PSY106 Fall 2024 Lecture Notes PDF

Question to Ponder: Why do we have a brain?  WEEK 5, OCT 28TH – NOV 3RD Two in-person lectures (Mon & Wed) Read Week 5 Readings on Canvas Complete Quiz 4 on Canvas by Sunday at 11:59pm Available at 5pm on Wednesday Optional: Attend a ULA session Optional: Participate in...

Question to Ponder: Why do we have a brain?  WEEK 5, OCT 28TH – NOV 3RD Two in-person lectures (Mon & Wed) Read Week 5 Readings on Canvas Complete Quiz 4 on Canvas by Sunday at 11:59pm Available at 5pm on Wednesday Optional: Attend a ULA session Optional: Participate in Week 5 Discussion by Sunday at 11:59pm If you wish to access your exam and see what you got wrong, please go to TA office hours – ULAs can go through exam questions, but can’t access your exam & grade  WEEK 5 & 6 TUTORING SESSIONS Structured sessions: sheep brain neuroanatomy! Thurs 10/31 2-3pm with Leia & Xi (Psych East 3834) Fri 11/1 2-3pm with Uma & Sukari (Psych East 3834) Tues 11/5 5-6pm with Joey & Grace (Psych East 3834) Thurs 11/7 4-5pm with Leia & Xi (Psych East 3834) Fri 11/7 1-2pm with Uma & Sukari (Psych East 3834) Fri 11/7 2-3pm with Joey & Grace (Psych East 3834) Drop-in sessions Mon 10/28 5-6pm with Grace & Uma (Library 4572) Wed 10/30 5-6pm with Grace & Sukari (Library 4574) Thurs 10/31 12-1pm with Joey & Leia (Transfer Student Center) Fri 11/1 11-12pm with Xi and Joey (ONDAS Student Center) ULAs can go through exam questions, but can’t access your exam Question to Ponder: Why do we have a brain? UNIT 2 Unit 1: Unit 2: The brain is composed of How do neurons link together neurons that communicate to into circuits to allow us to one another using a mixture sense and interact with the of chemical and electrical outside world? signals What is the purpose of a brain? Organisms have a variety of goals, largely related to survival & reproduction – need to evaluate the environment and interact with it to accomplish these goals  SENSING AND MOVING Organisms have a variety of goals, largely related to survival & reproduction – need to evaluate the environment and interact with it to accomplish these goals Inputs Output (sensory information) (behavior) The brain is a complex biological system that collects information about the environment, processes it, and sends commands to the body to interact with the world in order to achieve certain goals  SENSING AND MOVING Light Energy Sound Somatosensation Voluntary & Touch Involuntary Movements Self (body) Internal state: Odors Hunger/thirst Chemicals Emotion Hormones Tastes Memories GOALS OF THE SECOND UNIT OF THIS COURSE Unit 1: Unit 2: The brain is composed of How do neurons link together neurons that communicate to into circuits to allow us to one another using a mixture sense and interact with the of chemical and electrical outside world? signals Week 5/6: we’ll focus on vision as an example of how external information gets processed by various elements of the nervous system (more on the other senses in weeks 6 and 7) Week 7: How do signals in our brain result in the movement of our body to interact with our environment? Todays Topics: 7A: Getting Into the Brain 7B: Cerebral Cortex 7C: Everything but the Cortex DR. SCUDDER PSY106  WEEK 5 TAKEAWAYS By the end of this week, you should be able to: Use anatomical terms to describe the locations of brain regions Label key regions of the brain, including cortical lobes and subcortical areas Lecture 7 Explain some of the methods used to gain information about what different brain regions contribute to Describe the components of the brainstem and what role they play in brain function and behavior Identify the regions responsible for creating and releasing the modulatory neurotransmitters dopamine, serotonin, and norepinephrine List the major components of the visual system Lecture 8 Describe the overall anatomy of the retina, including cell layers and important features Compare and contrast rods and cones Describe the transduction mechanism for light INTRODUCTION TO BIOPSYCHOLOGY FALL 2024 LECTURE 7A: GETTING INTO THE BRAIN DR. SCUDDER PSY106 GOALS OF THIS SECTION Define some key anatomical terms for navigating the brain Describe the three layers of meninges that surround the brain ANATOMICAL TERMS ANATOMICAL TERMS Directions in the 3-D space of the brain Anterior or Rostral: towards the nose or front of the head (think “rostral = nostrils”) Posterior or Caudal: toward the back of the head Dorsal: top surface of the brain Ventral: bottom surface of the brain Medial: towards the midline Lateral: away from the midline Midline: line running down the middle of the nervous system (symmetrical halves) ANATOMICAL TERMS ANATOMICAL TERMS Nucleus (nuclei): collection of cell bodies in the CNS Ganglion (ganglia): collection of cell bodies in the PNS Afferent: incoming axons/information towards an area Efferent: outgoing axons/information away from an area Contralateral: opposite side Ipsilateral: same side ANATOMICAL PLANES Coronal Sagittal Horizontal We use special terms to describe the plane (the “view”) of the nervous system that we are looking at TYPES OF