Question

1. What role does biology play in understanding Psychology? Students will express an understanding of how both the Evolutionary Theory; the body’s systems (e.g.  nervous, endocrine, and limbic systems); and Nature vs. Nurture along with the new theory of Epigenetics help us explain human behavior.
2. What are the particular functions of one side of the brain as compared to the other hemisphere?

         Left-side functions:                                            

     Right-side functions:

3. Describe the functions of the following parts of the brain:

        Cerebral functions:

        Cerebellar functions:

        Motor Cortex:

        Visual Cortex:

        Auditory Cortex

        Somatosensory Cortex:

        Broca’s Areas:

      Wernicke’s Areas:

        Brain Stem:

Answer 1

Biologists believe that we humans were not always like this, the way we are. We have undergone a complex and slow process of “Evolution”. Our behaviours are highly complex and is much more developed than any of the other species because of the high level of development of our brain. This evolution were a result of environmental adaptations and survival.

Psychology is defined as the study of “Behaviours”. An important factor that determines our behaviour is the biological structures that we have inherited. This role and importance of biology can also be observed in cases when a person in many instances develops some kind of behavioural and physical disabilities in the aftermath of accidents which leads to destruction of brain cells or children who have low IQ to the level of mental retardation because he/she may have faulty gene from his/her parents.

The two main system that work together to shape our behaviours are the Nervous System and Endocrine System:

Nervous System:

The nervous system can be divided into two parts- the Peripheral Nervous System (PNS) and Central Nervous System (CNS). All the parts of the nervous system that is found inside bony cages like the brain, spinal cord are a part of CNS and all the parts of nervous system other than CNS is PNS which can be further classified into Somatic and Autonomic nervous system.

The PNS consists of all the neurons and nerve fibres that connects the CNS with the rest of the body. It provides information from the body to CNS and takes instructions from CNS to body parts. The somatic division of PNS is concerned with the voluntary actions while the autonomic division takes care of the involuntary actions.

The CNS is the centre of all neural activities and integrates all the sensory information and performs cognitive actions and functions. It comprises of Brain and Spinal cord. The brain has organised structures and regions for performing specific functions. The brain has three parts:

Hindbrain: Which consists of Medulla Oblongata (which regulate life supporting activities like heart rate, blood pressure etc), Pons (involved in sleep mechanism and affects respiratory movements and facial expressions) and Cerebellum (controls posture and body equilibrium and coordination of muscular movements).

Midbrain: An important part is Reticular Activating Systems (RAS) which is responsible for arousal and also makes us alert and active by managing sensory inputs.

Forebrain: This regulates most of the important cognitive, emotional and motor activities. It consists of Hypothalamus (regulates emotion and behaviours like sleeping, drinking etc), Thalamus (regulates ingoing and outgoing motor signals), Cerebrum (regulates all higher levels of cognitive functions like attention, perception, memory, learning etc) and the Limbic system

• The Limbic system consists of a group of structures that are believed to be a part of the old mammalian brain. The main function of this system is to maintain the internal homeostasis by regulating and controlling the body temperature, blood sugar level and blood pressure.

It also consists of hippocampus and amygdala. Hippocampus plays an important role in long term memory and Amygdala plays an important role in emotional behaviour

            Another important part is the Spinal Cord which is a ling rope like structure that is the collection of nervous fibres. It consists of association neurons and other cells that is shaped like mass of grey matter. It is surrounded by white matter of ascending and descending neural tracts which connects the brain with rest of the body. The two main functions of spinal cord is: to carry sensory impulses from the brain to all over the body and perform simple reflexes that do not involve brain.

Endocrine System:

The endocrine system plays a crucial role in our behaviour by secreting specific chemical substances called hormones that control some of our behaviours. This system is also known as neuroendocrine system as it acts like a conjunction with different parts of nervous system.

It consists of various glands that secrete various hormones throughout life like:

Pituitary Gland: It leads to the secretion of growth hormones and gonadotropic hormone.

