Cognitive Psychology bundle

IBP Cognitive Psychology

IBP Cognitive Psychology- Introduction-ch1

IBP: Introduction to cognitive psychology

Chapter 1: Introduction

Cognitive psychology: the study of the way in which the brain processes information

Stages of cognitive processing:

Perception: analysis of the information taken in by the sense organs
Learning and memory storage: recording the input received
Retrieval: being able to recall stored information
Thinking: in addition to recalling, it involves the rearrangement and manipulation of stored information to make it ft in with a new problem or task

Approaches to the study of cognition:

Experimental cognitive psychology: involves the use of psychological experiments on human subjects to investigate the ways in which they perceive, learn, remember or think
Computer modelling of cognitive processes: the simulation of human cognitive processes by computer. Often used as a method of testing the feasibility of an information processing mechanism
Cognitive neuropsychology: the study of the brain activities underlying cognitive processes, often by investigating cognitive impairment in brain-damaged patients
Cognitive neuroscience: the investigation of human cognition by relating it to brain structure and function, normally obtained from brain imaging techniques

Early cognitive psychology:

Among the first to investigate mental processes were the Gestalt psychologists in Germany, and the British psychologist Frederick Bartlett
- Gestalt psychology: an approach to psychology which emphasized the way in which the components of perceptual input became grouped and integrated into patterns and whole figures
The schema theory proposed by Bartlett states that all new perceptual input is analyzed by comparing it with items which are already in our memory store, such as shapes and sounds which are familiar from past experience. These items are referred to as ‘schemas’
Inspired by the schema theory, Neisser identified two main types of input processing, known as top-down and bottom-up processing
- Top-down: Processing which makes use of stored knowledge and schemas to interpret an incoming stimulus
- Bottom-up: Processing which is directed by information contained within the stimulus

Computer models of information processing:

Computer modelling has provided models of human cognition based on information-processing principles
Selfridge and Neisser devised a computer system which could identify shapes and patterns by means of feature detectors
Limited-capacity processor: people have difficulty in attending to two separate inputs at the same time

The structure and function of the brain:

The frontal lobes: include the motor region of the cortex, which controls movement.
- Damage to this area is likely to cause problems with the control of movement, or even paralysis.
- Broca’s area: also in frontal lobe, controls the production of speech, and it is normally in the left hemisphere of the brain
- Other parts of the frontal lobes are involved in the central executive system which controls conscious mental processes such as the making of conscious decisions.
The occipital lobes: concerned with the processing of visual input, and damage to the occipital lobes may impair visual perception.
The parietal lobes: also largely concerned with perception.
- They contain the somatic sensory cortex, which receives tactile input from the skin as well as feedback from the muscles and internal organs. This region is also important in the perception of pain.
The temporal lobes: known to be particularly concerned with memory.
- Temporal lobe lesions are often associated with severe amnesia.
- The temporal lobes also include the main auditory area of the cortex, and a language center known as Wernicke’s area, which is particularly concerned with memory for language and the
- Either short-term memory or long-term memory can be separately impaired while the other remains intact. This is known as a double dissociation

Information storage in the brain:

Cell assembly: A group of cells which have become linked to one another to form a single functional network. Proposed by Hebb as a possible biological mechanism underlying the representation and storage of a memory trace.
Long-term potentiation: a lasting change in synaptic resistance following the application of electrical stimulation to living brain tissue. Possibly one of the biological mechanisms underlying the learning process.

Automatic vs controlled processing:

Controlled processing: processing that is under conscious control, and which is a relatively slow, voluntary process
Automatic cognitive processes: not under conscious control, not voluntary
- Example: reading is automatic (“do not read this message” -impossible for practiced readers)
- Blindsight: The ability of some functionally blind patients to detect visual stimuli at an unconscious level, despite having no conscious awareness of seeing them

Resources:

An Introduction to Cognitive Psychology: Processes and Disorders 3rd edition (Groome, David)

IBP Cognitive Psychology- Attention-ch3

IBP: Introduction to cognitive psychology

Chapter 3: Attention

Attention: systems involved in the selection and prioritization of information processing, and it is intimately linked with perception and memory

What is attention for?

