The Impact of Brain Lobe Lesions on Human Function

This report discusses the main four lobes of the brain (frontal, parietal, temporal, and occipital) and their respective structures and functions. The impact of lesions to these lobes is explored, including difficulties in vision, movement, and locating objects. The report also references various studies and sources on the topic.

Discuss the roles of each of the brain’s
4 lobes. Outline their key structures and
their functionality. What are the
possible effects of lesions to each of
them?

Table of Contents
INTRODUCTION...........................................................................................................................1
MAIN BODY...................................................................................................................................1
CONCLUSION................................................................................................................................5
REFERENCES................................................................................................................................6

INTRODUCTION
Brain refers to an organ composed of a big mass of nerve tissue which is secured within
the skull. It has several roles such as regulation of breathing & blood pressure, processing
sensory data and releasing hormones. However, brain is separated into several relevant lobes
like parietal, temporal, occipital and frontal lobe. This presented report will focus on lobes of
brain with their key structures as well as functionality. It will also include possible effects of
lesions on these lobes of brain.
MAIN BODY
Brain can be described as one of the largest and most complex organs in human body. It
is known as central organ of human nervous system and it consist several parts including
cerebrum, brainstem and cerebellum. Meanwhile, brain is responsible for consisting four lobes
that can be categorised into frontal, parietal, occipital and temporal lobes. Initially, frontal lobe is
known as essential for regulating cognitive functions and controlling voluntary activity or
movement of human body. However, parietal lobe is responsible to process data related to taste,
touch, movement and temperature whereas occipital has function to regulate vision. Moreover,
the processing of memories, integrating them through sensations of sound, sight, taste and touch.
Frontal lobe comprise 2/3rd of human brain and it is composed to two paired lobes of
cerebral cortex including left & right frontal cortex. This lobe is situated close to foremost of
head, below the frontal skull bones as well as nearby forehead. However, it has been analysed
that left frontal lobes are responsible for affecting muscles on right side of the body whereas
right side of frontal lobe is controlling left part of human body. Moreover, there are several
functions which are regulating by frontal lobe of brain in which its key role is planning of future
that consist self management and decision making respectively. Hence, number of other roles of
frontal lobe are explained here.
Initially, Broca's region of frontal lobe helps to convert thoughts into words that results
into ability of a person of speech and language creation. It is also helpful to few of motor skills
like running and walking along with classifying objects to compare and distinguish them from
one another. Basically, it has a key role of forming long term memories and understanding to
feelings expressed by others to react for the same in suitable manner. It also consist the role of
forming personality which is a complicated interplay of memory, impulse control and other tasks
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in order to formulate key characteristics of an individual. In addition to this, frontal lobe is
responsible for consisting dopamine sensitive neurons of brain which is a chemical for
supporting reward seeking behaviour as well as motivation. Moreover, it plays an important role
to manage attention including selecting attention in different situations.
Impacts of lesions to frontal lobe consist altering personality of an individual and create
issue like Attention-deficit/hyperactivity disorder (ADHD). If frontal lobe get damaged then a
person often struggle to gather data, remember previous experiences and make decisions
accordingly. Meanwhile, lesions on frontal lobe results into several symptoms such as falling,
weakness, inability to problem solving, impaired judgement, decreased creativeness, reduced
sense of smell or taste, depression, low encouragement, decreased sexual interest, low attention
span and impulsive or risky behaviour. Moreover, number of mental health problems cause by
damage in frontal lobe that includes dementia, stroke & transient ischaemic attacks, cerebral
palsy, Huntington's disease, brain tumours, infections, Parkinson's disease, traumatic injury and
Alzheimer's disease. Additionally, these the problems can be generated as an impact of lesions
on frontal lobe of brain and requires immediate medications for maintaining appropriate
psychological health of a person.
Parietal lobe is superior to an occipital lobe and posterior to the frontal lobe & central
sulcus in brain. It sits directly over the skulls hence it is known as parietal lobe of brain. The key
role of parietal lobe is to interpret sensory information like letting a person know about location
of body parts and aiding into physical navigation. However, there are number of functions which
are regulating by parietal lobes of brain that are described here. Basically, parietal lobes consist
somatosensory cortex within them which is responsible to help for determining location of touch
sensation and differentiate among different sensations including pain and temperature. This lobe
contains neurons that receive information related to vision, touch and another sensations from
thalamus. It is also helpful for processing specific information in order to identify specific object
by touching the same. Meanwhile, it has been analysed that parietal lobes perform with other
parts of brains including motor and visual cortex in respect of performing certain tasks properly.
