Week 1 Flashcards
Bottom-up processing
Directly influenced by environmental stimuli.
Top-down processing
Influenced by internal subject factors.
Stimulus processing that is influenced by factors such as the individual’s past experience and expectations.
Ventral
Inferior, or towards the bottom of the brain.
BOLD
Blood oxygen level-dependent contrast; this is the signal measured by functional magnetic resonance imaging (fMRI)
Case series study
Study in which several patients with similar cognitive impairments are tested; this allows consideration of individual data and of variation across individuals
Sulcus
A groove or furrow in the surface of the brain
Sydrome
The notion that symptoms that often co-occur have a common origin.
Transcranial magnetic stimulation (TMS)
A technique in which magnetic pulses briefly disrupt the functioning of a given brain area. It is often claimed that it creates a short-lived “lesion”.
More accurately, TMS causes interference when the brain area to which it is applied is involved in task processing as well as activity produced by the applied stimulation.
A cap is placed on the head
Cognitive neuroscience
an approach that aims to understand human cognition by combining information from behaviour and the brain
Cognitive psychology
An approach that aims to understand human cognition by the study of behaviour; a broader definition also includes the study of brain activity and structure
Cognitive architecture
Comprehensive framework for understanding human cognition in the form of a computer program.
Connectionist models
Models in computational cognitive science consisting of interconnected networks of simple units; the networks exhibit learning through experience and specific items of knowledge are distributed across numerous units.
Converging operations
An approach in which several methods with different strengths and limitations are used to address a given issue.
Computational model
This involves constructing computer programs that simulate or mimic human cognitive processes.
Lateral
Situated at the side of the brain.
Lesions
Structural alterations within the brain caused by disease or injury.
Magneto-encephalography (MEG)
A non-invasive brain-scanning technique based on recording the magnetic fields generated by brain activity.
MEG has excellent temporal resolution (at the millisecond level) and often has very good spatial resolution as well.
Implacable experimenter
The situation in experimental research in which the experimenter’s behaviour is uninfluenced by the participant’s behaviour.
Meta-analysis
A form of statistical analysis based on combining the findings from numerous studies on a given issue.
Parallel processing
Processing in which two or more cognitive processes occur at the same time.
Medial
Situated in the middle of the brain.
Paradigm specificity
This occurs when the findings with a given experimental task or paradigm are not obtained even when apparently very similar tasks or paradigms are used.
Serial processing
Processing in which one process is completed before the next one starts.
Single unit recording
An invasive technique for studying brain function, permitting the study of activity in single neurons.
Artificial intelligence
This involves developing computer programs that produce intelligent outcomes.
Association
The finding that certain symptoms or performance impairments are consistently found together in numerous brain-damaged patients.
Back-propagation
Learning mechanism in connectionist models based on comparing actual responses to correct ones.
Domain specificity
The notion that a given module responds selectively to certain types of stimuli (e.g., faces) but not others.
Dorsal
Superior, or towards the top of the brain.
Dissociation
As applied to brain-damaged patients, intact performance on one task but severely impaired performance on a different task.
Double dissociation
The finding that some brain-damaged individuals have intact performance on one task but poor performance on another task, whereas other individuals exhibit the opposite pattern.
Ecological validity
The applicability (or otherwise) of the findings of laboratory studies to everyday settings.
Electroencephalography (EEG)
Recording the brain’s electrical potentials through a series of scalp electrodes.
Event-related functional magnetic resonance imaging (efMRI)
This is a form of functional magnetic resonance imaging in which patterns of brain activity associated with specific events (e.g., correct vs. incorrect responses on a memory test) are compared.
Event-related potentials (ERPs)
The pattern of electroencephalograph (EEG) activity obtained by averaging the brain responses to the same stimulus (or very similar stimuli) presented repeatedly.
Functional magnetic resonance imaging (fMRI)
A technique based on imaging blood oxygenation using an MRI machine; it provides information about the location and time course of brain processes.
BOLD
Functional specialisation
The assumption that each brain area or region is specialised for a specific function (e.g., colour processing, face processing).
Gyri
Prominent elevated areas or ridges on the brain’s surface (“gyrus” is the singular).
Plasticity
Changes in brain structure and function dependent on experience that affect behaviour.
Positron emission tomography (PET)
A brain-scanning technique based on the detection of positrons; it has reasonable spatial resolution but poor temporal resolution.
