WEEK 3 - Methods in Biological and Cognitive Psychology Flashcards
What did Bruce & Young propose in 1986?
that the human mind is turned to the analysis of faces and that the human face processing system has a set of differnents processing modules promoting different aspects of facial analysis
how does evidence suggest that faces are processed?
by neutral mechanisms that differ from those used to process other objects
what are the 6 lines of evidence that support how faces are processed by neutral mechanisms?
- Behavioural evidence
- Lesion studies
- High spatial resolution imaging techniques
- high temporal resolution imaging techniques
- high spatial AND temporal resolution imaging techniques
- brain stimulation techniques
what is an experiment?
where the experimenter/scientist does something and measures the consequences
what does it mean when something is correlated?
when it can be observed that there is a relationship between two things
what is the IV
independent variable. presumed to change in another varable, often manipulated by the researcher
what is the DV
the presumed effect or outcome. the variable that is measured by the researcher and influenced by the IV
what is causation?
a condition in which one event (the cause) generates another event (the effect)
what is a relationship condition?
where the cause (IV) must be related to the effect (DV)
what is a temporal order condition?
changes in the IV must precede changes in the TV
what does correlation fail to prove?
causation
what is the facial inversion effect?
A variety of types of judgements about faces are more difficult when faces are presented upside down. they imply orientation sensitive proceses that are specific to faces as opposed to other classes of objects
what is the question in regard to the Gilard Effect?
Does changing “shading” of the eye region influence accuracy in recognising faces?
what were the findings of Gilard effect?
that eyes with normal shading are important to recognition, but only when in the context of the overall facial feature arrangements
what does localising brain function mean?
different parts of the brain are responsible for different mental faculties
what happened in the High velocity rifle circa 1890?
small bullets that were fired could penetrate the skull and often exit it, leaving relatively small observable regions of brain damage.
in lesion studies, what does disassociation mean?
Brain damage is associated with impairments in a particular domain of cognitive functioning
in lesion studies, what does double-disassociation mean?
Where:
Person A is impaired in Task1 but not Task2
Person B is impaired in Task2 but not Task1
= stronger evidence for dissociable brain mechanisms
what does prosopagonsia mean?
Face blindness. Where people have brain damage that affect their ability to recognise faces
what parts of the brain are associated with prosopagnosia?
occipital-temporal regions
what are the problems with lesion studies?
- patients are rare
- damage is often not very circumscribed
- “plasticity”
what is involved in the High Spatial resolution brain mapping solution?
MRI and PET
what does PET stand for?
positron Emission Tomography.
what is PET
where the participant or patient is infused with radio-isotope. the radioactive decay can be used to measure cerebral blood flow that can show what part of the brain is busy. It also provides good spatial resolution (radioactivity)
What does MRI stand for?
Magnetic Resonance Imaging
what does paramagnetic man?
attracts to magnetic field
what does diagmatic mean?
repels magnetic field
what does BOLD imaging stand for?
Blood OXygen Level Depedent imaging
how does BOLD imaging work?
Hemoglobin is inserted into the blood stream and attaches itself to oxygen molecules.
what is the haemodynamic response?
the neuroal fire triggers change the oxygenated bloodflow to the active brain area
what is deoxyhaemoglobin?
a paragmagnetic
what is Oxyheimoglobin?
diagmatic
what does fMRI reveal?
patches or cortex in the fusiform gyrus that show increase BOLD response to faces
what is the area that shows increased BOLD in response to faces?
Fusiform Face Area (FFA)
what does the Occipital Face Area respond to?
facial features/parts of faces
what are the two other brain regions that are activated by viewing faces?
occipital face area and the STS face area
do dynamic and static face emotion stimuli invoke different brain mechanisms?
the STS is activated to actual and implied facial motion
what does STS stand for?
Superior Temporal Sulcus
what does high sparial resolution techniques allow?
allows usto identify brain areas whose activation is correlated with particulat types of cognitive operation
what does EEG stand for?
