TB6 Flashcards
(52 cards)
Configurual processing in CP
Loss of configural processing seen - not affected by inversion it faces and are slower at deriving global whole letters from local smaller letters, implying failure representing the spatial relations between components.
Areas involved in facial perception
FFA- identity
OFA- face parts but not the space between them
STS- expressions (likes moving faces and eye Data too )
Evidence for FFA involvement in face recognition
Kanwisher fmri- especially rFFA responds differentially to faces rather than scrambled faces, houses, objects etc
Wojdiulik- covert visual attention modulated face specific activity in fusiform
Andrews- CONSCIOUS perception as a face (Rubin figure)
Epstein and kanwisher- DD of faves and scenes
Evidence for OFA
Patient PS had FFA intact but no OFA. TMS by Pitcher showed involvement in face recognition. and is involved at early stage 60-100ms
Face inversion superiority
Prosos are better at inverted faces or perform the same, arguably because they don’t perceive faces holistically
What do the 2 types of proso tell us?
AP tells us what the FFA does
CP challenges this, but they never had a normal system so have had their whole lives to adjust, but can’t be overcome so not plastic
How do CP patients perform in face matching?
Sometimes succeed but may just be matching features, but when reaction time and sensitivity looked at can see the difference
What activity do CP patients tend to show in FFA?
Normal activity
Therefore having a working FFA doesn’t mean you have the skill of recognising faces
Faust within category recognition hypothesis
Proso patients can still assign objects to functional categories but can’t individuate within a category which is seen in items of similar appearance like birds, flowers, cats, as well as faces
Related conditions to proso- semantic memory and nominal dysphasia
Semantic memory- KS
Knowledge of singular things like people, temporal based issue. Poor face and name recognition eg this patient struggles with famous animals buildings products
Nominal dysphasia- GBL
Couldn’t recall names but face recognition fine! Could also give semantic info, TF face recognition, semantic info and name retrieval use separate mechanisms
Typical prosopganosia symptoms
Impaired face recognition
-some read we’ll
-associates wit colour blindness (achromotopsia)- damage of fusiform gyrus in ventral streams
Often bilateral but right side more damaged
What did Bruyer find with Mr W?
he could perceive facial expression but not identity tf double dissociation between facial expression and identity. links to bruce and young cognitive model
what did ungeleider and mischkin find about the ventral and dorsal streams?
they distinguished a temporal lesion for the “what” ventral stream, and the parietal lesion for the dorsal “where” stream by lesioning monkey brains. found double dissociation.
Newcombe supports this- JS had temporal injury and VRD a parietal injury and they found DD between maze and recognition tasks
cases of visual object agnosia
lissauer identified name with case GL who couldnt name objects but referred to them in convo still
Case CK- could draw objects and not recognise, showed dissociation of perceptual and memory, tests showed a purely visual issue. with many tests only issue seen on orientation of objects TF issue may be in constructing and manipulating 3D representations
How did Milner and Goodale update Ungeleider and Misckin’s double dissociation stream theory?
found DD of recognition and grasping with patient DF who had ventral damage and some lower level visual issues. Could pick up blocks but not match Efron’s shapes.
Case RV had dorsal stream damage and could see shapes but not pick them up-object ataxia.
Palmer- object recognition and the effect of context
and Biederman location, and Kim TMS
palmer found appropriate context faciltated recognition and made recognition of misleading objects harder, so acted as a primer.
Biederman- quicker visual search when item in correct location
Kim- if TMS the LOC, doesnt like objects in relation to each other anymore therefore LOC is something to do with where objects are in relation
What’s the difference between PPA and RSC
PPA does local scenes (it’s also active when imagined)
But RSC does the spatial relations between local and extended environment and is more active when info is familiar and intentionally retrieved
What did O’Keefe find about cognitive maps?
The hippocampus is involved with them (also known as entorhinal cortex)
what did fMRI subtraction find? (malach)
contrast to early visual areas with objects. EVC doesnt mind about image having structure but LO prefers intact object images. later studies used scrambled faces too.
comparing methods used to study recognition
TMS- cm spatial resolution and mm temporal resolution so good for timings of exactly when things are happening
fMRI- mm spatial resolution and very slow 2-6sec temporal resolution. only studies cortex but can map out larger area than TMS
NP- issue is depends of specificity and cannnot compare to their behaviour from before.
what areas are involved with place recognition
scenes are different as theyre spatially distributed, we act within them, foreground and background elements, fixed location, and give a gist rather than identity.
PPA- parrahippocampal place area, RSC (retrosplenial complex) and OPA (occipital place area) are involved
evidence for PPA in place recognition
responds to background elements (spatial relations) more than objects, but most when seeing whole scene.
Epstein- lego objects layed out as a scene gives more response so works for simple made up scenes too
NP patients-
GR- bilateral PPA lesion, and CO- right side PPA Lesion
Both intelligent with normal verbal memory but have severe topographical disorientation (get lost) and both impaired at scene recognition.
Steeves- DF the object agnosic showed a DD with scenes and objects.
evidence for RSC’s role in scene recognition
responds to spatial relations between the local and extended environment. more active with info that can be retrieved (Familiar) and when info is intentionally retrieved.
fMRI epstein-PPA responded equally in all scene conditions WHEREAS RSC responded more for the coordinates east/west Q, vs orientation of where looking, as calculating where we are in world. was affected by task location and familiarity too.
NP data- one patient could recognise buildings but not put them together in a scene as landmarks didnt provoke info about other places in relation.
evidence for OFA in face recognition?
Guathier-responds more to faces than bodies,objects etc. Patient PS has no OFA but does have FFA and cannot recognise faces.
Pitcher TMS- TMS disrupts face task for OFA but not object task. 3 DDs- face and objects, objects and bodies, faces and bodies.
