‘There functions could contribute to the study and

‘There are many areas of cognition
that contribute to its main function. Two of these, attention and response
inhibition, operate in the shadows of our minds and play enormous yet unseen
parts in the goings about of our daily lives.

 Attention has a very rich history that spans
across less than a century. In that time, attention study has reached levels
never imagined before and brain scans have become better than ever at mapping
the brain and locating different areas. Tests which measure attention have been
trialled hundreds of times, each one suited to a particular subset of
attention.

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 However, it would be an error to forget
response inhibition. Although there is little or no record of early attempts at
studying response inhibition, it continues to be researched unfailingly. To
date, three brain areas that are linked to response inhibition have been
located. Tests on this part of cognition are just as numerous as those on
attention. Differences aside, both attention and response inhibition are
important and interesting subjects of study for neuropsychologists worldwide.’

Cognition
is ‘the mental action or process of acquiring knowledge and understanding
through thought, experience and the senses’.1 It is considered
important to study cognition because the discovery of cognitive functions could
contribute to the study and treatment/prevention of mental disorders such as
Alzheimer’s and schizophrenia. Furthermore, the study of cognition sheds new
light on various aspects of how we function, from recalling how to walk to the
ability to make choices and factors that affect this ability. The areas of
cognition that will be discussed are attention and response inhibition. The two
different types of attention, emergency and precise, will be discussed, along
with the history of the study of attention, the reliability of experiments on
attention and disorders associated with attention. The brain regions associated
with response inhibition, experiments on response inhibition and disorders
associated with response inhibition will also be covered.

To
begin, attention is divided into two categories. There is precise attention,
where a person is consciously focused on a target, and emergency attention,
where a person unconsciously focuses on a target in response to a stimulus.
Neither of these is permanent, because attention is limited in both capacity
and duration. This evidence has been used to disprove the multitasking theory, which
states that a person is capable of doing and concentrating on two or more
things at once. Precise attention has been found to originate from the
prefrontal cortex, an area located right at the front of the brain that is
known for its involvement in cognitive thinking. Emergency attention,
meanwhile, is known to stem from the parietal lobe, an area of the brain that
processes sensory information. This is likely to explain why precise attention
requires conscious thought but emergency attention is activated in response to
a sensory stimulus without requiring any thought process.

            Attention
study was first recorded during the 1880s, when Wilhelm Wundt conducted and
published studies on attention.  To
Wundt, ‘consciousness was a function of attentional scope’, and his perception
of attention emphasises selectivity and focus.2 The next great
discovery in the field of attention was by Ivan Pavlov. In the 1920s, he found
that dogs would salivate when given food by tapping saliva from the dogs’
salivary glands. For his experiment, he rang a bell every time he fed the dogs.
After some time, Pavlov found that if he rang the bell but failed to present
food the dogs would salivate regardless.3 He then deduced that the
dogs had learned to associate the sound of the bell with food. This is called
classical conditioning. The dogs had paid attention to the sound of the bell
before they were fed so frequently that they began to focus on the sound of the
bell as an indication that they would be fed rather than the presentation of
the food itself. This experiment has been retried on other organisms using
different cues, such as a blind fish being fed in accordance with a click .4While
these findings appear irrelevant, a child will use a similar attention -based
association when scolded for bad behaviour. When ignored while keeping good
conduct, a bored child may do an unsavoury action. If this behaviour is
scolded, punished or reacted to in some way, the child will associate this
action or others affiliated with this action with attention or relief from
boredom and will therefore repeat it.5 Understanding this
cause-effect relation is key to help prevent future misbehaving for parents
struggling to deal with their hyperactive or troublesome young child.

1924
saw the first advance in brain mapping technology with the invention of the
first human electroencephalogram (EEG).6 This machine consists of
small sensors that are attached to the scalp and is normally used to help
patients with epilepsy.7 The field expanded again with the invention
of the full body Computed Tomography or CT scanner in the 1950s.8
Like the EEG, the CT scanner is used in hospitals to check for diseases and
uses X-rays and a computer to create a digital map of the body’s internal
workings.9

            Attention
has been an object of fascination in the science world, with many studies being
conducted on it. One of the most well-known principles of attention is Change
Blindness. This principle is founded on the basis that if precise attention is
directed at a certain object then another object irrelevant to the first may
appear invisible or unseen. The Change Blindness video depicts two teams, the
whites and the blacks. Each team has one ball. A question on the screen then
asks the viewer how many passes the white team make. After the video finishes
playing, the screen displays 13, the correct answer, then asks the viewer if
they saw a moonwalking bear. On the assumption that the answer is no, the video
rewinds and begins to play again. Now that the viewer knows there is a
moonwalking bear and is determined to find it, they apply precise attention to
anything that looks like a moonwalking bear. While they are now extremely
likely to spot the bear, the viewer won’t be able to calculate the passes and
may lose concentration after the bear walks offscreen. This proves the
principle while adding another piece of evidence against multitasking theory.

