Manipulations to practice organization of golf putting skills through interleaved matched or mismatched practice with a partner

There is some evidence that alternating physical and observational practice with a partner for the same skill can benefit learning compared to practice alone. What has not been studied is whether a partner's interleaved practice impacts multi-skill learning, when the partner either matches or mismatches their partner’s skill. Here we manipulated partners’ practice schedules of two golf putting skills. Partners practiced the same (“matched”) or different skills in alternation (“mismatched”). Based on previous research where interleaved demonstrations have induced beneficial contextual interference effects, we hypothesized that mismatching a partner on consecutive trials should also promote a similar type of interference in practice, which ultimately aids learning. A third control group was tested, where only one partner practiced while the other observed. All groups practiced for two days, with individual retention tests at the start of day 2 and one week later. Taking turns practicing and observing a partner did not benefit learning compared to the control, pure physical practice group and the matched and mismatched groups did not differ in outcomes. There was, however, evidence that partners were adapting their actions (i.e., compensating for over or undershooting of the target) based on the shots of their partner, in a similar manner to how they were adapting to their own errors. Thus, although partners were influencing each other’s performance, it was not ultimately to the benefit (or cost) of overall learning. Partner-mismatching of skills through alternating practice was not sufficient to promote interference in practice and ultimately promote learning.     

Attention to Explicit and Implicit Contrast in Verb Learning

Contrast information could be useful for verb learning, but few studies have examined children's ability to use this type of information. Contrast may be useful when children are told explicitly that different verbs apply, or when they hear two different verbs in a single context. Three studies examine children's attention to different types of contrast as they learn new verbs. Study 1 shows that 3.5-year-olds can use both implicit contrast (“I'm meeking it. I'm koobing it.”) and explicit contrast (“I'm meeking it. I'm not meeking it.”) when learning a new verb, while a control group's responses did not differ from chance. Study 2 shows that even though children at this age who hear explicit contrast statements differ from a control group, they do not reliably extend a newly learned verb to events with new objects. In Study 3, children in three age groups were given both comparison and contrast information, not in blocks of trials as in past studies, but in a procedure that interleaved both cues. Results show that while 2.5-year-olds were unable to use these cues when asked to compare and contrast, by 3.5 years old, children are beginning to be able to process these cues and use them to influence their verb extensions, and by 4.5 years, children are proficient at integrating multiple cues when learning and extending new verbs. Together these studies examine children's use of contrast in verb learning, a potentially important source of information that has been rarely studied.     

Performance bias: Why judgments of learning are not affected by learning

Past research has shown a performance bias: People expect their future performance level on a task to match their current performance level, even when there are good reasons to expect future performance to differ from current performance. One explanation of this bias is that judgments are controlled by what learners can observe, and while current performance is usually observable, changes in performance (i.e., learning or forgetting) are not. This explanation makes a prediction that we tested here: If learning becomes observable, it should begin to affect judgments. In three experiments, after practicing a skill, participants estimated how they performed in the past and how they expected to perform in the future. In Experiments 1 and 2, participants knew they had been improving, as shown by their responses, yet they did not predict that they would improve in the future. This finding was particularly striking because (a) they did improve in the future and (b) as Experiment 3 showed, they did hold the conscious belief that past improvement predicted future improvement. In short, when learning and performance are both observable, judgments of learning seem to be guided by performance and not learning.     

