Oct. 12 notes Flashcards
Focused Attention
- ability to respond discretely to specific visual, auditory or tactile stimuli
- least likely to be compromised by brain injury
Selective Attention
- ability to maintain focus in the face of distracting/competing stimuli
- ex. task counting # of E’s and R’s surrounded by other letters
- Load stress: too much information at once
- Speed stress: information presented too quickly
Sustained Attention
-ability to maintain attention and remain alert to stimuli over prolonged periods of time
Alternating Attention
-ability to shift focus and move between tasks with different cognitive requirements
Divided Attetention
- ability to do more than one task at the same time
- multitasking
Posner’s Model of Attention
- Alerting network -> intrinsic awareness & phase alertness
- Orienting network
- Executive network
- alerting network activates orienting network which activates executive network to take action or return to intrinsic awareness
Orienting network structures
Posner’s model
- superior parietal
- temporal parietal junction
- frontal eye fields
- superior colliculus
Alerting network structures
Posner’s model
- locus coeruleus
- right frontal
- parietal cortex
Executive network structures
Posner’s model
- anterior cingulate
- lateral ventral
- prefrontal
- basal ganglia
Inattention
- inattentional blindness
- change blindness
- attentional blink
Inattentional blindness
- failure to notice something during the performance of another task
- ex. monkey video
Change blindness
-failure to detect changes in the presence, identity, or location of objects in scenes
Attentional blink
-failure to detect a second stimulus if its is presented within 500 ms of the first
Attention => Memory
-sensory memory transfered to short term memory transfered to long term memory
Models of memory
sensory modality, content, time
- sensory modality based: auditory, visual, tactile, gustative, olfactive
- content based: faces, objects, names, spatial memory, autobiographical memory
- time based: retrograde (past), anterograde (present), prospective (future)
Encoding, Retention, Recognition
- forming
- maintaining
- recognizing
Sensory memory
- very short (1-5 s)
- visual input (iconic store)
- auditory input (echoic store)
- input from other senses (gustative, olfactory, tactile stores)
Short term memory
- temporary storage of information that is being processed in any range of cognitive tasks (30s - 1 min)
- limited space
- relay station -> sends info to long-term memory or uses info right away and then forgets
Working memory
- temporarily stores and manipulates information (oppose to short term which temporarily stores but does not manipulate)
- visuospatial sketchpad (visual), episodic buffer (visual & auditory or other), phonological loop (auditory)
Long-term memory
- explicit
- implicit
- emotional
Explicit memory (LTM)
- conscious
- episodic, semantic
Implicit memory (LTM)
- unconscious
- skills, habits, priming, conditioning
Emotional memory (LTM)
- conscious and unconscious
- attraction, avoidance, fear
Anatomy of memory/amnesia
-hippocampus, amygdala, parahippocampal gyrus, temporal cortex, basal ganglia, cerebellum, frontal lobe, papez circuit (fornix, mammillary bodies, anterior thalamic nuclei, cingulate)
Hippocampus
- familiar surroundings/where objects are located
- appointments or events
- memory encoding
- verbal (left), and visual (right) memory
Amygdala
- emotional conditioning, storing emotional events, coding emotional signals
- stimulation results in emotional feelings, damage disrupts emotional memory but not implicit & explicit
Parahippocampal gyrus
-role in semantic memory
Temporal cortex
-semantic memory (anterior temporal lesions impair semantic memory, and retrograde memories)
Frontal cortex
-encoding, autobiographical retrieval, and working memory
Cerebellum
- plays role in classical conditioning (implicit)
- lesions to cerebellum abolish conditioned response to puff of air to eye
Basal ganglia
-loss of cells in basal ganglia lead to implicit memory deficits (ex. huntingtons disease, learning skills)
Papez Circuit
- fornix: mammillary body and hippocampal projections
- mamillary bodies: receive input from medial temporal lobe and project to anterior thalamic nuclei, Korsakoffs syndrome
- anterior thalamic nuclei: hippocampal connections, projects to cingulate, anterograde amnesia
- cingulate: anterior->goal directed behaviors, posterior->highly connected, associated with amnesia
Anterograde Amnesia
-inability to aquire new memories
Retrograde Amnesia
-inability to remember old memories
Global Amnesia
-transient, loss of old memories and inability to form new memories
Patient H.M.
- history of epilepsy
- had bilateral hippocampectomy (removed medial temporal lobes), resulted in onset of amnesia (still had intact intelligence)
- lead to finding that hippocampus is essential for memory encoding
- able to learn to complete a task (implicit, procedural memory), but no explicit memory of ever having performed the task
Korsakoff’s Syndrome
- anterograde/retrograde amnesia, confabulation (saying untrue things as if they were true), lack of insight, apathy
- caused by thiamine (B1 vitamin) deficiency due to alcoholism or malnutrition
- damage to medial thalamus, mammillary bodies, and general atrophy
Alzheimer’s Disease
- begins with anterograde amnesia, cellular change in medial temporal cortex
- later results in retrograde amnesia with damage to temporal association areas and frontal cortical areas
Herpes Simplex Encephalitis
- medial temporal lobe damage that leads to anterograde amnesia
- damage to insula and surrounding regions produces retrograde amnesia
