Intro to Cognitive Science - Unit 2 Flashcards
What prior element contributes to our perceptions?
Our expectations of what we should be perceiving (34)
What wavelengths of light are visible to humans?
400-700 nm (35)
Which eye structure contains photoreceptors?
The retina
Which two eye structures work together to bring an image into focus?
Cornea and lens
Where does detailed vision occur?
In the fovea of the retina
Where are neural signals in the retina sent?
To the lateral geniculate nucleus of the thalamus
What kind of sensory input does the thalamus receive?
Auditory, visual, other, etc.
Where does the visual neural signal go after the lateral geniculate nucleus of the thalamus
To the primary visual cortex in the occipital lobe
Where is the primary visual cortex?
Occiptal lobe
By which hemispheres are visual inputs to the left and right eyes processed?
By both, no matter which eye (36)
What happens at the optic chiasm?
The nasal (only the nasal) optic axons cross over to the other side (36)
Why does the optic chiasm function as it does?
So that objects in the LVF are processed by the RH, and objects in the RVF are processed by the LH (36)
Where do 20% of visual signals leaving the retina go?
The superior colliculus (38)
Superior colliculus
Top of the midbrain, controls eye movements (38)
Do all visual signal pathways terminate in the primary visual cortex?
Nope, to be explained later :P (38)
What structure is essential to visual consciousness, besides the functional retina, optic nerve, and lateral geniculate nucleus?
Primary visual cortex in the occipital lobe (38)
What kind of cells are specifically needed for visual awareness?
Cortical cells that have consistently been stimulated to the type of vision (38)
What did the “D.B.” experiment prove?
The occipital primary visual cortex is essential to visual awareness, regardless of vision capability (39)
What did the horizontal/vertical kitten experiment prove?
That during the “critical period,” the visual cortex cells must receive stimulation in order to achieve visual awareness (38)
What is blindsight?
Vision without awareness as a result of lesions in the occiptal cortex (39)
How does perception begin?
With the transduction of physical energy to an initial neural representation of the stimulus (60)
What does pattern recognition mean?
The step between transduction and perception of a stimulus in the environment and its categorization as a meaningful object (40)
What does the ability to perceive depend upon?
Pattern recognition: recognizing the same object’s patterns in a variety of ways: eg: dogs from different angles (41)
What is agnosia?
When a person can see an object, but not recognize it or categorize it (41)
Appercertive agnosia
Object recognition fails as a results of difficulties in identifying the visual features that define a perceptual category (41)
What part of the brain is required for perceptual categorization?
The right posterior hemisphere (42)
Associative agnosia
Object recognition fails due to difficulties in identifying the functional features that define a semantic category (42)
Cane, closed umbrella, and open umbrella: describe the reactions of the perceptive agnosia and associative agnosia.
Perceptive: open and closed umbrella have same function; Associative: can’t identify that the open and closed umbrella have same function because cane and closed umbrella look similar (42)
What do the two types of agnosia demonstrate?
That pattern recognition involves two levels of categorization: 1) visual features must be matched to long-term memory images to identify perceptual categories; 2) the functional features must be matched to long-term memory representations to identify semantic categories (42-3)
What brain area mediates perceptual categorization?
Posterior regions of right hemisphere (42)
What brain area mediates semantic categorization?
Left hemisphere (43)
schema
Mental representation that organizes knowledge about related concepts (43)
top-down processes
Conceptually-driven
What do top-down processes do?
reduce the need to sample all info available: provides expectations (43)
bottom-up processes
Data-driven
What do bottom-up processes do?
Allow analysis of the “edges, lines, areas of light and dark, colors, sounds, and other physical features available briefly in sensory memory” (43)
How do data-driven and conceptually-driven processes interact?
Conceptually-driven provides and expectation, and data-driven picks up info to confirm or refute the expectation (43)
When is data-driven vision more prominent?
In good viewing conditions: able to see all the details, whereas in poor conditions, you rely more on conceptually-driven process to make hypotheses (43)
Word superiority effect
Letters are recognized faster when in the context of a word than alone (44)
Why do data-driven processes still exhibit change blindness?
Because their partner, conceptually-driven processes, haven’t produced an expectation of change, so they’re not watching out for it (46)
What evidence do Hubel and Weisel (1959, 1963) give for feature detectors?
They found that different occipital lobe nerve cells fired for different stimuli (46)
What evidence does Neisser (1963) give for feature detection?
Participants were more quickly able to find an angular letter among rounded letters than among angular letters, suggesting that the visual cortex analyzes based on broad, general feature characteristics first (46)
How does the theory of structural descriptions modify that of feature descriptions?
Structural theory argues that it’s not just the features that determines recognition, but the structure in which they’re arranged: the visual relationship among features: both together facilitate pattern recognition (47)
What is a module?
a set of processes that are automatic, fast, encapsulated apart from other cognitive systems, and instantiated in a localized area of the brain (Fodor 1983) (49)
Holistic processing
Perceiving the whole object (49)
Analytic processing
Perceiving the features that compose the whole
How would one holistically process a face?
Using the spatial-relational aspects of the features of the entire face (49)
How would one analytically process a face?
By targeting the nose, eyes, lips, etc, instead of their relations to each other (49)
In which way are faces generally perceived?
Holistically, rather than analytically: think of the upside-down experiment (49)
prosopagnosia
Selective inability to recognize faces (51)
What brain area are crucial for face recognition?
Temporal lobe: fusiform face area; Occipital lobe: face area in the inferior occipital cortex (52)
In what hemisphere is there a strong preference for face recognition?