Sleep deprivation impairs object recognition in mice

Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in an object recognition task in OF1 mice subjected to 6h SD either immediately after the acquisition phase (0-6 SD) or 6h later (7-12 SD), and in corresponding undisturbed controls. Motor activity was continuously recorded with infrared sensors. All groups explored two familiar, previously encountered objects to a similar extent, both at the end of the acquisition phase and 24h later during the test phase, indicating intact familiarity detection. During the test phase 0-6 SD mice failed to discriminate between the single novel and the two familiar objects. In contrast, the 7-12 SD group and the two control groups explored the novel object significantly longer than the two familiar objects. Plasma corticosterone levels determined after SD did not differ from time-matched undisturbed controls, but were significantly below the level measured after learning alone. ACTH did not differ between the groups. Therefore, it is unlikely that stress contributed to the memory impairment. We conclude that the loss of sleep and the activities the mice engaged in during the SD, impaired recognition memory retrieval, when they occurred immediately after acquisition. The delayed SD enabled memory consolidation during the 6h when the mice were allowed to sleep, and had no detrimental effect on memory. Neither SD schedule impaired object familiarity processing, suggesting that only specific cognitive abilities were sensitive to the intervention. Sleep may either actively promote memory formation, or alternatively, sleep may provide optimal conditions of non-interference for consolidation.     

The early ontogeny of infants’ imitation of on screen humans and robots

Traditionally, infants have learned how to interact with objects in their environment through direct observations of adults and peers. In recent decades these models have been available over different media, and this has introduced non-human agents to infants’ learning environments. Humanoid robots are increasingly portrayed as social agents in on screen, but the degree to which infants are capable of observational learning from screen-based robots is unknown. The current study thus investigated how well 1- to 3-year-olds (N = 230) could imitate on-screen robots relative to on-screen and live humans. Participants exhibited an imitation deficit for robots that varied with age. Furthermore, the well-known video deficit did not replicate as expected, and was weak and transient relative to past research. Together, the findings documented here suggest that infants are learning from media in ways that differ from past generations, but that this new learning is nuanced when novel technologies are involved.     

Olfactory discrimination learning in mice lacking the fragile X mental retardation protein

An automated training system was used to compare the behavior of knockout (KO) mice lacking the fragile X mental retardation protein with that of wild-type (WT) mice (C57Bl/6 strain) in the acquisition and retention of olfactory discriminations. KO and WT mice did not differ in the acquisition of a four-stage nose poke shaping procedure. In two separate experiments, mutant mice required substantially more training to acquire a series of novel olfactory discrimination problems than did control mice. The KO mice required significantly more sessions to reach criterion performance, made significantly more errors during training, and more often failed to acquire discriminations. Both KO and WT mice showed similar error patterns when learning novel discriminations and both groups showed evidence of more rapid learning of later discriminations in the problem series. Both groups showed significant long-term memory two or four weeks after training but WT and KO mice did not differ in this regard. A group of well-trained mice were given training on novel odors in sessions limited to 20–80 trials. Memory of these problems at two day delays did not differ between WT and KO mice. Tests using ethyl acetate demonstrated that WT and KO mice had similar odor detection thresholds.     

Display vs. memory search for digits and faces among mentally handicapped and MA-matched non-handicapped youngsters

This experiment was designed to explore possible explanations for handicapped individuals' characteristically poor performance on memory scanning tasks. Independent variables included group (mentally handicapped vs. non-handicapped), type of search (display vs. memory), type of stimuli (digits vs. pictures of unfamiliar boys' faces), and load (2, 3, or 4 items to be searched). Results indicated that handicapped and non-handicapped groups did not differ when searching displays but did when searching memory, which suggested that the handicapped group's most significant impairment was specific to some aspect of memory search. Handicapped youngsters were also hindered by increasing loads more than control youngsters were. This result as well as impairment in memory search may have been due to handicapped youngsters' relatively short visual spans. The groups did not differ in their response to the two types of stimuli, faces and digits. Facial search was a considerably more demanding task than digit search for handicapped and normal children.     

Stimulus Preexposure, Comparison, and Changes in the Associability of Common Stimulus Features

In four experiments, rats received preexposure either to both of two compound flavours (AX and BX), or to just one (BX). Experiment 1 demonstrated a perceptual learning effect, showing that, for animals given preexposure to both flavours, an aversion conditioned to AX generalized only poorly to BX. Subsequent experiments assessed the properties of the common feature, X. Experiment 3 showed that the two preexposure treatments did not differ in the extent to which they produced habituation of the neophobia evoked by X. Experiment 2 showed that conditioning to X proceeded more rapidly in subjects given preexposure to both AX and BX than in subjects preexposed to BX alone. In Experiment 4, a similar effect was found when the elements of the compounds were presented serially. It is concluded that the perceptual learning effect of Experiment 1 occurs in spite of the fact that preexposure to two stimuli tends to maintain the associability of their common elements.     

