2Psy Neuro ZELF 6.-7.

Limbic system

=integrates emotions with higher mental functions (reasoning, memory) into a cohesive whole

Amygdala

=assigns emotional significance to experiences and is responsible for the sensation of fear.

1) Utilizes knowledge from the past (stored in associative areas) to assess current situation

2) Can trigger the fight-or-flight response when necessary

  (eg. in response to fear).

3) Responsible for emotionally charged memories

 (fear conditioning:  associating st. with danger based on past experiences)

Kenm limbic system

1. Evolutionarily ancient system with functionally (as opposed to anatomically) connected structures

2. Leads to certain activities being experienced as pleasurable (e.g., sex, eating)

->& causes stress response in reaction to certain other sensations/emotions

 

3. Connected with & influenced by frontal cortex

=>situation reassessment & inhibition/execution of emotional responses

Hippocampus

=plays a role in learning and memory

=>acts as bridge between prefrontal cortex (where memories are used) & sensory associative areas (where memories are stored).

1. Serves as gateway during learning process: determines which information is stored & how it is encoded and retained

2. Communicates with frontal cortex: memories are important part of decision-making processes.

3. Significantly smaller in Alzheimer’s patients

Cortical areas

~work together with lower areas (limbic system) for learning & memory

 ->short-term, long-term & skill memory

Short-term memory

~involves prefrontal areas

 (eg. briefly remembering phone number)

Long-term memory

~involves various sensory associative areas throughout the cerebral cortex.

 ->integral, inseparable mix of semantic (words, numbers, knowledge...) & episodic (people, events) memory
 ->images are processed in visual associative cortex, smells in the olfactory associative cortex…

Skill memory

~involves all cerebral motor areas below the level of consciousness (i.e., implicit memory).

 ->initially, several cerebral areas involved during learning process

 ->later, fewer involved as skill becomes automated

Prefrontal cortex

~communicates with hippocampus when memories are being stored & retrieved
 ->meanwhile amy provides emotional tone of memories

Neural basis of memory

~after intensive use of synapses for a short time

 =>more neurotransmitters are temporarily released (process known as long-term potentiation)

 

Amnesia >disruption of memory pathways

 ->can be temporary or permanent

Anterograde amnesia

=damage to limbic system separates old memories from more recent memories (the here and now)

 =>only able to recall distant past memories (eg. not what you had for breakfast)

Retrograde amnesia

=reverse of anterograde (variable periods before accident erased)

 ->often occurs after blow to head/brain trauma

Language

~depends on semantic memory

 ->same regions involved as in memory & language

 ->areas involved in reading: visual cortex → Wernicke's area → Broca's area → primary motor cortex

L & R hemispheres

~have specific functions (in addition to cooperating effectively)

=both hemispheres process same information but in different ways

 ->differences studied through Pts with severed corpus callosum (split-brain patients): often done for epileptic Pt to prevent further seizures

 Bv: Pt views object with only right eye: image only sent to right hemisphere

 =>Pt will be able to choose proper tool for particular use (eg scissors to cut paper): but unable to name object

Left hemisphere

=global processing

1. Language (verbal)
2. Logical/analytical
3. Rational processing

Right hemisphere

=specific processing

1. Visuospatial (non-verbal)
2. Intuitive
3. Creative processing