Relationships between the determinants of performance in serial feature-positive discriminations.

Conducted 3 experiments using an appetitive behavioral observation procedure to investigate the effects of pre- and postdiscrimination treatments on learning and performance in serial feature-positive discriminations. Previous work suggests that performance in this discrimination is based on feature–UCS associations, feature–common element associations, and a conditional occasion-setting relation. Exp I examined the effects of prediscrimination reinforcement of the components of the discrimination. 26 male and 6 female Sprague-Dawley rats were assigned, in groups of 8, to 1 of 4 prereinforcement conditions (involving administration of a tone, a light, and a trace interval). Ss then trained on a serial feature-positive discrimination. Behavioral observations were recorded. Exps II and III investigated the effects of postdiscrimination nonreinforcement and reinforcement procedures on performance of established discriminative responding by 64 Ss. Results of the studies and of previous work are interpreted to show that the conditional occasion-setting relation may be independent of feature–UCS associations and may not depend on feature/common element associations. (61 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retraction of Ross and LoLordo findings concerning blocking in serial feature-positive discriminations.

Findings concerning the effectiveness of stimuli from various conditioning procedures in blocking conditioned excitation and occasion-setting functions of an added stimulus in a serial feature-positive discrimination training procedure (V. M. LoLordo and R. T. Ross; see record 1987-24106-001; Ross and LoLordo; see record 1987-14728-001) are retracted. Videotapes on which the published data were based were rescored by 2–5 people, most of whom were uninformed about group memberships of the Subjects. In no case did the rescoring confirm any of the original findings of blocking. Possible factors contributing to the discrepancies are discussed. The experiments should be repeated with feature stimuli that are less similar to each other and with several scorers, at least one of whom is unaware of the group assignment of the Subjects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal specificity in serial feature-positive discrimination learning.

Two experiments examined the temporal specificity of learning in operant serial feature positive discriminations (feature?→?target+/target–). Test performance was better when the target cues were presented at their customary times after the features than when they were presented at earlier or later times. When features trained with one feature–target interval were combined with targets trained with another interval, performance was best when the test interval was the same as the interval associated with the feature, suggesting that the temporal information was coded with the feature cue. Finally, the temporal specificity of the responding controlled by occasion setters was unaffected by feature extinction. Implications for the nature of learning in occasion setting are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative processes in differential outcome discriminations.

This study assessed the role of stimulus–outcome (S–O) and response–outcome (R–O) associations in differential outcome performances. In Experiment 1, pigeons learned one-to-many matching-to-sample with differential R–O associations but with either differential or nondifferential sample-outcome (S–O) associations. Later, both groups showed strong transfer of matching to novel samples that were differentially associated with the same outcomes used in training. Experiment 2 reversed the training conditions for each group. The switch from differential to nondifferential S–O associations produced a large drop in matching accuracy, whereas the opposite switch had only a small effect. Following recovery, both groups again showed positive transfer to novel samples, although transfer was stronger following differential S–O training. These data support a 2-process ("outcome expectancy") account of differential outcome performances but also indicate a contribution of bidirectional R–O associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perirhinal cortex lesions impair simultaneous but not serial feature-positive discrimination learning.

The role of the perirhinal cortex in discriminative eyeblink conditioning was examined by means of feature-positive discrimination procedures with simultaneous (A-/XA+) and serial (A-/X→A+) stimulus compounds. Lesions of the perirhinal cortex severely impaired acquisition of simultaneous feature-positive discrimination but produced no impairment in serial feature-positive discrimination. The results suggest that the perirhinal cortex plays a role in discriminative eyeblink conditioning by resolving ambiguity in discriminations with overlapping stimulus elements. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative structure and the serial reproduction experiment.

This study investigates the changes that occur in the serial reproduction of lists of words that vary in their associational relationship with each other. Lists of words were presented to groups of Ss; the results were based on the responses of the group as a whole. It was hypothesized that the closer the association relationship of words, the greater the ease of recall; the less the relationship, the greater the intrusion of idiosyncratic responses. The hypothesis was, to a great extent, confirmed. The results are related to the nature of social communication. From Psyc Abstracts 36:04:4CL95D. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Blocking in rat serial pattern learning.

Both associative and rule-learning theories have been proposed to account for rat serial pattern learning, but individually they are unable to account for a variety of recent behavioral and psychobiological phenomena. The present study examined the role of rule learning versus discriminative learning in rat pattern learning using a classic associative phenomenon: blocking. Rats learned to press levers in an 8-lever circular array according to a rule-based serial pattern, 123–234–345–456–567–678–781–812, where digits indicate the correct lever in the array for each trial. Each pattern presentation contained a chunk with a final element violation, such as 454 instead of 456. Rats learned in a first phase that a noise signaled the violation chunk; then, a concurrent spatial cue was added in a second phase. A test with spatial cues alone showed that blocking occurred. The results suggest that associative learning mediated cuing of violation elements. Taken together with other behavioral and psychobiological evidence already reported in the literature implicating rule learning when rats learn this pattern in this paradigm, these results implicate multiple concurrent learning processes in rat serial pattern learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus-response compatibilities during top-bottom discriminations.

