Chapter 7 Key Terms Flashcards
In class, we saw a “change blindness” demo in which two versions of an image,
with a large difference in detail, were alternated repeatedly? How do these phenomena demonstrate the importance of attention for determining what we
consciously experience?
In this demo, there was a failure to detect a change in a visual scene due to brief interruptions such as a saccade or flicker. This demonstrates that attention is crucial for conscious perception, as unattended changes are often missed, highlighting attention’s
role in filtering sensory input.
What is the distinction between early and late selection? How does evidence from the dichotic listening paradigm provide some support for each of these ideas?
Early selection suggests that stimuli are filtered before perceptual processing, while
late selection suggests all stimuli are processed to a semantic level before attention acts. Dichotic listening supports both: early selection is seen in the inability to recall unattended details, but late selection is evident when salient stimuli like one’s name in the unattended channel are noticed
What is meant by “space-based,” “object-based,” and “feature-based” attentional
selection? Describe evidence supporting object-based selection from behavioral
and neuropsychological studies.
Space-based selection focuses attention on a spatial region, object-based on a specific
object, and feature-based on an attribute like color or shape. Behavioral studies show
faster responses to cued objects even in new locations, while patients with parietal
damage demonstrate object-based neglect, ignoring specific objects regardless of their spatial position
Describe the neural architecture of attention. How does attentional allocation affect processing in visual cortex, frontal and parietal cortex, and subcortical
structures like the pulvinar and superior colliculus?
Attention involves frontal and parietal cortices for top-down control and subcortical
structures like the pulvinar and superior colliculus for filtering and shifting attention. Allocation enhances processing in the visual cortex for attended stimuli and suppresses unattended information, improving task performance.
What is the Posner spatial cueing paradigm? What are the typical results in normal subjects and patients with neglect?
The Posner paradigm involves a cue indicating the likely location of a target. Reaction times are faster for valid trials and slower for invalid ones in normal subjects. Neglect patients show slower responses or fail to respond to contralesional targets even when cued
How do results from visual search experiments support feature integration theory?
Feature integration theory posits parallel processing of basic features and attention-
dependent integration of multiple features. Experiments show that targets differing in a
single feature are rapidly detected, while conjunction targets require slower, attention-driven search.
Discuss how feature integration and biased competition theories relate to early and late attentional selection?
Feature integration theory involves late-stage integration of features into objects requiring attention, supporting late selection. Biased competition theory involves early
competition between neural representations, favoring attended stimuli, consistent with
early selection.
How would one distinguish visuospatial neglect from blindness in a hemifield? How would one distinguish visuospatial neglect from simultagnosia?
Visuospatial neglect can be distinguished from blindness in a hemifield by using tests
like locating objects or drawing tasks. Neglect patients fail to attend to stimuli in the
deficit hemifield but can perceive them when cued. In simultagnosia, individuals fail to
attend to multiple objects, even in separate spatial regions
What is a spatial reference frame? In what reference frame or frames does visuospatial neglect commonly operate?
A spatial reference frame is a coordinate system used to describe object locations. Neglect often operates in egocentric reference frames (relative to the observer),
particularly relative to the point of fixation, but can also occur in allocentric frames
(relative to the environment or objects)
What happens to visual information that is “neglected”? What evidence is there
that neglected information can be processed up to the level of meaning?
Neglected information is not consciously perceived but can still undergo some processing. Evidence includes experiments showing priming effects or semantic processing of stimuli presented in the neglected field
How do covert and overt attention differ in their mechanisms and effects on behavior?
Covert attention allows focusing on a location without eye movements, while overt attention involves shifting gaze to the attended location. Neural mechanisms include top-down control for covert attention and motor control regions like the superior
colliculus for overt attention
What evidence from neuropsychological and imaging studies supports the
distinction between endogenous and exogenous attention?
Endogenous attention, driven by goals and expectations, activates the dorsal attention
network, while exogenous attention, triggered by salient stimuli, engages the ventral
attention network. Studies using tasks like the Posner cueing paradigm highlight these
distinct mechanisms
allocentric reference frame
arousal
attentional bottleneck
attentional control networks
attentional enhancement
attentional suppression
attentional filtering
attentional orienting
Balint’s syndrome
biased competition theory
change blindness
cocktail party effect
