Cognitive psychology is the scientific study of how people and animals process information. It studies how we acquire information, store information in memory, retrieve information and work with information to reach goals. In all these cases, individuals deal with internal or mental representations.

There is a long history of cognitive psychology:

1. Ancient Greeks (500 B.C)
   Plato stated that there is ultimate knowledge and we only see representations of that. The ancient Greeks are also the founders of epistemology.
2. Empiricism and associationism (17th – 19th century)
   Empiricists stated that all knowledge comes from experience and the followers of the associationism stated that ideas and memories were linked by associations (e.g: cow and milk are associated and thus easier remembered together).
3. Introspectionism
   The followers of Introspectionism stated that all cognitive processes could be consciously reported by using introspection. The disadvantages of this are that it required a lot of training and could not be used with a lot of people, with children and with people with reduced mental capacities. The idea that all cognitive processes could be consciously reported was later debunked because a person is not able to report how that person perceives visual illusions. Besides that, reporting a process also has the potential to slow down the process.
4. Behaviourism
   This approach states that it is impossible to know what cognitive processes are active. The only observable things are the input and the output. It also states that all behaviour can be explained by reinforcement and punishment; all mental phenomena could be traced to behavioural activity. Behaviourists also state that language is learned by reinforcement and punishment as well.

Tolman was a behaviourist but was the beginning of the end for behaviourism. He stated that rats have mental maps or mental representations of a spatial layout. Tolman partially debunked the behaviourist approach of describing basic behaviour by his experiment showing latent learning; animals learning even though there was no reward. The behaviourist approach had many successes in accounting for basic animal learning, it was less applicable to complex mental phenomena such as reasoning, problem-solving, decision making and language.

An information processing approach is an approach for understanding mental activity, based on computing. Computer programs to solve suitable problems could be seen as comparable strategies that humans might use to solve the same problems. Strategies are systematic ways to carry out a cognitive task. A simulation program is a program which expresses a model of human thinking and involves programming computers to solve problems in a similar way to humans. The difference between a simulation program and artificial intelligence is that A.I tries to solve the problem as effectively as possible, without any attempt at mimicking human strategies.

Theorists using the information processing approach try to explain performance in cognitive tasks by using concepts of internal representations, which are transformed by mental operations. Internal representations are the mental representations of external objects and events. Mental operations are inner actions manipulating mental representations. Connectionism is an approach to cognition in terms of networks of simple neuron-like units that pass activation and inhibition through the receptor, hidden and output units. The link strength is modified through learning rules such as backward propagation, which modifies the weight on the links between units in a connectionist network, in response to error, to obtain the desired output. The basic components of a connectionist network are:

1. A set of processing units
2. Weighted connections between units
3. A learning strategy

Units affect each other by excitation or inhibition. Functionalists state that we don’t need to know the processes of the brain, as long as we know the functions and the functional properties.

The brain is divided into two hemispheres, connected by the corpus callosum. The outer layer consists of the frontal lobe, the primary motor cortex, the somatosensory cortex, the parietal lobe and the occipital lobe. Deeper in the brain are the thalamus, the hippocampus and the amygdala. At the base of the brain is the cerebellum. There are specific terms for determining the location of something in the brain:

1. Dorsal and ventral
   Dorsal means towards the top and ventral means towards the bottom.
2. Anterior and posterior
   Anterior means toward the front and posterior means towards the back.
3. Lateral and medial
   Lateral means toward the side and medial means toward the middle.

Broca’s area is vital for speech production. Language functions are strongly localized in the left hemisphere. Neuropsychology states that all specific cognitive functions are linked to a specific brain area. Phrenology attempted to localize psychological functions to bumps in the skull taken to reflect the growth of the brain in specific areas. Cases of double disassociation are cases in which patients can be found with opposite patterns of impairment in two functions (e.g: poor short-term memory but good long-term memory). This is particularly useful for localization. There is a difference between structural imaging and functional imaging. Structural imaging is methods showing brain anatomy and functional imaging are methods showing brain activity.

There are several structural imaging methods:

1. Magnetic resonance imaging (MRI)
   A magnetic field and provides high-resolution anatomical images.
2. Functional magnetic resonance imaging (fMRI)
   This measures the degree to which oxygen in the blood flow goes to certain brain areas. The brain exists of voxels, some sort of pixels of hundreds of thousands of neurons.

