Week 3: Macro-neuroantomy - Central nervous system, limbic system and neuro techniques

Question 1

Psychosurgery/Hemispherectomy

Answer 1

This type of research involves ablation (which is the surgical removal of brain tissue), or by inserting electrodes into specific areas of the brain, to examine how this disrupts behaviour.

Question 2

Deep Brain Stimulation (DBS)

Answer 2

In this technique, electrodes are inserted into the brain so that those regions can be electrically stimulated for therapeutic benefit.

Deep brain stimulation is used in treatment of multiple conditions, such as treatment-resistant major depression disorder and motor tremor associated with Parkinson’s disease.

Question 3

Neuroimaging

Answer 3

Neuroimaging techniques basically attempt to measure neural activity in the brain.

These techniques can be categorised as either ‘non-invasive’ or ‘invasive’ techniques.

Three neuroimaging techniques most commonly used in human brain research are electroencephalography (EEG), functional magnetic resonance imagery (fMRI), and positron emission tomography (PET).

Question 4

Electroencephalography (EEG)

Answer 4

This non-invasive technique involves the use of recording electrodes that are placed at various locations on the scalp to record the electrical activity being produced in the underlying regions of the brain.

One strength of EEG is that has very high temporal precision (“temporal” = time; “precision” = accuracy).

One weakness of EEG is that it has poor spatial resolution (“spatial” = location; “resolution” = clarity).

Question 5

Magnetic Resonance Imaging (MRI)

Answer 5

MRI uses powerful magnetic fields to detect and measure different types of tissue in the brain and body.

This technique offers a high level of spatial resolution and can identify different regions of the brain with millimetre precision.

Question 6

Functional Magnetic Resonance Imaging (fMRI)

Answer 6

fMRI measures neural activity indirectly by measuring oxygenated blood versus deoxygenated blood levels within specific regions of the brain.

This technique can be used to measure which different brain regions become active when people perform or undergo different types of tasks.

One strength of fMRI is that it is incredibly accurate at showing where things occur in the brain (i.e., it has high spatial resolution) with millimetre precision.

However, because it is measuring changes in blood flow, and it can take blood takes several seconds to reach those brain regions it is needed it, it is incredibly imprecise at measuring when a change occurs within the brain (i.e., it has low temporal resolution).

Question 7

Positron Emission Tomography (PET)

Answer 7

invasive neuroimaging technique, involves the use of radioactive chemicals which are injected intravenously.

Although PET offers relatively good spatial resolution, the technique is similar to fMRI in having somewhat poor temporal resolution.

Question 8

Transcranial Magnetic Stimulation (TMS) (Brain Stimulation Technique)

Answer 8

A non-invasive technique that uses electromagnetic fields to induce an electrical current inside the brain.

It is also possible to use TMS to examine the parts of the brain which are associated with psychological processes, such as language, executive functioning or thinking. TMS can be administered above a region of the brain thought to be involved in a cognitive ability to temporarily “turn on” or “turn off” that brain region.

Question 9

Deep Brain Stimulation (DBS)

Answer 9

an invasive form of brain stimulation that involves the insertion of electrodes into the brain via psychosurgery.

Question 10

The Hindbrain

Answer 10

The hindbrain sits at the base of the skull and is comprised of several brain regions including (i) the medulla oblongata, (ii) the pons, (iii) the reticular formation, and (iv) the cerebellum.

Question 11

The Medulla Oblongata (Hindbrain)

Answer 11

The medulla oblongata is found just on top of the spine and is considered an extension of the spinal cord.

This region is very important for several critical life functions including cardiovascular control such as breathing and heart rate, and many life-critical reflexes such as vomiting, coughing, and sneezing.

Question 12

The Pons

Answer 12

The pons sits on top of the medulla oblongata. It contains several pathways that send information from the face, eyes, and ears to the brain.

The word “pons” is Latin for “bridge”, and it is this because it is the location where neurons from one side of the brain crossover and connect with the opposite or “contralateral” side of the body.

The pons is also involved with regulation of sleep, particularly a type of sleep known as “rapid eye movement” (REM) sleep.

Question 13

The Reticular Formation

Answer 13

The reticular formation is found deep within the medulla and the pons. Its role is the regulation of attention, arousal, wakefulness, and sleep.

The reticular formation contains a pathway known as the “ascending pathway”. This ascending pathway sends information from the lower sections of the nervous system - that is, from your body - to higher cortical regions of the brain to be further processed and understood.

Question 13

Hypothalamus

Answer 13

The word “hypo-” means “below” or “under”, so the hypothalamus describes the brain structure located just below the thalamus.

