lecture 1 - brain tour

Question 1

how many neurons do we have?

Answer 1

10 - 15 billions

Question 2

how many synapses do we have?

Answer 2

trillions

Question 3

cortex

Answer 3

higher level things supported by cortex - 4 lobes/cortex. the number of cells in cortex is related to how much processing power we need.

Question 4

functional specialisation - rule of thumb

Answer 4

frontal cortex is evolved from action planning, the 3 posterior cortices are evolved from sensory processes.

Question 5

frontal lobe function

Answer 5

motor control including speech, planning, changing task, working memory, motivation and personality.

Question 6

what damage to frontal lobe can cause

Answer 6

aphasia, alien hand syndrome

Question 7

features of alien hand syndrome

Answer 7

top of frontal lobe lose control of automatic things body is primed to do eg can’t control arms

Question 8

brocas aphasia in frontal lobe

Answer 8

knows and recognises words but can’t say them so lacks fluency

Question 9

temporal lobe function

Answer 9

hearing, language, object recognition, memory for things

Question 10

what damage to temporal lobe can cause

Answer 10

amnesia, prosopognasia (inability to recognise faces), aphasia (inability to recognise speech)

Question 11

features of aphasia

Answer 11

inability to recognise speech, has motor control of speech, auditory and fluency. lost representation of speech, can’t recognise words or find words - wernikes aphasia

Question 12

features of visual prosopagnosia

Answer 12

can’t recognise any faces

Question 13

cerebellum

Answer 13

automatic actions eg walking, learning, motor skills. correcting actions (contains nearly half all neutrons).

Question 14

parietal lobe function

Answer 14

perception to action, attention, spatial understanding

Question 15

what damage to parietal lobe can do

Answer 15

hemispatial neglect

Question 16

occipital lobe function

Answer 16

visual perception

Question 17

what damage to occipital lobe can do

Answer 17

partial blindness, specific visual deficits, hemispatial neglect, hemeonopia

Question 18

visual cortex

Answer 18

plasticity is less so leads to hemispatial neglect and hemeonopia

Question 19

hemeonopia features

Answer 19

know can’t see one side and look to that side

Question 20

hemispatial neglect features

Answer 20

can be from a stroke or alchzeimers. only use one side of space eg plate, only put makeup on one side. about representation of space and visual.

Question 21

the brain is not like a computer

Answer 21

they store data like units but brain stores memories in a network of neural activations in the brain - enormous storage possibilities. humans are good at generalising and computers are not.

Question 22

why use rehabilitation

Answer 22

successful early on - bing parts of network back online

Question 23

look at diagrams of brain on notes

Question 24

what are 5 major senses

Answer 24

vision, audition, olfaction (smell), gustation (taste) and the somatosenses (‘body’ senses: touch, pain and temperature).

Question 25

what three areas of the cerebral cortex that receive info from the sensory organs?

Answer 25

• The primary visual cortex - received visual info, located at the back of the brain, on inner surfaces of cerebral hemisphere
  
  • The primary auditory cortex - receives auditiory info, located on inner surface of a deep fissure in side of brain
• The primary somatosensory cortex - a vertical strip near the middle of the cerebral hemispheres, receives info from the body senses. Different regions of the primary somatosensory cortex receive info from different regions of the body. The base of the somatosensory cortex, the insula, receives info concerning taste.

Question 26

primary sensory cortex

Answer 26

• 3 regions of primary sensory cortex in each hemisphere receive info from the opposite side of the body. the primary somatosensory cortex of the left hemisphere learns what the right hand is holding, the left primary visual cortex learns what is happening towards the person’s right and so on. The connections between the sensory organs and the cerebral cortex are said to be contralateral.

