ch 15 temporal lobe Flashcards
temporal lobe located
below the sylvian fissure, anterior to occipital cortex
3 subcortical strucutres: limbic cortex, amygdala, hippocampus
subdivisions of temporal lobe
10 temporal areas
lateral surface-auditory areas, ventral stream of visual information (inferotemporal cortex)
insula-under sylvian fissure, gustatory cortex, auditory association cortex
multimodal cotex-area under STS, input from multiple areas
medial temporal (limbic cortex)-amyg(uncus), hipp(subiculum, entorhinal cortex, perirhinal cortex), fusiform gyrus (lateral temp cortex)
TH&TF-posterior end of temporal lobe
connections
afferent projections from sensory systems, efferent projections to parietal and frontal association regions (limbic system and basal ganglia)
L&R connected by corpus callosum and anterior commissure
5 connections: hierarchial sensory pathway
stimulus recognition, incoming auditory and visual info, progression from primary and secondary auditory and visual areas that end in temporal pole, visual projections from ventral stream processing, auditory projections from parallel ventral stream auditory processing
5 connections: dorsal auditory pathways (where)
location and movement, auditory cortex to posterior parietal, analogous to dorsal visual pathway-directing movements in respect to auditory info, role in detecting spatial location of auditory inputs
5 connections: polymodal pathway
auditory and visual areas to polymodal cortex, stimulus categorization, parallel projections from visual and auditory in STS
5 connections: medial temporal projection
long term memory, medial temporal lobe (perforant pathway-auditory and visual area), limbic cortex, hippocampus, amygdala
5 connections: frontal lobe projection
auditory and visual cortex to frontal lobe, movement control, short term memory, affect, temporal association areas to frontal lobe
3 basic sensory functions
processing auditory input, visual object recognition, long term storage of info
sensory processes
identification and categorization of stimuli, cross modal matching (matching visual and auditory info, depends on STS), object recognition (ventral visual), object categories-helps perception/memory (inferior temporal), cross modal matching(matching visual and auditory info), long term memory processes depend on entire ventral visual stream and paralimbic cortex
affective responses
emotional response associated with a particular stimulus
heart rate and blood pressure increase-amyg funct
sensory input and emotion association critical for learning
spatial navigation
hippocampus, spatial memory, cells code places in spaces
biological motion
movements relevant to species, allow us to guess others intentions, social cognition (theory of mind)-imaging reveals activation in STS during perception of biological motion, STS cells thought to play role in social cognition(awareness)
hasson and friends-fMRI monitored cortical activity during film viewing, found
extensive activity in auditory and visual regions in temporal lobe, STS and cingulate regions
selective activation to precise moment to moment film content
regions of pari and frontal lobes show no intersubject coherence
tahaka and friends found
cells in TE area require complex features for activation, cells with similar selectivity cluster in vertical columns, specificity of neurons is altered by experience
faces
special face processing pathway-diff aspects of face perception analyzed in temporal part of ventral stream
R more important in face procession-split faces
auditory processing-speech perception
sounds come from 3 restricted ranges of frequencies (formants), vary from 1 context to another but perceived the same way, sounds change rapidly in relation to 1 another-sequential order important to understanding(perceive speech at avg rate of 8-10 seg/sec, nonspeech at 5seg/sec)
L temp lobe
auditory processing-music perception
relies on relation between elements-classified by arrangement of pitches duration and intervals between
loudness-magnitude of a sensation as judged by given person
timbre-distinctive characteristic of a sound
pitch-position of a sound in a musical scale as judged by listener–periodicity pitch(determinity pitch of fundamental freq), spectral pitch(perceive complex tones of harmonies), emotion/prosody
L plays role in grouping for rhythm, R role in meter
R extracting pitch from sound-prosody
musicians have larger grey and white matter in heschl’s gyru (L)
pitch listeners-L asymmetry
spectral pitch listeners R asymmetry
L asymmetry
verbal memory, speech processing
R asymmetry
nonverbal memory, musical processing, facial processing
symptoms of lesions
auditory disturbance, disorders of music perception, disturbance of selection of visual and auditory input, impaired organization and categorization, inability to use contextual info, long term memory problems, altered personality and affective behavior, altered sexual behavior
imaging auditory hallucinations
auditory hallucinations most common in schizophrenia, patients hear fully formed verbal passages that may be hostile or paranoid, activate primary auditory cortex, brocas area, speech zone in posterior temporal cortex
disorders of auditory and speech perception
bilateral damage=cortical deafness-absence of activity in auditory regions, 50-60ms between sounds, with damage 500ms, L temp lesions=wernickes aphasia
disorders of auditory and speech perception-auditory hallucinations
perception of sounds not present
disorders of auditory and speech perception-impaired auditory processing
have trouble discriminating speech sounds
disorders of auditory and speech perception-speech disorders
wernicke’s aphasia-disturbed word recognition
disorders of auditory and speech perception-disorders of music perceptions
R superior temporal gyrus damage affects rhythm discrimination, meter discrimination affected by anterior damage to R or L lobe, congenital amusia (tone deaf), R temp lesions affect pitch discriminations
spectral sensitivity-L concerned with speed, R with distinguishing frequency diff
disorders of visual perception
impaired at object recognition, complex pattern recognition, R lesions lead to abnormal face perception and biological motion recognition, R lesion and faces in L visual field troubles
disturbance of selection of visual and auditory input
selective attention to auditory input is impaired in patients with temporal lobe damage and can be tested with dichotic listening
L damage impairs recall of visual stimuli in R visual field
R damage impairs recall of visual stimuli in both visual fields
L temp lobe lobectomies lead to
impairment in ability to categorize words or pics of objects
posterior lesions lead to
difficulty in recognizing specific word categories
contextual info
stimuli interpreted in diff ways depending on context
memory-antereograde amnesia
amnesia for events after bilateral removal of medial temporal lobes
memory-inferotemporal cortex
conscious recall of info
memory-L temp lobe
verbal memory
memory-R temp lobe
impaired recall of nonverbal material
Affect and personality
stimulation of anterior and medial temporal cortex produces feelings of fear
temporal lobe personality–personality that overemphasizes trivial and petty details of life, pedantic speech, egocentricity, perseveration, paranoi, preoccupation with religion, proneness to aggression
changes in sexual behavior after
bilateral lobe damage
general function
affect and personality, memory disturbance, transient disturbance of language
anatomy
tissue under lateral/sylvan fissure and anterior to occipital lobe
limbic cortex, amyg, hipp–subcortical structures
connections to and from extend throughout brain
visual processing theory
ventral visual stream processed in regions specializing in face/object recognition, large expanse in brain responsible to naturalistic audiovisual stimuli, view faces (high activity in fusiform face area), broad scenes-parahippocampal place area, static views places/faces-same regions
organization and categorization symptoms
L temp damage-can’t categorize words or pics, semantic categories-hierarchies of meanings where 1 word goes in multiple categories, post temp damage can recognize broad categories but not specific
