what is where and how to get there the neurocognition of space albert postma
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What is Where and How to Get There The Neurocognition of Space Albert Postma Psychological Laboratory, Utrecht [email protected] http://www.fss.uu.nl/psn/pionier/. Examples of tasks involving mental spatial processes. - PowerPoint PPT PresentationTRANSCRIPT
What is Where and How to Get There
The Neurocognition of Space
Albert Postma
Psychological Laboratory, [email protected]
http://www.fss.uu.nl/psn/pionier/
Examples of tasks involving mental spatial processes
- Does the trunk of elephant reach to the ground if the animal is standing in a normal (horizontal) position?
- Imagine the capital letter ‘d’. Turn it 90° to the left. Place the letter ‘j’ below it in the centre. What do you see?
- Lay down your pencil…
- Attend the entrance door of the classroom
DDJ
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Spatial Cognition:= the collection of mental abilities which involve the processing of spatial features of our environment or of complex objects
(ranging from perception, attention, motor action to memory).
Spatial features include distance (depth), relative and absolute position, orientation (direction)
Why Study Spatial Cognition?
- Essential for many daily activities (ecological importance)
- Several recent interesting neurocognitive findings
- Space is the common attribute of all our senses
- Other cognitive acts may essentially be ‘spatially motivated’ (e.g. language evolution)
- High extent of specialization of neural circuits for spatial tasks
How does our brain represent space?
frontaalkwabpariëtaalkwab
temporaalkwab
occipitaalkwab
cerebellum
CGL
V3AV3
V2
V1VP
V4v
V8
V7MT/V5
inferotemporaalcortex (IT)
V7V3AV3V1V2VPV4vV8
OptischezenuwChiasmaRadiatioV1
How is spatial information further processed after the primary visual cortex?
Dorsal and ventral stream
Dorsal and ventral stream• The anatomical separation of visual cortical
processing within a dorsal and ventral stream is
well established.
• What about the functions that are subserved by
these two visual streams?
Ungeleider & Mishkin (1982)
Based their distinction on stimulus attributes
Ventral stream: What is the stimulus
Dorsal stream: Where is the stimulus
Dorsal and ventral stream
Ungeleider & Mishkin (1982)
Experimental evidence that supports this functional
distinction:
Lesion studies with monkeys
Two tasks: Object discrimination and spatial
discrimination.
Dorsal and ventral stream
Ungeleider & Mishkin
(1982)
Lesion studies with monkeys
Object discrimination
• Delayed non-matching to
sample
• Monkeys with a bilateral
lesion of the inferotemporal
lobe are impaired on this
task.
Dorsal and ventral stream
Ungeleider & Mishkin (1982)
Lesion studies with monkeys
Spatial discrimination
• Landmark discrimination
• Choose the foodwell closer
to the ‘landmark’.
• Monkeys with bilateral posterior
parietal lesions are impaired on
this task.
Dorsal and ventral stream
The conclusion that the landmark task showed that
monkeys with parietal lesions were impaired in
spatial discrimination was criticized by Milner &
Goodale (1995) for several reasons.
Instead they proposed a different division of labour
based on what the visual information is used for,
rather than the stimulus characteristics.
Ventral: Visual perception
Dorsal: Visual guidance of goal-directed action
Dorsal and ventral stream
Patient studies:
• Optic ataxia:
– Disorder of spatial
perception or visually guided
action?
– Jakobson et al. (1991),
Jeannerod et al. (1994)
report a patient who was
impaired in adjusting their
grip aperture to the size of
the object.
Dorsal and ventral stream
Patient studies:
• Patient DF:
– Visual form agnosia
– Impaired recognition of
• form
• orientation, location
– However, she can use visual information to guide her actions
D.F. Controles
D.F. Controles
Dorsal and ventral stream
Patient studies:
• Patient DF:
Visual input
Visual perception
Visuomotor behaviour
Ilussion distortion larger in judgment than in pointing
However, with delayed pointing the illusion impact increases
Involvement of the ventral stream in visuomotor behaviour
Milner & Goodale (1995)
• Perceptual identification requires different visual
information than goal directed action
REFERENCE Allocentric Egocentric
Hoe werkt dit voor de haptische waarneming?
Zuidhoek, S., Kappers, A.M.L., van der Lubbe, R.H.J. and Postma, A. (submitted to Experimental Brain Research). Delay improves performance on a haptic spatial matching task.
Exploring the reference bar
Delay: waiting 10 s for the response signal
Response: setting the test bar parallel
Result: deviation in delay trials is smaller than in immediate trials
immediate
10 second delay
Na een pauze wordt de staaf minder aan de orientatie van de hand gecodeerd maar meer in ‘cognitieve’ termen (visualisatie strategie) =>
Kunnen blinden dit ook?
reftest
Remembering what was where:
How is spatial information stored in memory?
The hippocampal formation seems crucial (extending the ventral stream), receiving both egocentric and allocentric projections
Males
Females
Spatial performance in voles
The position of the hippocampus in the brain
Connections to and from the hippocampus
Hippocampus brings multimodal, highly processed information together and consolidates it into memory
Place and direction cells are found in the hippocampal formation, which code location, direction, and speed and distance (theta rhythm).
