Lecture notes Brain and Cognition: Introduction to
Neuroscience
Lecture 1: Introduction - CH1 (Bear) - 05/02/2025
Reductionist approach: To reduce the complexity of the problem, neuroscientists break it
into smaller pieces for systematic experimental analysis.
Level of analysis: The size of the unit of study. (molecular, cellular, systems, behavioral,
and cognitive)
Animal welfare: Making sure animals are treated well. Neuroscientists accept certain moral
responsibilities toward their animal subjects.
Animal rights: A philosophical position according to which animals have the same legal and
moral rights as humans.
Interaction in the brain is based on GABA (too much = too much sleepiness) and glutamate
(too much = epilepsia)
Alzheimer’s disease: Dementia
Loss of function, memory, personality, and identity
Atrophy of Cortex = loss of function
Left hemisphere = interpreter, as it is the language side
Stages:
1. Mild cognitive decline starts at hippocampus, takes 7 years (short-term memory).
2. Mild Alzheimer’s: Temporal and parietal decline for 2 years. Decline in reading,
objects, and spatial memory
- Fewer connections to memory areas, but stronger connections in the frontal
cortex to compensate for the memory loss. But also confabulations (making
things up, creating ‘false’ reasoning for why they did something) in the areas
that still work
3. Progressive Alzheimer’s: Declining attention and increased impulsivity, personality
change. This stage takes 2 years and also gets to the frontal cortex
Cognitive processes are gone, but the sensory input and motor output are intact
4. Final stage: Visual problems, impacts the visual cortex, duration of 3 years
Psychological disorders: ADHD, Autism, Anxiety, Schizophrenia, Depression, and OCD
- No Atrophy of the Cortex
- No to very few physical traces in the brain
- Major behavioral problems
Ventro-medial part: Emotional and social control. Example of damage is Phineas Cage
Dorso-lateral part: Cognitive Control
1
,Damage to the lateral PFC
Dysexecutive syndrome
- problems in planning, working memory, limited attention span, lack of insight into own
and others’ actions, confabulations, but no deficit in intelligence, language use, or
episodic and semantic memory
Damage to the ventral and Medial PFC: (Phineas Cage)
Disinhibition syndrome
- No Dysexecutive symptoms, Constant movement, Euphoric or manic, Abnormal
sense of humor, Fail to respond to normal social cues, Reveal embarrassing
personal information
Prefrontal cortex: cognitive control of behavior
Ventro-medial part: Emotional and social control.
Psychopaths have smaller connections between the
PFC and Amygdala
Dorsal - Ventral (or superior - inferior)
Medial - Lateral
Rostral - Caudal (or anterior - posterior)
Association fibers: Connections within hemispheres, connect the primary sensory areas in
the parietal, temporal, and occipital lobes to the association areas of the cerebral cortex, and
to each other
Commissural fibers: Connections between hemispheres, synchronization of left and right
hemispheres
Damage to corpus callosum:
- Split brain syndrome, two brain halves behave relatively autonomously (because they
are not connected)
Damage to the splenium of corpus callosum leads to
- Posterior disconnection syndrome of alexia
- Cannot understand written material
- Without agraphia (can speak and write without difficulty)
2
, Lecture 2: The Nervous System - CH7 + 15 (Bear) - 06/02/2025
CNS: Brain + spinal cord
Spinal cord:
- Transports info from the body to the brain and back. Communicates through the
spinal nerves, and each spinal nerve attaches to the spinal cord by two branches, the
dorsal root and the ventral root. The dorsal root contains axons bringing
information into the spinal cord, such as those that signal the accidental entry of a
thumbtack into your foot. The ventral root contains axons carrying information away
from the spinal cord e.g., to the muscles that jerk your foot away in response to the
pain of the thumbtack.
Brain:
- Cerebrum: contains left and right hemispheres
- Cerebellum: Small brain - center for movement
- Brainstem: vital functions (breathing, heart rate, etc.) and relay station from info of
the spinal cord and cerebellum
PNS: Everything except CNS
Nerves:
- Cranial nerves: 12 nerves from the brain
Important: Olfactory nerves (1), Optic nerve (2), cranial nerves related to brainstem (3-7),
cochlear nerve (8), Vagus (10)
- Spinal nerves: Innervate skin, joints, and muscles. The dorsal root ganglia contains
cell bodies of peripheral sensory neurons
- Visceromotor system (or autonomic NS): Starts fight or flight, digest and rest
Afferent axons: “carry to”, axons transport information toward a particular point.
Efferent axons: “carry from”, axons transport information away from a particular point.
Autonomic NS (ANS): Visceromotor system can be divided into sympathetic (fight or flight)
and parasympathetic (rest or digest). It innervates smooth muscles of internal organs, blood
vessels, and glands.
The spinal cord is divided into 4 parts:
Cervical cord, thoracic cord, lumbar cord, sacral cord
Primary sensory cortex: receives information from the skin, senses, and joints
Primary motor cortex: carries motor information to the brainstem and spinal cord to initiate
voluntary movement
Motor pathway: motor cortex → axons to the primary motor neuron → muscle
Sensory pathway: (Afferent) Senses (nociceptors) → thalamus → axons to brain neuron →
primary sensory cortex
Descending motor pathway = corticospinal tract = pyramidal tract
Ascending sensory pathway = spinothalamic tract
3
Neuroscience
Lecture 1: Introduction - CH1 (Bear) - 05/02/2025
Reductionist approach: To reduce the complexity of the problem, neuroscientists break it
into smaller pieces for systematic experimental analysis.
