Difficult to measure consciousness. A state of consciousness is referred to as

a hypothetical construct. I.e., a concept used to describe something

that is believed to exist, but that cannot be directly observed or measured.

Psychologists infer what they know about an individual’s SOC from information provided to them, behaviour that is demonstrated of physiological changes that can be measured.

EEG Brain wave patterns can

vary in frequency. High frequency = more

brain waves. Low frequency = fewer

brain waves. Brain waves can also

vary in amplitude.

High amplitude = bigger peaks and troughs.

Low amplitude = smaller peaks and troughs.

4 different brain wave patterns:› Beta, alpha, theta,

delta. Each has a different

combo of frequency and amplitude, indicating different kinds of brain activity.

Beta: high frequency, low amplitude.Alpha: high frequency (but lower than beta), low amplitude (but larger than beta).Theta: medium frequency, and mixture of high and low amplitude waves.Delta: low frequency and highest amplitude.

In some ASCs, heart rate increases from that recorded in normal waking consciousness and in others, decreases.

E.g, while meditating, heart rate tends to decrease or when using a substance, increases.

Body temp is less variable than heart rate.

General pattern identified indicating that body temperature changes with some ASCs (most predictable during sleep).

Body temp decreases by 1oC when sleeping.

GSR: a physiological response that indicates the change in the resistance of the skin to an electrical current.

Electrodes attached to sides of a finger or palm of a hand.

Electrodes enabled detection and measurement of how easily the electrical current passes through the skin.

Changes in GSR are closely associated with emotional experiences.

High emotional arousal = increased sweating = increased electrical conductivity.

Measures of physiological responses can provide useful information about an individual’s SOC, BUT can be misleading if used as the only indicator.

Changes in physiological responses occur for many reasons.

Therefore, they are used in conjunction with observations and self-reports from individuals to obtain more accurate information.