There are also several functional imaging methods:

1. Electroencephalography (EEG)
   This gives a record of function as a summary of electrical activity over a wide area of cortex, measured using sensors.
2. Positron emission tomography (PET)
   This is very good for localization, but it uses radioactive fluid.

fMRI uses reverse inference to draw conclusions, but this only works in cases where ‘if and only if’ applies. The default mode network reflects internal tasks and this is more active in rest than when focussing on external visual signals. In the infant's brain, there is limited evidence for the existence of the default mode network, but the activity in the default mode network is more consistent in children as they age.

Attention is a limited resource that is deployed to facilitate the processing of critical information. One basic taxonomy of attention states that there are two types of attention:

1. Internal attention
   This refers to selecting control strategies and maintaining internally generated information, such as rules, responses, long-term and working memory. It involves regulating our internal mental life. Internal attention deals with our internally generated thoughts, desires and motivations.
2. External attention
   This refers to selecting and controlling incoming sensory information.

Posner stated that there is an attention system, that exists of three different systems:

1. Alerting (brain stem and frontal cortex)
   This is responsible for achieving a state of arousal. It uses the neurotransmitter norepinephrine.
2. Orienting (frontal and parietal cortex, including the frontal eye fields)
   This is responsible for directing our processing resources to incoming information. It can be described as external attention. It uses the neurotransmitter acetylcholine.
3. Executive function (medial frontal and parietal cortex)
   This is responsible for the supervision of attention. It decides where the attention should go. It can be described as internal attention. It uses the neurotransmitter dopamine.

The cocktail party problem refers to focusing on one speaker in a background of noise and other conversations. There are several theories of attention. There are filter theories, that describe when we process the incoming information:

1. Theory of early selection
   The sensory memory briefly maintains information from all perceptual systems and only the relevant information gets stored in the short-term memory. The irrelevant information gets sorted out early on in the information processing cycle.
2. Theory of late selection
   All sensory information is identified, but only attended information gets stored for further processing. The irrelevant information gets sorted out late in the early information processing cycle and is processed before it gets filtered out.
3. Theory of attenuation
   The intensity of the irrelevant information is diminished, but not eliminated. The irrelevant information is processed, but the intensity of this information is diminished so that only the relevant information makes it to the working memory.
4. Workload theory of attention
   This theory states that the amount of processing the unattended stimuli receive depends upon how difficult it is to process the attended target. If the workload is low, the selection is late, if the workload is high, the selection is early. If a distractor is used in experiments, then this distractor has a larger effect with a low workload.

The resource theory of attention uses the metaphor of the spotlight. This refers to the ‘spotlight of attention’ that illuminates locations of interest. The zoom lens theory uses this metaphor. The size of the spotlight depends on the size of the object that requires our attention. Evidence that attention is a resource comes from experiments by Egly, that show that attention can be bound to an object, instead of a spatial area. An explanation for this could be that the spatial location of objects changes constantly, so it would be more useful to focus our attention on the object, instead of the spatial location of the object. To test whether tasks compete for resources (such as attention), the dual-task paradigm can be used, where two tasks are measured both independently and dependently. Our ability to do multiple tasks simultaneously depends on how far apart they are on the relevant dimensions (e.g: speaking and listening tasks will be more difficult simultaneously than seeing and speaking tasks).

When an individual sees a stimulus, the first component of activity is known as feedforward sweep, which describes how incoming sensory information travels across the brain. Once an area is activated it can interact with both higher and lower brain areas in a mode of recurrent processing. This is processing within a network, that involves computations that occur in a cyclic fashion. The receptive field of a neuron indicates the physical space that stimulates the neuron. The normalization model of attention states that attention increases the neural response to a stimulus in the visual cortex. This model focusses on two functions of attention:

1. Increasing sensitivity to faint stimuli presented alone
2. Reducing the impact of task-irrelevant distractors when multiple stimuli are presented.

The stimulus drive is the presented image. The suppressive drive is the perception using attention to decrease the impact of a part of the image and the population response is what the individual sees. Taking attention away from a location in working memory causes a decrease in the memory performance.

The feature integration theory states that recognition of a target was modelled to be determined by two processes:

1. Preattentive visual processes
   These processes simultaneously analyse the entire scene and detect the presence of unique features (e.g: this searches for stand-out features and if the item alone could be recognized by a simple primary feature, such as shape, then this preattentive stage alone could lead to recognition).
2. Binding problem
   This is the use of attention to bind the different features together in order to recognize the object. This needs to happen if a single feature is not enough to recognize something because features are not processed together.