Right hemisphere (52)
What did Steeves et al. suggest about face recognition in the brain?
First, the fusiform face area in the temporal lobe categorizes the face, and then the face area of the inferior occipital cortex in the occipital lobe provides detailed information needed to perceive that individual face (52)
What brain structure contributes to the perception of untrustworthiness in faces?
The amygdala (fearful stimuli sensing) (52)
In general, what do the fusiform face area and the inferior occipital cortex help us perceive?
complex, holistic visual objects that are repetitively perceived because of their importance to survival (53)
What is feature integration theory?
The theory that automatic preattention processing of features must be followed by controlled attentional processing to bind the features into a whole object (86)
What did Treisman and Gelade, 1980, suggest about object recognition?
That attention is essential (86)
How did Treisman and Gelade prove that object recognition requires attention in 1980?
Automatic identification of “red x” in “blue x and blue o”, but took much longer to identify “red x” in “red o and blue x” because attention is needed to integrate the color and shape aspects of the object (86)
What is the “glue that binds together stimulus properties into the perception of a single object?”
Attention! (86) (What? Go red team go, eh eh eh eighteen!)
What brain area is responsible for processing the shape of an object?
The temporal lobe (87)
What brain area is responsible for processing the location of an object?
The parietal lobe (87)
What is the binding problem?
How the features that are distributed in multiple brain regions are integrated to perceive a single object (87)
What is one important concept when trying to answer the binding problem?
Attention: you need attention to perceive something, whether or not the features are processed (87)
What is inattentional blindness?
Failure to perceive an object that is not attended (88)
What is attentional blink?
The interval of time after the targe is presented when other stimuli in the series are not perceived: for example, in increments of 500 milliseconds, the letters HTEX are shown: if attending to T, you’ll miss the E (89)
What did Anderson discover about attentional blink in 2005?
That the “refractory period” of attentional blink is shortened when that second target is emotional: for example, using words instead of letters, if the “E” placeholder was an emotional word (89)
Who pioneered the study of visual images by experimenting with mental rotation?
Shepard et al, 1974, 1983, 1971 (195)
Propositional code
An abstract means of mental representation not linked to any sensory modality (194)
What did Shepard et al discover about mental rotation?
That the time taken to identify that the rotated image matched the original increased linearly as a function of the angle of rotation, disqualifying the idea of propositional mental representations (197)
What did Kosslyn discover about scanning small mental images versus large ones?
It’s hard to scan to find features in small mental images (199)
What does it mean that mental imagery has an analog aspect?
That the representation’s features are analogous/correspond to the features of the object: for example, distance: if two cities are further apart on a map, it takes longer for the brain to mentally draw a straight line between then (199)
What is the functional equivalence hypothesis?
Claims that visual imagery uses the same mental representations, processes, and neural structures as does visual perception (199)
As found by Farah, 1988, lesions in visual areas affect not only sight, but what else?
Imagery, in accordance with the functional equivalence hypothesis (199)
What is the argument of Bar’s article?
That “viewpoint dependency reflects the utilization of neural paths with different levels of sensitivity en route to the same representation, rather than the existence of viewpoint-specific representations” (793)
object-centered theory of object recognition
Posits that objects are recognized based on their structural descriptions (793)
viewer-centered theory of object recognition
That we store multiple “snapshots” of the object in different views and thus that our perception of the object is viewer-based, since it depends on our “snapshot” library or matching of the current view to a template from our snapshots (793)
What experimental paradigm is used to test for one theory over the other?
Recognition performance under novel viewing conditions (793)
What does the object-centered theory predict about novel viewing recognition performance?
That as long as the defining features of the object are clearly visible and attended, there should be comparable speed and efficiency in recognizing the novel view (793)
What does the view-centered theory predict about novel viewing recognition performance?
That the added computation time in template-matching will slow down object recognition under novel circumstances (794)
What is priming?
facilitation in recognition of a perceptual stimulus that stems from previous experience (795)
What is a suggested neural basis for priming?
LTP: long-term potentiation, which is an increased sensitivity of cells due to their prior activation , and LTD: long-term depression, by which unused representation are inhibited in favor of others (795)
LTP is an example of what?
Activity-dependent plasticity (795)
Which neural pathway is thought to be most responsible for shape processing in object recognition?
The visual ventral pathway (796)
What does depth rotation of an object do regarding the visual ventral pathway?
The difference in perception of the features of the object trigger a slightly to very different neural pathway because of the cells’ specialized receptive fields (796)
Rotation in depth that modifies higher-level features results in what?
Larger costs in recognition performance: usually see more complex features less, so less priming (797)
In what state is the neural path used to recognize an object when the object is viewed from a different angle?
A “partially primed” state (797)
What is the “binding problem?”
The question of how all features of an object are merged into one representation of that object (7)
When is the binding problem a particular issue?
When there are more than one objects in the visual field: how do you avoid incorrect pairings? (7)
What occurs when the brain has issues with binding?
Illusory conjunctions, or the incorrect pairing of features with an object, Wolfe and Cave 1999 (7)
According to Roskies, what is “perceptual binding?”
Binding aspects of a percept, like the auditory sound of a ball hitting a bat with the visual image of them colliding (7)
According to Roskies, what is “cognitive binding?”
Unifying a concept and a percept (7)
simultagnosia
The inability to perceive more than one object at a time
What are two suggestions as to how the brain accomplishes binding?
1) an attentional requirement (Wolfe and Cave 1999) (8); 2) a temporal basis (Gray 1999 and Singer 1999b) (8)
