Midterm 2 Flashcards
What is object recognition and what is it’s goal?
Analysis of the shape and form of something
The aim is to identify and determine the object and location
What is the hierarchical coding hypothesis?
Idea that we recognize objects by building up recognition of features.
Features > Conjunction of features > Component shape > Object
What is the grandmother cell theory and how credible is it as an explanation to how we recognize things?
Idea that specific neurons code for specific stimuli (such as your grandma)
Not accurate as we know activation of neurons isn’t specific to a stimulus
What is the ensemble theory?
Idea that collective of neurons code for stimulus
Much more accurate than the grandmother cell theory
Describe the Ventral pathway and the evidence that supports it
The What path, located along the Parietal
Responsible for object perception and recognition
Describe the Dorsal pathway and the evidence that supports it
The Where path, located along the Temporal
Responsible for spatial perception
How is the auditory system similar to pathways for object recognition?
Where and What are split
Anterior auditory cortex encodes patterns (What)
Posterior auditory cortex encodes spatial location (Where)
How does the motor system play a role in object recognition?
Our kinesthetic sense gives us an idea of how we can manipulate an object, giving us clues to what the object may be
What is category-based hypothesis of organization of semantic knowledge?
Idea that semantic knowledge is organized by categorization of objects (alive vs. dead, animate vs. inanimate)
Discovered to be less effective/accurate
What is property-based hypothesis of organization of semantic knowledge?
Idea that semantic knowledge is organized by the properties and qualities of objects
Found to be more accurate by computer simulations
What is agnosia?
Inability to interpret sensation and thus hinder recognition of things
Usually results from brain damage
What is visual agnosia?
Deficit in visual recognition
What is optic ataxia?
Inability to reach for something you are looking at
What is apperceptive agnosia?
Ability to recognize something but not at odd angles
Lesions in right hemisphere, parietal, occipital
What is integrative agnosia?
Cannot put features together to recognize the object
Lesions in extrastriate cortex
What is associative agnosia?
Most severe type of agnosia
Able to perceive objects but cannot assign meaning
Lesions in bilateral inferior occipitotemporal cortex
Which region of the brain is involved in facial recognition and why is it controversial?
Fusiform face area, found in the ventral temporal lobe
Controversial as not sure if it is face specific or expert specific
What is the parahippocampal area (PPA) and posterior parietal cortex responsible for in recognition?
Information about places and scenes
What is the lateral occipital cortex and anterior inferior temporal cortex responsible for in recognition?
Object recognition
What is the fusiform gyrus and the superior temporal sulcus responsible for in recognition?
Face recognition
What is the posterior parietal responsible for in recognition?
Visually guided actions
What is attention?
Process by which the mind chooses from various stimuli that strike the sense at any given moment
What is voluntary attention?
Attention we are manually controlling
What is reflective attention?
Attention we are not in control of (automatic)
What is covert attention?
Focusing on something while attending to something else discreetly
What is overt attention?
Actively attending to something
What is change blindness and what does it tell us about attention?
When you cannot remember something unless you pay attention to it
Shows that there is limited capacity to our attention system
Describe Broadbent’s early selection theory
Stimuli is filtered (selected to be attended to) at an early point in processing.
Problem was that unselected stimuli still get attention
Describe the late selection theory
Everything from sensory comes in, and only what we want is filtered through.
Problem in that a lot is taken in then thrown out
Describe Treisman’s attenuation theory
Things not attenuated are entered in but weaker
What is the cocktail party effect?
You are attending to a person and ignoring all the other conversations around you, but you can still attend to your name from other groups.
Describe the dichotic listening task
Subjects were asked to attend to one ear while distracting information plays in the other ear.
This task showed that much of unattended information is lost, but some information retained.
Proves that sensory processing is directed by attention and supports early selection models
Describe the symptoms of neglect and typical location of lesions
Patients tend to ignore one side of space (left side)
Lesions usually found on right parietal
Remember the failure is to attend not perceive
Also affects imagination and memory
What is Balint’s syndrome? Where is the lesion?
Severe disturbance in visual attention and awareness following bilateral damage to posterior parietal and occipital cortex
Simultanagnosia, Oculomotor apraxia, and Optic ataxia
What is simultagnosia?