These functional properties form the basis for cognitive maps which support
a) wayfinding
b) goal identification and calculation of trajectories
c) predicting interactions between agents and objects
d) other cognitive abilities (temporal, linguistic etc..)
What about lateralisation?
=> Smith & Milner (1981, 1985, 1995)
In humans the hippocampus also supports spatial memory (Kessels, De Haan, Kappelle & Postma, Brain Reseerch Reviews, 2001)
Most studies suggest right sided lateralisation for spatial memory. However, this depends on the specific conditions
Apparently, there exists specific neural circuitries dedicated to spatial memory
- dorsal & ventral stream provide egocentric and allocentric reference, resp.
- left & right hemisphere provide categorical and coordinate spatial metrics, resp.
- hippocampus supports cognitive map for (allocentric) spatial memory
=> at a functional level, it might be hypothesized that spatial memory is relatively autonomous, working in an automatic fashion
Hasher & Zacks (1979)
Automatic Processes: -nonintentional -unaware -no load on central resources or attention -difficult to suppress
Effortfull Processes: -intentional, voluntary -conscious -capacity limited -flexible
Features coded automatically in memory:frequency and order of occurrence, location
Criteria for Automaticity
No effects of:
a) Intent to Learn
b) Age
c) Practice and Feedback
d) Individual Differences/ Intelligence
e) Concurrent Processing Loads
Table 1. Studies in support of the claim that spatial memory is automatic.
Authors Task Manipulations
Andrade &Meudell, 1993
words presented in one of 4 cor-ners.
Dual task interference
Dulaney &Ellis, 1991
4 pictures in a 2x2 matrix.Pictures on a page in 4quadrants.
Delay; Intelligence;Depth of encoding
Ellis et al,1987
idem age (3 - 6 yrs); intent;intelligence; depth ofencoding
Ellis et al,1989
idem age (children-adults);intelligence
Ellis andRickard, 1989
idem Intent; Delay
Ellis, 1990 idem Intent; Delay; Dual task
Katz & Ellis,1991
idem Delay; Depth ofencoding; Intelligence
McCormack,1982
A series of 4 words, verticallyaranged were presented
Intent; Age (20-70 yrs)
Shaidon &Ellis, 1993
4 pictures shown in a 2x2, 3x3,or 4x4 matrix
Intent
Schulman1973
4 words in a compass arrange-ment were presented
Intent
Zechmeister etal. 1975
recall of place on the page ofinformation in a MC test (whichone of the 4 quadrants).
Intent
Table 2. Studies which defy the claim that spatial memory is automatic.
Authors Task Manipulations
Acredeloet al 1975
Locate place where giveneventhappened.
Intent; Age (3-8 yrs)
Cherry &Park, 1993
24 objects placed in 3Denvironment (1x2m) or a2D map.
Age (20-67 yrs)
Finkel,1973
Displays of 2-5 positions,occupied by completelyequal or by completelydifferent objects
Age (children)
Kail &Siegel,1977
4x4 matrix containing 5or 7 letters.
Age (8-20 yrs)
Light &Zelinski,1983
Study a map with 12structures. Chose from anextended set of 18structures and positionsthe correct 12.
Age (25 vs 65 yrs); Intent
Naveh-Benjamin,1987
6x6 matrix, 20 items. Age (25-65 yrs); Intent; Dual task; Practice;Strategy (a certain spatial learning strategyis advised); Intelligence
Naveh-Benjamin,1988
6x6 matrix, 20 items.Recognition test
Age (25-70 yrs); Intent; Practice; Dual task;Intelligence
Park et al.,1982
drawings on the left orright side of a sheet
Age (25-65 yrs); Intent
Park et al.,1983
words or pictures in 4quadrants of a page
Age (20-75 yrs); Intent
Pezdek, 16 words or objects in a Age (17-68 yrs)
Conclusions on automaticity of spatial memory appear to depend upon the type of task used.
Both implicit (automatic) and explicit (effortfull) influences may drive spatial memory performance
Future research: to what extent do different neurological groups suffer specific implicit or explicit spatial memory impairments?
What can an Ordinary CKI Student Do in Space?
Implicit and Explicit Spatial Memory in Korsakoff Patients
Knowing where things are in our environment is so critically important that we may retain and use this information (implicit memory) without conciously remembering it (explicit memory)
Korsakoff patients suffer huge problems in spatial memory (e.g. binding of attributes and context memory seems particularly affected)
Question: does their implicit spatial memory survive?
Program created by Rob Broekmans (CKI student)
Test phase: choose one alternative from three locations
include
exclude
Inclusion condition:
probability target response = C + (1-C)U
C = explicit component; U = implicit component
Exclusion condition:
probability target response = (1 - C)U
Atractive features:
- ecological valid task
- connects to the everyday life problems of these patients
- sheds light on the interaction between implicit and explicit memory and their neural bases
Problem:
- working with clinical groups: do Korsakoffs understand the instructions?
0
0.1
0.2
0.3
0.4
0.5
implicit explicit
younger
older
Caldwell & Masson, 2001
Can a CKI student do some really pioneering work in Space?
Yes!!
Burgess, 2002
Arguably, spatial cognition is one of an organism’s most important abilities
Surprisingly, our knowledge of the neurocognition of space is relatively sparse
Future decades might show an increase in neurocognitive research in this domain
http://www.fss.uu.nl/psn/pionier/