Temporal Lobe Finals Flashcards
frontal temporal dementia (FTD)
semantic dementia (problems with categorization mainly due to damage to the “what” pathway), caused by atrophy in TE (inferotemporal cortex)
kindling
model for the development of seizures and epilepsy in which the duration and behavioural involvement of induced seizures increases after seizures are induced repeatedly
febrile seizures in children
caused by high temperature fluctuations
convulsive disorder
caused by anxiety or other event that causes seizure
medial temporal region (limbic cortex)
amygdala, the hippocampus and surrounding cortex (perirhinal, entorhinal cortex), fusiform gyrus, cortical areas TH and TF, fusiform and inferior temporal gyri
fusiform and inferior temporal gyri are functionally part of:
the lateral temporal cortex
cortical areas TH and TF
posterior end of the temporal lobe, make up the parahippocampal cortex
temporal-parietal junction (TPJ)
at the end of the Sylvian fissure, including the ventral regions of angular and supramarginal gyri (the inferior parietal lobe) and adjacent temporal cortex; central to decision making in a social context
afferent projections of the temporal cortex:
sensory systems
efferent projections of the temporal cortex:
to the parietal and frontal association regions, limbic system, basal ganglia
neocortex of left and right lobes are connected via:
corpus callosum
medial temporal cortex and amygdala are connected via:
anterior commissure
what are 5 distinct cortical-cortical connections of the temporal lobe?
1) hierarchical sensory pathway subserves stimulus recognition (primary and secondary auditory and visual areas ending in temporal pole)
2) dorsal auditory pathway is concerned with directing movements with respect to auditory info (from auditory cortex to posterior parietal cortex)
3) polymodal pathway probably underlies stimulus categorization (parallel projections from auditory and visual association areas converge into polymodal regions of STS)
4) medial temporal projection crucial to long-term memory (auditory and visual association areas to medial temporal/limbic regions-perirhinal to enterorhinal to hippocampus/amygdala)
5) frontal lobe projection necessary for various aspects of movement control, short-term memory, and affect (parallel projections reach from temporal association areas to frontal lobe, auditory and visual cortex project to different areas in the frontal lobe)
hippocampal projections forms:
perforant pathway (long-term memory)
original model of the ventral stream:
a hierarchical pathway traveling from the occipital cortex to the temporal lobe
modified model of the ventral stream
at least 6 cortical and subcortical pathways:
1) set of subcortical projections from every region of the occipitotemporal pathway extends to neostriatum (caudate nucleus, putamen of basal ganglia)
2) amygdala-bound projections from inferotemporal regions allows processing of emotionally salient info
3) inferotemporal cortex to ventral striatum (nucleus accumbens) to support the assignment of stimulus valence
4) medial temporal pathway - long term memory
5) orbitofrontal pathway - object reward associations
6) ventrolateral prefrontal pathway - object working memory
what are 3 basic sensory functions of the temporal lobe?
1) processing auditory input
2) visual object recognition
3) long-term storage of sensory input - memory
ventral stream intrinsic connectivity
occipitotemporal pathway
ventral stream extrinsic connectivity
occipitotemporal-neostriatal network
sensory process in temporal lobe function
identification and categorization of stimuli (object recognition); function of ventral visual pathway, developing object categories crucial to perception and memory; depends on inferotemporal cortex, cross-modal matching (match visual and auditory info, depends on cortex of STS)
affective responses in temporal lobe function
emotional response is associated with a particular stimulus, animals with no amygdala lose fear
spatial navigation in temporal lobe function
uses hippocampus; contains cells that code for places in space - spatial memory
activation in the STS during:
perception of biological motion (direction of eye gaze, head movement, facial expression, mouth movement)
biological motion
movements relevant to a species, allows us to guess others’ intentions, social cognition/theory of mind
fMRI study of cortical activity while participants view a film
extensive activity in the auditory and visual regions in the temporal lobe, in the STS, and in cingulate region; no intersubject coherence in parietal and frontal regions
findings from Tanaka and colleagues
- cells in area TE (temporal lobe) require complex features for activation (colour, size, orientation, texture)
- cells with similar selectivity cluster in vertical columns
- specificity of neurons is altered by experience
inferior occipital gyri
early perception of facial features
fusiform face area
invariant aspects of faces: perception of unique identity
superior temporal sulcus
changeable aspects of faces: perception of eye gaze, expression, and lip movement
anterior temporal cortex
personal identity: name and biographical info
amygdala, insula, limbic system
emotion
intraparietal sulcus
spatially directed attention
auditory cortex
prelexical speech perception
speech sounds come from three restricted ranges of frequences:
formants (speech sounds vary from one context to another, yet all are perceived as being the same)
right temporal cortex has important role in:
processing faces
left temporal cortex has important role in:
speech perception
left temporal lobe in music perception:
temporal grouping for rhythm
right temporal lobe in music perception:
complementary role in meter/temporal regularity or beat, extracts pitch from sound regardless if the sound is speech or music
fundamental-pitch listeners exhibit:
leftward asymmetry
spectral-pitch listeners exhibit:
rightward asymmetry
improvising/not memorizing/communication activates:
language areas as well as right hemisphere homologues, reduced activation in language regions related to semantic processing (angular gyrus & supramarginal gyrus)
left temporal lobe function
verbal memory, speech processing
right temporal lobe function
nonverbal memory, musical processing, facial processing
verbal/auditory hallucinations activate:
primary auditory cortex, Broca’s area, and the speech zone in the posterior temporal cortex
activation of limbic regions in schizophrenia produces what symptom?