A part of Balint’s syndrome, inability to perceive more than a single object at a time
What is Oculomotor apraxia?
A part of Balint’s syndrome, difficulty fixating the eyes
Describe ADHD statistics and facts
A neurodevelopment disorder associated with problems paying attention, excessive activity, or difficulty controlling behavior
Affects 5-7% children, 2-3% adults
Caused by genetics (dopamine receptor gene) and environment (exposure to teratogens reducing the size of prefrontal and posterior parietal cortex)
Treatment includes behavior therapy and stimulant drugs
Describe Posner’s spatial cueing paradigm
Participants fixate on a cross. An arrow cue indicates which part of the himishpere the participant should covertly attend to
The contralateral V3 and V4 were activated during the task
How does the visual system process visual information?
Color, shape, and motion are processed in parallel; but spatial attention is needed to bind the features that define an object
What is the frontal lobe’s role in attention?
Maintain vigilance
What is the Parietal (posterior) role in attention?
Orienting in space
What is the frontalparietal network role in attention?
Reorienting attention
What is the thalamic role in attention?
Reflective attention and attentional filtering
What is the superior colliculus role in attention?
Saccadic eye movement
Does attention influence perception? Describe the study that demonstrates this
Yes
In a study involving radiologist, many did not perceive the gorilla when focusing on tumors
What is the neuromuscular junction and how does it work?
a chemical synapse formed by the contact between a motor neuron and a muscle fiber. It is at the neuromuscular junction that a motor neuron is able to transmit a signal to the muscle fiber, causing muscle contraction via release of ACh
What is the role of primary motor cortex in motion?
Execution of movement
What is the role of secondary motor cortex in motion?
Planning and control of movement
What is the role of supplementary motor cortex in motion?
SMA (internally guided)
What is the role of premotor cortex in motion?
PMC (externally guided)
What is the role of association motor cortex posterior parietal cortex in motion?
Body position
What is the role of prefrontal cortex in motion?
Deciding movement
What is the role of area 8 in motion?
Eye movements
What is the role of posterior cingulate in motion?
Executive motor control
What is the role of primary somatosensory cortex in motion?
Body position
What is the role of the basal ganglia in motion?
Important in selection and initiation of movement
Takes all options we have and looks for the option that gives us the most input
What structures make up the basal ganglia?
Caudate (input), putamen, globus pallidus (output)
Also subthalamus and substantia nigra
How is the cerebellum involved in motor function?
Cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity
Unusual features is ipsilateral organization
How does the stretch reflex in the knee work?
When the knee is stretched and then hammer causes quad to contract
This helps maintain stability of legs after unexpected impact (not under cognitive control, though can control whether it happens consciously)
What are central pattern generator ?
Circuits that can generate an entire sequence of actions without any external feedback signals (walking, breathing, etc.)
Describe the symptoms and location of lesions in hemiplegia
Disorder resulting from contralateral loss of voluntary movement (loss of movement to one side of body)
Due to lesions to primary motor cortex
Describe the symptoms and location of lesions in apraxia
Impaired motor planning, normal strength but cannot link gestures to meaningful actions
Due to left hemisphere secondary motor cortex lesions
Cause, symptoms, and treatment of Huntington’s disease
Caused by autosomal dominant gene
Symptoms include severe, involuntary jerking movement (chorea), hyperkinsia (excessive movement), dementia, and finally death
No treatment
Cause, symptoms, and treatment of Parkinson’s disease
Caused by genetics, aging
Symptoms include reduced movement, slowness of movement, restin tremor, posural instability
L-DOPA, stem cells for treatment
Cause, symptoms, and treatment of Multiple sclerosis
Caused by genetics or environment
Symptoms include muscle spasms, vision problems, difficulty walking
Drugs that inhibit immune system can manage symptoms
What are mirror neurons?
Distributed network of neurons that respond when we do something and when we see it done
What is the relationship between memory and learning?
Learning is the process of acquiring new information while memory is the outcome of learning (how changes are stored and subsequently reactivated)
Describe the Atkinson and Shiffrin model of memory
Sensory input enters sensory registry, converted to short term storage depending on attention, then to long term with rehersal
What is iconic memory?
Immediate memory
lasts less than a second
What is echoic memory?
Longer than iconic
lasts 3 seconds
What’s the duration and capacity of sensory memory?
