RESEARCH POSTER PRESENTATION DESIGN © 2012

www.PosterPresentations.com

Power calculation. A placebo controlled double blind pilot study examining whether saturated fat (cream or coconut milk) affects memory observed a large effect size (d=1.38). An a priori power calculation using G-power revealed that with such a large effect size, with alpha set to .05 (two-tailed) a sample size of 15 would be required for 95% power (Erdfelder et al., 1996).

Participants. Sixty-two participants were recruited from KU Leuven. The data from three of these participants were not included in the final analysis because of 1) a technological problem, 2) failure to drink the entire milkshake solution, and 3) failure to follow directions. Of the remaining, 37 were female and 22 were male (Mage=19.89 yrs; SD= 2.46; range 18-31 yrs).

Design. Randomized, double-blind, placebo-controlled, between subjects design. Participants abstained from consuming anything with calories, caffeine, and nicotine for 3 hours prior to participating.

ABSTRACT  The treatment of anxiety-based psychopathology often hinges upon extinction learning. Research in nutritional neuroscience has observed that the regular consumption of perilla oil (50% alpha-linolenic acid (ALA)) facilitates extinction learning in rats (Yamamoto et al., 1988). However, acute facilitation of extinction learning by oils rich in ALA has not been reported for rats or humans, though the acute consumption of rapeseed oil (10% ALA) has been observed to improve cognitive processing speed in humans (Jones et al., 2014). For this reason, the present laboratory work examined the effects of adding walnut oil (12% ALA) to a chocolate milkshake on the acquisition, generalization, and extinction of a fear-based prediction in young adults. It compared performance between subjects. The other participants consumed a similar milkshake with either an equicaloric amount of cream (saturated fat), or with no added fat (control). Acquisition and generalization of the fear-based prediction were similar for all conditions. However, those who consumed walnut oil extinguished most rapidly and profoundly. This finding may be relevant to the clinical treatment of anxiety disorders.

METHODS  

1.  Pre-acquisition: •  The CS+ and the CS- were each presented

three times without the outcome. 2.  Acquisition:

•  The CS+ and the CS- were each presented 12 times; the CS+ was co-terminated with the outcome on eight of its twelve presentations.

3.  Generalization: •  Each of three generalization blocks consisted

of one presentation of each of the seven generalization stimuli, two presentations of the CS+ (50% reinforced), and two presentations of the CS-. The GSs and the CS- were never followed by the outcome.

4.  Extinction:

•  The extinction phase consisted of twelve identical trials: a presentation of the CS+ that was never followed by the outcome.

Procedure.

METHODS  (con1nued)   DISCUSSION  

REFERENCES  Davidson, T.L., et al. (2012). The effects of a high-energy diet on hippocampal-dependent discrimination performance and blood-brain barrier integrity differ for diet-induced obese and diet-resistant rats. Physiol Behav, 107(1), 26-33. Deopurkar, R., et al. (2010). Differential effects of cream, glucose, and orange juice on inflammation, endotoxin, and the expression of Toll-like receptor-4 and suppressor of cytokine signaling-3. Diabetes Care, 33(5), 991-997. Jones, E.K., et al. (2012). Acute ingestion of different macronutrients differentially enhances aspects of memory and attention in healthy young adults. Biol Psychol, 89, 477-486. Luyten, L., et al. (2015). Generalization of contextual anxiety: the role of glucose and the hippocampus (talk). Rome Workshop on Experimental Psychopathology (RWEP). Rome, Italy, 20-21 March 2015. Reichenberg, A., et al. (2001). Cytokine-associated emotional and cognitive disturbances in humans. Arch Gen Psychiatry, 58(5), 445–452. Yamamoto, N., et al. (1988). Effect of the dietary alpha-linolenate/linoleate balance on lipid compositions and learning ability of rats. Discrimination process, extinction process, and glycolipid compositions. J Lipid Res, 29(8), 1013-1021.

Acknowledgements    Preparation of this manuscript was supported in part by an F+ fellowship by KU Leuven financed by the Center for Excellence on Generalization Research (GRIP.TT; KU Leuven grant PF/10/005) and by a postdoctoral research fellowship grant from the Research Foundation Flanders (FWO).

