Harley Ponder (O1806310) DE200 TMA02
Change Types Effect on Change Blindness
Abstract
A study on change type (congruent, incongruent and within-category) on
change blindness, definitions explained below. The study recruited 250
university students to complete this study, a replication of the flicker test
(Rensink, O’Regan and Clark 1997). It was found that incongruent changes
were detected least quickly compared to the other two types, it has been
hypothesised that this could be due to expectations and top-down
processing, supporting the findings of Most et al. (2001, cited in Briggs
and Davies, 2015).
Introduction
Change blindness is the inability to notice changes in a visual scene
(Briggs and Hole, 2015). This is important to study because it reveals
limitations in human perception and attention. It can aid in improving
these areas. Change blindness shows that humans can only focus on a
small portion of what we see. Additionally, other things can affect
perception, such as top-down processing, which posits that expectations
can affect perception. For example, if one expects to see a face even
when there is not, one will perceive there to be. A study by Rensink,
O’Regan and Clark (1997) showed that people often miss large changes in
a scene when interrupted by a brief flicker or if one is not paying
attention. This study also suggests that visual memory is not stable and
static like many believed, it is dependent on attention, being constructed
from moment to moment. This is significant, as this can inform those in
careers where missing changes can have significant implications, such as
pilots or lifeguards. Another study, (Simons and Levin, 1998) had similar
results. An experimenter asked a pedestrian for directions and during this
conversation, a door was carried through the middle of them, and the
experimenter changed. Many participants did not notice this significant
change and continued the conversation. These results showed that many
changes go unnoticed if they are not within one’s perception, which has
important implications in things such as eyewitness testimony, where
many details can go unnoticed. Davis, Forrest, Treml, and Jansari (2018)
found that there was a certain group who were less susceptible to change
blindness, who were named Super-Recognisers, due to their superior
ability to recognise faces. These Super-Recognisers were police officers
who were able to spot people in a crowd with high levels of accuracy and
showed that training could lead to improvements in facial recognition and
therefore, potentially change blindness. Another study by Murphy and
Murphy, (2018) argued that perceptual load can directly affect change
, Harley Ponder (O1806310) DE200 TMA02
blindness. Perceptual load refers to the load taken on by completing
certain tasks, with certain tasks taking up more perceptual load.
Participants were in a room with either a high or low perceptual load,
conversing with a researcher. During the conversation, the researcher was
swapped out with a different person. More people noticed the change
when the perceptual load was low. This finding is significant, with it
suggesting that it could affect jobs such as security, where attention to
detail must be high. In addition, a study by Most et al (2001, cited in
Briggs and Davies, 2015) studied whether attention could affect
someone’s perception. They did this by using tracking software and asked
participants to focus on a central point on a screen, asking them to count
how many times the letters ‘T’ or ‘L’ bounced off of the side of the screen.
They were either black or white and in one trial, a black cross appeared on
the screen. Participants were more likely to notice it if they were asked to
track the black letters. This suggests that someone’s expectations can
affect perception, with the researchers suggesting that their expectations
led them to use biased sampling. Meaning, that not all information gets
processed. This current study researches change blindness using a type of
flicker method, with three types of change: congruent, incongruent or
within category. Changing the change type can tell us if one type is more
likely to be noticed. Additionally, this tests how quickly participants notice
changes, so it can show which change type is noticed quicker. I
hypothesise that the type of change will affect the results and that the
results will be most affected by incongruent changes. Incongruent
changes are changes that do not appear in a scene, such as a hairbrush or
a banana in an office space, as opposed to a stapler. A congruent change
is a change that you would expect to see in a scene but does not belong
to the same category as the original item, such as a plate on a dining
room table turning into a gravy boat. A within-category change is a
change that involves the object being replaced by an object in the same
category, such as a cushion with a different pattern. An incongruent
change may take longer to notice, as it is not what you expect to see in a
scene, this is known as top-down processing. Most et al (2001, cited in
Briggs and Davies, 2015) suggested that the unexpected change is less
likely to get noticed, therefore, this could be the case for the incongruent
changes, as they would be unexpected.
