words, such as articles and pronouns. People can’t easily add new ones to language: for example, ‘Peh’ as a singular but gender-neutral form of ‘he’ or ‘she’. Insult generator for 10 million insults.

Article / Updated 03-26-2016

You can see executive function as being the central processor or managing director of the brain. Cognitive psychologists have theorised that the executive function system is a network that controls other areas of cognitive functioning, which is why some people call it cognitive control. It’s like a supervisory system overseeing all other functions, directing resources to the most appropriate cognition and inhibiting competing signals. It’s vital for survival in an ever-changing world. Developing executive functions Unsurprisingly, given the importance of executive function, it develops late in your life. Most executive functions evolve in adolescence or even early adulthood. The ability to focus attention and inhibit irrelevant information and behaviours take time to grow. Indeed, the brain network thought to be responsible for executive function isn’t fully developed until adulthood. Understanding executive functions Executive functions cover a wide range of abilities, which we categorise broadly into three components: Updating: Monitoring the contents of working memory and altering it as the environmental demands require. Inhibiting: Preventing an automated behaviour and ignoring unwanted information. Shifting: Moving between different tasks, cognitive tasks or behaviours. Although these categories are apparent, subcategories of each also exist. Measuring executive function Psychologists have developed hundreds of different tests of executive function. Here are several of the most widely used tasks, some with more exotic names than others: Continuous performance task: Involves presenting participants with a sequence of letters. They’re asked to respond whenever they see a particular letter or a particular combination of letters. This task measures the monitoring ability of executive functions. Stroop task: Involves participants naming the ink colour of words. They’re slower when the word is a colour and doesn’t match the ink colour, because participants have to inhibit the automatic process of reading. Iowa gambling task: Involves the presentation of four decks of cards. Participants must draw cards, which can be rewards or penalties. Some decks contain more rewards and some decks contain more penalties. This task tests participants ability to change goals (updating) and identify strategies for success (attend to which decks are producing good rewards and problem solve). Tower of Hanoi: Involves participants moving rings of different sizes from one peg to another. One key rule exists: they can’t place a larger ring on top of a smaller ring. Again, this task measures updating. Wisconsin card sorting task: Tests a measure of set-shifting. Participants are presented with a number of cards and told to match them (but not given the rule). Participants are simply told whether they’re right or wrong and must work out the rule. Flanker task: Involves participants responding to the direction of a central arrow that’s surrounded by arrows that point in the same or a different direction. Participants must inhibit the direction of the surrounding arrows. This measures the ability to inhibit distracting information.