Electroencephalogaphy
what is EEG
real-time millisecond resolution of brain activity.
what are the limitations of EEG?
poor spatial resolution due to spatial smearing. does not look as glamorous as this in real-life
what are high temporal techniches?
where EEG and MEG activity can be recorded as voltage or magnetic fluctuations at/close to the scalp and reflects the summed effects of ionic current flow with a great many neurons
what is EEG a result of?
the combined activity of a large number of similarly orientated pyamidal neurons
What does EEG require to work?
synchronous actibity across groups of cells
what does EEG reflect
summed post synaptic activity of large cell ensembles
what does ERP stand for?
Event related potential
how is the EEG signal recorde?
as a “timeseries” at multiple channels across the scalp
What is ERP?
very small voltages generated in the brain structures in response to specific events or stimuli
what is N170?
an early electrophysiological response to visual stimuli. is a negative inflection of the ERP that occurs approximately 150-200ms following visual stimulus onset
what do dominant theories propose abut the N170?
that it measures face specific processes relating to the encoding of facial features. It measures “higher-level vision” and responds to faces than to other objects.
what are the pros and cons of the N170?
great temporal resolition but hard to know where the signal is generated
what is intra-cranial EEG?
is the practice of using electrodes placed directly on the exposed surface of the brain to record electrical activity from the cerebral cortex
what are the restrictiosn if intra-ranial EEG?
restricted by clinical electrode placement and not neuro typical
what does MEG stand for?
Magneteoncephalography
what is MEG?
real time millisecond resolution of brain activity
what are hte pros and cons of MEG?
better spatial resolution than EEG but arguable even less glamorous looking
how is the MEG signal generated
by the same process as the EEG signal, but the magnetic signature is a tangentd to the direction of hte electrical curent
what are the differences between the EEG and MEG signal
the MEG signical is not distorted by intervening tissue between the generator and the sensor. thus that signal inversion techniques are more effective for MEG, allowing us to identify brain regions which generate the signal
in relation to MEG what does the Fusiform Gyrus show?
an early latency (duration between the delivery of a stimulus and resonse) response that reduces the effect to repeated presentation of faces regardless of their identity and later latency responses that is sensitive to changes in identy
what is TMS?
a brain stimulation technique. stands for Transcranial Magnetic Stimulation
How does TMS work?
creates focal magnetic pulses that are used to disrupt brain function in localised brain areas
what is TMS used to create?
Transient lesions (rTMS or repetitive TMS) of event related TMS AND state dependent TMS
how does TMS create transient lesions?
brief magnetic pulses are used to generate transient lesions allowing casual inferences
how is motor-cortex excitability enhanced?
by viewing bodily motion
what did Enticott discover?
Motor-cortex excitability is enhanced by viewing bodily motion is correlated with facial emotion discrimination performance (to static but not dynamic depictions of face emotions).
what is Haxby’s model of the face processing system?
involves the core system (visual analysis) and the extended system (further processing with other neural systems)
what is involved in the core system in Haxby;s model?
inferior occipital gyri, superior temporal sulcus and lateral fusiform gyrus
what is the inferior occipital gyri in Haxby;s model?
early perception of facial features
Superior temporal sulcus (Haxby’s)
Changeable aspects of faces - perception of eye gae, expression and lip movement
Lateral fusiform gyrus (Haxby’s)
Invariant aspects of faces - perception of unique identity
what is involved in the extended system?
intraparietal sulccus, auditory cortex, amygdala, unsula, limbic system, anterior temporal
Intraparietal sulcus (haxby’s)
spatially directed attention
Auditory cortex (Haxby’s)
prelexical speech perception
Amygdala, insula, limbic system (Haxby’s)
emotion
anterior temporal (Haxby’s)
personal identity, name and biographical information
In Haxby;s what is structural encoding / perception of facial features related to?
inferior occipital gyri (left and right ‘occipital ace areas)
in haxby’s what is recognition units / percetion of unique identity involved with
laterial fusiform gyrus (fusiform face area)
In haxby’s what is the peripheral aspects of expression analysis (encoding the expression itsself) eye gaze and perception and speech relatied to?
superior temporal sulcus
How is ERP produced?
They are EEG changes that are time locked to sensory, motor or cognitive events that provide safe and noninvasive approach to study psychophysiological correlates of mental processes