Detection of positrons
Regional blood flow
Posterior.
Towards the back of the brain.
Production rules
If … then” or condition-action rules in which the action is carried out whenever the appropriate condition is present.
Production systems
These consist of very large numbers of “if … then” production rules and a working memory containing information.
Reverse inference
As applied to functional neuroimaging, it involves arguing backwards from a pattern of brain activation to the presence of a given cognitive process.
rostral
Anterior, or towards the front of the brain
Repetitive transcranial magnetic stimulation (rTMS)
The administration of transcranial magnetic stimulation several times in rapid succession.
Which ERP component has been used as a measure of the time to detect a semantic mismatch by researchers such as Hagoort et al. (2004)?
N400
A processor in the cognitive system that functions in an independent/separate fashion is termed a:
A module.
A unit in a connectionist network will produce an output when:
The weighted sum of all inputs exceeds a threshold.
The term that describes how precisely a technique can identify where in the brain a task is being performed is:
Spatial resolution
Which technique was famously used by Hubel and Wiesel (1962, 1979) to investigate visual processes in cats and monkeys?
Single cell recording
Averaging together time-locked portions of recordings of the brain’s electrical activity, to produce a single waveform, produces:
Event-related potentials
PET scans are used to detect changes in:
Regional blood flow
Which of the following techniques can only be applied to brain areas lying just beneath the skull but not to areas overlying muscle?
TMS
The technique in which a superconducting quantum interference device (SQUID) is used to measure brain activity is:
MEG
Which of the following techniques allows us to make the most confident CAUSAL statements?
TMS
When we find similar results using several different brain-imaging techniques, we say that we have:
Converging operations.
Reaction times and errors
The information processing approach assumes that information is processed at each step between registering a stimulus and generating a response—so that reaction times can provide insight into how information is processed.
Reaction time is the length of time that elapses from the onset of a stimulus until the response i.e. the processing. Many factors can affect reaction times, such as how many steps of processing need to take place and how quickly different systems process information. Different types of processing and different types of information processing architecture may additionally produce different types of errors.
Cognitive psychology .
Cognitive psychologists assume that top-down and bottom-up processes are both involved in the performance of cognitive tasks. These processes can be serial or parallel. Various methods (e.g., latent-variable analysis) have been used to address the task impurity problem and to identify the processes within cognitive tasks. In spite of the enormous contribution made by cognitive psychology, it sometimes lacks ecological validity, suffers from paradigm specificity and possesses theoretical vagueness.
Cognitive neuropsychology
Cognitive neuropsychology is based on various assumptions including modularity, anatomical modularity, uniformity of functional architecture and subtractivity. Double dissociations provide reasonable (but not definitive) evidence for separate modules or systems. The case-study approach is generally (but not always) more informative than the single-case approach. Cognitive neuropsychology is limited because patients can develop compensatory strategies, because it de-emphasises findings in cognitive neuroscience, because it underestimates integrated brain functioning and because the brain damage is often so extensive it is hard to interpret the findings.
Cognitive neuroscience: the brain in action
Cognitive neuroscientists study the brain as well as behaviour using techniques varying in spatial and temporal resolution. Functional neuroimaging techniques provide basically correlational evidence, but TMS can indicate that a given brain area is necessarily involved in a particular cognitive function. The richness of the data obtained from neuroimaging studies is so great that functional specialisation and brain integration can both be assessed. Cognitive neuroscience is a flexible and potentially self-correcting approach. However, findings are sometimes over-interpreted. More research is needed into possible problems with ecological validity in fMRI studies.
Computational cognitive science
Cognitive scientists develop computational models to understand human cognition. Connectionist networks make use of elementary units or nodes connected together. They can learn using rules such as backpropagation. Production systems consist of production or “If . . . then” rules. ACT-R is one of the most developed theories based on production systems. Computational models have increased in scope to provide detailed theoretical accounts of findings from cognitive neuroscience and cognitive neuropsychology. They have shown progress via the use of nested incremental modelling. Computational models are often hard to falsify and they generally de-emphasise motivational and emotional factors.
Comparisons of different approaches .
The major approaches are increasingly used in combination. Each approach has its own strengths and limitations, which makes it useful to use converging operations. When two approaches produce the same findings, this is stronger evidence than can be obtained from a single approach on its own. If two approaches produce different findings, this indicates additional research is needed to understand what is happening.