Question 27

motor cortex

Answer 27

The region of the cerebral cortex most directly involved in the control of movement is the primary motor cortex located just in front of the primary somatosensory cortex.
- Neurons in different parts of the primary motor cortex are connected to muscles in different parts of the body. The connections like in the sensory regions of the cerebral cortex are contralateral - the left primary motor cortex controls the right side of the body and vice versa
- Damage to the left primary motor cortex will result in paralysis in the contralateral hand and sometimes in the left hand - Haaland and Harrington 1989.
The hand you predominantly use appears to be related to the side of the brain that is involved in speech production

Question 28

primary sensory and motor cortex

Answer 28

There is some evidence that the regions recruited during perception (visual, auditory, olfactory, etc) overlap with the regions recruited when we imagine sensory stimuli (sights, sounds, scents) (McNorgan, 2012).

Question 29

association cortex

Answer 29

The regions of primary sensory and motor cortex occupy only a small part of the cerebral cortex the rest does what is done between sensation and action - perceiving, learning and remembering, planning and acting - these processes take place in the association areas of the cerebral cortex.

Question 30

what is the central fissure

Answer 30

it provides an important dividing line between the anterior (front) part of the cerebral cortex and the posterior (back) regions.

Question 31

the anterior region

Answer 31

involved in movement-related activities, such as planning and executing behaviours.

Question 32

posterior region

Answer 32

is involved in perceiving and learning.

Question 33

cerebral cortex has 4 lobes

Answer 33

frontal lobe, parietal lobe, temporal lobe and occupital lobe.

Question 34

how many lobes does the brain have?

Answer 34

Brain contains two of each lobe, one in each hemisphere.

Question 35

location of frontal lobe

Answer 35

everything in front of the central fissure

Question 36

location of parietal lobe

Answer 36

on side of cerebral hemisphere, just behind central fissure, behind the frontal lobe.

Question 37

location of temporal lobe

Answer 37

just forward from base of brain, beneath frontal and parietal lobes

Question 38

location of occipital lobe

Answer 38

lies at very back of brain, behind the parietal and temporal lobes.

Question 39

Brodmann’s Area (BA)

Answer 39

named after Korbinian Broadmann, a german physicisist who in 1909 piblished a map of the brain which divided in into 52 different areas based on cell type and connections between cells - Annesse 2009, Zilles 2018. - Brains cyoarchitecture
- Brodmann also supported idea brain has 6 layers.

Question 40

sensory association cortex

Answer 40

Each primary sensory area of the cerebral cortex sends information to adjacent regions, called the sensory association cortex. Circuits of neurons in the sensory association cortex analyse the information received from the primary sensory cortex; perception takes place there, and memories are stored there. The regions of the sensory association cortex located closest to the primary sensory areas receive information from only one sensory system. Eg region closest to the primary visual cortex analyses visual info and stores visual memories

Question 41

function of Regions of the sensory association cortex located far from the primary sensory areas

Answer 41

they receive information from more than one sensory system so are involved in several kinds of perception and memory. These regions make it possible to integrate info from more than one sensory system eg we can learn the connection between the sight of a particular face and the sound of a particular voice.

Question 42

frontal association cortex

Answer 42

The frontal association cortex is involved in the planning and execution of movements

Question 43

anterior part of frontal lobe

Answer 43

• The anterior part of the frontal lobe - known as the PFC - contains the motor association cortex.

Question 44

what does the motor association cortex control

Answer 44

the primary motor cortex so it directly controls behaviour.

Question 45

sensory association cortex of the posterior part of the brain function

Answer 45

• We behave in response to events happening in the world around us so the sensory association cortex of the posterior part of the brain sends Info about the environment to the motor association cortex (PFC) which translates the info into plans and actions.

Question 46

what is lateralisation of function?

Answer 46

Two cerebral hemispheres don’t perform identical functions. Some functions show evidence of lateralisation as are located primarily on one side of the brain. This is also called functional hemispheric asymmetry. - Human body provides several examples of lateralisation or laterality eg most have two arms, two legs etc. Even with these superficial lateralities there are subtle asymmetries - we are more proficient with one hand than the other etc. - The brain looks symmetrical but this physical feature belies some functional asymmetries.