Chocolate Milkshakes

Body Temperature. A Braun ear thermometer was used to assess body temperature at baseline, 60 and 100 min.

Interim activities. 20 Dutch five-letter word anagrams (10 min) TED lecture + 16 multiple choice questions (25 min)

Mood Measure. Profile of Mood States questionnaire (Dutch version; Wald and Mellenbergh, 1990).

Predictive Learning Task. Participants were required to learn which of 9 line stimuli predicted the appearance of an aggressive dog image. They responded using predictive rating scales.

The fear-based predictive learning task used this picture of an aggressively attacking German shepherd dog as the to-be-predicted outcome.

RESULTS  

Holly  C.  Miller,  Dieter  Struyf,  Pascale  Bap8st,  Ilse  Van  Diest  Centre  for  Excellence  on  Generaliza8on  Research  

Faster  ex1nc1on  by  walnut:  The  effects  of  polyunsaturated  and  saturated  fat  on  predic1ve  learning.    

RESULTS  Temperature.

Profile of Mood States. Those who consumed the Walnut solution scored lowest for depression (p<.05, 95% CI [0.81, 0.87]). Those in the Control condition scored highest in anger (p<.05, 95% CI [3.06, 3.2]) There were no differences in perceived fatigue, vigor, or anxiety.

The efficacy of exposure treatment (which relies on the extinction of fear) may be sensitive to the contents of a patient’s diet, and even the meal preceding a clinical session.

Habituation and Acquisition

The mean predictive ratings per condition, stimulus (CS+ and CS-), and trial during the pre-acquisition and acquisition phases. Error bars represent ± SEM.

Generalization

0

1

2

3

4

5

6

7

8

9

10

CS- GS1 GS2 GS3 CS+ GS4 GS5 GS6 GS7

Pre

dict

ive

Rat

ing

Stimulus

Cream Walnut Control

0

1

2

3

4

5

6

7

8

1 2 3 4 5 6 7 8 9 10 11 12

Pre

dict

ive

Rat

ing

Trial Number

Cream Walnut Control

Extinction

0

1

2

3

4

5

6

7

8

9

10

Pre

dict

ive

Rat

ing

Habitua8on      Acquisi8on                

Cream CS-

Cream CS+

Walnut CS-

Walnut CS+

Control CS-

Control CS+

CS+

CS-

The mean predictive ratings for all of the line stimuli presented during the generalization test phase. Error bars represent ± SEM.

The mean predictive ratings for the CS+ across trials during the extinction phase. Error bars represent ± SEM.

Time  

0 60 100

BT BT BT

Drink

Anagrams Video POMS Predictive Learning Task

CLINICAL  RELEVANCE  

•  Walnut oil improved extinction learning. •  Why no differences in acquisition and generalization?

•  Simple discriminative learning is not affected by dietary manipulations (Davidson et al., 2012).

•  Stimulus discrimination is not sharpened, and generalization reduced, by glucose administration (Luyten et al., 2015).

•  How did Walnut oil facilitate extinction? •  Vagal afferent activation by nutrients?

(Jones et al., 2012). •  Could explain differences between Walnut

and Control. •  Cannot explain differences between Walnut

and Cream. •  Why did those who consumed Cream extinguish more

slowly than those who consumed Walnut oil? •  Facilitation by cream attenuated by

systemic inflammation? •  Cream increases inflammation more than

other nutrients (Deopurkar et al., 2010). •  Increases in systemic inflammation impairs

mood and memory (Reichenberg et al., 2001).

Nutri1onal  Informa1on   Walnut  (g)   Cream  (g)   Control  (g)  Calories   395   395   165  Carbohydrates   23   23   24  Fat   31   31   4  (Saturated)   21   5   2  Protein   7   7   8  

36.2

36.4

36.6

36.8

37

37.2

0 60 100

Bod

y Te

mpe

ratu

re in

Cel

sius

Time in Minutes

Cream Walnut Control

CS+  CS-­‐   CS-­‐