Data Mining: Whats New, Whats Not

1

• Review Session Today, B11 Vance Hall. 500 pm.
  3733 Spruce St.
• Practice exam (link on schedule) and also last
  years exam is available on the web page.
• Exam Thrs, starts at 130 ends at 350.
• Exam is closed book.

2
Hemispheric Asymmetry

• Outline
• From last time -- hemineglect
• General properties of two hemispheres
• Further examples
• What pathway
• Agnoia
• Where pathway
• Split-brain patients
• Developmental considerations
• Hemispheric Asymmetry
• Cortical development

3
Consider Function Attention

• Hemineglect (hemi-inattention)
• The lack of attention to one side of space,
  usually the left, as a result of parietal lobe
  damage. It occurs despite intact sensory and
  motor functioning
• While hemineglect is usually associated with
  right parietal damage, it is associated with
  damage elsewhere as well

4
Hemineglect (Branick)
5
Consider Function Attention

• Hemineglect (hemi-inattention)
• The neglect is relative to the midline of the
  body
• In severe cases, the patient denies the left side
  of their body
• Note that changes in direction of gaze (change of
  left and right visual fields) does not alter the
  neglect relative to midline

6
Hemispheric Specialization

• FUNCTION In general left hemisphere is
  associated with language and right hemisphere is
  associated with spatial tasks.
• ANATOMY In general right frontal region is
  larger than left left occipital cortex is larger
  than right.
• HANDEDNESS localization of function is more
  marked in right- than left-handed individuals (as
  an average).
• For example95-96 of Right handed individuals
  have language in left hemisphere and 4 in left
  hemisphere. 70 of Left/Mixed handed
  individuals have language in the left hemisphere
  15 in right hemisphere, 15 both.

7
Hemispheric Specialization - Examples

• In the what ventral stream the right hemisphere
  has preference for global information (general
  outline) left hemisphere for local information
  (details).
• Consider hierarchically organized figures

8
hierarchically organized figures
9
Hemispheric Specialization - Examples

• In the where dorsal stream
• Local depth perception appears to depend on both
  left and right hemispheres
• Global depth perception (general shape) appears
  to depend dominantly on the Right hemisphere.
• Similarly, the ability to judge line angle
  appears to depend on Right hemisphere processing

10
Hemispheric Specialization - Examples

• Consider Split Brain Studies (Roger Sperry)
• Intractable epilepsy sever corpus callosum, the
  dominant pathway between the two cortices.
• No communication between the two hemispheres
• Present stimuli rapidly to one or another visual
  field which is one or another now separated
  hemisphere.
• Some results

11
(No Transcript)
12
Hemispheric Specialization - Examples

• Feel object with left or right hand. Report what
  the object is
• Oral report only when object is placed in right
  hand, not left hand. (when in right hand,
  speaking left hemisphere responded dont
  know)
• Next, demonstrate use of object in hand. Objects
  in left hand could be used correctly. Right
  hemisphere is mute, not useless.
• Right hemisphere is associated with spatial and
  nonverbal tasks
• For example, left hand can arrange blocks into
  patterns right hand fails.

13
Hemispheric Specialization - Examples

• Split-brain patients, cont.
• Chimeric picture
• Each hemisphere fills in the figure.
• Point to correct figure Left hand to woman.
  Left hemisphere (right hand) was less accurate.
• Superiority of right hemisphere for facial
  recognition

14
Hemispheric Specialization - Examples

• Consider individuals with normal neurological
  profiles
• Again, processing of verbal information superior
  when presented to left sensory regions.
  Nonverbal information tends to be processed
  better when directed initially to primary sensory
  regions of the right hemisphere.
• For example, rapidly presented words vs. pictures
  left and right visual field advantages,
  respectively.

15
Developmental Aspects Localization

• Anatomical differences are present at birth.
• Children with complete hemisphere removal do not
  attain complete competence in language (left
  hemisphere removed) or spatial tasks (right
  hemisphere removed).
• However, children with damage to left hemisphere
  regain language skills (for example) more so than
  their adult counterparts.
• These results suggest that the anatomical
  asymmetry at birth may lead to a left hemisphere
  boost to language processing and once begun the
  dominance grows.