Question 47

left hemisphere features

Answer 47

more involved in aspects of language - speech production and comprehension and appreciation of sounds in speech than the right hemisphere. - Left lateralisation of language is seen in 94% of right handers and in 74% of non-right handers - Johnstone et al 2021.
- Left hemisphere also plays a role in understanding metaphor

Question 48

right hemisphere features

Answer 48

• Right hemisphere is better than left at recognising faces, mental rotation and comprehending metaphors and it may undertake the linguistic duties of the left hemisphere when the left is damaged. People are known to pose asymmetrically, preferring to show their right side rather than lef

Question 49

wiseman and owen 2017

Answer 49

A study by Wiseman & Owen (2017) found a similar asymmetry for the presentation of the brain. They undertook a Google search of sagittal views of the brain which yielded 425 images. Eighty per cent were right facing. The researchers suggest that this may reflect an aesthetic preference, or it may result from people reading from left to right.

Question 50

corpus callous

Answer 50

• Two cerebral hemispheres are connected by a large band of axons called the corpus callosum = brains largest collection of connective fibre, comprising 200-300 million nerve fibres.
  
  • The corpus callosum connects corresponding parts of the left and right hemispheres: the left and right temporal lobes are connected, the motor areas on the left and right are connected, the left and right parietal lobes are connected, and so on (the technical term is ‘homotopic’)
  • The corpus callosum is divided into sections: from front to back, the genu, truncus, isthmus and splenium. Because of the corpus callosum, each region of the association cortex knows what is happening in the corresponding region of the opposite side of the brain. Some researchers have suggested that it plays a role in aggression because interhemispheric transfer of electrical signals is reduced in violent patients (Schutter and Harmon-Jones, 2013).
  • Some people have the corpus callosum surgically cut to alleviate the symptoms of epilepsy. Split brain patients are interesting to psychologists because their two hemispheres do not appear to be able to communicate.
    In 2019, Karolis et al (2019) attempted to map the architecture of functional localisation and its relation to the corpus callosum based on an analysis of fMRI and structural imaging data.

Question 51

handwriting and tool use

Answer 51

• Handwriting is a learned linguistic skill requiring precision and dexterity
  
  • A recent review of the role of the brain in handwriting has identified distinct regions that allow us to do this (Planton et al, 2013). They found that a network of regions in the left hemisphere showed activation when people used their hands for writing. Three were particularly involved: the left superior frontal sulcus/middle frontal gyrus, the left intraparietal sulcus and the right cerebellum. Other regions were involved in motor behaviour that was not linked to writing – areas such as the primary motor and somatosensensory cortex.
  • A more specific study has examined which regions of the brain are implicated in the movement of toes and fingers (Lee et al, 2013). This found that the primary somatosensory cortex was more active during finger than toe movements, whereas the primary motor cortex and prefrontal cortex were more active during toe movement
    Some studies find that the somatosensory cortex is activated more by knee movements than elbow or finger movements (Luft et al, 2002) and by fingers than ankles (LaPointe et al, 2009

Question 52

occipital lobe - vision

Answer 52

• Total damage to the primary visual cortex, located in the inner surface of the posterior occipital lobe, produces cortical blindness (to distinguish it from other forms of blindness such as congenital blindness). Because the visual field is ‘mapped’ onto the surface of the primary visual cortex, a small lesion in the primary visual cortex produces a ‘hole’ in a specific part of the field of vision
  
  • The visual association cortex is located in the rest of the occipital lobe and in the lower portion of the temporal lobe.
  • Damage to the visual association cortex will not cause blindness. In fact, visual acuity may be very good; the person may be able to see small objects and may even be able to read. However, the person will not be able to recognise objects by sight.
  • For example, when looking at a drawing of a clock, the person may say that they see a circle, two short lines forming an angle in the centre of a circle, and some dots spaced along the inside of the circle, but will not be able to recognise what the picture shows.
    On the other hand, if the person is handed a real clock, they will immediately recognise it by touch. This fact tells us that the person has not simply forgotten what clocks are. Similarly, the person may fail to recognise their spouse by sight but will be able to do so from the sound of the spouse’s voice. This deficit in visual perception is called visual agnosia

Question 53

temporal lobe - sound and social cognition

Answer 53

The temporal lobe contains the primary auditory cortex and the auditory association cortex. The primary auditory cortex is hidden from view on the inner surface of the upper temporal lobe. The auditory association cortex is located on the lateral surface of the upper temporal lobe.