Selection for perception: detecting and selecting what to process from a visual display
Selection for action: detecting and selecting which response or action to make

Capture: The ability of one source of information to take processing priority from another

For example: the sudden onset of novel information within a modality such as an apple falling may interrupt ongoing attentional processing

Binding problem: The problem of how different properties of an item are correctly put together, or bound, into the correct combination

For example, if there is a red colour in the shape of a circle on the left, and a green colour in the shape of a square on the right, the colour, shape and position of each property must be correctly bound together

Controlled attention: Attention processing that is under conscious, intentional control. It requires attentional resources, or capacity, and is subject to interference

Is said to operate top-down because it is influenced by a goal we have set ourselves such as searching for something in particular
The source of control is endogenous, it comes from within us

Exogenous attention: Attention that is drawn automatically to a stimulus without the intention of the participant.

Stroop effect: The effect of a well-learned response to a stimulus slowing the ability to make the less well-learned response; for example, naming the ink colour of a colour word

Slips of action: Errors in carrying out sequences of actions, e.g. where a step in the sequence is omitted, or an appropriate action is made, but to the wrong object

Where is the limit?

When two stimuli are presented in rapid succession and the participant must make a fast response to both, response time (RT) to the second stimulus depends upon the time interval between the presentation of the two stimuli
The psychological refractory period (PRP): The delay in responding to the second stimulus
Bottleneck: The point in processing where parallel processing becomes serial
- processing of the second stimulus must wait until processing of the first stimulus is completed
Shadowing: Used in a dichotic listening task in which participants must repeat aloud the to-be-attended message and ignore the other message
Early selection: Selective attention that operates on the physical information available from early perceptual analysis

Breakthrough: The ability of information to capture conscious awareness despite being unattended

Usually used with respect to the unattended channel in dichotic listening experiments
Late selection: An account of selective processing where attention operates after all stimuli have been analysed for their semantic properties

Subliminal priming effects:

Galvanic skin response: A measurable change in the electrical conductivity of the skin when emotionally significant stimuli are presented. Often used to detect the unconscious processing of stimuli.
Subliminal: Below the threshold for conscious awareness or confident report
Masking: The disruptive effect of an auditory or visual pattern that is presented immediately after an auditory or visual stimulus. This is backward masking, but there are other types of masking

Negative priming: the finding that the response time to categorise a target item will be slowed if that same item has been presented on the previous trial as a distractor item which was to be ignored

Directing the spotlight of visual attention:

When we search the visual environment, we can make an eye movement, or saccade, to direct the focus of visual attention to a location
- This movement is overt (plainly apparent)
- Usually where we are attending coincides with where we are looking, because when we fixate on an item the fovea is directed to the area of interest
We may also attend to something ‘out of the corner of our eye’, without making an eye movement
- In this case you are intentionally directing, or orienting, your attention in an endogenous way, using top-down control. This type of orientation of attention is covert (hidden)
Gaze-mediated orienting: An exogenous shift of attention following the direction of gaze of a face presented at fixation

Cross-modal cueing of attention:

Modality: The processing system specific to one of the senses, such as vision, hearing or touch
Experiments on attention have investigated cross-modal effects on orienting spatial attention, for example between seeing and hearing
Selective filtering: An attentional task that requires selection of one source of information for further processing and report in a difficult task such as dichotic listening or visual search for a conjunction of properties
Selective set: An attentional task requiring detection of a target from a small set of possibilities.

Visual search:

Conjunction: a term from feature integration theory of attention that describes a target defined by at least two separable features, such as a red O amongst green O’s and red T’s
When a target is defned by just one distinctive feature, that feature is available on its feature map and calls attention to itself, resulting in pop-out
- Pop-out: an object will pop out from a display if it is detected in parallel and is different from all other items in the display

Attention and cognitive control:

A routine behaviour requires little monitoring but the price paid for this low level of control is that we sometimes make a slip of action (e.g.: putting shaving cream on tooth brush)

Schema activation takes place unconsciously and is controlled by an automatic system, called the contention scheduler that allows automatic actions to run smoothly
Frontal lobe syndrome: The pattern of deficits exhibited by patients with damage to the frontal lobes. These patients are distractible, have difficulty setting, maintaining and changing behavioural goals, and are poor at planning sequences of actions

Combining tasks:

Sometimes we have to stop doing one task because it is impossible to do them both without making a mistake
Attentional blink (AB): the phenomenon that the second of two targets cannot be detected when it appears close in time to the first.

