Biological Bases Keywords 2008

Front 1

Double Dissociation (Definition)

Back 1

- H.L. Teuber introduced the term double dissocation.
- Double dissociation is an experimental technique by which two areas are functionally dissociated by behavioural tests.
- Each test affects one lesion zone and not the other.
- Broca's patients could no longer speak but could understand language.
- Wernicke's patients could no longer understand language but could produce jumbled speech.

Front 2

Double Dissociation (Study 1)

Back 2

- Martins and Farrajota (2006)
- Proper and common names
- ACB had an aphasic disorder with impaired naming, sparing proper names.
- JFJ had normal language abilities and semantic knowledge about people, but a marked anomia for people's names.
- Evidence for a double dissociation.

Front 3

Double Dissociation (Study 2)

Back 3

- Klauer and Zhao (2004)
- Double dissocations in visual and short term memory.
- A visual short term memory task was more strongly disrupted by visual then spatial interference.
- A spatial task was simultaneously more strongly disrupted by spatial than visual interference.
- Memory tasks comprised a spatial task and a visual task.
- Interference conditions comprised a movement discrimination task and a colour discrimination task.
- A reliable crossed double dissocation of a visual and spatial component in the short-term retention of single stimuli was demonstrated.

Front 4

Pure Alexia (Definition)

Back 4

- Pure Alexia is a reading disorder that occurs in literate individuals after a lesion in the left occipito-temporal rergion.
- There is the word-length effect.
- Pure Alexia was first extensively described by Dejerine.
- Dejerine describes pure alexia as a 'disconnection syndrome' that isolates the 'centre for optic images of the letters'.
- Because this language centre cannot be accessed through visual stimulation, the patient cannot read.

Front 5

Pure Alexia (Study 1)

Back 5

- Tadashi (2007)
- Longitudinal fMRI study
- 7 days after a haemorrhage in the left occipito-temporal region when patient showed LBL reading.
- Repeated again 50 days after, when his LBL reading had resolved.
- Broca's area was strongly activated during his LBL reading.

Front 6

Pure Alexia (Study 2)

Back 6

- Ingles and Eskes (2008)
- The extent to which LBL reading results from a specific orthographic deficit.
- The current study directly compared processing of letters and digits in a LBL reader.
- Using a RSVP task and a speeded matching task.
- In the RSVP task they had increased difficulty reporting the target identities when they were letters.
- LBL reading results from visuoperceptual encoding deficit that particularly affects letters.