Temporal lobes

Temporal lobes

1. Connections of the temporal cortex

   • Afferent projections from sensory systems
   • Efferent projections to the parietal and frontal association regions, limbic system and basal ganglia
   • Left and right connected via
     • Corpus callosum
     • Anterior commissure

2. Temporal lobe function

   • Processing auditory input
   • Visual object recognition
   • Long term storage of information
   • Sensory processes
     • Identification and categorization of stimuli
     • Cross modal matching
   • Affective responses
     • Emotional response is associated with a particular stimulus
   • Spatial navigation
     • Hippocampus

3. STS and biological motion

   • Imaging research reveals activation in the STS during perception of biological motion
     • Hassan et al
     • Thatcher illusion
     • Split faces test

4. Asymmetry of temporal lobe function

   • Left temporal lobe
     • Verbal memory
     • Speech processing
   • Right temporal lobe
     • Non verbal memory
     • Musical processing
     • Facial processing

5. 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
   • Dierks et al.

6. Disorders of auditory and speech perception

   • Cortical deafness
     • Absence of neural activity in the auditory regions
     • Auditory hallucinations
     • Impaired auditory processing
       • Have trouble discriminating speech sounds
     • Speech disorders
       • Wernicke's aphasia
         • Disturbed recognition of words

7. Disorders of visual perception

   • Patients with temporal lobe damage are impaired at object recognition, complex pattern recognition
   • Right temporal lobe lesions lead to abnormal face perception and biological motion recognition

8. 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
   • Damage to the left temporal lobe impairs recall of visual stimuli in the right visual field
   • Damage to the right temporal lobe impairs recall of visual stimuli in both visual fields.
   • Organization and categorization
     • Left temporal lobe lobectomies lead to impairment in the ability to categorize words/pictures/objects
       • Posterior lesions lead to a difficulty in recognizing specific word categories

9. Memory

   • Antereograde amnesia
     • Amnesia for events after bilateral removal of the medial temporal lobes
   • Inferotemporal cortex
     • Conscious recall of information
   • Left temporal lobe
     • Verbal memory
   • Right temporal lobe
     • Impaired recall of nonverbal material

10. Affect and personality

    • Stimulation of anterior and medial temporal cortex produces feelings of fear
    • Temporal lobe personality
      • Personality that overemphasizes trivia and petty details of life
      • Pedantic speech
      • Egocentricity
      • Perseveration
      • Paranoia
      • Preoccupation with religion
      • Prone to aggression