Article / Updated 03-26-2016

Cognitive psychology is concerned with how the brain interprets the information it receives through the senses. Now, you may think that you have five senses, but that’s not entirely correct. People have around 21 distinct senses that they use to interpret the world! Here you discover ten senses and how they interact with each other (and vision). Listening in on hearing When you close your eyes, you can truly appreciate the power of your ears. You’re able to hear so much (the clock ticking in the background, the sound of your partner snoring!). The size of the ear dictates the sounds that can be detected. A larger ear means that low (but not high) pitched sounds can be heard. This is why smaller animals make higher pitched vocalisations (like squeaks!) than larger animals. The brain can use the information the two ears supply to localise sounds. By working out the time difference between sounds reaching each ear (the interaural time difference), the brain can establish where a sound is coming from. Additionally, the brain can use the slight volume differences in the sound in each ear (the interaural intensity differences) to identify where something is. Kicking up a stink: Smelling The sense of smell works by detecting particular chemicals inside the nose. The sense of smell is one of your most powerful senses. Odours bring memories and emotions to life very easily. They can influence people to buy things: for example, estate agents use the smell of coffee to encourage people to buy houses because coffee brings about the sense of home. Odour (and taste) can be used as a warning – bleach and nail varnish remover have bad smells and tastes added to discourage people from drinking them. People are remarkably efficient at identifying smells associated with themselves. Mark Russell, a British psychologist, conducted the “dirty shirt study” in 1976. People wore the same shirt for 24 hours after washing and didn’t use any perfume. After the study, the same people were able to accurately identify which shirt was theirs. Here are a few more smelly facts: Women are generally much better at identifying smells, with a few exceptions: for example, moth balls, beer and ammonia. Smelling ability diminishes after the age of about 70 years. Cigarette smoking makes people worse at smell identification. Blind adults are better at identifying smells than those who can see. Chewing over the sense of taste Tasting is done by taste buds in the tongue and mouth. Taste buds aren’t distributed evenly over the tongue ‒ the middle has no taste buds. The number of taste buds varies with age, and tasting abilities are lost over the age of 40 years. Taste can be divided into five categories based on the different sources: Salty. Sour. Umami. Sweet. Bitter. The common myth that different parts of the tongue are sensitive to different tastes is entirely false. All tastes can be detected throughout the mouth and tongue. However, some tastes are easier to detect than others: salt is easier to detect than sweet. Some people are better able to detect bitter tastes than others, which is why some people like coffee and others don’t. Taste preference changes with age, with infants preferring sweeter tastes than adults. This is because sweet foods contain sufficient energy for a growing child and are less likely to be poisonous. Hunger also makes people better able to detect tastes. Taste interacts with vision and smell ‒ which is why food manufacturers dye foods. Foods that are coloured appropriately taste better than foods that aren’t coloured appropriately: would you eat a blue banana? Margarine is dyed yellow to mimic real butter. Feeling your way towards touch The skin ‒ the largest organ in the human body ‒ comprises many sensory cells that detect different types of sensory information. Many of the cells, called mechanoreceptors, respond to pressure applied to the skin. Touch abilities vary across different parts of the body. Better touch perception exists for the hands, tongue and face compared to the back. Part of the reason is that more brain processing exists for these relative to other parts of the body. Touch has been found to be distinct from pressure, temperature, pain and itch sensors. Touch perception is faster than pain and temperature perception, and so you can feel that you’ve touched something and then feel pain shortly afterwards. Scratching around to understand itching Itching is typically caused by irritations on the skin. Itching can be induced psychologically: Viewing pictures of fleas, mites, scratch marks, allergic reactions can cause participants to scratch. Itch can also be induced by the sound of and by watching someone scratching. Try it: surreptitiously scratch your arm noisily and see whether others around you scratch. Itching is a social contagion. One theory is that if people in your social group are scratching, they’ve probably come in contact with something bad that you need to remove from yourself. Neuroscientists have found that parts of the brain associated with reward (pleasure, addition, and craving) seem to be involved in the pleasure of scratching. Hey! Watch those hands! Proprioception Touch is an active process and so the brain has to know where the hands are (called proprioception). Whenever you have to touch your body (such as when putting on a shoe, or touching your nose) without looking at yourself, you’re using this sense. This sense is affected when intoxicated. Proprioception can cause illusions, for instance phantom limb syndrome, where people who’ve had a limb amputated still feel something on that limb (typically pain). Another illusion to do with proprioception is the Rubber Hand Illusion, a fairly unbelievable illusion that you can easily try out (it works in 80 percent of people). This illusion demonstrates proprioception drift: where the sense of proprioception moves from the body to something else that the eye can see. Vision dominates the sense of proprioception. Combining touch information with proprioception helps the brain identify what objects are being touched, a process known as haptics. Knowing where you are: Magnetoreception Many animals, especially birds, can navigate based on the Earth’s magnetic fields. Surprisingly, humans have this ability but it is far weaker than that of birds. The theory is that magnetoreception in humans is to do with iron in their noses. One study involved putting participants near a strong magnetic field and then disorienting them (by spinning them around). Participants placed next to the strong magnetic field performed much worse at identifying north, south, east and west than those participants who weren’t. “Time flies when you’re having fun”: Judging the passing of time Humans are surprisingly good at perceiving time, without counting or even thinking about it. But are less good if their attention is divided. Because the cognitive processing of a familiar (or typical, uninteresting) objects is easier time perception is tricked into thinking the familiar object is present for longer. Arousal also affects time perception. When things are highly negative they’re perceived (such as spiders for spider phobics and critical or angry faces) to last longer than highly positive things, although, interestingly, when things are slightly negative they’re perceived to last a shorter amount of time than slightly positive things. Consumer psychologists use this knowledge to develop techniques to improve customer satisfaction when waiting. Therefore mildly irritating music is played in lifts and during telephone queues! Age also affects time perception: Children under the age of 8 years judge things as lasting longer than they do. Young adults are most accurate at time perception. As people get older, they experience things as taking longer than they do. Disorders such as Parkinson’s disease and ADHD cause impaired time perception. Typically, sufferers perceive durations to be much longer than they are. ‘I’m gasping!’: Thirst and hunger These two separate senses allow your body to identify when you need to drink and eat. Food and drink are the easiest stimuli to use as rewards in behaviourist experiments because of their importance in survival: when training people, giving a reward of food to a hungry person is the most effective technique. Hunger and thirst, create an internal representation of the stimuli that alleviate them: when you feel thirsty, you immediately think of water (or a nice cool beer, hmmm . . . beer). Cognitive psychologists presented hungry participants (who hadn’t eaten for 16 hours) with an image containing many objects. Hungry participants were more likely to report seeing items that were related to food (such as a plate). Psychologists modified the Stroop task using food or non-food related words in coloured ink to hungry and not hungry participants. Hungry participants took longer to name the colour that the food-related words were written in than the non-food related words. Similar results are obtained in participants with anorexia nervosa and bulimia nervosa (psychological disorders regarding the perception of your own body, where sufferers believe they’re overweight when they’re in fact underweight). Food related words have preferential access to memory, and therefore interfere with processing more when hungry than when sated. Food Stroop stimuli: Participants should name the ink colour of the words. Naming the colour of the words on the left takes longer than the words on the right when a person is hungry. Feeling the pain: Nociception Nociception (pain perception) is not directly related to the extent of tissue damage: many psychological factors affect the feelings of pain. Neuroscientists have found evidence to suggest that a vast cortical network is associated with pain perception. Being able to feel pain prolongs life, because knowing that damage exists helps people to deal with it. People who can’t feel pain (due to damage to their pain receptors) don’t live as long as other people, because they’re unaware of physical damage that happens to them. Pain perception is much reduced if attention is paid to another task: if you can distract yourself from the pain, it is reduced. Similarly, the perception of pain affects performance in attention tasks, suggesting that pain uses cognitive resources. Anticipation of and anxiety over pain occurring activates the pain system in the brain, enhancing the feeling of pain rather than reducing it. Pain can be reduced when viewing happy but not angry faces. Pain perception can be reduced by taking placebos (drugs that contain no active ingredients), suggesting that if you believe your pain will be reduced, it will be.

