textbook chapter 4 Flashcards
what is apperceptive agnosia
they can see, they cant organize the elements they see in order to perceive the object
what is associative agnosia
they can see but they cant link what they see to their basic l=visual knowledge
how are various objects recognized
it is influenced by context in which you encounter these objects
what is bottom up processing
sequence of events that is governed by the stimulus input itself
bottom up processing : data driven
process directly shaped by stimulus
what is top down processing
a sequence of events that is heavily shaped by the knowledge and expectations that the person brings to the situation
what is top down processing guided by
your knowledge that common words or objects etc go together
how do you often recognize objects
through their parts
what is visual search tasks
study participants are asked to examine a display and judge whether a particular target is present or not
what is tachistoscope
a device that is designed to present stimulus for precisely controlled amounts of time
what is a mask
a random pattern of lines and curves, or a random jumble of letters. this interrupts any continued processing that participants might try to do for the stimulus just presented
what is priming
a process through which one input or cue prepares a person for an upcoming input or cue
what is repetition priming
a pattern of priming that occurs simply because a stimulus is present a second time; processing is more efficient on the second presentation
what is word superiority effects
it is easier to recognize if a letter is in a word than if it appears isolated
what is well formedness
a good predictor of word recognition, the more english like the string is the easier it is to recognize (for english speakers)
what are future nets
the bottom layer is concerned with features, as we move upwards in the network, each subsequent, layer is concerned with larger-scale objects
what is activation level
a level that reflects the status of detectors at that moment
what happen when a detector receives some input
the activation level increases
what is a response threshold
the quantity of information or activation needed to trigger a response in a mode or detector or, in a neuroscience context, a response from a neuron
what happens once the activation level reaches the response threshold
the detector will fire, sending signals to the other detectors to which is connected
what detectors fire more
a detector that has fired recently and a detector that has fired frequently
what are activation levels depend on
frequency and recency principles
what are frequent words
appear often in the things we read
what is recency of us allow
activation levels to be temporarily lifted once fired because presenting a word once will cause relevancy detectors to fire
what are bigram detectors
detectors of letter pairs, these detectors like all the rest, will be triggered by lower-level detectors and send their output to higher-level detectors
what is locally represented
a mode of representation in which information is encoded in a small number of identifiable nodes. they are sometimes spoken of a ‘one idea per node’ or ‘one content per location’
what is distributed representation
its knowledge is represented by a pattern of activations distributed across the network and detectable only if we consider now the entire network functions
McClellans and Rumelhart pattern recognition model
includes both excitatory connections and inhibitory connections
what are excitatory connections
connections that allow one detector to activate its neighbours
what are inhibitory connections
connections that decrease the activation level of its neighbours
what kind of detectors can influence eachother
higher levels can influence lower levels, and detectors at any level can influence other detectors at the same level
what is the recognition by component model
a model of object recognition, a crucial role is played by geons
what are geons
basic building blocks of all the objects we recognize, the alphabet from which all objects are constructed
what are the advantages of geon assemblies within this category
- geons can be identified from virtually any angle of view
- whatever position is relative to a cat you’ll be able to identify it
- can recognize objects even if many of the object geons are hidden from view
what is viewpoint independent
some cells fire strongly to virtually any view of the targets object
what is viewpoint-dependent
cells responding to inputs shape trigger
what is prosopagnosia
generally have normal visions but are unable to recognize individual faces.
what is the inversion effect
a pattern typically observed for faces in which the specific face is much more difficult to recognize if the face is presented upside down; this effect is part of the evidence indicating that face recognition relies on processes different from those involved in other forms of recognition
what is face recognition dependent on
orientation
what is holistic perception
face recognition depends on the faces overall configuration, the spacing of the eyes to the nose etc
whats the composite effect
this is where evidence of the holistic perception comes from. it is shown through combining two faces together and asking people to pick out which is which
what does priming gaurentee
detectors that have often been used in the past will be easier to activate in the future
what does top down priming involve
- participants need to understand each of the words being said in the instructions
- participants must understand the relation among the words in the instruction
- participants have to know some facts about the world and the kinds of things that can be eaten, without knowledge, priming wouldn’t be expected
how can we view object recognition
knowledge that is external to object recognition is imported into and influences the process
what does top-down priming depend on
what is in memory and how that knowledge is accessed and used, so we can’t tackle this sort of priming until we have said more about memory and knowledge
