Spatial Processing II

Banich, Ch. 7:

"Where" system (pp. 223-226)

Humans (pp. 226-233, not depth or rotation)

Constructional (pp. 233-234)

Lab ReportWorth: 20% of final gradeWorth: 20% of final grade

Due: Friday May 2 is the Due: Friday May 2 is the absolute final deadlineabsolute final deadline..

Start NOWStart NOW: there will be no extensions except in the : there will be no extensions except in the most most extremeextreme circumstances circumstances

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Your tutor: general questions about format, Your tutor: general questions about format, results,results, what’s requiredwhat’s required

Carolina (course TA): ditto. Avail. at office Carolina (course TA): ditto. Avail. at office hourshours

Carolyn: questions on specific aspects of Carolyn: questions on specific aspects of theory,theory, statisticsstatistics

Lab ReportRead lab manual pp. 19-20. Gives advice about how to Read lab manual pp. 19-20. Gives advice about how to write the report and how it will be evaluated.write the report and how it will be evaluated.

General marking schemeGeneral marking scheme

• Most important = General Discussion

• Next most important = Introduction

• Important because it affects everything = Results (make sure you draw correct conclusions from stats)

• Least important = "routine" sections, e.g. Method, Abstract, Refs (BUT basic knowledge of format required)

Lab ReportHow many papers should I read?How many papers should I read?• NOT a numbers game, we won't be counting refs!

• We strongly recommend you read the key papers. Use the secondary refs as a list to select from.

• Generally, the more you read, the better placed you will be to explain your results.

• Good reports generally cite more refs than weaker reports.

BUT, don't spend so much time reading that you BUT, don't spend so much time reading that you don't have time for the discussion!don't have time for the discussion!

Attention/Spatial Lectures1. Spatial Processing (JL)

• Introduction• Examples of animal and fMRI studies

2. Attention (JL)• Introduction• Examples of animal and fMRI studies

• 3. Spatial Processing (CW) THIS LECTURE• Re-cap• Some illustrations from patient data

4. Attention (CW) TOMORROW• Re-cap• Some illustrations from patient data

The "Where" Stream

Temporal/parietalTemporal/parietalLobesLobes

RetinaRetina ThalamusThalamus PrimaryPrimaryVisualVisualCortexCortex ExtrastriateExtrastriate

CortexCortex

rodsrods

conescones

Magnocellular pathwayMagnocellular pathway

Parvocellular pathwayParvocellular pathway

V4V4

V3V3V5V5

Dorsal regionsDorsal regions

Ventral regionsVentral regions

The "Where" Stream• Deciding which object is nearer

• Locating objects in 2D

• Reaching for objects

• Comparing the relative position of two objects

• Analysing movement and orientation

• Computing “spatial maps”

The "Where" Stream

Previous lecture (Jan):

• Examples of animal and fMRI studies

This lecture:

• Some illustrations from patient data

Simple analysis of position and movement:

Also hierarchically organisedAlso hierarchically organised::

The "Where" Stream

Extrastriate cortex (V3, V5/MT)Extrastriate cortex (V3, V5/MT)

Parietal lobes, esp. R. Parietal lobeParietal lobes, esp. R. Parietal lobe

2.2. Higher analysis of spatial relationships: Higher analysis of spatial relationships:

Simple Analysis of Location/Movement

I. Analysing position relative to viewer

-> Egocentric localisation

II. Perceiving movement

• Extrastriate CortexExtrastriate Cortex

Some examples of skillsSome examples of skills::

• ContralaterallyContralaterally organised organised

I. Egocentric localisation

• Coordinating retinal location with eye, head position

• May involve Extrastriate area V3

• Impairment = “Visual disorientation”

Private M: Asked which of two objects was nearer to him, he Private M: Asked which of two objects was nearer to him, he

commented: "When I look at one it seems to go further away. When I commented: "When I look at one it seems to go further away. When I

try to see which is the nearer they seem to change in position every try to see which is the nearer they seem to change in position every

now and then; that one at which I look directly seems to move away”now and then; that one at which I look directly seems to move away”

"Sometimes I can see it quite well, but sometimes I can not see what I "Sometimes I can see it quite well, but sometimes I can not see what I

want to look at".want to look at".

• Integrating changes in visual information over time to obtain sense of “movement”

• Probably involves Extrastriate V5

For MP, perception was akin to viewing the world in snapshots. For MP, perception was akin to viewing the world in snapshots.

Rather than seeing things move continuously in space, moving Rather than seeing things move continuously in space, moving

objects would appear in one position and then another, When objects would appear in one position and then another, When

pouring a cup of tea, MP would see the liquid frozen in air, like a pouring a cup of tea, MP would see the liquid frozen in air, like a

glacier. She would fail to notice the tea rising in her cup and would glacier. She would fail to notice the tea rising in her cup and would

be surprised when the cup overflowed. The loss of motion be surprised when the cup overflowed. The loss of motion

perception also made MP hesitant about crossing the street. As she perception also made MP hesitant about crossing the street. As she

noted, "When I'm looking at the car first, it seems far away. But then noted, "When I'm looking at the car first, it seems far away. But then

when I want to cross the road, suddenly the car is very near".when I want to cross the road, suddenly the car is very near".

II. Perceiving Movement

Simple analysis of position and movement:

Also hierarchically organisedAlso hierarchically organised::

The "Where" Stream

Extrastriate cortex (V3, V5/MT)Extrastriate cortex (V3, V5/MT)

Parietal lobes, esp. R. Parietal lobeParietal lobes, esp. R. Parietal lobe

2.2. Higher analysis of spatial relationships: Higher analysis of spatial relationships:

Higher Spatial Analysis• Analysis position of objects relative to one another = Allocentric spatial analysis

• Not contralaterally organised

• Shows strong hemispheric asymmetry

• Right parietal lobe (upper regions)

Higher Spatial Analysis

Includes:

I. Judging line orientations

II. Copying complex designs

III. Constructing complex designs

IV. Mental rotation

Higher Spatial Analysis

I. Judging line orientations

• Also shows LVF/RH Also shows LVF/RH advantage in normalsadvantage in normals

Higher Spatial Analysis

II. Copying or drawing complex spatial designs

Rey Figure:

Higher Spatial Analysis

Constructing complex designs using blocks or matchsticks

Higher Spatial Analysis

IV. Mental rotation