Intersensory redundancy facilitates prenatal perceptual learning in bobwhite quail (Colinus virginianus) embryos.

Information presented redundantly and in temporal synchrony across sensory modalities (intersensory redundancy) selectively recruits attention and facilitates perceptual learning in human infants. This comparative study examined whether intersensory redundancy also facilitates perceptual learning prenatally. The authors assessed quail (Colinus virginianus) embryos' ability to learn a maternal call when it was (a) unimodal, (b) concurrent but asynchronous with patterned light, or (c) redundant and synchronous with patterned light. Chicks' preference for the familiar over a novel maternal call was assessed 24 hr following hatching. Chicks receiving redundant, synchronous stimulation as embryos learned the call 4 times faster than those who received unimodal exposure. Chicks who received asynchronous bimodal stimulation showed no evidence of learning. These results provide the first evidence that embryos are sensitive to redundant, bimodal information and that it can facilitate learning during the prenatal period. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prenatal experience and postnatal perceptual preferences: Evidence for attentional-bias in bobwhite quail embryos ( Colinus virginianus).

Previous studies have indicated that concurrent multimodal sensory stimulation can interfere with prenatal perceptual learning. This study further examined this issue by exposing 3 groups of bobwhite quail embryos (Colinus virginianus) to (a) no supplemental stimulation, (b) a bobwhite maternal call, or (c) a maternal call paired with a pulsating light in the period prior to hatching. Experiments differed in terms of the types of stimuli presented during postnatal preference tests. Embryos receiving no supplemental stimulation showed no preference between stimulus events in all testing conditions. Embryos receiving exposure to the unimodal maternal call preferred the familiar call over an unfamiliar call regardless of the presence or absence of pulsating light during testing. Embryos exposed to the call-light compound preferred the familiar call only when it was paired with the light during testing. These results suggest that concurrent multimodal stimulation does not interfere with prenatal perceptual learning by overwhelming the young organism's limited attentional capacities. Rather, multimodal stimulation biases what information is attended to during exposure and subsequent testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prenatal auditory experience directs species-typical perceptual responsiveness in bobwhite quail chicks (Colinus virginianus).

The present study examined the role of the relationship between pre- and postnatal stimulus cues in directing perceptual preferences of bobwhite quail chicks. Bobwhite quail were exposed to either prenatal auditory or prenatal auditory-visual stimulation. Both prenatal auditory and auditory-visual stimulation resulted in accelerated responsiveness to combined postnatal auditory-visual cues. However, whether or not subjects displayed accelerated perceptual responsiveness depended on the relationship between the nature of the pre- and postnatal auditory stimuli used. These results demonstrate the salience of auditory cues in directing early postnatal perceptual behavior in precocial birds and help to explicate why prior research in this area has found that augmented prenatal sensory stimulation can result in either accelerated or decelerated patterns of perceptual functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Type of prenatal sensory experience affects auditory learning in bobwhite quail (Colinus virginianus).

This study examined the effects of specific types of prenatal auditory stimulation on the auditory learning capacity of bobwhite embryos (Colinus virginianus) incubated in either communal or isolation conditions. Results revealed that socially incubated embryos could learn an individual bobwhite maternal call, whereas embryos denied physical and tactile stimulation as a result of isolation incubation failed to demonstrate prenatal auditory learning of the maternal call. In contrast, embryos exposed to bobwhite chick contentment calls in the period prior to hatching demonstrated prenatal auditory learning, whether they were incubated socially or in isolation. Socially incubated and isolation-incubated embryos exposed to bobwhite chick distress calls failed to learn the individual maternal call, indicating that the type of sensory stimulation the developing organism encounters prenatally is important in fostering normal perceptual learning ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early visual experience affects postnatal auditory responsiveness in bobwhite quail (Colinus virginianus).

Results from 6 experiments suggest perinatal visual experience interferes with postnatal auditory responsiveness in bobwhite quail (Colinus virginianus). Light- or dark-reared control chicks responded similarly to bobwhite maternal Calls A or B following hatching. Light-reared chicks that experienced 10 min/hr of Call A or B from hatching until testing preferred the familiar call at Days 2-4, but dark-reared chicks preferred the familiar call at all ages. Increased amounts of exposure to maternal calls during postnatal Days 1-2 led to auditory responsiveness deficits in light-reared chicks. Similarly, embryos exposed to 10 min/hr of prenatal visual cues required 48 hr of postnatal Call A or B exposure to demonstrate auditory discrimination. These findings highlight the linkages between developing auditory and visual systems during infancy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modified sensory features of social stimulation alter the perceptual responsiveness of bobwhite quail chicks (Colinus virginianus).