Parietal lobe plays an important role to make an individual capable to determine the
location, position and movement of human body along with its various parts respectively. It
consist number of functions such as speech, cognition, visual perception, writing & reading,
mathematical computation, touch sensation (temperature, pain, etc.), movement coordination,
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information processing and understanding spatial orientation. Meanwhile, it has key function of
processing sensory information related to temperature and taste along with touching sensations in
human beings. It is not possible for humans to feel anything about sensations if parietal lobe get
damaged in any manner. For example, a person can only feel about location of their tongue due
to proper working of this lobe and it helps to avoid biting it while chewing the food.
Lesions occurring on parietal lobe are responsible for several symptoms and create
problem for an individual. Initially, it effects the main functions of parietal lobe which indicates
certain signs including loss of sensations such touch or pain and weakening of language
development that create problem of a person in daily life . In addition to this, lesions in parietal
role is responsible for developing a situation of astereognosis in which an individual face
inability to determine things placed in the hands (PARIETAL LOBES, 2019). However, damage
in right parietal lobe results into contralateral neglect that may damage personal aid abilities and
it can reason a trouble in constructing belongings i.e. constructional apraxia. It also consist
problem of anosagnosia including denial of deficits and drawing capability. Meanwhile, it has
been analysed that left parietal lobe get damaged then it will facilitate occurrence of Gerstmann's
Syndrome consisting right-left confusion, problem in mathematics (acalculia) and difficulty with
writing (agraphia). It is also responsible for causing language issues that is called aphasia and
disability to perceive objects normally i.e., agnosia.
Temporal lobe is located in largest section of brain in human body which is called as
prosencephalon (fore brain). It is located in inferior towards frontal & parietal lobes and anterior
to occipital in brain. This lobe plays key role in auditory perception, language & speech
production, organising sensory input and formation & association of memory. However, the
structure of temporal lobes consist limbic system involving amygdala, hippocampus and
olfactory cortex that helps in regulating its functions (Fang, Wang and Jiang, 2016). Moreover,
Fissure of Sylvius that is considered as a large deep groove which is responsible for separating
parietal and temporal lobes. Temporal lobes consist middle, inferior and superior temporal
convolutions and sidelong occipitotemporal convolutions. It also includes fusiform, lingual and
parahippocampal & hippocampal convolutions along with transverse gyri of Heschl that is
known as primary auditory receptive area of brain. The connection of temporal lobes involves
several pathways including hierarchical sensory, dorsal auditory, polymodal & medial (mesial)
temporal pathway along with frontal lobe projection.
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The main functions of temporal lobes consist number of aspects such as speech,
language comprehension, emotional responses, visual perception, facial recognition, memory
and auditory perception. The key temporal lobes has certain functions that are related to hearing,
memory and speech. Initially, amygdala is responsible for controlling several fear related
autonomic responses, fight or flight response and generate proper sense of fear via fear
conditioning. This part of temporal lobe collect data from thalamus & another section of cerebral
cortex to respond in an appropriate way. However, hippocampus has a function to aid
formulation of memory and link the emotions & senses including smell as well as sound. It has
been analysed the Wernicke's area of brain is founded in temporal lobes which supports to
process words along with understanding spoken language. It has a function of processing
auditory information from ears in context of hearing properly.
Lesions of the temporal lobe responsible for various problem such as change in
behaviour & emotions, language & speech issues, difficultly in context of vision, forgetfulness,
disable to concentrate and disruption in sense. It is responsible for disturbance in auditory
sensation & perception, difficulty in music & visual perception, disruption to select auditory &
visual input and disable for utilising relevant knowledge. The damage in temporal lobe results
into altered personality & affective behaviour, impaired long term memory and alter sexual
activity. Impact of lesions encourage occurrence of several syndrome like Wernicke's aphasia,
amusia, visual agnosia, homonymous upper quadrantanopia as well as alteration in mental test of
visually observed matter (Brain Lesions, 2019). Moreover, other syndromes related to temporal
lobes consist gustatory & olfactory hallucinations, dreamy states, behavioural & emotional
changes, delirium, disturbance of time perception, Korsakoff amnesic defect, placidity & apathy,
visual, auditory and Kluver- Bucy syndrome (hypermetamorphopsia, hyperorality,
hypersexuality and blunted emotional reactivity). Damage of temporal lobes may cause severe
health problems that requires medical attention immediately in order to take effective clinical
actions for making an individual well being.