The non-selective pathway uses distributed attention. This is reminiscent of preattentive vision and allows rapid statistical analysis of the entire scene. If attention is attracted to an event in the visual field there will be a facilitation of processing around this location. After attention moves away, this location suffers from delayed responding to events. This is called the inhibition of return. The function of this is to make sure that searchers don’t return to the place they’ve just searched right away.

If people are looking at a rapid moving sequence and they are trying to detect two things that are close to each other, the second thing is not detected. This is called the attentional blink.

There are several failures of attention:

1. Change blindness
   The substantial differences between two nearly identical things are not noticed when presented sequentially.
2. Inattentional blindness
   This is the failure to notice a clearly visible target due to attention being diverted from the target.

An afterimage occurs when the vision of an object remains after the presentation has ceased (e.g: looking in bright light). Continuity editing describes a filmmaking technique to produce a smooth continuous experience across changes in camera shot.

Consciousness is being aware of one’s existence evidenced by thoughts and perceptions. Subliminal perception is perception where the stimulus is presented under a certain threshold (e.g: the stimulus is too dim or presented too quickly, but the effects on behaviour can still be measured. There are two distinct views on the functions of consciousness:

1. Inessentialism
   Consciousness is not necessary, because any action that can be performed by a conscious agent can also be performed by a non-conscious agent (e.g: philosophical zombies are not conscious, yet appear to be so).
2. Epiphenomenalism
   Consciousness has no function. It is merely a by-product of our brain processes (e.g: consciousness is equivalent to the whistle of a steam-train, unnecessary for the main mechanism).

Volition is our ability to make conscious choices. This includes a free will. There seems to be a causal relationship between our actions and our conscious thoughts, but Libet’s experiment seemed to provide evidence against this view. Our readiness potential, which indicates brain activity reflecting the initiation of preparing a movement, precedes our conscious awareness of a movement.

Another theory of consciousness states that the function of consciousness is to provide us with an executive summary of our current situation. The global workspace theory states that consciousness facilitates flexible, context-driven behaviour and that consciousness requires interactions between a broad range of brain areas (e.g: consciousness is needed to determine the mental state of others and this is highly context-driven).

Attention and consciousness share the property of involving the selection of particular information above other information. In attention, the selected information receives deeper processing and in consciousness, the selected information receives privileged access to the stage of our mental life. There are different types of consciousness:

1. Phenomenal consciousness
   This includes the experiential properties of sensations, feelings and perceptions. It is experience.
2. Access consciousness
   This includes representations that are broadcast for use in reasoning and control of action and can be reported. It is the mental life.

The left hemisphere of the brain is responsible for language. People with a split-brain cannot talk about what they see in their left visual field, but they will be able to use their hand to point at the object. They will not know the reason for this, as language is produced in the left hemisphere. Blindsight is a condition in which people have damage to the primary visual cortex which has the effect that people cannot see anymore, although their eyes are functioning properly. Although they cannot consciously report seeing anything, they do respond in various ways to stimuli presented in this damaged visual field.

The neural correlates of consciousness are used to differentiate the empirical approach of studying consciousness with the philosophical approach. Binocular rivalry arises when different images are presented simultaneously to the two eyes and results in experiencing seeing one image and then the other alternatively. The visible image dominates the invisible one in consciousness.

The case of H.M demonstrates three important aspects of long-term memory processes:

1. Long-term memory processes are not distributed throughout the brain.
2. Long-term memory encompasses a number of different abilities.
3. Memory is separable from language, perceptual and other cognitive functions.

Amnesia refers to a pattern of memory loss affecting elements of long-term memory, while short-term memory remains intact. It is sometimes also called the amnesic syndrome. Amnesia has a number of general characteristics:

1. Short-term memory is intact
2. Memory for language and concepts is intact
3. There is severe and lasting anterograde amnesia: memory for events after the onset of amnesia will be impaired.
4. There will be retrograde amnesia, the patient will have a loss of memory for events prior to the onset of amnesia.
5. Skill learning, conditioning and priming will be unaffected.

Ribot’s law states that recently formed memories are more susceptible to impairment than are older memories. The Wechsler Memory Scale is a widely used neurocognitive assessment that measures visual memory, auditory memory and working memory. There are several causes for amnesia, such as brain surgery, infections, head injuries, a stroke or Korsakoff’s syndrome, in which a thiamine (vitamin B1) deficiency causes brain damage.

