Faces wk 10 Flashcards
(39 cards)
what is pareidolia?
the L+R fusiform gyrus detects facial patterns in objects where there should be none
this suggests our systems are predisposed to seeing faces in different kinds of inputs.
what did johnson (1991) show about newborn babies?
newborn babies have preferences for cartoonish faces on a racket – innate predisposition/sensitivity with faces
maybe its the configuration?
retest = no sig difference between config and face, so config may be the root
what do infants lose by 9m?
infants lose the ability to discriminate monkey faces as well as human faces (pascalis, 2002)
shows face processing in infants undergoes similar progression to language-related processes.
innate sensitivity to facial processing
features vs configuration
features = identifiable parts of the face, e.g., eyes, nose, mouth
configuration = the arrangement of face features, e.g., spacing, symmetry, position within outline
what does holistic face processing involve?
integrating information from everything there is on a faces
instead of part based facial processing though lack of evidence
examples of holistic face processing
inversion and thatcher effect:
show face processing is interrupted by interfering with configurations , not seen with other objects e.g. cola
Diamond and Carey (1987) show correlation between inversion effects and image familiarity, e.g. dog experts better at identifying inverted faces , though still an impact
as we become experts at something, the configurable processing becomes more important for us
what is getting a likeness (person recognition) influences by
configuration
hindering the config processing impacts face processing, not seen in breaking up featural processing
+ the holistic account
what do single-cell recordings show about face processing?
show double dissociations between identity and emotion processing systems
identity after-effect
adapting to an identity over time reduces the firing rate of their neurons,
this means a 50-50 image will be perceived as the other identity via neural adaptation (looking at one of them for a prolonged time before the 50/50 picture)
identity cells
Specific group of cells in that brain that encodes specific identity , doesn’t care for other elements
Expression cells
group of single cells active when viewing the same expression, identity not influences
different brain areas involved in processing identity and emotion
narumoto (2001) found the intraparietal sulcus (IPS) and lateral fusiform gyrus (LFG) showed higher activity when viewing faces,
the superior temporal sulcus (STS) heightened for viewing emotion.
emotion after-effect
adapting to a happy face makes a neutral one look angry, and vice versa
types of face processing models
bruce and young (1986) - A psychological face processing model
haxby, hoffman, and gobbini (2000)- A model of the disrupted human nueral system for face perception
bruce and young (1986) suggest there are two main stages of face processing:
- structural encoding – deals with visual information, e.g., viewpoint and lighting
- extended processing – splits into two pathways:
a. expression analysis – facial expression, mood, emotion (changing)
b. face recognition – person identity nodes and name retrieval (fixed)
what does the psychological face processing model suggest
familiar and unfamiliar faces are processed differently
outdated model
haxby, hoffman, and gobbini (2000) created a model for a distributed system of face perception:
- inferior occipital gyrus – early perception of facial features
a. lateral fusiform gyrus – processes fixed aspects of faces and unique identity
b. superior temporal sulcus – processes changeable aspects, e.g., gaze, expression
i. intraparietal sulcus – spatially directed attention
ii. auditory cortex – prelexical processing
iii. amygdala, insula, limbic system – emotion processing
iv. anterior temporal processes – personal identity and name
What does the model for a distributed system of face perception suggest
links different processes into different areas of the brain
has a system dedicated to face processing but an extended system that isnt face specific, rather has an interaction effect with facial processing
Brain imaging methods of face processing
ERP’s
fMRI
Single cell in monkeys
Lesion studies
Brain stimulation
what is N170?
N170 is a strong negative ERP waveform, which is assumed to reflect structural encoding in facial images.
occurs around 170 miliseconds following presentation of face
what did bentin (1996) show about N170?
ERP N170 is flexible for faces and differentiates faces from other visual input though doesnt care about changable aspects of a face
what is FMRI used for?
to identify brain areas sensitive for particular categories.
kanwisher (1997) subtracted activation for ‘scrambled faces’ and found:
LOC = sensitivity to objects
FFA = sensitive to unscrambled faces
PPA = activates for outdoor scenes
what did serences (2004) concldue about FFA?
found increased activation in FFA when asked to identify faces vs. houses for PPA.
concluded our attention selection mediates brain activity in perceptual regions , telling these areas whether they should boost or reduce activation.