Thyroid Gland: It produces thyroxin. The underproduction by this gland can lead to physical and psychological lethargy.

Adrenal Glands: This glad leads to the secretion of a variety of hormones like corticoids, epinephrine and norepinephrine which regulates important functions like heart rate, oxygen consumption, muscle tone etc and also regulates emotions.

Pancreas: It secretes insulin which regulated body sugar level and glucose levels.

Gonads: it releases hormones to regulate sexual behaviours in males and females.

The normal functioning of all hormones is crucial to our wellbeing of behaviour. Without a balance of these hormones in our body we would not be able to maintain an equilibrium like without the increased in release of some hormones at the time of stress we would not be able to deal and react to our surroundings effectively and also without the release of some of them at certain times, we would not be able to grow, mature and reproduce.

Nature V/S Nurture:

The nature V/S nurture debate in Psychology is old. The nature refers to our biological disposition in our genes which regulates our behaviour and responses in a particular circumstance and the nurture refers to our environment and culture which studies how these affect our behaviour and psychological development. Studies on identical twins, siblings and adopted children (like in intelligence) have shown that biology plays a very important role in psychological development because of the type of gene we inherit. At the same time, it also proves that not only the biological factor but also the environment influences our behaviours. (the behaviour of adopted children gradually become similar to their new parents). Thus, there is a psychological consensus that our behaviours are a product of interaction of heredity(nature) and environment(nurture). Heredity can be viewed as something that sets limits and within these limits individual’s development is actually shaped by the support of opportunities in the environment.

The brain is a complex organ and has specific parts that perform specific function. The brain as a whole can be divided into left and right hemisphere each of which perform some specialised activities:

Left Side: The left hemisphere is known for being more analytical and verbal and more ordered than the right side. It is better at functions like calculations, writing and reading. It is connected to logic, mathematical thinking and sequencing, fact checking and analysis, recognising and thinking of new words etc

Right Side: The right side is known for being more creative side and less organised. It is more visual and intuitive and is often connected to arts, rhythms, creative thinking and innovation, holistic thinking, visualisation and day dreaming etc.

Functions:

• Cerebral functions: Cerebral cortex is responsible for all the higher levels of cognitive functions like attention, reasoning, learning etc. The cerebrum is divided into two halves called the Cerebral hemispheres. The left hemisphere controls language behaviour and the right hemisphere is specialised with dealing with images, spatial relationships and pattern recognition.

Cerebral cortex is also divided into frontal lobe (concerned with attention, thinking, learning etc), Parietal lobe( cutaneous sensations and visual and auditory coordination), temporal lobe( processing auditory sensations) and Occipital lobe( concerned with visual information)

• Cerebellar functions: The cerebellum is a highly developed part of the hindbrain and has a wrinkled surface, it maintains and controls posture and equilibrium of the body and is responsible for muscular coordination and movements. It receives all the motor commands and coordinated them to relay the muscles. It also stores the movement patterns for future use.
• Motor Cortex: Motor cortex is a part of cerebrum situated in the frontal lobe and is responsible for producing neural impulses to control movement and other motor activities
• Visual Cortex: Visual cortex is situated in the occipital lobe and is mainly concerned with understanding the visual information and the interpretation of visual impulses and memory of visual stimuli.
• Auditory Cortex: It is situated in the temporal lobe and is concerned with processing auditory information like language recognition, response, language switching etc
• Somatosensory Cortex: It is the part of sensory system that deals with the

conscious perception of sensations like touch, pain, temperature etc that happens in skin, muscles and joints.

• Broca’s Areas: Broca's area is responsible for the production of language and all the motor functions involved in the production of speech.
• Wernicke’s Areas: This area is also involved in speech and language production but is more active in the comprehension of speech.
• Brain Stem: Brain stem’s functions include regulation of heart rate, sleeping, breathing, eating etc and also is involved in the coordination and conduction of information from the brain to rest of the body.