CH3

Question 1

function of attention for perception:

Answer 1

attention is necessary because the perceptual system has limited processing capacity so attention selects a few items to receive perceptual processing. It basically prevents overload. Also, the binding problem can be solved with attention by selecting a limited spatial area for processing, so that the features within that area can be combined to reconstruct the objects.

Question 2

function of attention for awareness:

Answer 2

attention is needed to bring perceptual information to consciousness. Unattended objects are present on the retina, and they may be processed a little, but attention is needed to register the results of this processing

Question 3

function of attention for action

Answer 3

attention is needed to constrain possible actions; to make sure there’s no behavioural chaos

Question 4

Binding problem

Answer 4

how is it all combined into one conscious experience?

Question 5

early-selection view by Broadbent

Answer 5

the human information processing system is
like an information channel with limited capacity. He thought that attention works to
select information at an early level based on attributes like the location or pitch. His
filter theory says that there is a filter that protects the information-processing model
from being overloaded. It assumes that information from the senses first enters a
buffer where it can be held for a short time. Information that fits the filter is then
passed along to the limited capacity channel, where it can be identified. The results
of this analysis are then sent to a response system and may be used to update
expectations about what is likely to occur in the given situation. However, sometimes
potentially relevant information gets past the selective filter, like hearing your name.
This is why Treisman proposed the filter attenuation theory: the selective filter does
not completely block out unwanted information, but only attenuates or reduces the
strength of unattended stimuli.

Question 6

Treisman proposed the filter attenuation theory:

Answer 6

the selective filter does
not completely block out unwanted information, but only attenuates or reduces the
strength of unattended stimuli.

According to
Treisman, early selection is necessary when perceptual load is high in order to prevent
interference within the various perceptual analyzers.

Question 7

late-selection view by Deutch and Deutch & Norman:

Answer 7

attention is not needed to
perceptually process and identify items, but is needed to create a more durable
representation of the information. All information is processed to a semantic level;
this can explain why relevant information sometimes is identified.

Question 8

Shiffrin, Diller and

Cohen argue that

Answer 8

basic visual information is processed in parallel across the visual field, and
attention is applied to a location only when a response must be selected.

Question 9

Focusing the attentional spotlight:

Answer 9

it can be adjusted to focus on a small or larger

region. This can also be manipulated.

Question 10

Moving the attentional spotlight:

Answer 10

the time needed to focus attention at a location
increased as the eccentricity of the target increased, so attention probably travels
through space at a constant velocity. However, this has been criticised because it can
also be interpreted differently: in terms of the time needed to identify peripheral
targets. It seems like attention jumps from one position to another such that
resources are allocated to a new location as they are released at the old location.

LaBerge: one letter or whole word. Zoom lens for which
there is inverse relation between illuminated area and the concentration of attentional resources.

Question 11

The resolution of the attentional spotlight

Answer 11

not everything within the focus of the
attentional spotlight may be attended. However, detection of a probe is faster when
attention is directed at the probe’s location than when it is not, and attention operates
differently on objects than on empty space. We can conclude that attention moves
from item to item, but that the items might sometimes be perceptual groups.

Question 12

A better metaphor of selective visual attention is

Answer 12

that of a gradient of resources that is
allocated to a region in space rather than a spotlight. The gradient may vary in size, and
resources are assumed to fall off from the center of the gradient to the edges. The gradient
contains not only the current focus of attention, but also the results of previous attentional
allocation. So, activation can build up over time and across more than one attentional
fixation.

Question 13

Directing attention to an object or region…

Answer 13

increases the efficiency of processing. The frontal
cortex may exercise attentional control by inhibiting areas or objects that should not be
attended. Paying attention to one thing can imply decreasing the weights of unwanted inputs
rather than simply increasing the weights of desired inputs.

Question 14

Overt orienting

Answer 14

changing the positioning of the senses to improve

perception.

Question 15

Covert orienting

Answer 15

attention is directed to a location other than the focus of the eyes. Covert orienting does not affect which information is registered by the senses, but it
may affect the output of perceptual processes by directing attention to specific locations or
items. You can study covert orienting with “filtering” tasks, in which participants are shown a
number of stimuli and asked to attend to just one of them.

