Cognition Flashcards
Lateralisation
Division of labour in l/r hemisphere
Information is exchanged across the longitudinal fissue via
Corpus callosum (results from axonal myelination)
Anterior commissure
Posterior commissure
Hippocampal/fornix commissure
Habenular commissure
Auditory connections:
hemisphere pays more attention to contralateral side.
Define epilepsy and provide treatments
neuro condition, synchronised neural activity.
Treatments: antiepileptic drugs, surgical removal of focus. Severing corpus callosum may be effective – called split brain operation, which prevents neural exchange across hemispheres.
Right hemisphere is responsible for
comprehending spatial relationships, patterns, language comprehension and emotion.
Consolidation of memory
Suggested to rely on protein synthesis. Significant time variability, eg emotional events
Amnesia
Inhibition of transcription and translation
Hippocampus
forming learning and memory loop in cortex. Vulnerable to atrophy (depression and Alzheimer’s)
Alzheimers
dementia categorised by gradual decline in memory. Neural degeneration seen in cortical and subcortical regions.
Amyloid hypothesis
APP broken down, Amyloid beta produced, plaques formed in synapse. Amyloid can detach tau proteins (stabilising microtubules), leading to a breakdown of microtubules
Working memory
assessed using delayed response task
• Phonological loop (Brocas and wernickes)
• Visuospatial sketchpad (occipital lobe and right hemisphere)
• Episodic buffer (Parietal lobe)
• Executive control (DLPFC and ACC)
Types of amnesia
Anterograde: loss of ability to form new memory
Retrograde: Loss of memory prior to occurrence of damage
Types of memory
• Semantic: Factual information/general knowledge
• Episodic: Events, spatial and temporal relationships
• Explicit: Deliberate recall of information
• Implicit: Influence of experience on behaviour
Phonological loop:
assessed through lists of digits/repetition of non-words, evolution of language
Brocas aphasia
Spech labored and hesistant, but meaningful
Wernickes aphasia/fluent:
Sound/word substitution (paraphrasia) and difficulty in naming (anomia). Speech remains fluent, language comp impaired
Pattern of activity in brain leaves
path of physical changes.
Presynaptic, postsynaptic. Greater neurotransmitter release, More/less sensitive receptors.
Hebbian synapse:
Neurons that fire together wire together. Synapse that increases in effectiveness because of simultaneous activity in presynaptic and postsynaptic neurons.
Long term potentiation (LTP):
one or more axons bombarded a dendrite with simulation. Leaves the syapse “potentiated” and more responsive.
Long term depression (LTD):
prolonged decrease in response at a synapse. As one synapse strengthens, another weakens
Biomechanicam mechanisms
LTP depends on change at glutamate synapses (AMPA and NMDA receptors)
Biomechanicam mechanisms in hippocampus neurons
Caused by sodium entry. Depolarisation displaces magnesium molecules blocking NMDA receptors, glutamate then excites NMDA opening channel for calcium ions, triggering activation of intracellular enzymes, altering the make-up of the cell
LTP is the
neuronal mechanism underling learning and memory.
