Attention 3

Question 1

define inattentional blindness

Answer 1

failure to identify an unexpected stimulus that is shown in plain sight

this is as a result of lack of attention

Question 2

define change blindness

Answer 2

when a stimulus undergoes a change without being noticed by its observer

can be very difficult to detect changes

Question 3

identify 2 difference between change blindness and inattentional blindness

Answer 3

• memory plays a role in change blindness, memory is not required in inattentional blindness
• change blindness can occur even when looking for changes (it is still difficult to spot), inattentional blindness occurs when observer is performing another task (gorilla effect) and if asked to look for changes they will become very obvious and easy to spot

Question 4

what is a structural MRI?

Answer 4

non-invasive technique for examining the anatomy and pathology (understanding how diseases work) of the brain

fMRI examines brain activity

Question 5

How many lobes are there in the brain?

Answer 5

4 main lobes

Question 6

Identify the main lobes of the brain

Answer 6

• frontal lobe
• temporal lobe
• occipital lobe
• parietal lobe

Question 7

what is the front of the brain referred to as?

Answer 7

anterior

Question 8

what is the back of the brain referred to as?

Answer 8

posterior

Question 9

what is the top of the brain referred to as?

Answer 9

superior/dorsal

Question 10

what is the bottom of the brain referred to as?

Answer 10

inferior/ventral

Question 11

what are large-scale attentional networks?

Answer 11

large scale because these networks extend across areas in different lobes of the brain

activity is controlled by attention (attentional)

networks are areas tightly interconnected by neuronal pathways (these are often activated together)

Question 12

identify two major attention networks

Answer 12

1. dorsal attention network
2. ventral attention network

Question 13

what makes up the dorsal attention network

Answer 13

dorsal = top of brain

made up of two major components

lobes involved: frontal lobe and parietal lobe

in frontal lobe = the frontal eye field
in parietal lobe = intraparietal sulcus

Question 14

what makes up the ventral attention network?

Answer 14

ventral = towards bottom of brain

also made up of two major components

lobes involved: frontal lobe and parietal lobe

in frontal lobe = ventral frontal cortex
parietal lobe = temporoparietal junction

Question 15

what is the dorsal attention network involved in?

Answer 15

• activated by top-down control
  voluntary allocation of attention to certain features
  i.e.: subject can decide to focus all attention of only red objects
• activated by goal-driven orienting
  this is a top-down signal from environment that re-configures visual system to reflect current goals and expectations
  i.e.: absence of a signal to guide visual processing could lead to uncertainty as to what a confusing image shows
• involves left and right hemisphere

Question 16

what is the ventral attention network involved in?

Answer 16

• activated by bottom-up control
  sensory-driven, directs perception towards stimulus that is considered attention-grabbing
• activated by stimulus driven (re-)orienting
  i.e.: someone calls your name, you will reorient your attention towards person who called your name
• involves right hemisphere

Question 17

define spatial neglect

Answer 17

the failure to report or orient attention to stimuli in uninjured part of the brain after an injury that is not explained by primary or motor deficits

Question 18

what is spatial neglect a consequence of?

Answer 18

a consequence of damage to ventral attention network

Question 19

identify some symptoms of spatial neglect

Answer 19

• ignoring sides of space
• objects, people, sounds on a particular side get ignored
• deficit is usually on the left side
• extinction phenomenon
• patients are unaware of the deficit, unaware that they’re missing something as imagination space has gone too
• patients realise something is wrong when it is pointed out to them

Question 20

what sort of deficit is spatial neglect?

Answer 20

attentional deficit NOT a perceptual deficit

Question 21

how is spatial neglect an attentional deficit and not a perceptual deficit?

Answer 21

• neglect patients are unaware of deficit (patients with a perceptual deficit are aware)
• extinction phenomenon not seen in patients with a perceptual deficit
• spatial neglect can affect imagination

Question 22

what is the extinction phenomenon?

Answer 22

• visual extinction
• as damage is usually follows with right inferior parietal damage –> characterized by impaired attention and lack of awareness for stimuli on left side of space

Question 23

how frequent does spatial neglect occur?

Answer 23

• quite frequent ~ occurs in 40% of patients with right hemisphere lesions