Question 16

Exogenous orienting:

Answer 16

reflexive orienting, driven by stimuli, also called peripheral cues. Most
often happen for stimuli that appear suddenly.

Exogenous orienting can be prevented by top-down attentional control.

Question 17

Endogenous orienting:

Answer 17

controlled orienting,
done by the observer. They need to be processed by the observer and intentionally acted
upon in order to have an effect.

Question 18

Cuing benefits (or costs)

Answer 18

are computed by comparing the
reaction time and accuracy on valid trials with that of invalid trials. Valid peripheral cues
benefit performance, especially when the interval between the cue and target is only about
100 ms. A reversal of this benefit happens when it’s >300 ms. This is called inhibition of return. Not only the stimulus onset but also the stimulus offsets can attract attention. The
attention-attracting effect of abrupt onsets or offsets may be due to the changes in
luminance that they create.
Effects on the P1 component are seen for both nonpredictive and predictive exogenous
cues.

Question 19

inhibition of return

Answer 19

Valid peripheral cues
benefit performance, especially when the interval between the cue and target is only about
100 ms. A reversal of this benefit happens when it’s >300 ms, and is called inhibition of return

Question 20

Is space special?

Answer 20

Space is more important for selection than is form, but it is possible
that selection can be based on nonspatial features. Attending to an object of a
relevant colour does not facilitate the identification of objects with the same colour,
but objects that were near the location of the attended object. Attention seems to
operate on a spatial representation of visual space, so you could argue that space is
special.

Question 21

According to purely space-based models of selection

Answer 21

attention directly operates on a spatial representation of visual space. Eg, in the
feature integration theory, attention is allocated to regions of space and acts to bind
features in those regions to form objects. So, objects are identified only after
attention has been directed to regions of space. Other models assume that attention
selects objects rather than regions of space. They say that attention selects only
regions of space that are occupied by objects. Space-based theories assume that
attention can select regions of space whether they are occupied by objects or not.

Question 22

Duncan proposed that

Answer 22

we attend to objects and not to
space, and that when judgements are made about two objects, attention must
be switched from one object to the other, which takes time. Space is not the dominant factor of attention, but attention operates on objects formed on the
basis of earlier perceptual processes.

Question 23

Moore, Yantis, and Vaughan:

Answer 23

if attention is truly object-based, it should
operate not only on object representations that are explicit but also on
perceptions that are the result of earlier perceptual completion processes,
e.g. Gestalt principles. They had an experiment where two vertical rectangles
were presented that were either occluded by a third horizontal rectangle or
not. They found that selection can occur on object-based representations that
are formed by perceptual completion processes.

Question 24

Evidence suggests that attention operates on…

Answer 24

objects, even when these objects are only virtually present. However, spatial location and distance also play important roles in selection. Maybe attention is either space-based or object-based depending on task demands.

Question 25

Probe dot procedure

Answer 25

detection of probe faster when attention is directed at probe’s location than
when it is not. Rather than illuminating all areas within focus, attention operates differently on objects
than empty space. Ability to change size of focus to include different numbers of items seems to
depend on presence of perceptual groups in the display.

Question 26

Conjunction search is well described by

Answer 26

the serial self-terminating search model: half of the
items will need to be checked before the target is found on target-resent trials, but all items
will need to be checked on target-absent trials.

Very efficient
search (finding a vertical line among horizontal lines) results in slopes of zero, and very
inefficient search (conjunction of two orientations) can take more than 30 ms per item,
resulting in a much steeper search slope.

Question 27

Wolfe argues

Answer 27

it is better to think of search as

being more or less efficient and to examine the factors that influence efficiency.

Question 28

The original version of feature integration theory assumed that

Answer 28

features were represented
independently of their locations, and that locations were used only to bind different features
together. However, the disassociation between “what” and “where” is way less extreme than
that. They then proposed that attention may modulate activity in the master map of locations
via the feature maps.

Question 29

Guided search 2.0 - Wolfe:

Answer 29

attention can be directed to the locations of interesting
objects in the visual field by means of preattentive processes. So, before attention is
directed to locations or objects, preattentive processes are at work in a bottom-up or
top-down way. This is suggested by the finding that basic features presented in the
periphery of a display can be still be identified even when attention is busy. Attention
is needed to bind features together in order to identify objects.