Response Stress Dampening Model
o o Alcohol intoxication produces a direct, pharmacological suppression of activity in the defensive (fear/anxiety) system. Therefore, alcohol consumption is reinforcing -- particularly when consumed in stressful contexts.
Attention Allocation Model o Alcohol intoxication reduces "attentional capacity" o Alcohol focuses attention on the most salient stimuli in the environment o If the most salient stimulus in the environment is pleasant, stress response will be reduced
Measurement of Emotion (the Startle Reflex)
The Basics o o o Startle reflex is a defensive response The magnitude of the reflex is INCREASED when the organism is fearful The magnitude of the reflex is DECREASED when the organism is "feeling good"
The Startle Reflex (continued)
o o
Measurement
Elicited with brief burst of white noise ("startle probe") presented over headphones Eyeblink response is indexed by recording electrical activity in the orbicularis oculi muscle
ANOVA effects
Main effect: The overall effect of an independent variable on the dependent variable. Main effects make no reference to levels of the other IVs. It is assumed that the effect is consistent across levels of other IVs. Interaction: The effect of a specific IV on the dependent variable differs based on the level of a second IV. In other words the effect of the IV is not consistent. It varies across the levels of the other IV. Simple effect: The effect of an IV on the dependent variable at a specific level of second IV. Simple effects are important when interactions exist. The interaction indicates that the IV effect varies across levels of a second IV. The simple effects report the effect of the IV at each level of the second IV
The Interaction
A single factorial ANOVA tests for a number of effects. Specifically, it will provide separate tests for each main effect (overall effect of an IV) and for all interactions between IVs. An interaction, by definition, exists if: The effects of one IV on the DV differed based on the level of another IV. In the presence of an interaction, the main effects often become uninterpretable. Therefore, instead of main effects, you will typically report simple effects. Simple effects are effects of one IV restricted to only one level of another IV
Curtin et al., 2001
Participants 48 social drinkers assigned to 2 beverage conditions o Alcohol (Peak BAL of 0.08 g/100 ml) o No-alcohol Emotion Manipulation Discrete threat of electric shock cued semantically o Safe and shocked words Cognitive Processing Manipulate "attentional focus" o Threat focus (Shock only) o Task focused (divided attention)
Next Block: SHOCK Only
Read each word as it is presented Shocks to animal words
HEAD
NECK
BEAR
!!!SHOCK!!!
END BLOCK
Next Block: TASK & SHOCK
Press button quickly to square after GREEN word Do not press button after RED word Shocks to ANIMAL words
HAND
MOUTH
TIGER
!!!SHOCK!!!
END BLOCK
10 of 10 points earned in this block
Fear Potentiated Startle
1
2
3
4
Main effect of beverage: (Average of 1 & 2) vs. (Average of 3 & 4) Main effect of attentional focus: (Average of 1 & 3) vs. (Average of 2 & 4) mple effects of beverage: During threat focus: 1 vs. 3 During divided attention: 2 vs. 4 mple effects of attentional focus: Among sober participants: 1 vs. 2 Among intoxicated participants: 3 vs. 4
Measuring Cognitive Processing
Event Related Potentials (ERPs)
o o o o Discrete brain electrical activity in response to sensory or cognitive events Occur in context of much larger, ongoing spontaneous EEG activity Time-locked to stimulus and can be "extracted" from EEG through signal averaging ERP waveform consists of a series of peaks and valleys with early (exogenous) components related to sensory processing and later (endogenous) components produced by "cognitive" events
P3 to Threat Cues
P3 Difference (Threat Cue Attention)
7
Threat-only
6
Conflict (Task&Threat)
5
P3 difference ( volts) P
4
3
2
1
1
0
2
No-Alcohol Beverage Group
3
Alcohol
4
Main effect of beverage: (Average of 1 & 2) vs. (Average of 3 & 4) Main effect of attentional focus: (Average of 1 & 3) vs. (Average 2 of & 4) mple effects of beverage: During threat focus: 1 vs. 3 During divided attention: 2 vs. 4 mple effects of attentional focus: Among sober participants: 1 vs. 2 Among intoxicated participants: 3 vs. 4
Response Time
255
3
Reaction time (ms)
225
4 1
No-Alcohol
195
165
2
CUECue Type CUE+
Alcohol
(Average of 1 & 2) vs. (Average of 3 & 4) Main effect of Threat: Main effect of Beverage: (Average of 1 & 4) vs. (Average of 2 & 3) mple effects of beverage: During CUE-: 1 vs. 2 During CUE+: 3 vs. 4 mple effects of threat: Among sober participants: 2 vs. 3 Among intoxicated participants: 1 vs. 4
Curtin et al., 1998 Participants
o 48 social drinkers assigned to 2 beverage conditions o Alcohol (Peak BAL of 0.070 g/100 ml) o No-alcohol
Emotion Manipulation
o Cued Threat of Electric Shock o Threat focused and Distraction (divided attention) conditions
Emotional Response Measurement
o Startle reflex (and other measures)
Methods
o o o o 8 blocks alternating between "shock threat" and "safe" conditions 6 slides presented in each block Startle probes presented in each block
o o Half during slide presentation (Distraction) Half during inter-slide interval (Threat focused/no-distraction)
Fear poteniated startle measured as the difference between startle response in "Shock threat" vs. "Safe" blocks
! !
!
! !
Key - Slide - Startle probe
! !
Fear Potentiated Startle
10 Blink mag. change (mircovolts) 8 6 4 2 0 No-distraction Distraction No-alcohol Alcohol
Threshold for simple threat effect
Stritkze et al., 1995
Participants 36 social drinkers assigned to 2 beverage conditions o Alcohol (Peak BAL of 0.075 g/100 ml) o No-alcohol
Emotion Manipulation Emotional Slide viewing o Positive, negative and neutral slides
Emotional Response Measurement o Startle reflex (and other measures)
Valence-modulated Startle Response
2
Blink mag. change
1 0 -1 -2
No alcohol Alcohol
Pleasant
Neutral
Unpleasant
Stress Response Dampening Prediction
2
Blink mag. change
1 0 -1 -2
No alcohol Alcohol
Pleasant
Neutral
Unpleasant
Increased Positive Affect Prediction
2
Blink mag. change
1 0 -1 -2
No alcohol Alcohol
Pleasant
Neutral
Unpleasant
The Real Deal......
2
Blink mag. change
1 0 -1 -2
No alcohol Alcohol
Pleasant
Neutral
Unpleasant
Donohue et al., in preparation o A replication of the Stritzke et al (1995) slide viewing study o Incorporates an examination of Dose Response
o o o o No-alcohol Low dose (0.02 - 0.04 g/100ml) Moderate dose (0.05 0.08...