- The temporal lobe is associated with processing our knowledge of object categories and our semantic memory - our memory for info. 
- Some have proposed that there is a division between those areas involved in processing information about associating names with people, objects and landmarks (the anterior temporal region) and those involved in information about places (the posterior middle temporal region) (Morton et al, 2021). Both are connected to a structure beneath the cortex, hippocampus,  One of the more asymmetrical regions of the brain is found in the temporal lobe – the auditory association cortex of the planum temporale in the superior temporal gyrus. This seems to be an important region because of its involvement in the phonological processing of language; it represents the region we know as Wernicke’s area, an area responsible for understanding speech

Question 54

damage to the primary auditory cortex

Answer 54

leads to hearing losses, while damage to the auditory association cortex produces more complex deficits. Damage to the left auditory association cortex causes severe language deficits. People with such damage are no longer able to comprehend speech, presumably because they have lost the circuits of neurons that decode speech sounds. However, the deficit is more severe than that. They also lose the ability to produce meaningful speech; their speech becomes a jumble of words.
Research with healthy individuals undergoing neuroimaging shows that the temporal lobe is involved in phonological aspects of processing language, extracting meaning from speech and text, mentalising and theory of mind (being able to see things from the perspective of others) as well social cognition (Braundsdorf et al, 2021)

Question 55

damage to the right auditory association cortex

Answer 55

does not seriously affect speech perception or production, but it does affect the ability to recognise non-speech sounds, including patterns of tones and rhythms. The damage can also impair the ability to perceive the location of sounds in the environment. The right hemisphere is important in the perception of space. The contribution of the right temporal lobe to this function is to participate in perceiving the placement of sounds

Question 56

medial part of the temporal lobe

Answer 56

also known to be involved in our ability to perceive personally meaningful information. Neurons here respond to images of famous people (Quian Quiroga et al, 2005) and there is also evidence that neurons respond to images of family members. Viskontas et al (2009) recorded activity from 2,330 neurons while participants viewed unfamiliar faces and landscapes, familiar faces and participants’ own faces. Neurons in the medial temporal lobe (MTL) are more likely to respond to the familiar faces than the unfamiliar stimuli.

Question 57

parietal lobe - somatosensation and visuospatial perception

Answer 57

• the primary sensory function of the parietal lobe is perception of the body. It contains the somatosensory cortex and so is responsible for the perception of touch. However, the association cortex of the parietal lobe is involved in much more than somatosensation
  
  • Damage to a particular region of the association cortex of the left parietal lobe can disrupt the ability to read or write without causing serious impairment in the ability to talk and understand the speech of other people.
  • Damage to a particular region of the association cortex of the left parietal lobe can disrupt the ability to read or write without causing serious impairment in the ability to talk and understand the speech of other people.
    Damage to another part of the parietal lobe impairs a person’s ability to draw. When the left parietal lobe is damaged, the primary deficit seems to be in the person’s ability to make precise hand movements, their drawing looks shaky and sloppy. The parietal and frontal lobes, especially the left sides, are also involved in various types of drawing in healthy individuals with no brain injury (Raimo et al, 2021)

Question 58

pariteal lobe - drawings of figurative stimuli

Answer 58

• Drawings of figurative stimuli – attempted drawings of people, objects and places – is associated with activation in the inferior frontal and temporal gyri. Compared with drawing from memory, copying is associated with activation in another area called the extrastriate cortex. Collectively, drawing involves network of regions including the precentral cortex, both sides of the inferior parietal lobe and a structure called the precuneus.
  