Occipital lobe consist bottom and back part of cortex which is responsible for regulating
vision of an individual. It consist number of structures & neural tracts considering dorsomedial
stream, the lateral geniculate bodies, lingula, Brodmann area 17 and ventral stream. However,
these are located in posterior region of cerebral cortex and known as main centres of processing
the vision. The occipital lobes contains visual processing and cortex centres exist in human brain
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of the body. It consist visual cortex that is responsible for acquiring unprocessed sensory data
with the help of sensors in retina of eyes that will transformed by optic tracts to the visual cortex.
Functions of occipital lobe consist various aspects including key role of regulating
vision in human being. Initially, it is helpful in mapping the visual world that provide support in
visual memory as well as spatial reasoning. However, it plays an important role to identify
properties of colour relevant to different objects exist in visual area and facilitate in evaluating
the size, distance as well as depth. In addition to this, it functions to facilitate determining visual
stimuli specifically familiar faces and items and receive unprocessed visual information from
perceptual sensors in retina of the eyes. Moreover, occipital lobe is accountable for transmitting
visual data toward another section of brain so that the desired functions can be carried out by
brain lobes. Meanwhile, these functions includes assign meaning, craft motor & linguistic
responses, encode memories and respond toward data acquired from surrounded world
continuously (Heilman, 2016).
Impact of lesions to occipital lobe consist certain problems including epilepsy in which
few of seizures take place and increase vulnerability to occurrence of the same. It consist the
difficulties in movement face by an individual or if they can move then changes in depth
perceptions and vision leads to improper movements as well as difficulty in navigating the visual
field. Basically, they face problems in terms of perceiving various types of colours, shapes,
dimensions and size. Meanwhile, the difficulty to recognise familiar objects or faces, read
written words and hallucinations occurs (Occipital lobes, 2019). However, damage to occipital
lobe create disability of an individual to detect about movement of object, reading writing as
words may appear to move on the page. Moreover, it can develop disruption in order to locate
items within an atmosphere even when these objects are seen. Additionally, it is also creating
difficulties with gross and fine motor abilities as well as balancing skills.
CONCLUSION
The above report has been concluded that brain has main four lobes such as frontal,
parietal, temporal and occipital with their own structures and functions. It involves impacts of
lesions creating difficulties in vision, movement and locate things in proper way.
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REFERENCES
Books and journals
Baris, M. M. & et. al., (2016). Role of mass effect, tumor volume and peritumoral edema volume
in the differential diagnosis of primary brain tumor and metastasis. Clinical neurology
and neurosurgery. 148. 67-71.
Fang, S., Wang, Y., & Jiang, T. (2016). The influence of frontal lobe tumors and surgical
treatment on advanced cognitive functions. World neurosurgery. 91. 340-346.
Heilman, K. M. (2016). Possible brain mechanisms of creativity. Archives of Clinical
Neuropsychology. 31(4). 285-296.
Levan, A. & et. al., (2016). Right frontal pole cortical thickness and executive functioning in
children with traumatic brain injury: the impact on social problems. Brain imaging and
behavior. 10(4). 1090-1095.
Neulinger, K. & et. al., (2016). Prospective memory and frontal lobe function. Aging,
Neuropsychology, and Cognition. 23(2). 171-183.
Online
Brain Lesions. (2019). [Online]. Available
through:<https://my.clevelandclinic.org/health/diseases/17839-brain-lesions>
Frontal lobe: Functions, structure, and damage. (2019). [Online]. Available through:
<https://www.medicalnewstoday.com/articles/318139.php>
Occipital lobes. (2019). [Online]. Available through:<https://www.braininjury-
explanation.com/consequences/impact-by-brain-area/the-occipital-lobe>
PARIETAL LOBES. (2019). [Online]. Available
through:<https://www.neuroskills.com/braininjury/parietal-lobes/>
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