The Temporal Lobe Flashcards
What are the subdivisions of the temporal lobe?
- Lateral surface (auditory areas, ventral stream of visual information)
- Insula
- Multimodal Cortex/Polymodal Cortex
- Medial temporal cortex
- TH and TF
What are the subcortical temporal lobe structures?
- Limbic cortex
- Amygdala
- Hippocampal formation
What does the lateral surface of the temporal lobe consist of?
- Auditory areas (Brodmann’s areas 41, 42, and 22)
- Ventral stream of visual information (inferotemporal cortex or TE, Brodmann’s areas 20, 21, 37, and 38)
What does the insula do?
- Gustatory cortex (taste perception)
- Auditory association cortex
- Located under Sylvian fissure
What does the multimodal cortex do?
- Receives input from auditory, visual, and somatic regions
- Located under superior temporal sulcus
What does the medial temporal cortex contain?
-Amygdala and adjacent cortex (uncus), hippocampus and surrounding cortex, and the fusiform gyrus
Where are the TH and TF regions?
- Posterior end of temporal lobe
- Parahippocampal cortex
What are the major connections of the temporal lobe? What are their functions?
- Hierarchical sensory pathway (incoming auditory and visual information, stimulus recognition)
- Dorsal auditory pathway (from auditory to posterior parietal; detection of spatial location/movement)
- Polymodal pathway (from auditory and visual areas to polymodal cortex; stimulus categorization)
- Medial temporal projection (from auditory and visual areas to medial temporal lobe, limbic cortex, hippocampal formation, and amygdala; perforant pathway, long-term memory)
- Frontal lobe projection (auditory and visual cortex to the frontal lobe; movement control, short-term memory)
What are the three basic sensory functions of the temporal lobe?
- Processing auditory input
- Visual object recognition
- Long-term storage of information (memory)
What are the sensory processes of the temporal lobe?
- Identification and categorization of stimuli (shape, size, colour)
- Cross-modal matching (match visual and auditory stimuli, depends on cortex of superior temporal sulcus)
- Directional attention (focus on different aspects of object)
What are the affective responses of the temporal lobe?
-Emotional responses associated with a particular stimulus
What controls spatial navigation in the temporal lobe?
-The hippocampus (spatial memory)
What is the superior temporal sulcus (STS) and what is its role in biological motion?
- The STS is activated during biological motion
- Biological motion = movement relative to a species; allows us to guess others intentions; allows for social cognition (“theory of mind”)
How is language processed in the temporal lobe?
- Speech sounds come from three restricted ranges of frequencies, known as formants
- Speech sounds vary between contexts, but all are perceived as being the same
- Mechanism for categorizing differing sounds as being equivalent
- Special mechanism for speech perception is in the left temporal lobe
What are the three categories of music?
- Loudness: Magnitude of a sensation as judged by a given person
- Timbre: Distinctive characteristic of sound
- Pitch: Position of a sound in a musical scale as judged by the listener (frequency)
How is music processed in the temporal lobe?
- Relies on relation between elements
- Loudness, timbre, and pitch
- Patients with temporal lobe injuries illustrate that left temporal lobe plays a role in temporal grouping for rhythm, whereas the right temporal lobe plays role in meter
- Segmentation of sequences of pitch into groups based on duration of sounds (temporal grouping)
- Identification of temporal rhythm, or beat
- Right temporal lobe special function is extracting pitch from sound, regardless of if sound is speech or music (prosody - “tone or voice” or pitch in speech)
In music perception, what are the functions of the left and right temporal lobes?
- Left temporal lobe = Rhythm
- Right temporal lobe = Pitch
Musicians have a larger volume of gray and white matter in which part of their brain?
-Heschl’s gyrus
Fundamental-pitch listeners and spectral-pitch listeners have asymmetry in which side of the brain?
- Fundamental-pitch listeners = leftward asymmetry
- Spectral-pitch listeners = rightward asymmetry
What are the symptoms of temporal lobe lesions?
- Auditory disturbance
- Disorders of music perception
- Disturbance of selection of visual and auditory input
- Impaired organization and categorization
- Inability to use contextual information
- Altered personality and affective behaviour
- Altered sexual behaviour (amygdala)
- Long-term memory problems
What is anterograde amnesia?
Amnesia for events after bilateral removal of the medial temporal lobes
What is the function of the inferotemporal cortex?
Conscious recall of information
What is the function of the left temporal lobe?
Visual memory
What is the function of the right temporal lobe?
Impaired recall of nonverbal material (drawings etc.)
