Psych 120 General Psychology Christopher Gade Office: 1030A Office hours: MW 4:30-5:30 Email: gadecj@gmail.com Class MW 1:30-4:30 Room 2240

Pop Quiz Questions Where do our thoughts, memories, and perceptions occur in the human body? 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)? What makes human unique from other animals, and what makes each of us unique from our peers?

Notes about the brain… 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.

Why do we know so little? Time: Money: Variety: 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.

How the mind/brain is studied… In the past: Philosophy and debate Autopsy

How the brain/mind is studied (cont.) Currently: Histology Stains Invasive Studies Recording Imaging

Stains

How the brain/mind is studied (cont.) 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

The Most Popular Lesion Example Ever… 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”

Example of Chance Anatomy Studies: Parietal Stroke (Hemisphere Neglect)

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

TMS Studies

How the brain/mind is studied (cont.) Currently: Histology Invasive Studies Recording Electroencephalogram (EEGs) Event related potentials (ERPs) Electrocorticography (ECog) Imaging

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

Applications of Electroencephalography (EEG) INDIVIDUAL NEURON ACTIVITY COMBINED NEURON ACTIVITY

Electrocorticography (ECoG)

How the brain/mind is studied (cont.) Currently: Histology Invasive Studies Recording Imaging Computerized Tomography (CT Scans) Positron Emission Tomography (PET Scans) Magnetic Resonance Imaging (MRIs, and fMRIs)

Why Neuroimaging? 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.

Blood Flow Measures Example 1: 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

PET PROs CONs Decent spatial resolution (5-10mm3) Invasive Very expensive Poor temporal resolution (minutes) Cannot detect the neural response to discrete cognitive events. PROs Decent spatial resolution (5-10mm3) Can also measure neurotransmitter metabolism.

Functional MRI (fMRI) Advances over PET How does it work? 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

How the brain/mind is studied (cont.) 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)

So what have we learned by examining the brain and nervous system through these techniques?

Researchers look at the brain in two ways. Functional specialization – what is NECESSARY for the mind to complete a task. Functional integration – what is USED by the brain in the completion of a cognitive task. LESION NEUROIMAGING

Example of Specialization: Language Function Broca’s Area Wernicke’s Area

Examples of Integration: Sensory Pathways

What have imaging techniques also let us understand about the brain? Sometimes, small numbers of neurons can travel to a place where they activate large numbers of neurons

And… The fact that many of our areas are arranged very intricately Layering and columns (related to brain structures and the paths to those structures) Specialization of function Location receptors Orientation receptors Ocular information receptors Color receptors

One final thing that looking at the brain can tell us about sensation and perception Modularity – the idea that areas of the brain are specialized for very specific tasks Modules – areas of the brain that specialize in specific tasks FFA – fusiform face area (identifying faces) Prosopagnosia – the inability to recognize faces Autism – a disorder that often involves detached behavior and an inability to understand/relate effectively with other individuals PPA – parahippocampal place area (identifying places and scenes) EBA – extrastriate body area (identifying body parts)

One final note: When studying the necessity and correlation of these measures, we need to remember that these areas and paths are associated with the brains of MOST people. Neural plasticity allows a number of individuals to display behaviors that they should not be capable of conducting based on the damage and underdevelopment of different regions of their brain/nervous system.