            A
second test on attention – the psychomotor vigilance task – measures sustained
attention, hence the word ‘vigilance’. Participants are instructed to
concentrate on a blank or coloured screen until numbers appear. At this point,
they are required to press a button as quickly as possible. The test can last
any amount of time, with random intervals between number showings, but longer
testing periods are preferable for scientific studies, particularly on sleep
deprivation and other related circumstances. The task itself is a good way of
measuring sustained attention, but the data must then be correctly interpreted.
Nonetheless, results include performance becoming less efficient as a test
drags on and slower reaction times in the sleep-deprived.

The
third of these tests is the selective attention measuring dot probe task.
Official dot probe tasks consist of one practice block of stimuli (16 pairs of
pictures) and four test blocks containing 24 picture pairs each.11
The test begins with two fixation crosses on the screen for 500 milliseconds,
then shows picture stimuli at those places for 250-500 milliseconds.12
Finally, an asterisk, or ‘dot probe’, hence the name, replaces each picture,
requiring the participant to press a corresponding key13. Stimuli
are grouped into positive stimuli such as kittens, neutral stimuli such as
chairs and negative stimuli such as flies.14 Two of these stimulus
groups would be selected for each pair of pictures. This task has been called
unreliable before; not least because some stimuli may fail to elicit the
expected response (e.g. arachnophilic participants will associate spiders with
positivity).

 Attention can be affected in a number of ways
if someone has a disorder. The most well-known of the attentional disorders is
attention deficit hyperactivity disorder (ADHD). People with ADHD are known for
being easily distracted and unable to sit still. They are often associated with
troublesome behaviour at school age. A study found that children with ADHD have
brains up to 4% smaller than those without it because of smaller frontal lobes,
cerebellums and caudate nuclei.15 These are the brain areas that
control many of the problem areas in the ADHD child.16 ADHD children
are also found to get injured more often and will sustain injuries longer.17

                        Response
inhibition is the prevention or stalling of an action in a situation where said
action would be incorrect or threatening in some way. A lack of response
inhibition may be to blame in children who are particularly talkative or
otherwise disruptive. The role of associated brain areas in response inhibition
are somewhat unknown due to response inhibition not being divided into types
like attention. The subthalamic and caudate nuclei play a part in response
inhibition, along with the prefrontal cortex.18

            Response
inhibition is a widely studied area of cognition in testing terms and there are
many tests to measure it as well as attention, which is closely related to
response inhibition, especially emergency attention. One of these tests is the
stop signal task. This task requires the participant to press a button if an
onscreen arrow points to it.19 After 16 trials are completed, the
participant continues but is also told to withhold a response if an auditory
stimulus (e.g. a beep) is heard.20 In this task, good response
inhibition can be measured by the number of responses in accordance with the
beep. In healthy adults over the age of 25, a lower number of incorrect
responses would be expected than for teenagers or sleep-deprived adults.

            Probably
the most popular of all response inhibition measuring tasks is the Go-NoGo
task. This widely used task is known to be useful for enhancing the reliability
of a study, since it has been tried and tested many times before, with the
conclusion and often upheld opinion that it is an effective and reliable task.
Before the test, participants will be shown, either verbally or visually, the
Go and NoGo stimuli. Participants are required to press a button when a Go
stimulus appears, but to withhold that response when a NoGo stimulus appears.
The stimuli would usually be shapes that are similar in colour and relative
size.  Errors on a report using the
Go-NoGo task are probably likely to be results errors caused by incorrect
analysis of the data and/or insufficient researching on what results of a
Go-NoGo task show.21

            The
final test which will be discussed is the Stroop effect task. This task
measures both attention and response inhibition. Participants are instructed to
respond with the colour of the word on the screen. For example, if green
coloured text saying ‘purple’ was shown, the correct response would be ‘green’.
‘Purple’, as well as no response, would be deemed an incorrect response. The
Stroop effect itself was discovered by J. Ridley Stroop in 193522
and refers to the fact that the brain will respond to a word such as ‘blue’
with the colour blue. Since the brain has associated words with colours,
conscious thought is often required for a colour word that is a different
colour to the one it describes. Young children about 3-5 years old may find
this test easier, as they have probably learnt the colours but not the words,
so the words and associations mean nothing to them.23

One
of the reasons why response inhibition is studied so much is that there are
many diseases associated with or directly linked to it. Obsessive compulsive
disorder (OCD) is at the forefront of these. OCD is a condition where someone
obsessively repeats an action again and again or ‘must’ have a particular thing
a certain way. Response inhibition in the former type of OCD is usually normal,
but when applied to the action in question it becomes ineffective or even
nonexistent. The person has no ability to stop this action, even in an
undesirable situation, and may become stressed if prevented from doing it.
Causes of OCD include low levels of serotonin and stressful events.24

In
conclusion, attention and response inhibition are key factors in cognition. The
history of attention is better documented than response inhibition, including
far more known key events and there is a better global understanding of it. They
are however very closely linked. Attention and response inhibition are usually
measured simultaneously in most tasks, since said tasks generally contain
particular stimuli or instructions that require both attention and response
inhibition to interpret or fulfil. Finally, attention and response inhibition
are equally important in study terms because they both hold the keys to better
understanding and ultimately more effective treatment of various mental
disorders, along with shedding new light upon the inner workings of our brains.