L3 - attending and spatial brain

Question 1

space in the brain: different forms

Answer 1

1. RETINOCENTRIC SPACE = location on sensory surfaces (e.g. retina)
2. EGOCENTRIC SPACE = location of objects relative to the body
3. ALLOCENTRIC SPACE = location of objects relative to each other

Question 2

attention

Answer 2

• the process by whcih certain info is selected for further processing and other information is discarded.

Question 3

spotlight metaphor of attention

Answer 3

• visual search : spotlight may move from one spatial location to another.
• may zoom in or out (narrow or wide beam)
• location of attention not necessarily same as eye fixation
• limited capacity

Question 4

what controls the spotlight of attention

Answer 4

EXOGENOUS CONTROL: externally guided by a stimulus

INHIBITION OF RETURN (IOR)

Question 5

Posner 1980

Answer 5

cue paradigm - cue captures attentional spotlight and this facilitates subsequent perceptual processing at that location (reduced RT)

Question 6

Mitroff and Biggs (2013)

Answer 6

• airport search games

- groups of people who were very good at this - could have implications for who works this job

Question 7

feature integration theory

Answer 7

• perceptual features are encoded in parallel and prior to attention
• if object has unique perceptual feature then it may be detected without need for attention
• if object shares features than cannot be detected from a single perceptual feature and attention is needed to search all candidates serially.

Question 8

Attentional Networks

Answer 8

DORSAL (WHERE) PATHWAY - from the parietal lobes and is important for identification of objects within space

VENTRAL (WHAT) PATHWAY) - from the temporal lobes - leads to recognition and identification of objects.

Question 9

dorso and ventro dorsal streams

Answer 9

dorso-dorsal network involved lateral intraparietal area (LIP) and frontal eye fields (FEF)

ventro-dorsal stream (right temporo-parietal junction and ventral frontal cortex) that interrupts any cognitive task in order to divert attention away from processing (i.e. you hear a scream)

Question 10

hemispheric differences in parietal lobes

Answer 10

• hemispheric asymmetry
• right PL richer representation of space (left space and some right space)
• left PL less so

= pseudoneglect

Question 11

types of neglect

Answer 11

unilateral, spatial or hemispatial

Question 12

clinical tests of neglect -

Answer 12

• cancellation tasks (cross al the lines you can perceive) - patients with hemispheric neglect will cross lines only
• drawing: copying or from memory

Question 13

perceptual versus representational neglect

Answer 13

• the brain contains different references for spatial and imagined events in external space
• neglect can affect memories of scenes (representational neglect

Question 13

perceptual versus representational neglect

Answer 13

• the brain contains different references for spatial and imagined events in external space
• neglect can affect memories of scenes (representational neglect

Question 14

plazza del duomo

Answer 14

• Ps with right PL lesions - asked to describe familiar place (the plazza)
• first asked to imagine themselves looking at the front of the cathedral from the opposite side of square AND then reverse the perspective
• what ever area was on the left visual field was neglected - however the spatial knowledge of the square is not lost but unavailable to report.
• hippocampus - considered to store ALLOCENTRIC map of space … and
• parietal lobes required for IMAGINING IT from a given viewpoint.
• example of a double dissociation

Question 14

neglect for near versus far space

Answer 14

DOUBLE DISSOCIATION

• line bisection using pen and paper - impaired / laser
• backed up by single recordings from animals
• near space: supported by right parietal and frontal space
• far space : supported by visual cortex

Question 14

personal versus peripersonal space:

Answer 14

body neglect = failure to groom left side of body, notice position of limbs or feel pain on left side

near space neglect: visual search of array of external objects

(Hussein et al 2001)

Question 15

within objects versus between objects

Answer 15

• some neglect patients attend to object on left side of space but omit to attend to one half of object itself (object based neglect) - associated with damage to the SUPERIOR TEMPORAL GYRUS
• forms a double dissociation with space-based neglect

Question 16

spatial versus object based neglect

Answer 16

patient with object neglect can detect differences on left side of an object even when falling onto right side of space

Question 17

neglect as a disorder of attention

Answer 17

• not low level perception
• neglect patients still activate visual regions in OCCIPITAL LOBES
• They are often able to detect objects on the left if they are cued

affects auditory and tacticle judgements

Question 18

visual extinction

Answer 18

• unawareness of a stimulus in the presence of a competing stimulus
• frog and sun.

Question 19

neglect types (in terms of attention)

Answer 19

egocentric (with respect to observer) - e.g. line bisection

allocentric (with respect to another extrapersonal event) e.g. plazza del duomo

object-centred (with respect to a principal axis in the canonical representation of an object) e.g. with half of object, or half a picture

Question 20

prism adaptation

Answer 20

patients wear prism lens glasses that shift view to the right

• visual feedback allows for correction
• effects persist after removal of lens

Question 21

spatial memory

Answer 21

hippocampus

• Maguire et al 2006 and 2001 - cab drivers

Question 22

hippocampus versus parietal lobes

Answer 22

parietal lobes: linking sensory and egocentric maps of space to create representations of visual environment

hippocampus stores long-term memory of space

(can work together)

Question 23

video games - role in attention and learning

Answer 23

action video game playing = capable of altering range of visual skills

• perceptual learning tends to be specific with a trained task
• Ps who did action video games were much better at visual search tasks and contrast sensitivity and mental rotation

Question 24

The test of variables of attention (TOVA)

Answer 24

• TOVA assesses impulsivity and sustained attention
• Ps required to press a key as fast as possible in response to target and to withhold responding to non-target stimuli
• in one condition - targets are rare and non-targets appear frequently (this measures SUSTAINED ATTENTION)
• in other condition - targets are frequent, non-targets are rare (this measures IMPULSIVITY)

Question 25

TOVA and video games

Answer 25

video game players were faster in both conditions.

• but no difference in accuracy from controls.