  • In contrast, the primary deficit produced by damage to the right parietal lobe is perceptual. The person can analyse a picture into its parts but has trouble integrating these parts into a consistent whole. Thus, they have difficulty drawing a coherent picture.
  • The parietal and frontal cortices and their connections, especially the primary and secondary motor, and premotor, cortex are involved in preparatory movement – the preparing to move (Svoboda & Li, 2018). Different neurons might be active just before the movement and during the delay between an instruction and moving, with the premotor and supplementary motor cortex being more involved than other areas.
  • The left parietal lobe plays an important role in our ability to keep track of the location of the moving parts of our own body, whereas the right parietal lobe helps us to keep track of the space around us.
  • People with right parietal lobe damage usually have difficulty with spatial tasks, such as reading a map.
  • People with left parietal lobe damage usually have difficulty identifying parts of their own bodies by name.
    For example, when asked to point to their elbows, they may point to their shoulders. There is also evidence showing that this region of the brain, together with the frontal lobe, is involved in our ability to perform mental arithmetic. This region is smaller in children with mathematical deficits when compared with children with normal maths performance (Isaacs et al, 2001)

Question 59

posterior part of the parietal cortex (PPC)

Answer 59

• The posterior part of the parietal cortex (PPC) appears to be specialised for storing representations of motor actions (Milner, 1998).
  
  • Snyder et al (1997) found that some neurons in the PPC of two adult macaque monkeys were active before and during visually guided arm movements, whereas others were active during eye movements.
    However, rather than directing attention to objects in space, the PPC seems to be responsible for the intention to move. Manipulation of body part information appears to involve the left frontal and parietal lobes whereas manipulation of numbers appears to involve the right parietal lobe (Le Clec’H et al, 2000).

Question 60

frontal lobes - thinking, doing, feeling

Answer 60

• The frontal lobe is the largest, and most recently developed, lobe in the human brain. It contains 13 distinct anatomical areas including motor cortex and the frontal eye fields and occupies about a third of the brain’s volume. Because of its size it contains a number of regions that appear to undertake specific functions.
  
  • The front part, the prefrontal cortex (PFC), for example, is involved in emotional expression, the inhibition of inappropriate behaviour, decision-making, certain types of memory, creativity, among other functions. The PFC also plays a role in navigation and wayfinding.
  • One region, the dorsal anterior cingulate, is involved in helping us adjust to taking different routes if we are required to and allows us to make plans to accommodate these adjustments (Javadi et al, 2017; 2019).
    A recent idea is that it may also be involved in the related function of hunting (Goodroe et al, 2022). The PFC itself is not a unitary region, that is, there are regions within it which, if injured, produce different deficits. The two principal regions are the dorsolateral PFC (DLPFC) and orbitofrontal cortex (OFC)

Question 61

damage to frontal lobes

Answer 61

Damage can produce some unusual behaviour such as the inability to identify odour, to regulate our behavioural responses and to use cues to predict future reward or unpleasant events (Zald and Andreotti, 2010). For example, a person with PFC damage will react to events in the environment but show deficits in initiating behaviour. When asked to say or write as many words as possible or asked to describe as many uses for an object as possible, they will have great difficulty in coming up with more than a few, even though they have no problem understanding words or identifying objects by name (Eslinger and Grattan, 1993)

People with damage to the frontal lobe have difficulty changing strategies. If given a task to solve, they may solve it readily. However, if the solution is changed, they will fail to abandon the old strategy and learn a new one. The Wisconsin Card Sorting Test, for example, presents patients with packs of cards on which are printed symbols of different shape, colour or number (see Chapter 11). The experimenter decides on a sorting criterion (e.g. shape) and the patient has to detect which criterion it is by sorting the cards into piles, receiving feedback from the experimenter. When the criterion unexpectedly shifts, some patients are unable to detect this shift and carry on responding as if the previous criterion still applied. This is called perseveration. Not all frontal lobe patients will exhibit this behaviour (Anderson et al, 1991) – only those with damage to a specific region of the frontal lobe, the dorsolateral PFC