Level of analysis: The size of the unit of study. (molecular, cellular, systems, behavioral,
and cognitive)
Animal welfare: Making sure animals are treated well. Neuroscientists accept certain moral
responsibilities toward their animal subjects.
Animal rights: A philosophical position according to which animals have the same legal and
moral rights as humans.
Interaction in the brain is based on GABA (too much = too much sleepiness) and glutamate
(too much = epilepsia)
Alzheimer’s disease: Dementia
Loss of function, memory, personality, and identity
Atrophy of Cortex = loss of function
Left hemisphere = interpreter, as it is the language side
Stages:
1. Mild cognitive decline starts at hippocampus, takes 7 years (short-term memory).
2. Mild Alzheimer’s: Temporal and parietal decline for 2 years. Decline in reading,
objects, and spatial memory
- Fewer connections to memory areas, but stronger connections in the frontal
cortex to compensate for the memory loss. But also confabulations (making
things up, creating ‘false’ reasoning for why they did something) in the areas
that still work
3. Progressive Alzheimer’s: Declining attention and increased impulsivity, personality
change. This stage takes 2 years and also gets to the frontal cortex
Cognitive processes are gone, but the sensory input and motor output are intact
4. Final stage: Visual problems, impacts the visual cortex, duration of 3 years
Psychological disorders: ADHD, Autism, Anxiety, Schizophrenia, Depression, and OCD
- No Atrophy of the Cortex
- No to very few physical traces in the brain
- Major behavioral problems
Ventro-medial part: Emotional and social control. Example of damage is Phineas Cage
Dorso-lateral part: Cognitive Control
1
,Damage to the lateral PFC
Dysexecutive syndrome
- problems in planning, working memory, limited attention span, lack of insight into own
and others’ actions, confabulations, but no deficit in intelligence, language use, or
episodic and semantic memory
Damage to the ventral and Medial PFC: (Phineas Cage)
Disinhibition syndrome
- No Dysexecutive symptoms, Constant movement, Euphoric or manic, Abnormal
sense of humor, Fail to respond to normal social cues, Reveal embarrassing
personal information
Prefrontal cortex: cognitive control of behavior
Ventro-medial part: Emotional and social control.
Psychopaths have smaller connections between the
PFC and Amygdala
Dorsal - Ventral (or superior - inferior)
Medial - Lateral
Rostral - Caudal (or anterior - posterior)
Association fibers: Connections within hemispheres, connect the primary sensory areas in
the parietal, temporal, and occipital lobes to the association areas of the cerebral cortex, and
to each other
Commissural fibers: Connections between hemispheres, synchronization of left and right
hemispheres
Damage to corpus callosum:
- Split brain syndrome, two brain halves behave relatively autonomously (because they
are not connected)
Damage to the splenium of corpus callosum leads to
- Posterior disconnection syndrome of alexia
- Cannot understand written material
- Without agraphia (can speak and write without difficulty)
2
, Lecture 2: The Nervous System - CH7 + 15 (Bear) - 06/02/2025
CNS: Brain + spinal cord
Spinal cord:
- Transports info from the body to the brain and back. Communicates through the
spinal nerves, and each spinal nerve attaches to the spinal cord by two branches, the
dorsal root and the ventral root. The dorsal root contains axons bringing
information into the spinal cord, such as those that signal the accidental entry of a
thumbtack into your foot. The ventral root contains axons carrying information away
from the spinal cord e.g., to the muscles that jerk your foot away in response to the
pain of the thumbtack.
Brain:
- Cerebrum: contains left and right hemispheres
- Cerebellum: Small brain - center for movement
- Brainstem: vital functions (breathing, heart rate, etc.) and relay station from info of
the spinal cord and cerebellum
PNS: Everything except CNS
Nerves:
- Cranial nerves: 12 nerves from the brain
Important: Olfactory nerves (1), Optic nerve (2), cranial nerves related to brainstem (3-7),
cochlear nerve (8), Vagus (10)
- Spinal nerves: Innervate skin, joints, and muscles. The dorsal root ganglia contains
cell bodies of peripheral sensory neurons
- Visceromotor system (or autonomic NS): Starts fight or flight, digest and rest
Afferent axons: “carry to”, axons transport information toward a particular point.
Efferent axons: “carry from”, axons transport information away from a particular point.
Autonomic NS (ANS): Visceromotor system can be divided into sympathetic (fight or flight)
and parasympathetic (rest or digest). It innervates smooth muscles of internal organs, blood
vessels, and glands.
The spinal cord is divided into 4 parts:
Cervical cord, thoracic cord, lumbar cord, sacral cord
Primary sensory cortex: receives information from the skin, senses, and joints
Primary motor cortex: carries motor information to the brainstem and spinal cord to initiate
voluntary movement
Motor pathway: motor cortex → axons to the primary motor neuron → muscle
Sensory pathway: (Afferent) Senses (nociceptors) → thalamus → axons to brain neuron →
primary sensory cortex
Descending motor pathway = corticospinal tract = pyramidal tract
Ascending sensory pathway = spinothalamic tract
3