This study examined the sensory features of postnatal social experience that bobwhite quail chicks (Colinus virginianus) require to maintain species-typical responding to maternal auditory–visual cues. Chicks were reared in 1 of 3 conditions after hatching: altered tactile, auditory, or visual experience with siblings. Findings revealed that altered tactile, auditory, or visual experience during the first 36 or the first 72 hr following hatching modified chicks' preferential responding to species-specific maternal cues. During the second 36 hr, altered tactile or auditory experience disrupted chicks' perceptual development, whereas altered visual experience did not affect species-typical responsiveness. Results indicate that (a) timing of early postnatal visual experience can affect early filial responsiveness to maternal cues and (b) normal sensory experience derived from early social interaction affects species-typical perceptual development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interactive and vicarious acquisition of auditory preferences in Northern bobwhite (Colinus virginianus) chicks.

Studies examining the effects of stimulus contingency on filial imprinting have produced inconsistent findings. In the current study, day-old bobwhite chicks (Colinus virginianus) received individual 5-min sessions in which they were provided contingent, noncontingent, or vicarious exposure to a variant of a bobwhite maternal assembly call. Chicks given contingent exposure to the call showed a significant preference for the familiar call 24 hr following exposure and significantly greater preferences than chicks given noncontingent exposure. Chicks given vicarious exposure to recordings of another chick interacting with the maternal call showed significant deviations from chance responding; however, the direction of chick preference (toward the familiar or unfamiliar) depended on the particular call used. These results indicate that both direct and indirect (vicarious) exposure to stimulus contingency can enhance the acquisition of auditory preferences in precocial avian hatchlings. Precocial avian hatchlings thus likely play a more active role in directing their own perceptual and behavioral development than has typically been thought. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Species-specific auditory preference of bobwhite quail chicks (Colinus virginianus) is altered by social interaction with siblings.

The study examined whether reinstating specific aspects of the normally occurring postnatal setting (ongoing social interaction with siblings during rearing and/or testing) would influence bobwhite quail chicks' attraction to their species-typical maternal call. Results revealed that incubator-reared chicks exhibit a strong preference for the species-typical bobwhite maternal call over a group of the same-aged siblings in simultaneous choice tests at 24 hr and 48 hr after hatching, but only if the birds are kept in relative social isolation. No preference for the maternal call was found at 24 hr or at 48 hr if chicks were reared in a group of same-aged chicks from hatching and tested to the maternal call vs. siblings or the maternal call paired with a live adult bobwhite hen vs. siblings. These results raise doubts about the appropriateness of the usual methods of isolation rearing in the study of species-typical perceptual preferences and underscore the importance of considering features of the natural social context in the analysis of early perceptual and social behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social experience with siblings fosters species specific responsiveness to maternal visual cues in bobwhite quail chicks (Colinus virginianus).

Examined the role of visual and social experience with siblings in the development of bobwhite quail chicks' preference for species-specific maternal visual cues. Chicks were reared in 1 of 4 conditions: group, isolation, partial isolation, and heterospecific group. They were tested in simultaneous choice tests with species-typical and species-atypical audiovisual stimuli. Results revealed that only Ss that were reared in a group with same-aged conspecifics preferred the visual features of a bobwhite hen model. Ss in the other 3 conditions did not exhibit species-specific visual preference. Findings suggest that visual experience and direct social interaction with siblings facilitate the development of bobwhite chicks' species-specific responsiveness to static maternal visual cues and illustrate the important influence of experience with conspecifics in the development of early perceptual preferences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intersensory experience and early perceptual development: Attenuated prenatal sensory stimulation affects postnatal auditory and visual responsiveness in bobwhite quail chicks (Colinus virginianus).

