Hjärnans dynamiska organisation 1

Question 1

Vad kallas det primära syncentrumet med ett annat ord och var sitter det?

Answer 1

Striate cortex, occipitalloben

Question 2

Vägen från synintryck till cortex

Answer 2

Visual receptors > thalamus > cortex(primära syncentrum)
^ detta e enligt föreläsning så det är bara det vi behöver veta egentligen

I boken tar dom dock upp 2 olika vägar:
1. Geniculostriate
Eye > optic tract > lateral geniculate nucleus(thalamus) > striate cortex > other visual cortical areas
- pattern, motion and color perception
- conscious visual perception

Symptoms of damage:
- impairments in pattern, color and motor perception
- visual-form agnosia: the inability to see the shapes of objects or recognize them

2. Tectopulvinar pathway
   Eye > superior colliculus(midbrain tectum) > lateral-posterior pulvinar(thalamus) > visual cortical areas
   - motion and location
   - provides information to the cortex about absolute spatial location of objects(independent of viewer’s gaze)

Symptoms of damage:
- visual ataxia/optic ataxia: inability to recognize location of objects and reach for them

Question 3

Vad är sinnessystemens uppbyggnad och var går gränsen mellan sensation och perception?

Answer 3

(stimuli) -> receptor -> nerver -> hjärnan
Gränsen mellan sensation och perception är mellan nerv-”stadiet” och hjärn-”stadiet”

Question 4

Vägen från ljudintryck till cortex

Answer 4

Auditory receptors > hindbrain > midbrain > thalamus > cortex

Question 5

Vägen från somatosensoriska intryck till cortex

Answer 5

Somatosensory receptors > Spinal cord > Brain stem > Thalamus > Cortex

Question 6

Vad finns det för 2 huvudtyper av visuell agnosi?

Answer 6

Apperceptive agnosia: a failure to construct an internal representation of an object. Object recognition through verbal description by the examiner is preserved, instead. is thought to arise from a breakdown at relatively early stages of visual processing, where the elementary features of the stimulus are processed.

Associative agnosia: “perception stripped of meaning.” patients can form a structural description of the visual object , yet being unable to recognize it. A person with associative agnosia can make recognizable copies of a stimulus that he or she may not recognize subsequently and can also successfully perform matching tasks.

Question 7

Vad för typ av visuell information skickas i den ventrala respektive dorsala strömmen och var leder strömmarna till? Vilka visuella dysfunktioner är relaterade till skador i respektive ström?

Answer 7

Ventrala - “vad?” - till temporalloben - bl.abl.a visual agnosia, prosopagnosia
Dorsala - “var”?/”hur?” - till parietalloben - visual ataxia/optic ataxia, akinetopsia(rörelse)

Question 8

Relays for pain receptors

Answer 8

• Spinal cord - When you touch something hot, the first relay for the pain receptors in the spinal cord makes you reflexively remove your hand from the hot object.
• Brain stem - The pain pathway then relays in the brainstem, especially in the midbrain periaqueductal gray matter(PAG) nuclei that surround the cerebral aqueduct. This prompts many complex responses, including behavioral activation and emotional responses. The enduring pain after you removed your hand may be related to neural activity in PAG.
• Cortex - Pain relays in the neocortex localize pain, identify the felt pain, its external cause and possible remedies. Can also adapt to our experience so that we know in advance not to touch the object again.