Physiology Lab Quiz 2

What are brain waves?

• are patterns of electrical activity in the brain, generated by the collective firing of neurons

• different brain waves are associated with different states of consciousness or mental activity.

How are brain waves measured?

using an EEG (electroencephalogram) and are classified by their frequency (cycles per second, Hz)

Delta Waves

Frequency:

• 0.5-4 Hz

State/Function:

• Deep sleep, unconsciousness, very slow brain activity

Theta Waves

Frequency:

• 4-8 Hz

State/Function:

• Light sleep, drowsiness, relaxation, creativity

Alpha Waves

Frequency:

• 8–13 Hz

State/Function:

• Calm but alert, relaxed wakefulness, meditation

Beta Waves

Frequency:

• 13–30 Hz

State/Function:

• Active thinking, problem-solving, focused attention, anxiety

Gamma Waves

Frequency:

• 30–100 Hz

State/Function:

• High-level cognitive functioning, memory processing, perception

What is the main difference between brain waves?

• Frequency

  • Faster Waves = higher frequency (more active processing)

  • Slower Waves = less frequency

Which brain waves are known to be slower?

• Delta

• Theta

Due to linkage of relaxation and sleep

Which brain waves are known to be faster?

• Beta

• Gamma

Due to linkage of intense focus or complex mental tasks

What are reaction times?

The time it takes to respond to a stimulus

What are the factors that influence reaction time?

• Stimulus type: Visual vs auditory (auditory is usually faster).

• Complexity of task: Simple reaction tasks are faster than choice reaction tasks.

• Alertness: Sleepiness or fatigue slows RT.

• Practice and familiarity: More practice speeds RT.

What is the expected trend for reaction times?

• Simple reaction time (one stimulus, one response): Fastest.

• Choice reaction time (multiple stimuli, different responses): Slower.

• Unexpected stimuli or distractions: Slower reaction times.

How do faster reaction times occur?

• Alert

• Well-rested

• Practiced on the task

• Simple stimulus.

How do slower reaction times occur?

• Tired

• Stressed

• Distracted

• Complex or novel task.

What is osmosis?

the movement of water across a selectively permeable membrane from a region of low solute concentration to high solute concentration.

Hypotonic Solution

• less solute outside than inside

• higher mass

• Water moves into the cells → cells swell

Hypertonic Solution

• more solute outside than inside

• lower mass

• Water moves out of cells → cells shrink

Isotonic Solution

• equal solute inside and outside

• constant mass

• No net movement → cells stay the same size

Greater change = _______

greater osmotic effect

Osmosis Highest Mass

9.72 g

Osmosis Lowest Mass

7.42 g

Fastest Reaction Time Overall

0.01 sec

Slowest Reaction Time Overall

0.947 sec

Visual Cue Mean Reaction Time

Fastest:

• 0.073 sec

Slowest:

• 0.947 sec

Warning Mean Reaction Time

Fastest:

• 0.01 sec

Slowest:

• 0.47 sec

Predictable Mean Reaction Time

Fastest:

• 0.036 sec

Slowest:

• 0.383 sec

Distraction Mean Reaction Time

Fastest:

• 0.149 sec

Slowest:

• 0.615 sec

Auditory Mean Reaction Time

Fastest:

• 0.104 sec

Slowest:

• 0.588 sec