James made the difference between primary and secondary memory. Secondary memory is long-term memory. Verbal learning refers to the area of experimental psychology concerned with how we learn and remember language-based items. There is a distinction in long-term memory between the following to long-term memory types:

1. Non-declarative memory (implicit memory)
   This is the memory that is not accessed consciously and that we are not able to report verbally. It includes memory which benefits from previous experience but without our awareness of that experience.
2. Declarative memory (explicit memory)
   This is the memory that involves conscious recollection of memories such as events, facts, people and places.

There are three types of recollection of information from the memory:

1. Free recall
   Participants in a task recall the information in any order, without hints or clues to recall.
2. Cued recall
   Participants in a task recall the information and are given a hint to aid the recall.
3. Recognition
   Participants must verify if an item is a target.

Tulving proposed a distinction within declarative memory. The distinction can also be seen as a difference between remembering and knowing.

1. Episodic memory
   This is the memory for events, experiences and episodes (e.g: yesterday was a good day).
2. Semantic memory
   This is the memory for facts and knowledge about the world (e.g: Paris is the capital of France).

There are different types of non-declarative memory, all showing implicit memory:

1. Procedural memory
   This includes skill learning. It is closely associated with motor performance, but cognitive skills and some perceptual learning skills are also aspects of procedural memory. Focussing our attention on a skill can disrupt the processes involved and performance can suffer. This is also called paralysis by analysis or ‘choking’. Procedural memory is generally preserved in patients with amnesia.
2. Habit learning
   This refers to memory acquired over time through repeated associations between stimuli and responses. One set of tasks that have been used to investigate habit learning in the absence of input from declarative memory involves probabilistic classification learning. This involves learning a set of associations that cannot be readily memorized and information from across many trials must be used to complete the task.
3. Priming
   This refers to an implicit memory effect whereby exposure to a stimulus affects a subsequent response (e.g: the cow drinks milk). Conceptual priming tasks include category exemplar tasks. These tasks are those where participants are given category names one by one and are asked to generate exemplars for each. Some categories will have been encountered during an earlier stage.

Tulving notes three key properties of episodic memory. It is associated with our subjective sense of time, there is a connection to the self and the mental time travel is associated with a special kind of conscious awareness called autonoetic consciousness. Autonoetic consciousness allows humans to use memory to relive past events and imagine ourselves in the future, from a self-perspective.

Memory is constructive and when we recall our past experiences, we reconstruct the event in our minds, using information gained before, after and at the time of the event itself. Schemas are organized memory structures that allow us to apply past experience to novel situations so as to guide behaviour. Schemas produce expectations that reduce the ambiguity of new situations, although these expectations an lead to erroneous judgements. The adaptive function of memory is using the cognitive functions to focus on the aspects that contribute to thinking about the future. The memory that allows us to keep track of plans and carry out intended actions is called prospective memory. Prospective memory allows us to remember to perform certain actions. Prospective memory lapses often involve a failure to interrupt habitual routines. Action slips involve an action being completed when it was not intended (e.g: sugar in the teapot instead of the pot).

There are event-based and time-based prospective memory tasks. Event-based memory may be triggered by a particular cue. Time-based memory may be triggered by a particular time. Pulses are intentions that are time-locked (e.g: dinner has to be taken out of the oven in 30 minutes). The intentions must be carried out at a particular time. Steps are intentions that have a wider time frame in which they can occur (e.g: I have to call John some time this week). There is evidence that obsessive-compulsive behaviours arise from a deficit in prospective memory.

Autobiographical memories are episodic memories for personally experienced events in a person’s life. False memories are inaccurate recollections of events that did not occur or distortions of events that did occur. Imagining false events increases the likelihood that they will be recalled. This is called the imagination inflation, the strengthening of a false memory through repeated retrieval. Demand characteristics are the aspects of a research study which convey hypotheses or aims to the participants and may thereby shape performance. Disputed memories happen with siblings that are close in age, where the ownership of the memory is not clear. The siblings both believe that they were the protagonist of the memory.

Déjà vu is a type of illusion of autobiographical memory. It is the knowledge that a situation could not have been experienced, combined with the feeling that it has. There are three possible mechanisms for déjà vu:

1. Split perception
   We get a brief glimpse of a visual scene before becoming fully aware of the scene.
2. Implicit memory
   We have already experienced the scene or part thereof, but it has been stored such that only a feeling of familiarity is elicited when we re-encounter it.
3. Gestalt familiarity
   The scene we encounter closely resembles a scene we have encountered in the past.

