Concurrent evidence of extinction making acquisition context specific and ABA and ABC renewal effects in human predictive learning.

Two experiments evaluated whether the experience of extinction makes acquisition context specific (EMACS) while the extinction learning itself also becomes context dependent under ABA and ABC renewal designs in a human predictive learning situation. Two groups of participants received X-Outcome pairings in context A followed by P-Outcome pairings in context B. For participants in group E, cue X was then extinguished in context B while cue P was trained. Participants in group NE were trained with P, but they did not have the extinction experience. Testing target cues outside the context B (i.e. the context in which P was trained and X was extinguished) in group E led to an increase in responding to cue X (Renewal effect) and a decrease in responding to cue P (EMACS effect) regardless of whether the test was conducted in context A (Experiment 1) or in an alternative context C (Experiment 2). Combined results suggest that Renewal and EMACS effects may be based on the same underlying mechanism. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Extinction contexts fail to transfer control: Implications for conditioned inhibition and occasion-setting accounts of renewal.

The renewal effect is often explained as a side effect of the extinction context acting as a negative occasion setter. Four experiments tested whether extinction contexts show the selective-transfer property of occasion setters. Experiments 1-3 used a predictive judgment task where participants rated the probability of certain foods (cues) producing gastric malaise (outcomes) in different restaurants (contexts). Experiment 4 used a behavioral suppression task where sensor lights (cues) served as signals to suppress firing responses in certain galaxies (contexts). All 4 (Experiments 1-4) addressed whether a potentially negative occasion-setting context transferred its modulatory power to an extinguished (presumably occasion set) target in the test phase of an ABC renewal design. Experiments 2-4 further assessed the possibility that the extinction context acts as a conditioned inhibitor by testing a simple excitor on a context where extinction occurred. Neither selective (occasion-setting) nor nonselective transfer (conditioned inhibition) was demonstrated. Implications for theories of renewal and occasion-setting are discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Discrimination reversal facilitates subsequent acquisition of temporal discriminations in rats' appetitive conditioning.

Three experiments with rats assessed the effects of introducing predictive ambiguity by reversing a Pavlovianly trained discrimination on subsequent context and temporal conditioning. The experience of discrimination reversal did not facilitate context conditioning when the food was presented on a variable time schedule (Experiment 1a). However, in Experiment 1b, discrimination reversal enhanced subsequent learning of a fixed temporal interval associated with unsignaled food presentation in comparison with consistent training. In Experiment 2, temporal discrimination after reversal and consistent training was compared with a naïve control. The experience of discrimination facilitated subsequent temporal conditioning with respect to the naïve control, and discrimination reversal enhanced temporal conditioning even further. In Experiment 3, reversal enhanced learning of the fixed temporal interval, regardless of whether it was relatively short or long (i.e., 30 s or 60 s). Results are discussed in terms of current associative theories of human and nonhuman conditioning and attention. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The effects of extinction-aroused attention on context conditioning.

Two experiments assessed the effects of extinguishing a conditioned cue on subsequent context conditioning. Each experiment used a different video-game method where sensors predicted attacking spaceships and participants responded to the sensor in a way that prepared them for the upcoming attack. In Experiment 1 extinction of a cue which signaled a spaceship-attack outcome facilitated subsequent learning when the attack occurred unsignaled. In Experiment 2 extinction of a cue facilitated subsequent learning, regardless of whether the spaceship outcome was the same or different as used in the earlier training. In neither experiment did the extinction context become inhibitory. Results are discussed in terms of current associative theories of attention and conditioning.

Contextual control of conditioning is not affected by extinction in a behavioral task with humans.

The Attentional Theory of Context Processing (ATCP) states that extinction will arouse attention to contexts resulting in learning becoming contextually controlled. Participants learned to suppress responding to colored sensors in a video-game task where contexts were provided by different gameplay backgrounds. Four experiments assessed the contextual control of simple excitatory learning acquired to a test stimulus (T) after (Exp. 1) or during (Exp. 2-4) extinction of another stimulus (X). Experiment 1 produced no evidence of contextual control of T, though renewal to X was present both at the time T was trained and tested. In Experiment 2 no contextual control of T was evident when X underwent extensive conditioning and extinction. In Experiment 3 no contextual control of T was evident after extensive conditioning and extinction of X, and renewal to X was present. In Experiment 4 contextual control was evident to T, but it neither depended upon nor was enhanced by extinction of X. The results presented here appear to limit the generality of ATCP.

