3.5 Neuropsychology
Week 2
Language & Emotion
System
,Kolb & Wishaw (2015) → Chapter 15: The Temporal
Lobe
Temporal lobe anatomy
● General
○ Everything below lateral fissure and anterior to
occipital cortex
○ Subcortical → limbic cortex, amygdala, hippocampal
formation
● Subdivisions of the temporal cortex
○ Lateral surface temporal regions can be divided into
those that are auditory and those that form the
ventral visual stream
■ Visual regions are referred to as
inferotemporal cortex (TE)
○ Lateral fissure contains the insula, which contains
the gustatory and auditory association cortex
○ STS separates the superior and middle temporal
gyri → polymodal, receives information from all
regions and paralimbic cortex
○ Medial temporal region (limbic cortex) includes
amygdala and adjacent cortex (uncus),
hippocampus and surrounding cortex (subiculum, entorhinal cortex, perirhinal
cortex) and fusiform gyrus
○ Posterior end has TH and TF → parahippocampal cortex
○ Boundary of temporal & parietal lobe → temporal-parietal junction, includes the
ventral regions of the angular and supramarginal gyri
■ Active in attention, memory, language, social processing
■ Proposed to be central in decision making in a social context
● Connections of the temporal cortex
○ Many internal connections → projections from sensory systems and projections
to the parietal and frontal regions, limbic system, basal ganglia
, ○ Left and right neocortex lobes are connected by corpus callosum, medial cortex
is connected by anterior commissure
○ Five distinct cortical connections
■ Hierarchical sensory pathway subserves stimulus recognition
● From primary and secondary auditory and visual areas ending in
temporal pole
■ Dorsal auditory pathway concerned with directing movements with
respect to auditory information
● Projecting from auditory areas to posterior parietal cortex,
analogous to the part of dorsal visual pathway (locating auditory
input)
■ Polymodal pathway probably underlies stimulus categorization
● Parallel projections from visual & auditory association areas
converge in STS
■ Medial temporal projection crucial to long term memory
● Projection from auditory and visual association areas to medial
temporal regions goes first to perirhinal, then entorhinal,
hippocampal formation or amygdala or both
● Hippocampal projection forms the perforant pathway → if
disrupted causes major hippocampal activity dysfunction
■ Frontal lobe projection necessary for various aspects of movement
control, short term memory and affect
● Series of parallel projections from temporal association areas to
frontal lobe
● Anatomy of the ventral stream
○ Originally thought to be hierarchical from occipital cortex to temporal pole
○ Now seen as an anatomical and functional network → at least six distinct
pathways comprise the ventral stream
■ Subcortical projections from every region of the occipitotemporal pathway
extend to neostriatum (caudate nucleus & putamen of basal ganglia),
supports habits and skill learning dependent on vision
■ Amygdala bound projections from inferotemporal regions allow
processing of emotionally salient stimuli
■ Inferotemporal cortex to ventral striatum (nucleus accumbens of basal
ganglia), supports the assignment of stimulus valence
■ Three remaining pathways → inferotemporal cortex to other cortical
regions (medial temporal, orbitofrontal, ventrolateral prefrontal) linked to
long term memory, object-reward associations and object working
memory
Theory of temporal lobe function
● General
○ Temporal lobe has the primary auditory cortex, secondary auditory and visual
cortex, limbic cortex, amygdala and hippocampus