- The most famous case study of frontal lobe damage resulting in shifts in emotional and social behaviour is that of Phineas Gage and you read about him in Chapter 1 (his case is also discussed in Chapter 13).
- In terms of daily living, the most important consequences of damage to the frontal lobe are probably lack of foresight and difficulty in planning. A person with injury to part of the frontal lobe might perform fairly well on tests of intelligence but be unable to hold down a job or organise their day (Eslinger and Damasio, 1985; Wood and Rutterford, 2004). Sequencing – the organisation of material in logical, correct or learned order – is grossly impaired in frontal patients (Sirigu et al, 1995). Often, when given tasks that tap everyday activities (such as undertaking an errand or following a recipe), patients with frontal lobe damage perform poorly (Fortin et al, 2003) and may engage in obsessive collecting behaviour (Anderson et al, 2005). When asked to explain what a proverb means, or when asked to organise the type of activities you would expect to do if you were running a hotel, or when asked to identify social faux pas, patients with damage to the right PFC are poor at doing these (Roca et al, 2010). Patients with damage to different regions of the frontal lobe exhibit different symptoms. For example, patients such as Phineas Gage with damage to the OFC tend to exhibit impairments in social behaviour, personality and emotional expression but have relatively intact intellect. They are impulsive and do not care what others think or feel. Eslinger and Damasio’s (1985) patient, EVR, is a good example. EVR, an ex-accountant who had a tumour removed from the same part of the brain injured in Phineas Gage, has superior intellect but an impaired ability to plan and organise his daily life. He performs at normal levels on tests such as the Wisconsin Card Sorting Test and he has superior IQ. However, his ability to maintain close relationships and a job and his ability to plan and organise his life are grossly impaired.

Question 62

damage to the primary motor cortex

Answer 62

Damage to the primary motor cortex produces a very specific effect: paralysis of the side of the body opposite to the brain damage. If a portion of the region is damaged, then only the corresponding parts of the body will be paralysed (Passingham, 1995). The frontal eye fields are responsible for preparing the eyes for movement and for creating involuntary saccades (lateral eye movement – moving the eyes from side to side) (Vernet et al, 2014). The frontal lobes can also use information received from the visual part of the brain and use and convert this information to coordinate and initiate movements (Schall, 2015

Question 63

functions of frontal lobes

Answer 63

• Parts of the frontal lobes are involved in sophisticated cognitive and social functions such as reasoning, long-term memory retrieval (Euston et al, 2012), control over attention to threat (Peers et al, 2013), making decisions about whether abstract paintings are beautiful (Flexas et al, 2014), deciding which actions to undertake in response to reward or perceptual cues (Domenech and Koechlin, 2015), creativity (Gonen-Yaacovi et al, 2013) and inhibiting behaviour that is wrong. Chapters 11 and 15 consider the role of the frontal lobe in functions such as reasoning, social cognition and emotion.
  Some areas of the frontal lobes are involved in a variety of ‘higher’ functions including planning, changing strategies, being aware of oneself, empathising with others, evaluating emotional stimuli, inhibiting inappropriate behaviour and behaving spontaneously; these are called executive functions because they involve executive control over our actions and involve switching between behaviours based on changes in rules

Control of inhibition – suppressing an inappropriate response to a stimulus or event – is thought to be one of the frontal lobes’ primary functions and its specific locus is considered to be the right inferior frontal cortex (Aron et al, 2014). It does this via its connections with other brain regions, such as the basal ganglia and other parts of the frontal lobe, such as the DLPFC. Aron et al characterise the region as a brake which either stops or pauses an individual’s response and that this brake can be applied internally (self-control) or in response to an external stimulu

Question 64

dorsolateral PFC

Answer 64

The dorsolateral PFC is involved in a variety of cognitive functions, including mental effort and mental fatigue (Soutschek & Tobler, 2020) and social cognition. It also appears that if general intelligence is taken into account, performance on this task is not impaired, suggesting that it is a test of intelligence rather than frontal lobe performance (Roca et al, 2010)