Semantic memory is our store of general knowledge about the world. Metamemory is the ability to monitor and inspect the content of memory. It allows us to know whether we know something (e.g: the likelihood that we know something, which we cannot currently recall). The long-lasting store of knowledge was referred to by Bahrick as the permastore. The permastore involves the long-term retention of content that has been acquired and relearned over a period of time, even if rarely used thereafter (e.g: people remember Spanish words learned in high school up to 50 years after high school).

Concepts are mental representations of classes of items (e.g: dogs). Imagery is the mental representation of sensory properties of objects, experiences as like perceiving the object but with less vividness than in reality. There are different approaches to concepts.

The definitional approach looks at the definition of an object in order to form a concept. The concepts are based on the definition of the word. This approach looks for well-defined concepts. The main problem with this approach is that most everyday concepts are not so well defined.

The prototype approach looks at the most typical of a ‘family’ of concepts which represents the other concepts. Typicality is the extent to which an object is representative of a category. Members of a category share a family resemblance. This is the tendency for members of a category to be similar to each other but without having any characteristic in common to all of them. The more an item of a category has a family resemblance, the more typical it is deemed to be. The item in a category that has the highest overall family resemblance to the other category members is the prototype of that category. The prototype is an ideal example that best represents a category. The prototype does not have to exist. It is the statistically average member of the category. Categories and concepts typically form into hierarchies. Lower level categories are nested within higher-level categories. The mid-level category is the basic level of categorization. These are categories formed of items that are highly similar and at an intermediate level in a concept hierarchy. The problems with the prototype approach are that some objects are more readily categorized as something, even though it looks more like a different prototype and some things don’t have prototypes, such as rules or beliefs. Ad hoc categories are categories formed of items that meet a given goal. The family resemblance does not work for ad hoc categories.

The exemplar-based approach proposes that categories are represented purely by stored examples or instances and each example Is linked to the category name. If a new item’s similarity to already known items is above a certain threshold it becomes a member of that category. The exemplar approach readily represents variability within a category, which the prototype approach does not.

The theory/knowledge-based approach uses knowledge in order to categorize items. It includes causal information and causal knowledge is used in order to categorize items.

Essentialism is the view that all members of a given category share some key property. This does not have to be something that can be seen from the outside (e.g: a bird without feathers is still a bird). Barton argued that there are different types of concepts which may have different forms of essential properties:

1. Nominal concepts
   These are concepts which have clear definitions. The essential part is easy to locate here (e.g: triangles are three-sided closed figures).
2. Natural kind concepts
   These are concepts that are commonly identified as naturally occurring (e.g: cats, rainy days).
3. Artefact concepts
   These are concepts that are human-made objects and are generally defined in terms of their function (e.g: laptops).

Barton asked participants to imagine three types of transformation of natural kind and artefact categories: functional, physical and molecular. The artefact concepts were more prone to changing categories when functional changes occurred and the natural kind concepts were more prone to changing categories when molecular changes occurred. The sensory-functional distinction states that for some categories perceptual features were critical and for others functional characteristics were critical.

Barsalou proposed the view that concepts are grounded in modality-specific systems for perception, action and introspection with no need for amodal abstract symbols. This view is called grounded representations, which are representations that involve sensory-motor codes. Amodal representations are representations that are abstract and do not involve any sensory codes. The role of simulation, the extended re-enactment of previous experience is important in cognition according to Barsalou. Re-enactment is the partial repetition of the internal processes involved in previous perceptions or actions. The larger the property that a participant has to imagine, the slower the verification. Switching from one modality to another also slows verification. The brain areas that are active when objects are perceived are also active when the object’s name is being said.

Imagery is imagining a certain concept and see it in the mind’s eye. It replicates actual experiences, but it is less vivid. Visuospatial processing is the mental manipulation of visual or spatial information. Imagery and perception draw on the same mental and neural resources. The self-reported vividness of imagined items reduces because of a tapping task, but not because of a counting task. The further away some imagined things are, the longer the response time is. Images encode relative distance with some accuracy. Difference judgements between symbolically presented items are made more easily for items that are indeed widely different in reality is known as the symbolic difference effect. Mentally rotating items takes about as long as really rotating the physical item.

Pylyshyn criticised the scanning of mental images because it could be very prone to bias. He argues that the experience of imagery has no real causal role in cognition. It is a by-product of the machine’s operation according to him but does not contribute to the machine’s functioning. The Gestalt theory of perception states that ambiguous figures cause unstable representation that resolves themselves into alternating representations. Images are not exactly like pictures but rather always have some fixed interpretation on which they are based.