1. Where do our thoughts, memories, and perceptions occur in the human body? 2. How do we direct the motion of our bodies (e.g. how do we get our eyes, limbs, mouth, and other parts to move the way we want them to)? 3. What makes human unique from other animals, and what makes each of us unique from our peers?

 The brain is a dense, location specific organ that controls conscious and unconscious human functioning.  The spinal cord and nervous system allow our brains to efficiently communicate with our bodies.  Our knowledge about the specific regions of the brain and how they communicates is still limited.

 Time: We have just begun to develop technology that allows us to look at the brain in a very efficient manner.  Money: Most of the current technologies that we have are very, very expensive to use. This limits us in both the number, and type of individuals that conduct research on this topic.  Variety: The brain and nervous system are, in relative terms, HUGE! There’s a lot to examine, and we’re just getting started.

 In the past: Philosophy and debate Autopsy

 Currently: Histology  Stains Invasive Studies Recording Imaging

 Currently: Histology Invasive Studies  Autopsies  Experimentation/stimulation on animals  Chance and correlation lesion studies  Phineas Gage case  Hemisphere neglect example  Transcranial Magnetic Stimulation (TMS) Recording Imaging

 Phineas Gage Worked for a railroad company Had a metal rod shot through his head Survived the incident, but his behavior changed dramatically after the incident  Much more impulsive  More excitable and agitated  Struggled with the ability to maintain friendships, relationships, and conversation  “what was once a well mannered man, now became something that resembled a mere animal”

 Strengths: Can determine the necessity of a region for a certain cognitive process.  Weaknesses: Lack of experimental control. Time for plasticity. Low number of subjects.

 Currently: Histology Invasive Studies Recording  Electroencephalogram (EEGs)  Event related potentials (ERPs)  Electrocorticography (ECog) Imaging

 Electrophysiology can record electrical potentials of large populations of simultaneously active neurons at the scalp  A direct measure of neural activity

INDIVIDUAL NEURON ACTIVITYCOMBINED NEURON ACTIVITY

 Currently: Histology Invasive Studies Recording Imaging  Computerized Tomography (CT Scans)  Positron Emission Tomography (PET Scans)  Magnetic Resonance Imaging (MRIs, and fMRIs)

 In comparison to lesion studies, neuroimaging experiments tell us a whole slew of information about the brain with some distinct advantages. Noninvasive Allows us to look at people while living Allows us to get larger samples of individuals Note: they also look at more specific activity that mere recording methods.

 The Beginning: CT Scans CT scans were first introduced in order to see the structure of the brain (great for detecting abnormalities)

Positron Emission Tomography (PET) Measures variations in cerebral blood flow by tracking the decay of a radioactive tracer (an unstable isotope) usually tagged to water molecules. More blood = more neural activity…an indirect measure of neural activity

 PROs Decent spatial resolution (5- 10mm 3 ) Can also measure neurotransmitter metabolism.  CONs Invasive Very expensive Poor temporal resolution (minutes) Cannot detect the neural response to discrete cognitive events.

 Advances over PET Non-invasive (no radioactive agents required) Better spatial resolution (1mm) Better temporal resolution (seconds rather than min)  How does it work? Similar to PET in that it is an indirect measure of changes in blood flow Blood flow is measured by the deoxygenating of the hemoglobin in your brain and a giant magnet spinning around your head

 Currently: Histology  Stains Invasive Studies  Autopsies  Chance and correlation lesion studies  Experimentation/stimulation on animals  Transcranial Magnetic Stimulation (TMS) Recording  Electroencephalogram (EEGs)  Event related potentials (ERPs)  Electrocorticography (ECog) Imaging  Computerized Tomography (CT Scans)  Positron Emission Tomography (PET Scans)  Magnetic Resonance Imaging (MRIs, and fMRIs)