Attention 3 Flashcards
define inattentional blindness
failure to identify an unexpected stimulus that is shown in plain sight
this is as a result of lack of attention
define change blindness
when a stimulus undergoes a change without being noticed by its observer
can be very difficult to detect changes
identify 2 difference between change blindness and inattentional blindness
- 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
what is a structural MRI?
non-invasive technique for examining the anatomy and pathology (understanding how diseases work) of the brain
fMRI examines brain activity
How many lobes are there in the brain?
4 main lobes
Identify the main lobes of the brain
- frontal lobe
- temporal lobe
- occipital lobe
- parietal lobe
what is the front of the brain referred to as?
anterior
what is the back of the brain referred to as?
posterior
what is the top of the brain referred to as?
superior/dorsal
what is the bottom of the brain referred to as?
inferior/ventral
what are large-scale attentional networks?
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)
identify two major attention networks
- dorsal attention network
- ventral attention network
what makes up the dorsal attention network
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
what makes up the ventral attention network?
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
what is the dorsal attention network involved in?
- 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
what is the ventral attention network involved in?
- 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
define spatial neglect
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
what is spatial neglect a consequence of?
a consequence of damage to ventral attention network
identify some symptoms of spatial neglect
- 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
what sort of deficit is spatial neglect?
attentional deficit NOT a perceptual deficit
how is spatial neglect an attentional deficit and not a perceptual deficit?
- 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
what is the extinction phenomenon?
- 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
how frequent does spatial neglect occur?
- quite frequent ~ occurs in 40% of patients with right hemisphere lesions