Experiment comparing consistent and varied mapping:

In the consistent mapping condition, targets were always consonants and distractors were always digits. Results showed that with consistent mapping, search time was virtually independent of both the number of items in the memory set and the number of items in the display, as if search is taking place in parallel – refecting ‘automatic processing’
In the varied mapping condition,both the memory set and distractors were a mixture of letters and digits. In the varied mapping condition, participants were slower to detect targets and RTs increased with the number of distractors in the display – refecting attention demanding ‘controlled processing’

Production system: A computational model based on numerous IF–THEN condition–action rules. IF the rule is represented in working memory THEN the production stored in long-term memory is applied

Procedural knowledge: Unconscious knowledge about how to do something

Resources:

An Introduction to Cognitive Psychology: Processes and Disorders 3rd edition (Groome, David)

IBP Cognitive Psychology- Perception-ch2

IBP Cognitive Psychology - Long-term memory (ch6)

IBP: Introduction to cognitive psychology

Chapter 6: Long-term memory

Long-term memory: the mechanism which enables us to store information and experiences in a lasting fashion, for possible retrieval at some point in the future.

Memory process:

Input stage: where newly perceived information is being learned or encoded
Storage stage: where the information is held in preparation for some future occasion
Output stage: where the information is retrieved from storage

The first memory experiments:

Ebbinghaus and the forgetting curve: a list of non-sense syllables would be learned, and then retested after a certain retention interval, where scores were plotted as a ’forgetting curve’
- Forgetting curve: memories tend to dissipate over a period of time
Interference and decay: theories on why memories dissipate over time
- Decay: memories fade away with the passage of time, regardless of other input.
- Interference: memories are actively disrupted by the influence of some other inpu
- Retroactive interference: memory scores for the learning of one list are considerably reduced by the subsequent learning of a second list.
‘Decay with disuse’ theory: Thorndike suggested that decay only affects memory traces which remain unused for a long period
Retrieval-induced forgetting: there may be inhibitory mechanisms at work in the brain, which actively suppress unretrieved memories

Meaning, knowledge and schemas:

Bartlett’s schema theory: we perceive and encode information into our memories in terms of our past experience
- Eyewitness testimony for a crime or accident can be distorted by subsequent events as well as by previous knowledge
Scripts (a form of schemas): provide us with a general framework and help us understand events and the behavior of others
Mnemonic: a technique or strategy used for improving the memorability of items, e.g. by adding meaningful associations

Input processing and encoding

Levels of processing theory: the processing of new perceptual input involves the extraction of information at a series of levels of increasing depth of analysis, with more information being extracted at each new level
An orienting task: essentially a set of instructions which are intended to direct the subject towards a certain type of processing
- Example: Acoustic orienting task: “does this word rhyme with bat?”
- Semantic orienting task: does this word fit the sentence “the cat sat on the…”
- Structural orienting task: “Is the word in block capitals?”
Revised levels of processing theory: structural, acoustic and semantic forms of processing are assumed to take place simultaneously and in parallel rather than in sequence
Elaborative and maintenance rehearsal:
- Rehearsal is commonly employed as a method of retaining a piece of information
- Elaborative rehearsal: the formation of associative connections with other memory traces, and this occurs most effectively where meaningful associations can be found (t assists relational processing)
- Maintenance rehearsal: input is merely repeated without further processing (assists item-specific processing)