Syntactic decoding times of learning disabled children

Syntactic decoding reaction times of 20 learning disabled children comprising two groups of subjects (mean age of 8 and 13 yr., respectively) were compared to the responses of normal controls matched for age and sex. An analysis of variance procedure showed that the learning disabled children and their normal peers did not differ significantly in responses to the experimental stimuli. This held true regardless of linguistic complexity, suggesting that delays in processing elementary syntactic constructions are not a concomitant of learning disabilities.     

Conditional discrimination in young children: the roles of associative and relational processing

Two experiments examined conditional discrimination in 4- to 6-year-olds. Children learned to choose one of two objects (e.g., circle) when the background was, say, red and to choose the other object (e.g., triangle) when the background was, say, blue. Awareness was assessed and interpreted as a marker of relational processing. In Experiment 1, most 4- and 5-year-olds did not reach the learning criterion. Children in Experiment 2 solved simpler reversal learning problems before the conditional discrimination problems. Most 4- to 6-year-olds reached criterion, but they did not necessarily demonstrate awareness, suggesting that reversal learning and conditional discrimination can be acquired through associative or relational processing. Relational processing increased with age and was used more on simpler problems. Fluid intelligence predicted Problem 2 performance in children who used relational (not associative) processing on Problem 1. Prior experience with simpler problems and awareness of relational structure are influential in children's conditional discrimination.     

Social mediation of puberty: an adaptive female strategy?

Females of two hamster species with contrasting degrees of gregariousness were tested for social influences on the timing of sexual maturation. When female dwarf hamsters (Phodopus sungorus campbelli), a gregarious species, were housed with an adult male at weaning, they began estrous cycles significantly earlier than when they were housed alone or with their family. Females housed with one or two female siblings at weaning matured significantly later than did all other females. Once mature, females housed with familiar males conceived later than did females housed with unfamiliar males. Rearing conditions also affected body weight; those housed with female siblings grew more slowly and attained a lower weight at 8 weeks of age than did females in all other groups. In contrast, when weanling female golden hamsters (Mesocricetus auratus), a solitary species, were housed with either an adult male, two female siblings, or alone, they did not differ in their rate of sexual maturation or growth. It is suggested that the degree to which social factors can accelerate or delay puberty is an adaptive characteristic and may be correlated with the degree of gregariousness of a species.     

Metacognitive regulation of text learning: on screen versus on paper

Despite immense technological advances, learners still prefer studying text from printed hardcopy rather than from computer screens. Subjective and objective differences between on-screen and on-paper learning were examined in terms of a set of cognitive and metacognitive components, comprising a Metacognitive Learning Regulation Profile (MLRP) for each study media. Participants studied expository texts of 1000-1200 words in one of the two media and for each text they provided metacognitive prediction-of-performance judgments with respect to a subsequent multiple-choice test. Under fixed study time (Experiment 1), test performance did not differ between the two media, but when study time was self-regulated (Experiment 2) worse performance was observed on screen than on paper. The results suggest that the primary differences between the two study media are not cognitive but rather metacognitive--less accurate prediction of performance and more erratic study-time regulation on screen than on paper. More generally, this study highlights the contribution of metacognitive regulatory processes to learning and demonstrates the potential of the MLRP methodology for revealing the source of subjective and objective differences in study performance among study conditions.     