Extinction arouses attention to the context in a behavioral suppression method with humans.

One experiment assessed predictions from the attentional theory of context processing (ATCP, J. M. Rosas, J. E. Callejas-Aguilera, M. M. Ramos-Álvarez, & M. J. F. Abad, 2006, Revision of retrieval theory of forgetting: What does make information context-specific? International Journal of Psychology & Psychological Therapy, Vol. 6, pp. 147-166) that extinction arouses attention to contextual stimuli. In a video-game method, participants learned a biconditional discrimination (RG+/BG-/RY-/BY+) either after extinction of another stimulus had occurred, or not. When contextual stimuli were relevant to solving the discrimination (i.e., all RG+/BG- trials occurred in one context and all RY-/BY+ in another), prior extinction of another stimulus facilitated the discrimination, as if extinction enhanced attention to the contexts. Results are discussed briefly in terms of ATCP and the model of N. A. Schmajuk, Y. W. Lam, & J. A. Gray (1996, Latent inhibition: A neural network approach, Journal of Experimental Psychology: Animal Behavior Processes, Vol. 22, pp. 321-349).

Prenatal choline availability alters the context sensitivity of Pavlovian conditioning in adult rats.

The effects of prenatal choline availability on Pavlovian conditioning were assessed in adult male rats (3-4 mo). Neither supplementation nor deprivation of prenatal choline affected the acquisition and extinction of simple Pavlovian conditioned excitation, or the acquisition and retardation of conditioned inhibition. However, prenatal choline availability significantly altered the contextual control of these learned behaviors. Both control and choline-deprived rats exhibited context specificity of conditioned excitation as exhibited by a loss in responding when tested in an alternate context after conditioning; in contrast, choline-supplemented rats showed no such effect. When switched to a different context following extinction, however, both choline-supplemented and control rats showed substantial contextual control of responding, whereas choline-deficient rats did not. These data support the view that configural associations that rely on hippocampal function are selectively sensitive to prenatal manipulations of dietary choline during prenatal development.

Prenatal choline supplementation increases sensitivity to contextual processing of temporal information.

The effects of prenatal choline availability on contextual processing in a 30-s peak-interval (PI) procedure with gaps (1, 5, 10, and 15 s) were assessed in adult male rats. Neither supplementation nor deprivation of prenatal choline affected baseline timing performance in the PI procedure. However, prenatal choline availability significantly altered the contextual processing of gaps inserted into the to-be-timed signal (light on). Choline-supplemented rats displayed a high degree of context sensitivity as indicated by clock resetting when presented with a gap in the signal (light off). In contrast, choline-deficient rats showed no such effect and stopped their clocks during the gap. Control rats exhibited an intermediate level of contextual processing in between stop and full reset. When switched to a reversed gap condition in which rats timed the absence of the light and the presence of the light served as a gap, all groups reset their clocks following a gap. Furthermore, when filling the intertrial interval (ITI) with a distinctive stimulus (e.g., sound), both choline-supplemented and control rats rightward shifted their PI functions less on trials with gaps than choline-deficient rats, indicating greater contextual sensitivity and reduced clock resetting under these conditions. Overall, these data support the view that prenatal choline availability affects the sensitivity to the context in which gaps are inserted in the to-be-timed signal, thereby influencing whether rats run, stop, or reset their clocks.

Prenatal choline deficiency decreases the cross-sectional area of cholinergic neurons in the medial septal nucleus.

Levels of dietary choline in utero influence postnatal cognitive performance. To better understand this phenomenon, forebrain cholinergic neurons were studied in the 8-9 month old offspring of dams fed a control or choline-deficient diet from EDs 11-17. Serial sections were immunostained with antibodies against p75, a cholinergic marker. Neuronal morphology was analyzed in the basal forebrain, a heterogeneous area composed of several structures including the medial septal nucleus (MSN), nucleus of the diagonal band (DB), and the nucleus basalis of Meynert (NB). Neuronal cross-sectional areas were selectively reduced in the MSN of choline-deficient animals, compared to controls, but cell counts were not altered. Our findings suggest that cholinergic medial septal neurons may be selectively vulnerable to in utero choline deficiency.