Chapter 2: Neural Basis for Cognition
This disorder is rare on its own, but one of the most accompaniments to Alzheimer's syndrome.
This disorder can result from various injuries to the brain.
someone with this syndrome is fully able to recognize the people her world, but they aren't who they appear
facial recognition involves two separate systems in the brain:
1. cognitive appraisal "I know what my father looks like and I can perceive that you closely resemble
2. emotional appraisal "You look familiar to me and also trigger a warm response in me".
these lead to a certainty of recognition "You obviously are my father".
in this syndrome, the latter (emotional) processing is disrupted, leading to intellectual identification without
the familiarity response. "You resemble my father, but no sense of familiarity, therefore you're someone else."
Neural Basis for Capgras Syndrome
Neuro-imaging techniques: allow researchers to take high-quality, 3D pictures of living brains.
PET scan - tells about the structure of the brain (including abnormalities in the brain tissue).
one site of damage is in the temporal lobe
probably disrupts circuits involving the amygdala ("emotional evaluator")
o amygdala is important for detecting positive stimuli (indicators of safety or available
o essential for making judgements of "you look familiar to me and trigger warm feeling"
brain abnormalities in the frontal lobe; prefrontal cortex
o fMRI scan - allows to track moment-by-moment activity levels in different sites in a living
o tells us which parts of the brain are active, and are used heavily in the brain
o neuroimaging reveals diminished activity in the patients' frontal lobes whenever they are
o diminished activity reflects a decreased ability to distinguish internal events (thoughts),
from external ones (voices), or to distinguish imagined events from real ones.
What did we Learn from Capgras Syndrome?
the damage to the amygdala is the reason why patients experience no sense of familiarity
amygdala suggests the importance of remembering emotional events of peoples' lives
amygdala also plays a role in decision-making (especially for emotional evaluations of one's options)
the damage to the prefrontal cortex helps us understand why Capgras patients, when experiencing lack of
familiarity, offer such crazy hypotheses about their skewed perception.
there is evidence based on cognitive psychology and cognitive neuroscience
we can use Capgras syndrome to illuminate broader issues about the nature of the brain and of the mind.
Capgras syndrome tells us:
emotional evaluator works separate from our evaluation of factual information
emotional evaluation points toward a different conclusion Principle Structures of the Brain
Hindbrain, Midbrain, Forebrain
The human brain is divided into three main structures: hindbrain, midbrain, and forebrain.
hindbrain: sits directly atop the spinal cord and includes several structures that control key life functions.
e.g. the rhythm of heartbeats and the rhythm of breathing are controlled.
plays an essential role in maintaining the body's overall tone;
it helps maintain body's posture and balance and helps regulate brains' level of alertness
largest area of the hindbrain is the cerebellum.
cerebellum: main role was coordinating bodily movements and balance
also plays a diverse set of roles
damage to this organ can cause spatial reasoning, in discriminating sounds, and integrating input
received from various sensory systems.
midbrain: plays an important role in coordinating movements.
this includes skilled, precise movements of our eyes
in the midbrain are circuits that relay auditory information from ears to areas in the forebrain
other structures in the midbrain help to regulate our experience of pain
forebrain: largest region of the brain
cortex: thin covering on the outer surface of the brain
the cortex constitutes 80% of the human brain
consists of a very large sheet of tissue
the wrinkles or convolutions cover the brain's outer surface.
longitudinal fissure: deepest groove (section) of the brain
other fissures divide the cortex in each hemisphere into four lobes:
1. frontal lobes - front of brain to right behind the forehead
central fissure divides frontal lobes on each side of the brain
2. parietal lobes - brain's top most part
3. temporal lobes
4. occipital lobes
1. thalamus - acts as a relay station for nearly all sensory information going to the cortex
2. hypothalamus - plays a crucial role in the control of motivated behaviours (eating, drinking, sexual activity).
3. limbic system - essentially for learning and memory, and for emotional processing. The amygdala,
hippocampus is included here
Like most part of the brain, subcortical structures come in pairs, and so there is a hippocampus on the left side and
right, etc. There is a temporal cortex on the left and