hostile paranoia
cortical deafness
caused by bilateral damage to auditory cortex, absence of neural activity in the auditory regions
Wernicke’s aphasia
caused by disturbance of left temporal association cortex; disturbed recognition of words
affected rhythm discrimination
damage to right posterior superior temporal gyrus
affected meter discrimination
damage to anterior right or left temporal lobe
congenital amusia
tone deaf
right temporal lobe lesions
abnormal face perception and biological motion recognition, impairs recall of visual stimuli in both visual fields
damage to left temporal lobe
impairs recall of visual stimuli in right visual field, impairment in the ability to categorize words or pictures of objects
left posterior temporal lesion
difficulty in recognizing specific word categories, but can recognize the broader categorization
anterograde amnesia
amnesia for events after bilateral removal of the medial temporal lobes
inferotemporal cortex damage
interferes with conscious recall of info
left temporal lobe lesions
impaired recall of verbal memory
right temporal lesions
impaired recall of nonverbal material
temporal-lobe personality is associated with lobectomy of:
right temporal lobe
stimulation of anterior and medial temporal cortex produces feelings of:
fear
bilateral temporal-lobe damage
release of sexual behaviour
what are the 3 components of short-term memory?
sensory, motor, cognitive
anterograde amnesia
inability to acquire new memories
global anterograde amnesia
impairment in the ability to form new memories across a variety of areas
retrograde amnesia
inability to access old memories
time-dependent retrograde amnesia
commonly produced by TBI, severity of injury determines how far back in time the amnesia extends
what are 3 theories of amnesia?
1) system consolidation theory
2) multiple trace theory
3) reconsolidation theory
System Consolidation Theory
role of the hippocampus is to consolidate memories, making them permanent, hold them for a time, and then send them to be stored elsewhere in the brain
Multiple Trace Theory
3 kinds of memory (autobiographic, factual semantic, general semantic), each type is dependent on a different brain area, old memories are more resistant to amnesia because they change location in the brain as they are recalled
reconsolidation theory
memories rarely consist of single trace or neural substrate, each time memory used it is reconsolidated
episodic memory
autobiographic, person’s recall of singular personal events
explicit memory
events, facts, and episodic memories, conscious intentional remembering, top-down processing
what is the pathway that connects the temporal lobe with the ventral frontal lobe
uncinate fasciculus
semantic memory
does not depend on medial-temporal lobe-ventral-prefrontal-lobe memory system that subserves episodic memory
Petri & Mishkin found that temporal-frontal lobe is the neural basis for:
explicit memory
hippocampal formation consists of:
entorhinal cortex, DG (dentate gyrus), subiculum, CA1-CA4 (Ammon’s horn)
Ammmon’s horn
contains pyramidal cells divided into 4 groups (CA1, CA2, CA3, CA4), motor cells
dentate gyrus
contains stellate granule cells, “sensory” cells
perforant pathway
connection between the hippocampus and the posterior temporal cortex
fimbria-fornix
connects the hippocampus to the thalamus, prefrontal cortex, basal ganglia, and the hypothalamus
damage to the fimbria-fornix pathway
produces retrograde and anterograde amnesia
what are 4 conclusions from studies of hippocampal patients?
1) anterograde deficits are more severe than retrograde
2) episodic memories are more affected than semantic memories
3) autobiographic memory is especially severely affected
4) time “travel” is diminished
temporal lobe areas border rhinal fissure (rhinal cortex) which includes the:
entorhinal and perirhinal cortex, these areas project to the hippocampus
injury to parietal and occipital cortex may produce:
colour amnesia, prosopagnosia, object anomia, topographic amnesia
left prefrontal cortex
more engaged in encoding semantic and episodic information than in retrieving it
right prefrontal cortex
more engaged in episodic info retrieval than left
what neural structures are involved in a proposed circuit for implicit memory
basal ganglia, premotor cortex, thalamus, amygdala, substantia nigra, cerebellum
cerebellum role in implicit memory
plays a role in classical conditioning
herpes simplex encephalitis
medial-temporal-lobe damage leads to anterograde amnesia; damage to the insula contributes to retrograde amnesia
korsakoff’s syndrome
caused by a thiamine deficiency resulting from prolonged alcohol intake, damage may be in the medial thalamus, mammillary bodies of the hypothalamus, and frontal lobe atrophy
asperger’s syndrome
form of autism in which individuals have high intellectual function and excellent memory abilities
savant
person who has an intellectual disability but also has a special ability in math, memory, or music
HSAM
highly superior autobiographical memory: incredible memory ability - can completely recall events in their lives
verbal hallucinations
activate primary auditory cortex, Broca’s area, and the speech zone in the posterior temporal cortex
disorders of auditory and speech perception
- cortical deafness
- auditory hallucinations
- impaired auditory processing
- trouble discriminating speech sounds
- speech disorders (Wernicke’s aphasia)
- disorders of music perception
disorders of visual perception
impaired object recognition, complex pattern recognition (perception)
right temporal lobe lesions =impaired face perception and biological motion recognition
what is the neural circuit proposed for implicit memory
sensory and motor info to rest of neocortex to basal ganglia to ventral thalamus to premotor cortex
what is the neural circuit proposed for emotional memory
basal ganglia, medial temporal cortex and amygdala have reciprocal connections, amygdala connected with hypothalamus and PAG, which is connected with frontal/parietal/temporal/occipital/cingulate cortices
short term memory may be caused by damage to:
left posterior temporal lobe, frontal lobe
frontal temporal dementia (FTD)
semantic dementia (problems with categorization mainly due to damage to the “what” pathway), caused by atrophy in TE
HERA (hemispheric encoding and retrieving asymmetry) model
L-DLPFC = encoding, R-DLPFC = retrieval, DLPFC to temporal lobe interaction