The effect of hypothermia on the rat's spatial memory in the water tank task

The effect of hypothermia on the retention of the water tank navigation task has been examined in 21 male hooded rats. After a 3-min swimming test on Day 1 the animals were trained on Days 2 and 3 (2 X 12 trials) to find a small submerged platform 1 cm below the surface of a large pool (120 cm in diameter) of opaque water. On Day 4, the rats were divided into three groups (n = 7) which were cooled to colonic temperatures of 22-24 degrees C (H1), 25-27 degrees C (H2), and 28-31 degrees C (H3), respectively, and given 12 retrieval trials in the water tank. Average escape latencies increased from 6 s in normothermic rats on Day 3 to 33, 19, and 12 s on Day 4 in the H1, H2, and H3 groups, respectively. Under the same testing conditions the performance of groups H1, H2, and H3 improved on Day 5 to 20, 8 and 6 s, respectively. It is concluded that spatial memory retrieval is resistant to mild hypothermia (30 degrees C), but that it is severely impaired at body temperatures below 25 degrees C. Reacquisition of the task is slowed down but not fully prevented in deep hypothermia.     

Effects of deafening on the development of nestling and juvenile vocalizations in budgerigars (Melopsittacus undulatus).

The effects of complete and partial cochlear extirpation at ages 9-11 days posthatch were assessed in 5 nestling budgerigars (Melopsittacus undulatus) to determine if auditory feedback is necessary for the production of nestling vocalizations. Although early deafening had no effect on the production of food-begging calls produced during the first 2 weeks posthatch, deafening did disrupt the expected transition from these early calls to the longer and more complex frequency-modulated, patterned food-begging calls normally appearing 3-4 weeks posthatch. All birds sustaining either complete or partial cochlear extirpation failed to develop stereotyped contact calls around the time of fledging at 5 weeks. These results are consistent with previous research showing that deafened nestlings do not develop normal contact calls (R. J. Dooling, B. F. Gephart, P. H. Price, C. McHale, & S. E. Brauth, 1987) and also indicate that a form of sensorimotor learning is involved in the production of mature, patterned food-begging calls in budgerigars.     

Acoustic interactions in broods of nestling birds (Tachycineta bicolor)

Studies of acoustic interactions in animal groups, such as chorusing insects, anurans, and birds, have been invaluable in showing how cooperation and competition shape signal structure and use. The begging calls of nestling birds are ideal for such studies, because they function both as a cooperative signals of the brood's needs and as competitive signals for parental allocation within the brood. Nonetheless, studies of acoustic interactions among nestlings are rare. Here we review our work on acoustic interactions in nestling tree swallows (Tachycineta bicolor), especially how calls are used in competition for parental feedings. Nestlings attracted parental attention and responded to acoustic interference mainly by increasing call output. However, nestlings also gave more similar calls when they called together and decreased their call bandwidth when exposed to elevated noise. We suggest that these competitive uses of calls might intensify the cooperative brood signal, affecting both parental provisioning and vocal development. Given their tremendous variation across species, begging calls offer promising opportunities for developmental and comparative studies of acoustic signaling.     

Physical aggression as a function of objective self-awareness and attitudes toward punishment

Based on a theory of self-awareness, it was hypothesized that subjects would use their attitudes to determine their behaviors when (a) that attitude was salient and (b) their attention was directed toward themselves. Subjects, who on questionnaires had indicated that they opposed or condoned the use of punishment, were given the opportunity to shock a male confederate in two (bogus) learning experiments. Each subject was instructed to use his own attitude in choosing shocks to punish incorrect responses. Self-awareness was increased among half the subjects by the presence of a mirror. In each experiment a Punitiveness by self-awareness interaction resulted: High Punitive-Mirror subjects shocked higher than Low Punitive-Mirror subjects, but their respective No Mirror controls did not differ from each other.     

Does social environment influence learning ability in a family-living lizard?

