(A) Participants played a probabilistic task where they experienced different reward prediction error values, while reporting subjective mood every 2-3 gambling trials. In each trial, participants …
In the Primacy model, the expectation term is the unweighted average of previous outcomes. At each trial, all previous expectation terms are combined in an exponentially weighted sum: . Here, …
(A) Reward prediction error (RPE) values received during each task version, averaged across all participants (shaded areas represent SEM). (B) The influence of RPE values on mood reports along the …
(A) Model comparison between the Primacy and the Recency models, using the streaming prediction criterion, where the model is predicting each mood rating using the preceding ratings. On the left, …
(A) Equations S1 and S2 show the two additional parameters that were included in the Primacy model to test other scaling curves for most influential events on mood. (B) Examples of theoretical …
The left two columns show the task mood ratings and outcomes (A) above the expectation and reward prediction error (RPE) parameters of the Primacy (B) and the Recency (C) models (of a single …
(A) Extracting individual whole-brain BOLD signal activation maps () during the time interval preceding each mood rating, and individual model parameters by fitting mood ratings with the Primacy …
None of the Recency models’ clusters survived correction. Images show correlation across participants between the individual weights of the model expectation term, βE, and the individual whole-brain …
Cluster peaks in the nucleus accumbens (NACC) and covers the ACC and Caudate (337 voxels, t = 4.96).
Statistical comparison is of the streaming prediction errors. (MSE: mean squared error; IQR: interquartile range).
Model | MSE median | IQR | z-Value | p-Value | ||
---|---|---|---|---|---|---|
Reward environment | Random task | Primacy | 0.0165 | 0.0099 | - | - |
Recency | 0.0171 | 0.0091 | 1.8480 | 0.0323 | ||
Recency with dynamic win probability | 0.0170 | 0.0078 | 2.7440 | 0.0030 | ||
Recency without a Certain term | 0.0176 | 0.0099 | 1.9973 | 0.0229 | ||
Recency with outcome as expectation | 0.0187 | 0.0114 | 3.0053 | 0.0013 | ||
Recency with both dynamic win and no Certain | 0.0171 | 0.0079 | 2.7440 | 0.0030 | ||
Structured task | Primacy | 0.0088 | 0.0036 | - | - | |
Recency | 0.0097 | 0.0069 | 1.6613 | 0.0483 | ||
Recency with dynamic win probability | 0.0090 | 0.0043 | 1.8853 | 0.0297 | ||
Recency without a Certain term | 0.0109 | 0.0091 | 3.0053 | 0.0013 | ||
Recency with outcome as expectation | 0.0141 | 0.0044 | 3.8266 | 0.0001 | ||
Recency with both dynamic win and no Certain | 0.0090 | 0.0044 | 1.8853 | 0.0290 | ||
Structured adaptive | Primacy | 0.0137 | 0.0041 | - | - | |
Recency | 0.0160 | 0.0040 | 3.4533 | 0.0003 | ||
Recency with dynamic win probability | 0.0171 | 0.0040 | 3.7146 | 0.0001 | ||
Recency without a Certain term | 0.0189 | 0.0060 | 3.5279 | 0.0002 | ||
Recency with outcome as expectation | 0.0179 | 0.0063 | 3.6773 | 0.0001 | ||
Recency with both dynamic win and no Certain | 0.0172 | 0.0040 | 3.6770 | 0.0001 | ||
Age | Adolescents lab-based | Primacy | 0.0066 | 0.0021 | - | - |
Recency | 0.0077 | 0.0028 | 3.4533 | 0.0003 | ||
Recency with dynamic win probability | 0.0079 | 0.0026 | 2.8559 | 0.0021 | ||
Recency without a Certain term | 0.0094 | 0.0029 | 3.9013 | 0.0000 | ||
Recency with outcome as expectation | 0.0093 | 0.0038 | 3.6773 | 0.0001 | ||
Recency with both dynamic win and no Certain | 0.0079 | 0.0027 | 2.9306 | 0.0017 | ||
Diagnosis | Depressed adolescents | Primacy | 0.0043 | 0.0069 | - | - |
Recency | 0.0072 | 0.0053 | 3.2666 | 0.0005 | ||
Recency with dynamic win probability | 0.0075 | 0.0042 | 3.3039 | 0.0004 | ||
Recency without a Certain term | 0.0074 | 0.0042 | 3.3786 | 0.0003 | ||
Recency with outcome as expectation | 0.0089 | 0.0043 | 3.9013 | 0.0000 | ||
Recency with both dynamic win and no Certain | 0.0086 | 0.0069 | 3.4159 | 0.0003 |
Random online MTurk sample | Age | ||
---|---|---|---|
(n = 67) | Average | 39.81 | |
SD | 13 | ||
Sex | |||
Male | 37 | ||
Female | 32 | ||
Structured online MTurk sample | Age | ||
(n = 89) | Average | 37.55 | |
SD | 10.46 | ||
Sex | |||
Male | 48 | ||
Female | 41 | ||
Structured-adaptive online MTurk sample | Age | ||
(n = 80) | Average | 37.76 | |
SD | 11.23 | ||
Sex | |||
Male | 46 | ||
Female | 34 | ||
Structured-adaptive lab-based sample | Age | ||
(n = 72) | Average | 15.49 | |
SD | 1.48 | ||
Sex | |||
Male | 17 | ||
Female | 55 | ||
MFQ score | |||
Average | 5.81 | ||
SD | 5.98 | ||
Diagnosis | |||
Healthy volunteer | 29 | ||
MDD | 43 |
Model parameters recovery analysis: results of fitting the Primacy and Recency models on simulated datasets as well as a statistical comparison between the two models in both the training errors and the streaming prediction errors.
Note that only streaming prediction errors were used for model selection, and we show the training errors for illustrative purposes.
The formulation of alternative variants of the Recency model.