MATTER Visually, brain tissue generally appears as either gray matter or white matter Gray matter is known to mostly contain cell bodies of neurons, while white matter is largely long-range projections (axons) – the white color comes from the fatty myelin Before talking about the brain itself, let’s explore the structures & systems supporting it MENINGES Brains are delicate – need layers of protection and a circulatory system that can deliver oxygen and nutrients without contamination Meninges: Dura mater: thick outer layer surrounding brain Arachnoid membrane: web-like membrane between the dura mater and Subarachnoid space is filled the pia mater with cerebrospinal fluid, or Pia mater: thin membrane that clings CSF – this is also the fluid that neurons are surrounded closely to the brain itself by! Exploring the Brain (Bear, Connors & Paradiso) BRAIN VASCULATURE Brain has intricate network of blood vessels that deliver oxygenated blood – uses about 15% of total cardiac output! Duvernoy et al., 1981 Blockage of these vessels can be disastrous – a stroke is when a vessel becomes blocked or damaged, and can result in neuronal death CEREBROSPINAL FLUID Necessary molecules get pulled from blood vessels (through blood- brain barrier, regulated by astrocytes) and can be made available to neurons through CSF Brain has large caverns filled with CSF (ventricles), and this solution also surrounds all cells Let’s get into the brain! INTRODUCTION TO BIOPSYCHOLOGY FALL 2024 LECTURE 7B: CEREBRAL CORTEX DR. SCUDDER PSY106 GOALS OF THIS SECTION Identify some visible features on the surface of the brain Describe the four lobes of cerebral cortex and some of their functions  SURFACE OF THE BRAIN Wrinkled surface of the brain is called the cortex, or cerebral cortex Ridges are called gyri (plural of gyrus) and valleys are called sulci (plural of sulcus Split up into four lobes which broadly correspond to different functions Frontal (rostral to the central sulcus) Parietal (caudal to the central sulcus) Occipital (caudal to the parietal lobe) Temporal (ventral to the sylvian fissure) Exploring the Brain (Bear, Connors & Paradiso) DIVISIONS OF CORTEX Week 7 Week 7 Week 7 Week 5/6 Week 7 Week 6 Exploring the Brain (Bear, Connors & Paradiso) ASSOCIATION CORTEX Much of the surface area of human cortex is not devoted to direct sensory processing and motor control Primate brains have more association cortex than smaller, more “simple” brains Exploring the Brain (Bear, Connors & Paradiso) FRONTAL LOBE Contains the main controller of voluntary movements (motor cortex) Contains the prefrontal cortex (PFC) Important for planning, decision-making, and emotional control Humans have a much more developed PFC relative to other mammals Takes longer to fully mature compared to rest of the brain (could explain poor decision- making and impulse control in teens!) How do we have any idea what the PFC does? Exploring the Brain (Bear, Connors & Paradiso) PHINEAS GAGE Head was impaled by a railroad spike, destroying large chunk of his prefrontal cortex Survived, but showed strange changes to his behavior and personality Highlighted PFC’s role in impulse control, decision- making, and personality “He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires” “…no longer Gage” PARIETAL LOBE Contains brain tissue responsible for collecting information from several sensory systems (mostly somatosensation, or bodily senses, but also combines info from multiple senses) Works with PFC to evaluate situations and make decisions about what to do Exploring the Brain (Bear, Connors & Paradiso) PARIETAL LOBE How do we know what this part of the brain does? Scholarpedia.org Damage: injuries that kill neurons in the parietal lobe result in sensory issues and a strange disorder called hemispatial neglect or hemineglect Stimulation: take a small electrified wire (an electrode) and zap parts of the exposed brain Patients report sensations in different body parts when areas of parietal cortex are stimulated OCCIPITAL LOBE Much more about this lobe next week! Devoted to just one thing: vision! Humans have a very developed visual system and rely heavily on this sense – as a result, it takes up more real estate in our brain Think about what might be true about other animals How do we know? Again, damage (blows to the back of the head, gunshot wounds) and electrical stimulation Can also use a small wire to detect what the cells in this area are doing – find that they care about what the subject is looking at (electrophysiology) TEMPORAL LOBE Contains some regions devoted to sensory processing Primary auditory cortex Additional visual areas Deep inside (in the medial temporal lobe), contains regions critical for long-term memory Most notable part of this is the hippocampus – functions as the memory factory of the brain  MEDIAL TEMPORAL LOBE The interior surface of the temporal lobe contains an area called the medial temporal lobe (MTL) The hippocampus and other regions here play a critical role in the formation of new memories Some fascinating case studies have illuminated the role