Content
Memory consolidation ............................................................................................................................ 2
Basics of Electrophysiology ..................................................................................................................... 5
Electrophysiology .................................................................................................................................... 7
Study design ............................................................................................................................................ 9
Viral based techniques .......................................................................................................................... 10
EEG and MEG ......................................................................................................................................... 12
MRI 1 ..................................................................................................................................................... 17
MRI 2 ..................................................................................................................................................... 21
,Cognitive neuro-imaging
Memory consolidation
Episodic memory: Episodic memory refers to the conscious recollection of a personal experience that
contains information on what has happened and also where and when it happened. Examples: Your
skiing vacation last winter and who you were with. The first time you travelled by airplane.
Semantic memory: Semantic memory refers to a portion of long-term memory that processes ideas
and concepts that are not drawn from personal experience. Semantic memory includes things that
are common knowledge, such as the names of colours, the sounds of letters, the capitals of countries
and other basic facts acquired over a lifetime.
Memory consolidation is defined as a time-dependent process by which recent learned experiences
are transformed into long-term memory, presumably by structural and chemical changes in the
nervous system. (e.g., the strengthening of synaptic connections between neurons)
There are two major processes that lead to the final consolidation:
1. Synaptic consolidation which takes place within immediate hours of learning and encoding.
2. System consolidation where hippocampal memories are independent of hippocampus
storage after a certain period of time.
The long term potentiation ( LTP) is the consolidation convicted of increasing synaptic transmissions
between the neurons.
LTP is a discrete phenomenon linked to the synchronous neuronal firing of the same group type to
induce sensitization for future retrieval. The additional memories create more connections by
rearranging them and redirecting them to their specific points. A laid neuronal pathway will create
less resistance path for the further flow of information. This is concerned with protein formation for
the consolidation.
Important for this process are:
-Cofiring of neurons
-NMDA receptors
, -Dopamine
-Protein synthesis.
Basics of memory consolidation
There are three basic stages through which memory forms:
-Encoding: This refers to how sensory inputs are transformed into a kind of input that can be stored
as in the form of memory. (Short-term or long-term)
-Storage: This represents how to retain the encoded sensory information you get through your sense
organs.
-Retrieval: This accounts for how you get access to the actual memory stores in your brain.
Non-declarative memories can be incorporated into permanent stores by constant practices and
repeated procedural conditioning. Other wise the memory can get lost if it isn’t rehearsed or
practiced.
Long-term memory has two components: declarative (explicit) and non-declarative (implicit).
Declarative memory has to do with the storage of facts, and events we have personally experienced.
Recalling information from declarative memory involves some degree of conscious effort, as
information must be consciously brought to mind and “declared”.
Implicit memory (non-declarative) includes procedural memory and things learned through
conditioning.
The importance of the hippocampus and neocortex
It is vital to state that conscious memories are formed through consolidation which is initially stored
in the storehouses namely the hippocampus and neocortex. Then the hippocampus gets out of the
sentence and the consolidation is rather restricted to the neocortex after a certain time.
Hippocampus is collects new information for a temporary basis until it is calculated and transferred
(consolidated) to the neocortex.