16
Developmental Aspects Cortex

• Development of cortical organization role of
  extrinsic (vs. intrinsic) factors.
• Consider The relation between sensory inputs to
• cortex and the functional capacity of a sensory
• projection. (Sur and colleagues 1990 etc.).
• Consider role of sensory input for organization
  of the cortex
• Deprivations experiments
• Both behavioral and physiological changes
• Congenitally blind people have reorganization
  of V1.

17
Developmental Aspects Cortex

• Study of ferrets (neonates) where visual input
  has been re-directed to the auditory pathway.
• In one hemisphere deaffernate MGN (auditory
  thalamus plus a few others) so no auditory
  inputs to auditory cortex. Redirect portion of
  optic nerve to MGN. What is the resulting
  characteristic of auditory cortex?

18
Developmental Aspects Cortex
19
Developmental Aspects Cortex

• The auditory cortex is similar becomes similar to
  a typical visual cortex sensitivity to
  orientation, sequential receptive fields, 2-d
  representation of the retinal. Absent is the 1-D
  frequency map usually associated with the
  auditory cortex.

20
Developmental Aspects Cortex

• This suggests that the pattern of activity in the
  optic nerve is sufficient for the development
  cortical organization.
• But is the new cortex sensitive to light? Is
  there a perception of light?
• Consider behavioral task

21
Developmental Aspects Cortex
Ferret is taught using center speaker and light
in LVF (right, intact, hemisphere).
(a) examine response to central sound and light
in LVF (right, intact hemisphere). Animal learns
to go to correct spout.
22
Developmental Aspects Cortex
(a) examine response to central light and RVF
(re-wired left hemisphere). Animal treats
stimuli as light
(b) Remove LGN connections in left hemisphere.
Animal Continues to treats stimuli as light,
even if projected to Left Hemisphere
23
Developmental Aspects Cortex
(c) Finally, remove MGB connections in left
hemisphere. Now animal reacts to sound and light
in right visual field in the same manner.
24
From S. Thompson-Schill

• Transcripts of Cinderella Story
•  
• Patient MA (2,10)
• She picked she, sh- she did the beginning, then
  she met this one. And then, this one.
• You mean you want the whole thing?
• Ok, Cinderella - - I cant.
• Ok, Cinderella went to, septa- stepmother, with
  the sepsisters. They were like, um, sumpage,
  supa, I dont Sum you -

25

• Ok they had the out people. They, they not in the
  beginning but the big house. Not the big one but
  the front, in the front of it, is where they
  went.
• (The castle?)
• Yeah, but its in the back. This is S-something.
  Where they, these and they hold this up.
• (Scullery?)

26

• No, its where they work. Its like there, theyre
  theyre like, they keep this do-do-doo,
  do-do-doo.
• (The kitchen?)
• Yeah, something like that.
• Its where they, they

27

• (Servants quarters?)
•  
• Right, well, thats what shes like. Alright?
  Yeah, thats what she shuz. Cleans this, and this
  and that and that.
•  
• And , she went, um, she kept cleaning
  everything. You know, cleaning this, doing that,
  doing that. Scrape, scrape, scrape.
•  
• Not the other ones. The sep-sisters.
• No. They wanted to sleep, and you know, and then. 

28

• Theyre pretty ugly too.
• No, its not that. Its everybodys different,
  everybodys beautiful still.
•  
• No, its just
•  
• And then they went to, they went to, who was
  this?, yeah, they went to the king for the
  prince. And thats where they all went except
  Cinderella wasnt allowed to. They said she can
  go with them but after youre done with this
  cleaning and then you can go.

29

• Patient JS (1,24)
•  
• Um. Uh. Man and woman. Two girls. And, and, man
  one girl. Met, get married. And uh uh man
  died. Three, three, one woman and three girls.
• And uh, um, um, uh, one girl whole bunch of uh
  dirty work. Yeah.
• And uh, about uh, OK uh, king uh