of the MTL – more in Unit 3 of this course! Exploring the Brain (Bear, Connors & Paradiso) MEDIAL TEMPORAL LOBE Hippocampus: structure essential for the formation of long-term memories (more on that in Unit 3) Amygdala: set of nuclei essential for emotional processing and behaviors (more in Unit 3) INTRODUCTION TO BIOPSYCHOLOGY FALL 2024 LECTURE 7C: EVERYTHING BUT THE CORTEX DR. SCUDDER PSY106 GOALS OF THIS SECTION Explain the roles of the thalamus and hypothalamus Describe the three components of the brainstem Explore the sources of modulatory neurotransmitters in the brain Describe the organization and role of the cerebellum  BENEATH THE CORTEX Thalamus Corpus Callosum (Weeks 6, 7) White matter tract (axons) that connects the two hemispheres Hypothalamus (Unit 3) Cerebellum (Week 7) Exploring the Brain (Bear, Connors & Paradiso) THALAMUS Located in the center of brain, ventral to the cortex Two lobes, one on each side of the brain (connected by a white matter tract) Primary function: sensory relay to cortex Organizes incoming sensory information and sends it to the right places in the rest of the brain Divided into many nuclei Ex: lateral geniculate nucleus (LGN): visual nucleus that receives visual sensory information & sends it to occipital lobe THALAMUS Various thalamic nuclei are responsible for acting as “gatekeepers” for information on its way to sensory areas of cortex The thalamus can control how much information actually reaches cortex Exploring the Brain (Bear, Connors & Paradiso) HYPOTHALAMUS Located at the base of the brain, under the thalamus Contains many nuclei & fiber tracts Controls the autonomic & endocrine system (hormones) Organizes behavior related to survival The “Four Fs” Fighting, fleeing, feeding, and mating ☺ More on its role in reproduction and aggression in Unit 3 The pituitary glands dangle beneath the hypothalamus, enabling hormone release into the bloodstream BRAINSTEM Composed of midbrain, pons, and medulla Responsible for control of many automatic but essential functions and behaviors (like breathing, heartbeat, sleep) The various nuclei in this part of the brain are responsible for making many modulatory neurotransmitters that regulate transmission throughout the brain (dopamine, serotonin, norepinephrine) Exploring the Brain (Bear, Connors & Paradiso) BRAINSTEM: MIDBRAIN Tectum (“roof”): dorsal part of the midbrain Inferior colliculi: auditory system Superior colliculi: visual system (visual reflexes) Tegmentum (“floor”) Exploring the Brain (Bear, Connors & Paradiso) BRAINSTEM: MIDBRAIN Tegmentum: ventral part of midbrain beneath the tectum Substantia nigra (SN): movement Connected to caudate & putamen Produces dopamine for movement initiation areas Ventral tegmental area (VTA): motivational/reward Connected to prefrontal cortex & nucleus accumbens Produces dopamine for reward/motivation areas Reticular formation (rostral end) Collection of nuclei producing other modulatory neurotransmitters Raphe nuclei: produce serotonin Involved in sleep, arousal, attention, movement, reflexes BRAINSTEM: PONS Pons: Large bulge in brainstem between the midbrain and the medulla, ventral to the cerebellum Reticular formation continues Sleep and arousal regulation More raphe nuclei (serotonin-producing neurons) Locus coeruleus (norepinephrine-releasing neurons) Relay nuclei Pontine nuclei Information from cortex to the cerebellum (motor cortex) Some types of motor commands are routed through these nuclei BRAINSTEM: MEDULLA Medulla oblongata (or just medulla) Most caudal portion of the brain Lower border connects to the spinal cord Reticular formation continues here (more raphe nuclei) Regulates cardiovascular system, breathing, & skeletal muscle tone Some sensory systems make a stop here before information goes to other brain regions  NEUROTRANSMITTERS Dopamine projections Dopamine is synthesized and released by neurons in the ventral tegmental area and substantia nigra (both in midbrain) Norepinephrine is synthesized and released by neurons in the locus coeruleus, in the pons Serotonin is synthesized and released by neurons in the raphe nuclei, located Goodman & Gilman throughout brainstem Serotonin projections Norepinephrine projections Matchett et al., 2021 Tarland et al., 2019 CEREBELLUM “Little cerebrum” Composed of two cerebellar hemispheres Very densely packed with neurons – about half of the neurons in your brain are in the cerebellum! Important component of the motor system Involved in any movement that needs timing information Involved in complex movement patterns Ex. Walking, shooting a layup, playing the piano THE CEREBELLUM IS GORGEOUS! Baizer et al., 2014 UToronto  WEEK 5, OCT 28TH – NOV 3RD Two in-person lectures (Mon & Wed) Read Week 5 Readings on Canvas Complete Quiz 4 on Canvas by Sunday at 11:59pm Available at 5pm on Wednesday Optional: Attend a ULA session Optional: Participate in Week 5 Discussion by Sunday at 11:59pm If you wish to access your exam and see what you got wrong, please go to TA office hours – ULAs can go through exam questions, but can’t access your exam & grade