Motivational and avoidance type behaviours

The hypothalamus has been associated with what we call the “four F’s”: fighting, fleeing, feeding, and fornicating

Question 13

Basal Ganglia

Answer 13

The basal ganglia are involved with many aspects of motor control, memory, and emotional expression.

The basal ganglia are involved with the initiation of planned and coordinated motor movements

Question 13

Amygdala

Answer 13

Revolves around behaviour/emotion

In addition to its role in emotion, there is increasing evidence to show the amygdalae are involved with a much wider range of processes, for example, as a “relevance detector” for stimuli in the environment.

Question 13

The Cerebellum

Answer 13

The cerebellum is a part of the hindbrain that works unconsciously to coordinate aspects of motor control, including our balance, gait, and posture.

Specifically, the cerebellum helps to smooth out motor movements so that we can move effortlessly in our environments

Question 14

The Midbrain

Answer 14

The midbrain - sits just on top of the hindbrain.

The midbrain is made up of:
(i) the superior colliculus, which is involved with aspects of vision and eye movements and
(ii) the inferior colliculus, which is involved with aspects of hearing,
(iii) the tectum,
the (iv) the tegmentum and
(v) the substantia nigra which is involved with things including movement, reward, and motor control.

Question 14

Thalamus

Answer 14

‘Inner Chamber’

The thalamus acts as a relay station that sends sensory information - including our sense of touch, taste, vision and hearing - on to the primary cortices’ for further processing.

The thalamus is involved in spatial learning and non-spatial memory.

Question 14

Hippocampus

Answer 14

The hippocampi have an important role encoding new memories and in consolidating short-term memory into long-term memory stores.

The hippocampus is also involved in learning new facts and knowledge about the world

The hippocampus also consolidates information you have learned into “long-term” memory stores, allowing you store and then retrieve that information later one when it is needed

Question 15

Corpus Callosum

Answer 15

The two sides of the brain – called the left and right hemisphere - are connected by a bridge of neural tissues known as the “corpus callosum”. The corpus callosum allows information from one hemisphere to be shared with the corresponding contralateral, or opposite, side of the brain.

Question 15

The Lobes of the Cerebral Cortex

Answer 15

The outer layer of the cerebral cortex can be divided into four lobes: the frontal lobe, the parietal lobe, the temporal lobe, and the occipital lobe.

Question 16

Frontal Lobes

Answer 16

The frontal lobes comprise several regions which are involved with self-initiated voluntary movement, aspects of personality, working memory, and reward and punishment.

Question 17

Primary Motor Cortex (M1)

Answer 17

region of the frontal lobe that is involved with the initiation of voluntary movement.

This region is organised in a hierarchical fashion. The top regions of M1 control your feet, legs, groin, and torso. The lower parts of M1 control your hands, arms, face, and tongue muscles.

Question 18

Dorsolateral Prefrontal Cortex (DLPFC) (Frontal Lobe)

Answer 18

The DLPFC are involved with a collection of cognitive processes we call our executive functions.

“Executive functions” is an umbrella term for a collection of cognitive processes including problem solving, holding items in working memory, engaging in deep thought, maintaining goals or rules when performing tasks, manipulating information for problem solving, but also future planning and inhibition.

Essentially, the DLPFC is involved with advanced thinking capabilities, and is used in many different situations

Question 19

Broca’s area (Frontal Lobe)

Answer 19

This area is one involved with language processing, and specifically influences our ability to produce speech.

Question 20

Parietal Lobes

Answer 20

The parietal lobes are mainly known for their involvement with the processing of sensory information, but also help us with our spatial navigation and spatial awareness.

Question 21

Primary Somatosensory Cortex (S1) (Parietal Lobes)

Answer 21

The somatosensory cortex (or S1) is the region of the brain which processes incoming sensory information relating to feelings of touch.

Anatomically, the primary somatosensory cortex and the primary motor cortex are side-by-side.

Question 22

Occipital Lobes

Answer 22

These lobes house the regions of the brain involved with visual processing.

Question 23

Temporal Lobes

Answer 23

The temporal lobes are associated with several important functions including auditory processing, object recognition and facial perception, and memory processes.

Question 24

Temporal Lobe Areas

Answer 24

The temporal lobes contain the primary auditory cortex which is involved with processing of sound (i.e., “auditory”) information.

The right temporal lobe contains a region that appears to be specialised for the recognition of human faces, referred to as the fusiform face area.

Wernicke’s area is involved with language processing, and influences our ability to comprehend speech.