Related experiments examined the effects of attenuated prenatal sensory stimulation on subsequent postnatal auditory and visual responsiveness in precocial bobwhite quail chicks (Colinus virginianus). Results revealed that denying quail embryos the prenatal vestibular and tactile stimulation provided by broodmates during incubation altered pre- and postnatal perceptual functioning. Chicks incubated in physical isolation during the late stages of prenatal development responded to maternal auditory cues into later stages of the postnatal period and failed to respond to maternal visual cues at ages communally incubated chicks typically display such visual responsiveness. In addition, embryos incubated in physical isolation failed to exhibit early auditory learning of an individual maternal call, a behavior reliably seen in communally incubated embryos. Taken together, these results and those from related studies indicate that a substantial decrease or increase in the range of sensory stimulation normally present in the prenatal period can result in a slowing of the rate of species specific perceptual development and suggest that some optimal range of prenatal sensory stimulation is necessary for species-typical perceptual capacities to emerge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Timing of presentation of prenatal auditory stimulation alters auditory and visual responsiveness in bobwhite quail chicks (Colinus virginianus).

One group of bobwhite quail embryos (Colinus virginianus) was exposed to 10 min/hr of bobwhite chick contentment calls immediately followed by 10 min/hr of bobwhite chick distress calls. A 2nd group of embryos was exposed to the same auditory stimulation but in the opposite order of presentation. Postnatal testing revealed that chicks exposed prenatally to the bobwhite chick contentment call and distress call (in either order of presentation) continued to respond to maternal auditory cues into later stages of postnatal development compared with unmanipulated chicks. Chicks exposed prenatally to the contentment call followed by the distress call showed an accelerated pattern of visual responsiveness to maternal cues, whereas chicks exposed prenatally to the distress call followed by the contentment call showed deficits in the normal pattern of perceptual visual responsiveness, suggesting that the auditory stimulation precocial avian embryos encounter 1st is influential in directing early intersensory development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of punishment (electric shock) on perceptual learning.

3 experiments were conducted to explore the consequences of the association of punishment with percepts and to trace its residual effects. Electric shock was associated with tactual profiles of faces. Voltage, temporal contiguity, and ability to escape shock were varied. The results showed that there was more reporting of the non-shocked profile as intensity of shock increased, that escape conditions lead to more reporting of the shocked profiles, the shocked profile is recalled more vividly, and as the delay between exposure and recall increases there is more reporting of the nonshocked profile. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relational matching in baboons (Papio papio) with reduced grouping requirements.

Analogical reasoning is a corner stone of human cognition, but the phylogenetic origins of this skill are still unknown. Recent animal studies have suggested that only apes can solve the 2- by 2-item relational matching (RMTS) analogy problem, with potential benefits of language- (Premack, 1983) or token-training procedures (Thompson, Oden, & Boysen, 1997). In this study, 6 baboons were initially trained in an RMTS task in which the same and different relations were exemplified by compound stimuli made of 2 adjacent patches of colors. Learning occurred in this task with a first set of colors and transferred to probe trials with new colors (Experiment 1). Manipulation of the size of the sample or comparison stimuli (Experiment 2) showed that the performance was not merely controlled by the surface of the color patches, suggesting cognitive flexibility. Performance collapsed to chance level when a gap was introduced between the 2 elemental features composing the same or different displays (Experiment 3). Nevertheless, this effect of gap size was abolished by training (Experiment 4). It is suggested that monkeys share the ability to judge relations between relations with humans and apes, even in the absence of language or token training. However, this ability has been previously masked by a local mode of processing that hinders the processing of the stimuli as pairs rather than as independent objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lateralized scratching in chimpanzees (Pan troglodytes): Evidence of a functional asymmetry during arousal.

This study evaluated laterality in scratching by chimpanzees (n = 89) during socially arousing circumstances. Hand use and the side of the body scratched was recorded during a baseline and experimental condition. In the experimental condition, chimpanzees were shown a video of other conspecifics sharing, fighting over, and consuming a watermelon. Self-touches were categorized as either rubs or scratches. The chimpanzees showed a significant right hand bias for rubbing and also significantly directed the rubs to the right side of the body. For scratching, the chimpanzees showed no hand preference but a significant bias for scratching on the left side of the body. These results support the view that the right hemisphere regulates the autonomic nervous system during arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Category and perceptual interference in second-language phoneme learning: An examination of English /w/-/v/ learning by Sinhala, German, and Dutch speakers.

