NEUROPSYCHOLOGY L11

Auditory agnosia differs between both hemispheres in its expression.

In case of a (left/right) hemisphere lesion, the patient has problems with 'perceiving' the sound: it is e.g. a sound of a motor, but what is the nature of the sound of the motor: a train or a drill?

Concerning a (left/right) hemisphere lesion: as you know, more the detailed, analytic hemisphere, the 'meaning' of a sound could be disturbed.

categorization and organization are functions that belong to tertiary brain regions:

1. primary brain regions

2. secondary brain regions

3. tertiary brain regions

- a patient may recognize a 'broad' category like animal, but is not able to further specify e.g. bird...

to organize and to categorize you need to make associations, aha, in other words, you need associative brain regions, like tertiary brain regions. 

H.M. a patient with a bilateral removal of the hippocampus and amygdala. 

His retrograde amnesia is time-dependent, implying that 'remote' memories (old memories from his youth) are (well preserved/ cannot be remembered) whereas recents events (well preserved/ cannot be remembered)

H.M. a patient with a bilateral removal of the hippocampus and amygdala.  His retrograde amnesia is time-dependent, implying that 'remote' memories (old memories from his youth) may be well preserved whereas recents events cannot be remembered.

Interestingly, he still had an undamaged implicit memory. Why?

Has to do with

1. septum

2. hippocampus

3. Heschl gyrus

4. basal ganglia

The explanation is that for implicit memory you need your basal ganglia and that region was not removed in H.M.  

Which central structures are involved in memory?

- temporal lobes

- basal ganglia

- amygdala

-prefrontal cortex (PFC)

- all of the above

Next we discussed three diagrams: one for explicit memory, one for implicit memory and emotional memory. The central regions are: temporal lobes (medial temporal lobe: hippocampus), basal ganglia, and amygdala, respectively.  Do you know why in the diagram concerning explicit memory, the brainstem, and related neurotransmitters are so prominently highlighted.  Moreover, for memory, you also need the prefrontal cortex: left PFC for encoding and right PFC for retrieval.