Method
Participants
Participants were recruited from the DE200 cohort, through an online
platform, as a part of their course requirements. The sample size is 250,
with a minimum age of 18 and a maximum age of 74. The mean is 36 and
Change Types Effect on Change Blindness
Abstract
A study on change type (congruent, incongruent and within-category) on
change blindness, definitions explained below. The study recruited 250
university students to complete this study, a replication of the flicker test
(Rensink, O’Regan and Clark 1997). It was found that incongruent changes
were detected least quickly compared to the other two types, it has been
hypothesised that this could be due to expectations and top-down
processing, supporting the findings of Most et al. (2001, cited in Briggs
and Davies, 2015).
Introduction
Change blindness is the inability to notice changes in a visual scene
(Briggs and Hole, 2015). This is important to study because it reveals
limitations in human perception and attention. It can aid in improving
these areas. Change blindness shows that humans can only focus on a
small portion of what we see. Additionally, other things can affect
perception, such as top-down processing, which posits that expectations
can affect perception. For example, if one expects to see a face even
when there is not, one will perceive there to be. A study by Rensink,
O’Regan and Clark (1997) showed that people often miss large changes in
a scene when interrupted by a brief flicker or if one is not paying
attention. This study also suggests that visual memory is not stable and
static like many believed, it is dependent on attention, being constructed
from moment to moment. This is significant, as this can inform those in
careers where missing changes can have significant implications, such as
pilots or lifeguards. Another study, (Simons and Levin, 1998) had similar
results. An experimenter asked a pedestrian for directions and during this
conversation, a door was carried through the middle of them, and the
experimenter changed. Many participants did not notice this significant
change and continued the conversation. These results showed that many
changes go unnoticed if they are not within one’s perception, which has
important implications in things such as eyewitness testimony, where
many details can go unnoticed. Davis, Forrest, Treml, and Jansari (2018)
found that there was a certain group who were less susceptible to change
blindness, who were named Super-Recognisers, due to their superior
ability to recognise faces. These Super-Recognisers were police officers
who were able to spot people in a crowd with high levels of accuracy and
showed that training could lead to improvements in facial recognition and
therefore, potentially change blindness. Another study by Murphy and
Murphy, (2018) argued that perceptual load can directly affect change
, Harley Ponder (O1806310) DE200 TMA02
blindness. Perceptual load refers to the load taken on by completing
certain tasks, with certain tasks taking up more perceptual load.
Participants were in a room with either a high or low perceptual load,
conversing with a researcher. During the conversation, the researcher was
swapped out with a different person. More people noticed the change
when the perceptual load was low. This finding is significant, with it
suggesting that it could affect jobs such as security, where attention to
detail must be high. In addition, a study by Most et al (2001, cited in
Briggs and Davies, 2015) studied whether attention could affect
someone’s perception. They did this by using tracking software and asked
participants to focus on a central point on a screen, asking them to count
how many times the letters ‘T’ or ‘L’ bounced off of the side of the screen.
They were either black or white and in one trial, a black cross appeared on
the screen. Participants were more likely to notice it if they were asked to
track the black letters. This suggests that someone’s expectations can
affect perception, with the researchers suggesting that their expectations
led them to use biased sampling. Meaning, that not all information gets
processed. This current study researches change blindness using a type of
flicker method, with three types of change: congruent, incongruent or
within category. Changing the change type can tell us if one type is more
likely to be noticed. Additionally, this tests how quickly participants notice
changes, so it can show which change type is noticed quicker. I
hypothesise that the type of change will affect the results and that the
results will be most affected by incongruent changes. Incongruent
changes are changes that do not appear in a scene, such as a hairbrush or
a banana in an office space, as opposed to a stapler. A congruent change
is a change that you would expect to see in a scene but does not belong
to the same category as the original item, such as a plate on a dining
room table turning into a gravy boat. A within-category change is a
change that involves the object being replaced by an object in the same
category, such as a cushion with a different pattern. An incongruent
change may take longer to notice, as it is not what you expect to see in a
scene, this is known as top-down processing. Most et al (2001, cited in
Briggs and Davies, 2015) suggested that the unexpected change is less
likely to get noticed, therefore, this could be the case for the incongruent
changes, as they would be unexpected.
Method
Participants
Participants were recruited from the DE200 cohort, through an online
platform, as a part of their course requirements. The sample size is 250,
with a minimum age of 18 and a maximum age of 74. The mean is 36 and