Retrieval and retrieval cues

Two main ways of testing retrieval: recall and recognition
In recognition test, the original test material is presented again at the retrieval stage, whereas in a recall test they are not
Spontaneous recall: requires the generation of items from memory without any help
Cued recall: retrieval cues are provided to remind us of the items to be recalled
Recognition: the original test items are re-presented at the retrieval stage
Generate and recognize theory: explains that recall and recognition are fundamentally different processes, and that recall involves an extra stage – so recall is more difficult than recognition
Retrieval success is closely related to the number and quality of retrieval cues available
Encoding specificity principle: retrieval cues will only be successful if they contain some of the same specific information which was encoded with the original input
- memories are more easily retrieved if external conditions at the time of retrieval are similar to those that existed when the memory was stored
Chance of retrieving a memory trace depends on the amount of feature overlap between input and retrieval information, which is the extent to which features of the trace stored at input match those available at retrieval
Transfer-appropriate processing: the most effective type of input processing will be whatever offers the closest match with the available retrieval cues
Context-dependent memory: revisiting or reinstating an earlier context serves as a retrieval cue
State-dependent memory: retrieval can be assisted by the reinstatement of a particular mental state at retrieval which was also present at the learning stage
Memory can be mood-dependent too

Memory systems

Tulving: Long-term memory contains separate memory systems
- Episodic memory: our memory for events and episodes in our own lives
- Semantic memory: our general knowledge store
Mandler: recognition involves two different retrieval processes
- Familiarity: deciding whether or not an item has ever been encountered before (controlled)
- Recollection: when and where the item was encountered (automatic)
Explicit memory: conscious memory
Implicit memory: unconscious memory, whose influence can be detected by some indirect test of task performance

Retrieval practice and retrieval inhibition

Testing effect: actively testing a memory improves its subsequent retrievability
New theory of disuse: a memory trace which is not retrieved will eventually become inaccessible, whereas a frequently retrieved memory trace will be strengthened and becomes easier to retrieve in the future
Retrieval-induced forgetting: practicing the retrieval of a memory trace not only strengthens that trace, it also inhibits the retrieval of rival memory traces
- Only occurs as a consequence of actually retrieving an item, and not from passive study such as re-reading test items
Phobic responses may be strengthened by repeated retrieval, which might also suppress other less distressing memory responses to the same stimulus
Reconsolidation: the retrieval of a stored memory presents an opportunity to make that memory stronger or weaker before it is put back into storage

Memory in everyday life

Ecological validity: the extent to which the conditions of a research experiment resemble those encountered in real-life settings
Most people tend to recall more autobiographical information from recent years than from the distant past
‘Reminiscence bump’: older people tend to recall an increased amount from their early adult years
‘Infantile amnesia’: most people remember nothing at all from the first two or three years of their lives
Flashbulb memory: a subject’s recollection of details of what they were doing at the time of some major news event or dramatic incident (e.g.: 9/11)
Eyewitnesses are susceptible to reconstructive errors based on previous knowledge and expectations, but also on information acquired after the event
- They should be questioned as soon as possible after the event
- Should not be taken at face value, these memories are not 100% reliable

Resources: An Introduction to Cognitive Psychology: Processes and Disorders 3rd edition (Groome, David)

IBP Cognitive Psychology- Disorders in perception and attention-ch4

IBP: Introduction to cognitive psychology

Chapter 4: Disorders in perception and attention

Synaesthesia: A condition in which individuals presented with sensory input of one modality consistently and automatically experience a sensory event in a different modality

For example: seeing colour on hearing musical notes
Illustration of how a synaesthete would see numbers compared to how non-synaesthetes see them: http://www.scielo.br/img/revistas/dn/v9n1//1980-5764-dn-09-01-00016-gf02.jpg
Inducers: The triggers of synaesthetic experience
Synaesthesia is usually a unidirectional process; the letter A may give rise to the perception of red but not vice versa.
Synaesthetes are usually highly consistent – e.g.: Monday is always the smell of cheese
Even when blind, synaesthetes see colours on hearing or thinking about letters or numbers
Brain-imaging studies of synaesthesia:
- Functional magnetic resonance imaging (fMRI)
- Electroencephalography (EEG)
- Transcranial magnetic stimulation (TMS)
Most neural accounts of synaesthesia are based on the idea that regions related to the perception of the inducer (e.g. letter reading) become linked to regions related to the experience (e.g. colour perception) such that the occurrence of the former automatically activates the latter
Certain hallucinogenic drugs such as LSD can induce temporary synaesthetic experiences in non-synaesthetes, suggesting that the pathways connecting the different sensory modules exist in normal brains

