Lab 1: EEG and Psychophysiology Overview

Lab 1: PowerLab 1 - Electroencephalography (EEG), Psychophysiology & Wii Lab

• Objectives:

  • Recognize common EEG artifacts
  • Elicit alpha waves in an EEG recording
  • Observe mental activity effects on EEG
  • Examine auditory stimulation effects on EEG
  • Measure skin conductance, facial EMG, respiration, and EMG in response to visual stimuli
  • Test distraction effects using Wii Lab

• EEG Artifacts:

  • Common artifacts are recognized during an EEG recording.

• Alpha and Beta Rhythms:

  • Methods for eliciting alpha waves are learned.

• Effects of Mental Activity:

  • Simple arithmetic tasks illustrate EEG activity changes.

• Effects of Auditory Stimulation:

  • The effects of different music volumes and types on EEG are examined.

• Psychophysiology:

  • GSR amplifier measures skin conductance.
  • Facial EMG is measured using surface electrodes.
  • Measurements of skin conductance, respiration, and EMG in response to visual stimuli are taken.

• Wii Lab:

  • Effects of distraction are tested.

• Equipment/Procedure:

  • PowerLab equipment is used
  • Electrodes are placed on the scalp, forehead, and mastoid process.
  • EEG activity is recorded and analyzed
  • Different frequency ranges of brain activity are measured
  • Data analysis is conducted using LabTutor software.

• Background:

  • Normal brain function involves continuous electrical activity of neurons.
  • Electroencephalography (EEG) records these aspects of activity.
  • EEG is performed by placing electrodes on the scalp and connecting them to measure electrical potential differences between various cortical regions.
  • Characteristic patterns of brain waves are generated by synaptic activity at the cortex surface, not from action potentials in white matter.

• EEG Waveform Components:

  • Each individual's EEG waveform is unique.
  • Waves are represented as peaks and troughs; frequency (Hz) reflects the number of peaks per second.
  • Amplitude depicts peak height/trough depth and reflects synchronous neuronal activity.
  • Brain waves are normally complex, low-amplitude signals.
  • High-amplitude signals can indicate synchronous activity during sleep stages

• Categories of Brain Waves:

  • Alpha waves (8-13 Hz): Associated with wakefulness with eyes closed, lower frequency and higher amplitude.
  • Beta waves (14-30 Hz): Higher frequency, lower amplitude reflecting heightened mental activity.
  • Theta waves (4-7 Hz): Typically found in children and some adults, lower frequency and higher amplitude when concentrating.
  • Delta waves (4 Hz or less): Very low frequency, high amplitude associated with deep sleep/loss of consciousness

• Consciousness:

  • Consciousness involves conscious perception, voluntary movement, and higher mental processing.
  • Clinical measurement uses a graded response scale from alertness to coma.
  • Absence of spontaneous brainwave activity might indicate brain death

• Sleep and Sleep-Wake Cycles:

  • Sleep is a state of partial unconsciousness.
  • Stages of sleep (NREM stages 1-4, REM sleep) are part of a cyclic process roughly every 90 minutes.
  • Stages differ by EEG patterns; REM is associated with dreaming.
  • Suprachiasmatic nucleus in the hypothalamus regulates the circadian rhythm.

• Memory:

  • Procedural memory involves skills (e.g., playing piano).
  • Motor memory involves muscle movements.
  • Emotional memory involves emotional responses to events.
  • Declarative memory encompasses facts, names, dates, etc, utilizing short and long-term memory.
  • Factors like concentration, emotion, and repetition influence the level of memory formation and retention.

• Distraction:

  • Divided attention from a primary task to a distracting stimulus.
  • Examples include external stimuli and internal distractions like thoughts.

• Review Questions:

  • Questions on EEG waveforms, artifacts, memory, and distraction effects.