Textbook Notes: Attention
• Attention s the process that enables us to focus on a select number of
sensory inputs while disregarding others.
• How are we able to selectively filter out which stimuli are relevant and
which ones aren't?
• When can our attention be divided effectively and when can it not?
• The singular process of attention is actually the result of a collaboration of
processes that each perform a crucial function without which we would be
limited in our ability to focus effectively.
o Most of the processes that facilitate paying attention come at a cognitive
price. Focus ties up mental resources that are then unable to be used to
pay attention to other stimuli.
o If two tasks together do not require the enitrety of our mental resources,
we are able to effectively pay attention to both of them.
o Some processes are specialized and are only required when performing
certain behaviours whereas other processes are general and are used by
nearly every task.
o The cognitive price required can be reduced through practice.
o Attention is not a process - it is an achievement that is honed through
practice, a skill.
• Shadowing: A technique used to study attention where the individual must
repeat back word for word the message they are being heard played for
• Attended Channel: Focus of attention.
• Unattended Channel: Stimuli outside of the attended channel. These stimuli
are not attended to.
• Dichotic Listening: Experimental setup for testing attention. The participant
wears a pair of headphones and the attended channel is played in one ear
and the unattended channel is played in the other ear.
• Experiment with dichotic listening showed that the one message is
understood clearly while only physical characteristics of the unattended
message are heard.
o Participants can tell if it is music or silence or a person speaking.
o If it is a person speaking, participants can tell f the speaker is a man or
woman and whether they are talking quietly or loudly.
o No semantic content is understood. In one study, Czech read with
English pronunciations was used as the unattended message and only 4
out of 30 people were able to identify that the unattended message was
not in real English words.
• Experiment with divided watching or selective visual attention
demonstrated the same phenomenon
o Participants asked to follow the passing of a ball missed the giant gorilla
suited man in the center of the scene. Some Unattended Inputs are Detected
• Even though the unattended channel goes largely unnoticed, certain stimuli
that are particularly relevant to us or that we are primed for do catch our
• Cocktail Party Phenomenon: Being in a crowded room and being able to
attend only to the conversation of interest while the remaining
conversations become a dull buzz of noise.
o if you hear a relevant word such as your name or the name of your
friend, you may momentarily shift your attention away from the
conversation you were originally attending to.
Perceiving and the Limits of Cognitive Capacity
• Text proposes that we erect a filter that blocks out distractors like a bouncer
outside a club.
• Not all distractions are equal, we may be adept at preventing certain stimuli
from breaking our focus, but when new stimuli are introduced we must
learn new attentional skills to cope with the new distractions.
• Our minds are not only capable of blocking out unattended stimuli but also
enhancing processing for stimuli that are attended to
• In an experiment where participants were asked to focus on a plus sign and
make determinations about the difference between the length of the lines,
most failed to see shapes that were added in with the attended to stimulus
even though it was presented right before their eyes.
• Two theories currently explain this phenomenon:
o The eyes sense the stimuli but they are not attended to and thus not
o The mind s not prepared to receive the stimuli so the eyes literally do
not see the stimulus
• Inattentional Blindness: Failure to see or perceive a stimulus due to a lack
of focus on that stimulus.
Conscious Perception, Unconscious Perception
• "There is no conscious perception without attention"
• Experiment with lines and background dots asked participants to determine
which of the horizontal lines was longer. For the first few trials, the dots in
the background were arranged in random patterns.
• On the fourth trial the dots were arranged in the classical illusion Muler-Lyer
line illusion where each line has fins pointing inwards or outwards
• When asked if there had been any slide with patterned dots, none reported
seeing the pattern. When told difinitively, however, that there was a
pattern, 90% chose the correct pattern from a multiple choice selection.
• 95% of participants also responded to trial 4 by answering that one line was
longer even though they were the same. Clearly the participants were
influenced by the fins even though they did not consciously perceive them.
• Changes that occur in a film between cuts are often not noticed o This effect can be duplicated in real time. An experimenter asked
students on campus for directions and in the middle of the conversation
some men carrying a door walked between the student and the
experimenter. While the door was passing, the experimenter switched
places with one of the carriers and the carrier continued on the
conversation as if it had not been interrupted. Only about half the
participants noticed the switch.
• When being shown two nearly identical images with only a single difference
it is difficult to determine what the difference is between the two images.
Early Versus Late Selection
• Early Selection Hypothesis suggests that attended to stimuli are
priveledged right from the start and that unattended to stimuli receive
almost no processing.
• Late Selection hypothesis suggests that all inputs are perceived equally but
that stimuli we do not attend to go unremembered or are not registered in
our conscious stream. (But could still potentially influence us)
• There is evidence for both early and late selection
o When the attended to task is complex, there are fewer resources left
over to devote to unattended stimuli. In this case, attended to stimuli
are favoured from the start and there is evidence for early processing
o When the attended to stimuli are simple and do not require much
processing, the attended to stimuli require fewer resources and there
are more left resources left over for the unattended to stimuli. In this
case, there is evidence for late processing.
Chronometric Studies and Spatial Attention
• Spatial attention is the ability to focus on a stimulus in a particular
location in space
• Davidson's spatial attention detection test – ZAPS lab
• Participants are asked to monitor a screen for letters appearing and
press a key on the keyboard when they see it. In the center of the
screen and is either given a neutral warning or a warning pointing to the
left or right. The arrows correctly indicate where the letter will be 80% of
• Participants respond the fastest to correct cues, then to neutral cues
and slowest to incorrect cues
• In order to be paying attention to one side when the letter appears, one
has to pay less attention to the opposite side, so if the letter does not
appear on the side you expect, there is a delay in reaction time
Attention as a Searchlight
• Attention is theorized to act like a spotlight beam – with all the stimuli
that fall within the beam receiving extra processing and attention than
those that fall outside the beam
• Attention's beam can be widened or narrowed to encompass more or
less detail as needed
• Attention movement is unique from eye movement. ◦ In the lab, attention priming effects can be demonstrated at 150ms
after a stimulus is presented, 30-50ms before eye movements can be