Blinsight: the ability to respond to visual stimuli without consciously perceiving them

Scotomata (plural of scotoma): The areas of blindness
Perhaps blindsight patients are responding to light which was reflected from the object onto the functioning areas of the visual field
- This doesn’t explain, however, how the patients can distinguish between X’s and O’s
While patients do not have any conscious experience of perception, at some level below that accessible to introspection, the visual system does have access to information about the outside world.
The most widely accepted explanation for blindsight is that we have two separate visual systems, one primitive non-striate system and a more advanced striate system
- The primitive non-striate system: might be sensitive to movement, speed, and other potentially important characteristics of a stimulus without giving rise to conscious perception
- Striate visual system: conscious perception. Perhaps it has evolved to allow the identification of an object, whereas the non-striate system has evolved to allow the localisation of that object in space

Unilateral special neglect: A difficulty in noticing or acting on information from one side of space typically caused by a brain lesion to the opposite hemisphere (e.g. right-hemisphere damage producing lack of awareness for information on the left)

The main cause of unilateral spatial neglect (USN) is stroke, an interruption to the brain’s blood supply
Patients with USN may fail to notice object in ‘clear view’ on the left, ignore people approaching from the left, eat food only from the right side of the plate, or wash and dress only the right side of their own body.
The most obvious difference between USN and visual field loss is that the former can exert an influence across modalities whilst the later is restricted to vision.
USN varies in different spatial frameworks, it may occur for objects to the left side of the body (egocentric space) or for objects on the left side of something (like a page or room) regardless of where this is in relation to the person (allocentric space)
A common clinical observation is that patients with persistent (chronic) left neglect tend to be drowsy and appear to have difficulty remaining focused on all sorts of tasks.
Alerting patients with a loud tone temporarily but dramatically reduced or reversed their neglect, even when the tone was to their right. Stimulating medication or thoughts can cause similar gains.
An important factor influencing whether a given stimulus will win the competition for conscious awareness is therefore the state of activity relevant to that stimulus across all levels of the system
- Within this framework it is easier to see how unilateral brain damage could have cascading effects reducing the likely awareness of different sorts of information in contralesional space

Visual agnosia: the failure to recognise objects that are seen

Apperceptive agnosia: patients have normal visual acuity with an inability to draw an object, to say whether two similar objects were the same or different, or even to describe the component parts of an object
Associative agnosia: someone suffering from associative agnosia would be able to draw an object, to match similar objects and be able to describe the component parts but they would be unable to recognise the objects they had just seen or drawn
Form agnosia: term for patients who are unable to discriminate between objects and are unable to copy line drawings of objects (apperceptive agnosia)
Integrative agnosia: refers to patients who can perceive the individual shapes and elements of objects but are unable to integrate these into a representation of the whole object (associative agnosia)

Prosopagnosia: An inability to recognise faces despite adequate visual acuity.

The fusiform area: has been shown to be a key structure in face and object processing, and numerous studies have shown that the fusiform gyrus contains an area dedicated to face processing called the fusiform face area (FFA). There is variability, however, in the location of this area across individuals.
Individuation: people with prosopagnosia are less able to recognize one specific item from other members of that class of item
Many patients with acquired prosopagnosia have bilateral lesions
Some prosopagnosic patients show evidence of covert recognition, that is, an indication that at some level their brains are discriminating between faces
- for example: showing differences in neural electrical responses (evoked potentials) produced by viewing familiar and unfamiliar faces
Congenital prosopagnosia: thought to be present from birth and was traditionally thought to occur without any apparent brain injury
Developmental prosopagnosia: thought to be a result of early neurological trauma that might be caused by accident or injury