Question 65

orbitofrontal cortex (OFC)

Answer 65

People with damage to the orbitofrontal cortex (OFC) may have rather bland or, conversely, eccentric personalities. They seem indifferent to events that would normally be expected to affect them emotionally (Stuss et al, 1992). For example, they may show no signs of distress at the death of a close relative and do not show the typical physiological response to stress (see Martin, 2006, for a comprehensive description). They have little insight into their own problems and are uncritical of their performance on various tasks

Two of the major functions of the OFC is allowing us to make predictions about future events and use these to guide behaviour (Barreiros et al, 2021; Gardner & Schoenbaum, 2021), and to help us make decisions (Klein-Flügge et al, 2022). How it does this is still unclear although people with OFC damage can make very poor economic decisions; computing economic value is important when making real-time decisions such as spending large amounts of money, or gambling. One view suggests that the OFC is part of a network which maintains a model of the environment, thus enabling a ‘cognitive map’, and that the OFC might be necessary for keeping track of locations; an alternative view is that it is not needed to support this cognitive map but is necessary for forming and updating it (Gardner & Schoenbaum, 2021)

Question 66

control of internal functions and automatic behaviour

Answer 66

• The cortex consists of only the outer 3 mm of the surface of the cerebral hemispheres. There are other structures such as the brain stem, the cerebellum and the interior of the cerebral hemispheres which are important to the regulation of behaviour.
  
  • The cerebellum helps the cerebral hemispheres to control movement and to initiate some automatic movements, such as postural adjustment, on its own.
  • The brain stem and much of the interior of the cerebral hemispheres are involved in homeostasis and control of species-typical behaviours.
  • Homeostasis (from the root words homoios ‘similar’, and stasis ‘standstill’) refers to maintaining a proper balance of physiological variables such as temperature, concentration of fluids and the amount of nutrients stored within the body.
    Species-typical behaviours are the more-or-less automatic behaviours exhibited by most members of a species that are important to survival, such as eating, drinking, fighting, courting, mating and caring for offspring

Question 67

Brain stem

Answer 67

• The brain stem contains three structures: the medulla, the pons and the midbrain.
  
  • The brain stem contains circuits of neurons that control functions vital to the survival of the organism in particular and of the species in general. For example, circuits of neurons in the medulla, the part of the brain stem closest to the spinal cord, control heart rate, blood pressure, rate of respiration, and – especially in simpler animals – crawling or swimming motions.
    Circuits of neurons in the pons, the part of the brain just above the medulla, control some of the stages of sleep, and circuits of neurons in the midbrain control movements used in fighting and sexual behaviour and decrease sensitivity to pain while engaged in these activities

Question 68

cerebellum

Answer 68

• The cerebellum plays an important role in the control of movement but may also be involved in cognitive and emotional processing (Popa et al, 2014; van Overwalle et al, 2020).
  
  • It receives sensory information, especially about the position of body parts, so it knows what the parts of the body are doing.
  • It also receives information from the cortex of the frontal lobes, so it knows what movements the frontal lobes intend to accomplish.
  • The cerebellum acts like a computer that compares the location of the body parts with the intended movements and assists the frontal lobes in executing these movements.
  • Without the cerebellum, the frontal lobes would produce jerky, uncoordinated, inaccurate movements – which is exactly what happens when a person’s cerebellum is damaged.
  • Besides helping the frontal lobes to accomplish their tasks, the cerebellum monitors information regarding posture and balance, to keep us from falling down when we stand or walk and produces eye movements that compensate for changes in the position of the head.
  • Some studies have suggested that the cerebellum may also be involved in a variety of other functions such as cognition and language (Schmahmann and Sherman, 1998).
  • Neuroimaging studies show that various parts of the cerebellum become active during tasks involving movement and touch, language and verbal memory, spatial memory, executive function and emotional processing (Stoodley and Schmahmann, 2009).
    Some psychologists have also implicated the cerebellum in the reading disorder, developmental dyslexia