CHAPTER 18

Major weakness of psychophysiology as a field is the lack of theory. The theories that have been acvanced have been very limited in scope. Usually psychophysiological measures are used to help elucidate concepts derived from theories of behavioral performance. However, ther have been several influential concepts in psychphysiology that have often been invoked as if they were explanitory. Some of these are:

I.Law of Initial Values (LIV)

The size of the physiological response to a stimulus or situation is dependant upon the prestimulus (baseline) level of the response. In general, the higher the initial level the smaller the increase and the larger the decrease, whereas the lower the initial level the larger the increase and the smaller the decrease. Equivalent to ceiling and floor effects in performance.

Not all physiological responses obey LIV in laboratory situations. Whether or not a physiological response does obey LIV may be a complex function of individual differences, environmental variables and the distributional properties of the response in question. Probably should not be treated as a law, but rather as a principle (Furedy).

II. Autonomic Balance

Concept proposed by M. Wenger and assosciates. Autonomic balance (denoted as ) indicates the relative dominance of the SNS or PNS. Wenger's was based on a series of responses entered into a prediction equation. not used much today, but the concept has found some support using cardiovascular measures of relative SNS/PNS balance as predictors of essential hypertension and other cardivascular dysfunction.

III. Activation

Descibes relation between levels of physiological activity and behavior change (e.g., performance). Usually proposed to follow the Yerkes-Dodson inverted-U function. Duffy, Hebb, Lindsley, & Malmo all propose a central role for the "reticular activating system (RAS) or ascending RAS (ARAS)" in regulating physiological activation (also sometimes called arousal) that has behavioral consequences. Several problems with a unitary activation concept: 1) different physiological response systems sometimes associate and sometines dissociate; 2) inverted-U function is not always observed; 3) inverted-U can describe any pattern of results when only 2 levels of "activation" are compared.

Figure 4. Yekes-Dodson Inverted-U

IV. Stimulus-Response Specificity

The concept that physiological response patterns are elicited by specific stimulus situations.

A.Directional fractionation (Lacy)

Physiological response patterns differ in response direction

B. Intake/Rejection (Lacy)

Perceptual taks that require the intake of stimulus information from the environment are facilitated by cardiac slowing; whereas cognitive tasks that require the rejection of stimulus information from the environment are facilitated by cardiac acceleration. Lacy's orignial hypothesis that cardiac slowing and acceleration have afferent effects on the brain has not been well supported. However, the evidence is more consistent that perceptual tasks are associated with slowing and cognitive tasks are associated with acceleration.

V. Individual Response Specifity (also Stereotypy)

Individuals also differ in their response patterns.

VI. Cardiac-Somatic Concept

Cardiac changes are associated with the general metabolic demands of the task.

A.Coupling - occurs during passive coping tasks. Cardiac-somatic coupling elicits in cardiac decleration that occurs as a result of somatic quieting of muscles that are not active during task performance. PNS activation.

B.Uncoupling - occurs during active-effortful coping tasks. Cardiac-somatic uncoupling elicits in cardiac acceleration that occurs as a result cognitively effortful or stressful active task demands. SNS activation.

VII. Autonomic Determinism (Bernston, Cacioppo, & Quigley, 1991)

A. Autonomic Space

1. Principle of Multiple Modes

a. Coupled Reciprocal
b. Coupled Nonreciprocal
c. Uncoupled

Table 5
Possible Modes of Autonomic Control for Heart Rate

VIII.Conditioning Concepts (Pavlov)

A. Habituation - adaptation to repeated stimulation

B. Rebound - response returns to lower level than before noxiuos stimulus

C.Orienting response - "what is it?" novelty response, habituates quickly (except very relevant stimuli like our own name), enhances perceptual discrimination of stimuli.

D. Defensive response - (Sokolov) protects against intense stimuli, habituates slowly,