The present study investigated the perception and production of English /w/ and /v/ by native speakers of Sinhala, German, and Dutch, with the aim of examining how their native language phonetic processing affected the acquisition of these phonemes. Subjects performed a battery of tests that assessed their identification accuracy for natural recordings, their degree of spoken accent, their relative use of place and manner cues, the assimilation of these phonemes into native-language categories, and their perceptual maps (i.e., multidimensional scaling solutions) for these phonemes. Most Sinhala speakers had near-chance identification accuracy, Germans ranged from chance to 100% correct, and Dutch speakers had uniformly high accuracy. The results suggest that these learning differences were caused more by perceptual interference than by category assimilation; Sinhala and German speakers both have a single native-language phoneme that is similar to English /w/ and /v/, but the auditory sensitivities of Sinhala speakers make it harder for them to discern the acoustic cues that are critical to /w/-/v/ categorization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What perceptual rules do Capuchin Monkeys (Cebus Apella) follow in completing partly occluded figures?

Capuchin monkeys (Cebus apella) matched a variety of rodlike figures, distinguishable only by their central portions. The monkeys were then tested for perceptual completion rules by examining which comparison figures they would choose as matching the sample with the critical central portion occluded by a horizontal belt. In Experiment 1, the monkeys overwhelmingly chose a straight rod over disconnected rods and rods having irregular shapes at their center, irrespective of the presence-absence of common motion of visible parts of the samples. The monkeys chose a connected rod for relatable rods and disconnected rods for nonrelatable ones in Experiment 2. In Experiments 3 and 4, some of the monkeys chose rods specified by the global regularity of the contour, whereas others did not. Experiment 5 showed that humans and capuchin monkeys basically follow similar perceptual rules in completing occluded contours, but the global regularity rule may be stronger in humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The easy-to-hard effect in human (Homo sapiens) and rat (Rattus norvegicus) auditory identification.

The authors examined whether progressively training humans and rats to perform a difficult auditory identification task led to larger improvements than extensive training with highly similar sounds (the easy-to-hard effect). Practice improved humans' ability to distinguish sounds regardless of the training regimen. However, progressively trained subjects were more accurate and showed more generalization, despite significantly less training with the stimuli that were the most difficult to distinguish. Rats showed less capacity to improve with practice but still benefited from progressive training. These findings indicate that transitioning from an easier to a more difficult task during training can facilitate, and in some cases may be essential for, auditory perceptual learning. The results are not predicted by an explanation that assumes interaction of generalized excitation and inhibition but are consistent with a hierarchical account of perceptual learning in which the representational precision required to distinguish stimuli determines the mechanisms engaged during learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quokkas ( Setonix brachyurus ) demonstrate tactile discrimination learning and serial-reversal learning.

Two male quokkas (Setonix brachyurus: a herbivorous macropod marsupial) were trained to discriminate pairs of stimuli in the laboratory. Quokkas indicated their choice by pulling on 1 of 2 simultaneously presented cords. The quokkas' discrimination abilities were tested on 6 tactile and 6 visual discrimination tasks. Correct responses were rewarded with food. For both quokkas, all tactile tasks were learned to a criterion of 75% correct in up to 4 20-trial sessions. No visual task maintained criterion performance in 4 sessions. One tactile discrimination was reversed 10 times. After the 1st reversal, the error rate declined sharply and fell to a level well below the initial discrimination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imitative learning in male Japanese quail (Coturnix japonica) using the two-action method.

The study of imitative learning in animals has suffered from the presence of a number of confounding motivational and attentional factors (e.g., social facilitation and stimulus enhancement). The two-action method avoids these problems by exposing observers to demonstrators performing a response (e.g., operating a treadle) using 1 of 2 distinctive topographies (e.g., pecking or by stepping). Japanese quail (Coturnix japonica) observers exposed to conspecific demonstrators showed a high correlation between the topography of the response they observed and the response they performed. These data provide strong evidence for the existence of true imitative learning in an active, precocious bird under conditions that control for alternative accounts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanisms of same-different abstract-concept learning by rhesus monkeys (Macaca mulatta).

Experiments with 9 rhesus monkeys (Macaca mulatta) showed, for the first time, that abstract-concept learning varied with the training stimulus set size. In a sameldifferent task, monkeys required to touch a top picture before choosing a bottom picture (same) or white rectangle (different) learned rapidly. Monkeys not required to touch the top picture or presented with the top picture for a fixed time learned slowly or not at all. No abstract-concept learning occurred after 8-itern training but progressively improved with larger set sizes and was complete following 128-itern training. A control monkey with a constant 8-item set ruled out repeated training and testing. Contrary to the unique-species account, it is argued that different species have quantitative, not qualitative, differences in abstract-concept learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)