Brain, Anatomical Structures & their Functions. Lesson 1 (REACH Psychology, week 3)

Transcription

1 Brain, Anatomical Structures & their Functions Lesson 1 (REACH Psychology, week 3)

2 Overview of the week The brain s anatomy and basic physiological processes Functions of different brain structures Lesions and what they teach us Some of the cognitive processes and how they are instantiated by the brain Methods of cognitive neuroscience How is information encoded and processed in the brain

3 Before we start Why do we study the brain? (take 3 minutes to write down the 3 reasons you think are most important) Also think - why do You personally want to study the brain and its functions?

4 Before we start Why do we study the brain? 1. New scientific ground! 2. Potential for treating conditions and improving various aspects of cognition/intelligence 3. Multidisciplinary projects (the real strength of neuroscience)

5 A brief history of the brain (or how very smart people can be very wrong) Aristotle - noticed that the brain s size matters. But he also thought that cognition is produced by the heart, while the brain is the cooling system. Gall and Spurzheim (18th century) - different regions of the brain perform different functions and skull shape can tell you about personality? ( phrenology )

6 A brief history of the brain (or very right) Only in the 19th-20th century Broca(1861) - empirical research on the brain through brain damage Ramon y Cajal ( ) - saw the synapse through neuronal staining. Sherrington in 1897 described synaptic properties. Broadbent(1958) - much of cognition consists of a sequence of processing stages, mind as a computer Neural network, connectionist or parallel distributed processing (PDP) approach (McClelland et al., 1986)

7 A brief history of the brain (or again very wrong) Modern culture is plagued by brain myths Every day we use only 20 % of the brain using more makes you super-smart? More truth in this cartoon than in so-called Sci-Fi Well if Morgan Freeman said so But are we robots driven by our emotions?

8 Quick Question Tell me some brain myths (or what you suspect might be...) Write as many as you can in 3 minutes

9 The nervous system (anatomy refresher) Signals to and from the brain go via the spinal cord Eyes (optic nerve) and ears (cochlear nerve) are connected to the brain via midbrain structures

10 The central nervous system

11 The nervous system (the Brain)

12 The nervous system (the neuron) Resting potential: -60 mv Threshold potential: -50mV Excitatory (+) and inhibitory (-) potentials via dendrites (sometimes soma, or even axon) Ation potential, passing of the signal Chemical synapse Neuron: cell body, dendrites, axon Axon slits and terminates - terminal button Membrane with gaps These feed into the synapse, where the communication between neurons happens

13 To summarise - the cell body and axon

14 Synapse

15 The Real Neuron This is what neurons really look like and we know very little

16 How does action potential carry information? The amplitude of an action potential does not vary much But the number of action potentials per second varies for different neurons Information about the stimulus is encoded in this pattern of action potentials - spike trains

17 Brain structures Neurons form white matter and gray matter. Can you tell which one is which?

18 Brain structures

19 Brain structures Hindbrain - Vital processes: breathing, the function of the heart, dilation/contraction of blood vessels, vomiting, coughing, swallowing and sneezing, coordination and fine motor control. Emotions and the associated physical stimuli such as increased heart rate are under the control of the cerebellum, as is long-term and short-term memory. Midbrain - partially responsible for vision, hearing, motor control, sleep/wake, arousal (alertness), and temperature regulation. Forebrain - we will focus on!

20 Forebrain areas - cytoarchitectural organization Organized into two hemispheres (left and right) Guri and Sulki Has layers - 6 on average Each layer has its own cell type Different parts of the cortex have different densities in each of the layers.

21 Brodmann areas Korbinian Brodmann defined and numbered areas based on their cytoarchitectural organization correlated closely to diverse cortical functions boundaries in any individual brains vary

22 Brain lobes and their function

23 Caution! Devotion to lobes is a very rough approximation. Function of each areas varies depending on its connections to other areas Neuroscience is coming to an understanding that functional information is encoded in activity patterns, not is single areas or neurons

24 Brain patterns

25 Finally What would you like to learn in this course?

26 Next lesson Lesioned brain Basic reading for today(more on neurons) gov/disorders/brain_basics/ninds_neuron.htm Advanced reading for next lesson - Insights into Human Behavior from Lesions to the Prefrontal Cortex (Szczepanski and Knight, 2014)