Early developmental environment can have profound effects on individual physiology, behaviour, and learning. In birds and mammals, social isolation during development is known to negatively affect learning ability; yet in other taxa, like reptiles, the effect of social isolation during development on learning ability is unknown. We investigated how social environment affects learning ability in the family-living tree skink (Egernia striolata). We hypothesized that early social environment shapes cognitive development in skinks and predicted that skinks raised in social isolation would have reduced learning ability compared to skinks raised socially. Offspring were separated at birth into two rearing treatments: (1) raised alone or (2) in a pair. After 1 year, we quantified spatial learning ability of skinks in these rearing treatments (N = 14 solitary, 14 social). We found no effect of rearing treatment on learning ability. The number of skinks to successfully learn the task, the number of trials taken to learn the task, the latency to perform the task, and the number of errors in each trial did not differ between isolated and socially reared skinks. Our results were unexpected, yet the facultative nature of this species’ social system may result in a reduced effect of social isolation on behaviour when compared to species with obligate sociality. Overall, our findings do not provide evidence that social environment affects development of spatial learning ability in this family-living lizard.     

Asymmetries in the production of self-directed behavior by chimpanzees and gorillas during a computerized cognitive test

Self-directed behaviors (SDBs) are a commonly used behavioral indicator of arousal in nonhuman primates. Experimental manipulations, designed to increase arousal and uncertainty, have been used to elicit SDB production in primates. Beyond measuring rates of SDB production, researchers have also recorded their lateralized production by primates, thought to reflect laterality of hemispheric brain control and response to emotion. Although a handful of such studies exist, all have been conducted with chimpanzees. Expanding on this line of inquiry, we tested both chimpanzees (N = 3) and gorillas (N = 3) in a serial learning task presented on a touchscreen interface that incorporated both EASY (two-item list) and HARD (four-item list) versions of the task. Although SDB production by the apes did not differ across the two levels of task complexity, both species produced higher rates of SDB when they made an error, regardless of task difficulty. Furthermore, the apes made more SDB with the left hand—directed to the right side of their body (contralateral SDB) and left side of their body (ipsilateral SDB)—when they made an incorrect response. There was no difference in the rate of SDB produced with the right hand across correct compared to incorrect trials. The apes’ responses reflect previous reports that show humans are quicker at selecting negative emotional stimuli when using their left, compared to their right, hand (the reverse is true for positive stimuli). However, previous work has shown that chimpanzees are more likely to produce (contralateral) SDB with their right hand when aroused and so we discuss our results in relation to these findings and consider how they relate to the ‘right hemisphere’ and ‘valence’ models of emotional processing in apes.     

The associative-memory basis of cognitive skill learning: adult age differences

It has been established that memorizing common problems and their solutions underlies cognitive skill development, and that there are substantial age deficits in the rate of this learning. In a between-groups design, the authors compared learning rates for the same set of problems in skill (SK) training and paired-associate (PA) training. The authors found main effects due to condition (PA problems were acquired earlier) and to age (older adults' learning was delayed), but no condition-by-age interaction. The authors concluded that the age deficit in SK can be accounted for by the age deficit in associative memory; no further explanation is needed. The authors also analyzed fast and slow retrieves in SK and PA, and found that the frequency of fast retrieves did not differ in the two conditions. The overall advantage of PA was due to the occurrence of slow retrieves, which were absent in SK presumably because the skill algorithm displaces slow, explicit memory search in SK, but not fast, familiarity-based retrieval.     

Levels of processing and memory in mentally retarded and nonretarded persons

Individual differences in memory were examined from the levels of processing perspective. Mentally retarded persons were expected to be more superficial processors. The recall of nonretarded and two IQ levels of retarded young adults was compared following the presentation of pictorial stimuli with either a shallow processing, deep processing, or control orienting task. Shallow processing was induced by directing subjects to name the colors of the pictures. In the deep processing condition, subjects were told to say what the pictured object was used for. In the control condition, they were directed to look at the pictures. The stimuli were presented as an incidental learning task. Encoding condition was a between-subjects variable. Nonretarded subjects remembered more overall than did the two retarded groups, which did not differ. At each intelligence level, more stimuli were remembered in the deep processing condition than in the shallow condition. There was no interaction of intelligence level with encoding condition. The hypothesis that retarded persons process at a more superficial level was not supported. A “spread of encoding” deficit in retarded persons is favored to explain the recall differences obtained in this experiment.