Participants indicated whether a small dot was located near the top or bottom pole of a rotated object. Response times increased as a function of object orientation more for top trials than for bottom trials. The interaction between orientation and response was shown to be due to a relationship between response times and the dot's height on the screen. The orientation effect was influenced, positively and negatively, by a vertical arrangement of the response keys depending on whether the upper or lower key was used for the top response. Horizontal key placement produced an intermediate orientation effect, with asymmetries of about 180° depending on which hand was used for top responses. This task appears to reflect spatial stimulus-response compatibilities more than object processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Composition during serial learning: A serial position effect.

Composition is a computational learning mechanism that merges serially performed elementary processes into hierarchically organized knowledge structures. The main goals of this research were to explore (1) the role of serial position in composition and (2) the relation between degree of composition and explicit serial recall in serial learning. In 3 experiments, Ss performed a rule-based serial reaction time (RT) task in which they had to categorize a sequence of 12 stimuli shown simultaneously on a video monitor. A procedure based on the comparison of RTs to random sequences and a repeating sequence identified a serial position effect of composition that was, however, moderated by Ss' explicit, postexperimental recall of the repeating sequence. A production-system-based computational model of composition is described that qualitatively reproduces the empirical findings. Implications for the mechanisms governing serial learning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative relatedness enhances recall and produces false memories in immediate serial recall.

The influence of permanent lexical network in immediate serial recall is well established. The corresponding influence of permanent semantic networks is less clear, although such networks are known to both facilitate memory in long-term memory tasks and to produce false memories in those same tasks. The current experiment involves the study of Deese-Roediger-McDermott (DRM) lists for immediate serial recall. The trials in the experiment involved presenting the six strongest items from the DRM lists either in intact associatively related lists or where those items had been randomly mixed to produce unrelated lists. The results of the experiment indicated that the associatively related lists were better recalled in order than unrelated lists and the nonpresented critical lure was falsely recalled relatively frequently. The results of the experiment confirm the importance of associative semantic networks in short-term memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Linking associative and serial list memory: Pairs versus triples.

Paired associates and serial list memory are typically investigated separately. An "isolation principle" (J. B. Caplan, 2005) was proposed to explain behavior in both paradigms by using a single model, in which serial list and paired associates memory differ only in how isolated pairs of items are from interference from other studied items. In the present study, 2 experiments identify a critical dissociation between the 2 paradigms, challenging this unified account. Specifically, forward and backward probes were highly correlated for pairs and less so for short lists (triples). The authors asked whether the isolation principle could quantitatively accommodate this type of dissociation. A simulation confirmed that a single model incorporating the isolation principle can adequately explain this and other dissociations, supporting the common processes view. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer across delayed discriminations: II. Differences in the substitutability of initial versus test stimuli.

In 2 experiments, pigeons were trained on, and then transferred to, delayed simple discriminations in which the initial stimuli signalled reinforcement versus extinction following a retention interval. Experiment 1 showed that discriminative responding on the retention test transferred to novel test stimuli that had appeared in another delayed simple discrimination but not to stimuli having the same reinforcement history off-baseline. By contrast, Experiment 2 showed that performances transferred to novel initial stimuli whether they had been trained on-baseline or off-baseline. These results suggest that the test stimuli in delayed simple discriminations acquire control over responding only in the memory task itself. On the other hand, control by the initial stimuli, if coded as outcome expectancies, does not require such task-specific training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye Gaze and Individual Differences Consistent With Learned Attention in Associative Blocking and Highlighting.

The associative learning effects called blocking and highlighting have previously been explained by covert learned attention, but evidence for learned attention has been indirect, via models of response choice. The present research reports results from eye tracking consistent with the attentional hypothesis: Gaze duration is diminished for blocked cues and augmented for highlighted cues. If degree of attentional learning varies across individuals but is relatively stable within individuals, then the magnitude of blocking and highlighting should covary across individuals. This predicted correlation is obtained for both choice and eye gaze. A connectionist model that implements attentional learning is shown to fit the data and account for individual differences by variation in its attentional parameters. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative priming by targets and distractors during rapid serial visual presentation: Does word meaning survive the attentional blink?

In 5 experiments, 432 college students viewed lists of words containing 2 targets (Target 1 [T1] and Target 2 [T2]) presented by rapid serial visual presentation at 10 words per second. Identification of T1 caused a 500-ms impairment in the identification of T2 (the attentional blink [AB]). Improved recall of T2 was observed throughout the time course of the AB when T2 was a strong associate of either T1 or a priming distractor (PD). When participants ignored T1, the AB was eliminated, but the amount of priming was not affected. Priming of T2 by PD was temporary (100–200 ms after the onset of PD). Although target priming and distractor priming both survived the AB, the 2 forms of priming appeared to have different bases. In contrast to priming by PD, priming by T1 was larger, modulated by backward associative strength, and longer lasting. Priming and the AB are hypothesized to result from on-line attentional processes, but recall from RSVP lists is also influenced by off-line memory processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in learning serial patterns: Direct versus indirect measures.

