Class Notes (837,785)
Canada (510,464)
Psychology (4,227)
PSY318H5 (40)

Chapter 6 Lecture.docx

4 Pages
Unlock Document

Ayesha Khan

Chapter 6 – imaging the brain’s activity - Diencephalon is usually lumped into forebrain, but textbook mentions it as in midbrain (this structure is on the border of midbrain) so both are correct, but we will not be asked to make this distinction - Where has damage occurred in the brain? Diagnostic POV Positron Emission Tomography (PET) o Could blood flow in the brain provide information about function? o Angelo Mosso: blood flow in the brain is important to figure out if that area was active; looked at infants’ brains b/c skull not fully developed at front part of head -> looked at blood pressure: pulsating brain at front; also heard pulsating in people with damage to skull & brain  You can make a connection b/w blood movement and brain activity  Compared pulses in forearm & region of brain showed identical pulses; but if asked a math question or heard church bells increased blood flow in brain therefore blood helps in thought process -> selective blood flow  What does increased blood pulsation mean? That that area needs more oxygen -> more release of K+ synapses to blood capillaries and helps in movement of blood  More blood flow = more oxygen = increased output of K+ into synaptic cleft and allow local capillaries to give more blood o Scan gives image in different colors which show high and low activity of brain -> dependent on given task o NO (nitric oxide) dilates blood vessels in brain therefore more movement of blood = more oxygen and nutrients o Metabolic activity generates heat -> fluctuations in temp. - Imaging helps make educated guesses in neuropsychology - Dynamic imaging has a fuzzy boundary -> MRI is placed under it (why? You’ll find out soon!) Electrical Recording o Electrical activity of neurons -> graded potentials 1. Single Cell Recording: usually in animals’ studies with access to their live tissue -> in lab, measure activity of animal’s brain by measuring their electrical activity with an electrode -> spikes indicate action potentials 2. Electroencephalograph (EEG) Recording: human studies (sleep clinics); gives overall activity of neurons -> graded potentials (smaller fluctuation) and action potentials (spikes) -> fluctuations in voltage are measured; makes a polygraph -> can see amplitude (high = AP, low = graded) and frequency (#/time); records activity of pyramidal cells in particular; represents phases of sleep cycle; can gain knowledge of seizures from a diagnostic POV (abnormal electrical activity) a. Two types of electrodes: i. Active: measures electrical activity ii. Control: placed somewhere near earlobe (bone or soft area) where not that much electrical activity is occurring 3. Event Related Potential (ERP) Recording: event happens in environment -> “What happens in the brain?”; brief change in EEG -> smooth out EEG signals; response to discrete sensory stimulus is classified as an ERP -> stimulus is presented repeatedly and recorded responses are averages; P1, N1, P2 are generated in ERP studies -> based on previous research we know where these Ps (+ve) and Ns (-ve) occur -> signals generated from EEG and where it occurs in the brain o What is Neuronal Code? When exactly does a neuron fire?  Information can be encoded as a time code (as long as an event occurs, neuron fires -> length of stimulus), event code (AP occurs when an event occurs), frequency of firing (# of AP) (seen in pain: AP occur a lot; goes down when given painkillers)  Describes AP o Levels of Neural Processing: how is information represented in the brain? What parts of the brain are recruited to represent a picture of the world (olfactory picture for example)  Narrow behavior repertoire  Neural activity in disperse areas  Widespread excitability during new learning (frequency of firing tends to be high when learning something new)  Inhibition also important (hyperpolarization) -> neurons behave differently, based on where they are o Pacemaker cells: regulate electrical activity of neurons; don’t need stimulation; automatic continuous generation of electrical activity w/o external stimuli therefore need lots of energy but can be influenced by autonomic innervations  In the heart: involved in the frequency of heart beat  Also found in t
More Less

Related notes for PSY318H5

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.