Article / Updated 03-26-2016

Cognitive psychologists have long sought ways to study processes within the brain and the particular function of its cells. In the past, neuroscientists measured directly the neural activity of cells in the monkey brain by drilling holes into the monkey’s skull. This unethical practice can’t be run on humans, and therefore researchers must find other techniques to record the brain’s activity. Psychophysicists developed a technique called adaptation that reveals what the brain processes. Adaptation is when the response of a particular cell (or group of cells) is reduced following stimulation and therefore it allows cognitive psychologists to identify what particular cells do. That’s why adaptation is called a microelectrode (it’s not an electrode!). Adapting to the world One of the clearest examples of adaptation comes in the colour after-effect. The opponent-processing theory of colour suggests that colours are processed in opposition to each other. The after-effect of adaptation to red is green. The after-effect of adaptation to blue is yellow. The after-effect of black is white. Stare at the dot on the figure on the left for 30 seconds. Then move your eyes quickly to the white page on the right. If you look to a blank wall, the afterimage should remain and can be brought back with a blink. Understanding the mechanisms of the colour after-effect The explanation for the colour after-effect is that cells in the eye selectively respond to one colour. When these cells are fatigued they stop responding, and the cells that code the opposite colour are relatively more active. This behaviour creates the perception of the opposite colour. By this logic, anything you can adapt to must have a neural population located in the brain. What else can people adapt to? You can adapt to spatial frequencies, size, motion and tilt. (The motion after-effect is demonstrated in a YouTube video.) Cognitive psychologists call these abilities low-level ‒ they’re abilities that occur early in cognitive processing and aren’t greatly affected by knowledge and experience. To cognitive psychologists’ surprise, you can adapt to higher-level stimuli ‒ such as shapes and even faces. Locating faces Consider the example of adaptation below. If you stare at the slightly distorted face in part (b) for 40 seconds and then look at the undistorted face in part (a), the latter appears distorted in the opposite direction. An understanding of adaptation would suggest that cells in the human brain process the height of the eyes. However, if you do the same exercise with the face in part (c), where the eyes are at different heights, do you get an after-effect when switching to the undistorted face in part (a)? Most adults don’t. This result shows that people don’t have cells in the brain that process the height of one eye. Further results with faces show that cells in the adult brain can adapt to particular facial identities, suggesting that humans have neural representations of the identity of someone. Stare at the left face for one minute and then look at the middle face. Try it again but stare at the face on the right for one minute, then look to the middle face. Understanding adaptation These results suggest that people’s brains have neural populations for facial arrangements that exist normally. Interestingly, cells in the child’s brain can adapt to the stimuli in image c, indicating that the neural representation of faces develops slowly. This tendency allows psychologists to measure the development of the brain without drilling holes into the skull and directly measuring the response of particular cells.