Brief transient sensory store
<1 sec to <3 sec
high capacity
What’s the duration and capacity of short term memory?
Area to rehearse information so it can be recalled from LTM
seconds to minutes
capacity: 7 +/- 2 chunks
What’s the duration and capacity of LTM?
Categorized into implicit and explicit
capacity is high and can last years
What is the difference between implicit and explicit memory?
Implicit is nonconscious memoy also known as nondeclarative
Explicit or declarative memory is the conscious memory further split into semantic and episodic.
What’s the difference between semantic and episodic memory?
Semantic is the facts and knowledge
Episodic is the experience-based memory
What is working memory?
A limited capacity store for retaining information over the short term
What is chunking?
Remembering chunks of information to increase maximum retention in short term memory
What is encoding?
Forming a memory representation in the brain
What is acquisition?
Sensory stimuli make the cut into STM
What is consolidation?
Changes in the brain stabilize a memory over time, resulting in LTM storage (maintenance of information)
What is retrieval?
Process of accessing stored memories
What is recollection?
Retrieval of information out of storage to consciousness
What is familiarity?
Identifying items you previously learned
What is relearning?
Learning something more quickly when you’ve learned it before
What is serial position effect?
Tendency of a person to recall the first and last items in a series best compared to middle
What are false memories?
Memory that has been put in your mind through priming words, but wan’t actually said. Words similar to needle, and you recall needle despite it never being said
Describe HM case study
Removed medial temporal lobes including the hippocampus, amygdala, and some cortex
He was unable to make new long-term episodic memories
What is retrograde amnesia?
Can’t recall past memories
What is anterograde amnesia?
Short term memory intact but cannot make new long-term memories
More common
What is infantile amnesia?
Inability of adults to retrieve episodic memories before the age of 2-4 years
Nature: due to progressive brain development
Nurture: cultural differences in the age ar first memory
What structures in the brain are invovled in declarative memory?
MTL including hippocampus
What structures of the brain are involved in nondeclarative memory?
Cerebellum and basal ganglia
What is dementia?
A loss of cognitive abilities such as memory, perception, verbal ability, and judgement
Describe the cause, symptoms, brain changes, and treatment for Alzheimer’s disease
Cause: genetics, aging, cerebrovascular
Symptoms include slowly progressive memory loss, motor deficits, and eventual death
Brain change: atrophy in hippocampus
No treatment
What is PIB imaging?
Radioactive analog of thioflavin T used in tomography scans through neurotissue
Allows investigation into Alzheimer’s
How does episodic memory change with age?
Retrieval gets worse due to an increase in white matter disease as age increases
What is the delayed match to sample task?
Having a monkey find where food is under an object to study memory
Does the tissue surrounding the hippocampus contribute to memory functions?
Yes
parahippocampus, it is associated with successful memory retrieval
How is the MTL involved in encoding of declarative memories?
Encoding long term activity in the hippocampus, parahippocampal and frontal cortex is necessary for long term memory
How is the MTL involved in retrieval of declarative memories?
Hippocampus was selectively active for items corrtectly recollected
What structure is involved in familiarity memory?
Perirhinal and entorhinal cortex
How is the frontal cortex involved in memory?
Left frontal cortex houses episodic encoding or linguistic memory
Right frontal cortex houses episodic retrieval or spatial memory task
What is the frontal aging hypothesis?
Normal age related cognitive deficits are mediated by cognitive deficits associated with prefrontal cortex dysfunction. PFC myelinates last and degrades first
Is the parietal cortex involved in memory?
Yes
Successful memory retrieval is associated with activity in posterior parietal cortex
Where are memories stored in the brain?
Memories are stored as distributed representations throughout the cortex, involving the areas in which they were perceived
What is consolidation?
Process by which immediate memories are transformed into LTM
What is the standard consolidation theory?
Hippocampus is used to form memories that become LTM, but it isn’t used for retrieval once it becomes LTM
What is the Multiple trace theory?
Hippocampus is used to encode and store memories but not used in retrieval except for highly contextual episodic memories
What is LTP (long term potentiation)?
A long lasting strenghening of the response of a postsynaptic nerve cell to stimulation across the synapse that occurs with repeated stimulation and id thought to be related to learning and long-term memory