Adult age differences in learning and retention of a nonverbal sequence were examined using the serial reaction-time (RT) task of M. J. Nissen and P. Bullemer (see record 1987-13436-001), with 20 younger and 20 older Ss. An asterisk appeared in one of 4 spatial locations, and the Ss responded with a corresponding key press. The first 4 blocks each contained 10 repetitions of a 10- or 16-element spatial sequence, and the 5th block contained a random sequence. The difference between response time on Blocks 5 and 4 served as an indirect measure of pattern learning. The direct measure was accuracy in a final generation block in which the Ss predicted which location would appear next. Results were similar to those with verbal materials; the indirect measure revealed age similarity for patterns of both lengths, but the direct measure yielded age differences favoring the young. For both ages and types of measures, the long patterns led to poorer learning than did the short patterns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The serial use of child neurocognitive tests: Development versus practice effects.

When serial neurocognitive assessments are performed, 2 main factors are of importance: test-retest reliability and practice effects. With children, however, there is a third, developmental factor, which occurs as a result of maturation. Child tests recognize this factor through the provision of age-corrected scaled scores. Thus, a ready-made method for estimating the relative contribution of developmental versus practice effects is the comparison of raw (developmental and practice) and scaled (practice only) scores. Data from a pool of 507 Portuguese children enrolled in a study of dental amalgams (T. A. DeRouen, B. G. Leroux, et al., 2002; T. A. DeRouen, M. D. Martin, et al., 2006) showed that practice effects over a 5-year period varied on 8 neurocognitive tests. Simple regression equations are provided for calculating individual retest scores from initial test scores. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative symmetry versus independent associations in the memory for object-location associations.

The formation of associations between objects and locations is a vital aspect of episodic memory. More specifically, remembering the location where one experienced an object and, vice versa, the object one encountered at a specific location are both important elements for the memory of an event. Whether episodic associations are holistic representations of individual components or whether there are unidirectional, separately modifiable connections between them has been investigated nearly exclusively using verbal stimuli. A preliminary conclusion concerning this controversy is that verbal associations are, at least, highly correlated (M. J. Kahana, 2002). This theoretical debate, which in the past has undergone a major empirical effort, is still of relevance for the concurrent global matching models of associative memory (S. E. Clark & S. D. Gronlund, 1996). The authors used variations of a novel object-location learning paradigm to complement the accumulated evidence regarding the nature of episodic associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of the relation between Pavlovian occasion-setting and instrumental discriminative stimuli: A blocking analysis.

Retracted October 1990. (See record 1991-03475-001.) Conducted 2 experiments with 72 male Sprague-Dawley rats, using a blocking design (A+, then AB+) to assess the relation between Pavlovian occasion-setting and instrumental discriminative stimuli. Prior conditioning of both associative and occasion-setting functions of A in a serial feature-positive procedure blocked acquisition of an instrumental discriminative function by a novel stimulus (B) trained in compound with A. Neither prior conditioning of only an A/unconditioned stimulus/stimuli (UCS) association nor prior conditioning of Stimulus A using a Pavlovian simultaneous feature-positive procedure, which does not endow A with an occasion-setting function, blocked acquisition of an instrumental discriminative function by B. Prior acquisition of an instrumental discriminative function by A blocked acquisition of a Pavlovian occasion-setting function by a novel stimulus (B) trained in compound with A but did not block acquisition of an association between B and the UCS. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye movements during parallel–serial visual search.

Two experiments (one using O and Q-like stimuli and the other using colored–oriented bars) investigated the oculomotor behavior accompanying parallel–serial visual search. Eye movements were recorded as participants searched for a target in 5- or 17-item displays. Results indicated the presence of parallel–serial search dichotomies and 2:1 ratios of negative to positive slopes in the number of saccades initiated during both search tasks. This saccade number measure also correlated highly with search times, accounting for up to 67% of the reaction time (RT) variability. Weak correlations between fixation durations and RTs suggest that this oculomotor measure may be related more to stimulus factors than to search processes. A third experiment compared free-eye and fixed-eye searches and found a small RT advantage when eye movements were prevented. Together these findings suggest that parallel–serial search dichotomies are reflected in oculomotor behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contextual effects in conditioning, latent inhibition, and habituation: Associative and retrieval functions of contextual cues.

Rats were used as subjects in four experiments to investigate the transfer of learning from one context to another. Subjects received two sessions of training each day, one in each of two different contexts. Experiment 1 showed that the habituation of the unconditioned response to a stimulus presented in one context was left intact when the stimulus was presented in another context, but that latent inhibition was attenuated when preexposure and conditioning phases occurred in different contexts. Experiments 2 and 3 demonstrated that a conditioned response made on the basis of an appetitive reinforcer was diminished when conditioning and testing occurred in different contexts, but that aversive conditioning was not influenced by the context in which testing occurred. In Experiment 4, the presence of an aversive reinforcer during training did not preclude the occurrence of context-specific conditioning on the basis of an appetitive reinforcer. Associative and retrieval-based interpretations of the results are explored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)